diff --git a/imgui.cpp b/imgui.cpp
index 850ea24..2510fb7 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -214,7 +214,10 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.
+                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.
  - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.
+ - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.
  - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.
  - 2017/11/02 (1.53) - marked IsRootWindowOrAnyChildHovered() as obsolete is favor of using IsWindowHovered(ImGuiHoveredFlags_FlattenChilds);
  - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.
@@ -703,13 +706,17 @@
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
+    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
     ChildRounding           = 0.0f;             // Radius of child window corners rounding. Set to 0.0f to have rectangular child windows
+    ChildBorderSize         = 1.0f;             // Thickness of border around child windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     PopupRounding           = 0.0f;             // Radius of popup window corners rounding. Set to 0.0f to have rectangular child windows
+    PopupBorderSize         = 1.0f;             // Thickness of border around popup or tooltip windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     FramePadding            = ImVec2(4,3);      // Padding within a framed rectangle (used by most widgets)
     FrameRounding           = 0.0f;             // Radius of frame corners rounding. Set to 0.0f to have rectangular frames (used by most widgets).
+    FrameBorderSize         = 0.0f;             // Thickness of border around frames. Generally set to 0.0f or 1.0f. Other values not well tested.
     ItemSpacing             = ImVec2(8,4);      // Horizontal and vertical spacing between widgets/lines
     ItemInnerSpacing        = ImVec2(4,4);      // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     TouchExtraPadding       = ImVec2(0,0);      // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -734,8 +741,8 @@
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {
     WindowPadding = ImFloor(WindowPadding * scale_factor);
-    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     WindowRounding = ImFloor(WindowRounding * scale_factor);
+    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     ChildRounding = ImFloor(ChildRounding * scale_factor);
     PopupRounding = ImFloor(PopupRounding * scale_factor);
     FramePadding = ImFloor(FramePadding * scale_factor);
@@ -2215,12 +2222,14 @@
     ImGuiContext& g = *GImGui;
 
     // Check user data
-    IM_ASSERT(g.IO.DeltaTime >= 0.0f);               // Need a positive DeltaTime (zero is tolerated but will cause some timing issues)
-    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f);
-    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0);           // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded());     // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f);  // Invalid style setting
-    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f);  // Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)
+    // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
+    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
+    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting");
+    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)");
+    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
 
     // Initialize on first frame
     if (!g.Initialized)
@@ -2764,7 +2773,8 @@
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // ImGui::EndFrame() called multiple times, or forgot to call ImGui::NewFrame() again
+    if (g.FrameCountEnded == g.FrameCount)          // Don't process EndFrame() multiple times.
+        return;
 
     // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
     if (g.IO.ImeSetInputScreenPosFn && ImLengthSqr(g.OsImePosRequest - g.OsImePosSet) > 0.0001f)
@@ -3093,10 +3103,11 @@
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     window->DrawList->AddRectFilled(p_min, p_max, fill_col, rounding);
-    if (border && (window->Flags & ImGuiWindowFlags_ShowBorders))
+    const float border_size = g.Style.FrameBorderSize;
+    if (border && border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3104,10 +3115,11 @@
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    const float border_size = g.Style.FrameBorderSize;
+    if (border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3683,14 +3695,12 @@
 bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     if (!IsPopupOpen(id))
     {
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
 
-    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGuiWindowFlags flags = extra_flags|ImGuiWindowFlags_Popup|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings;
 
     char name[20];
@@ -3700,9 +3710,7 @@
         ImFormatString(name, IM_ARRAYSIZE(name), "##popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
     bool is_open = Begin(name, NULL, flags);
-    if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
-        g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
-    if (!is_open) // NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
+    if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
     return is_open;
@@ -3716,7 +3724,7 @@
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
-    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::IsPopupOpen(ImGuiID id)
@@ -3765,8 +3773,6 @@
     IM_ASSERT(window->Flags & ImGuiWindowFlags_Popup);  // Mismatched BeginPopup()/EndPopup() calls
     IM_ASSERT(GImGui->CurrentPopupStack.Size > 0);
     End();
-    if (!(window->Flags & ImGuiWindowFlags_Modal))
-        PopStyleVar();
 }
 
 bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
@@ -3792,7 +3798,7 @@
     IM_ASSERT(id != 0);                                                  // However, you cannot pass a NULL str_id if the last item has no identifier (e.g. a Text() item)
     if (IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
@@ -3804,7 +3810,7 @@
         if (IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
             if (also_over_items || !IsAnyItemHovered())
                 OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
@@ -3814,11 +3820,12 @@
     ImGuiID id = GImGui->CurrentWindow->GetID(str_id);
     if (!IsAnyWindowHovered() && IsMouseClicked(mouse_button))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 static bool BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags extra_flags)
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = ImGui::GetCurrentWindow();
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_ChildWindow;
     flags |= (parent_window->Flags & ImGuiWindowFlags_NoMove);  // Inherit the NoMove flag
@@ -3830,8 +3837,10 @@
         size.x = ImMax(content_avail.x, 4.0f) - fabsf(size.x); // Arbitrary minimum zero-ish child size of 4.0f (0.0f causing too much issues)
     if (size.y <= 0.0f)
         size.y = ImMax(content_avail.y, 4.0f) - fabsf(size.y);
-    if (border)
-        flags |= ImGuiWindowFlags_ShowBorders;
+
+    const float backup_border_size = g.Style.ChildBorderSize;
+    if (!border)
+        g.Style.ChildBorderSize = 0.0f;
     flags |= extra_flags;
 
     char title[256];
@@ -3844,8 +3853,7 @@
     bool ret = ImGui::Begin(title, NULL, flags);
     ImGuiWindow* child_window = ImGui::GetCurrentWindow();
     child_window->AutoFitChildAxises = auto_fit_axises;
-    if (!(parent_window->Flags & ImGuiWindowFlags_ShowBorders))
-        child_window->Flags &= ~ImGuiWindowFlags_ShowBorders;
+    g.Style.ChildBorderSize = backup_border_size;
 
     return ret;
 }
@@ -3892,16 +3900,17 @@
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    PushStyleColor(ImGuiCol_ChildWindowBg, style.Colors[ImGuiCol_FrameBg]);
+    PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
     PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+    PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
-    return BeginChild(id, size, (g.CurrentWindow->Flags & ImGuiWindowFlags_ShowBorders) ? true : false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
+    return BeginChild(id, size, true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
 }
 
 void ImGui::EndChildFrame()
 {
     EndChild();
-    PopStyleVar(2);
+    PopStyleVar(3);
     PopStyleColor();
 }
 
@@ -4099,7 +4108,7 @@
     if (flags & (ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup))
         return ImGuiCol_PopupBg;
     if (flags & ImGuiWindowFlags_ChildWindow)
-        return ImGuiCol_ChildWindowBg;
+        return ImGuiCol_ChildBg;
     return ImGuiCol_WindowBg;
 }
 
@@ -4283,13 +4292,15 @@
             }
         }
 
-        // Lock window padding so that altering the ShowBorders flag for children doesn't have side-effects.
+        // Lock window padding so that altering the border sizes for children doesn't have side-effects.
         window->WindowPadding = style.WindowPadding;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)))
+        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)) && style.WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->WindowBorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
+        window->WindowBorderSize = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildBorderSize : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;
+        const ImVec2 window_padding = window->WindowPadding;
         const float window_rounding = window->WindowRounding;
+        const float window_border_size = window->WindowBorderSize;
 
         // Calculate auto-fit size, handle automatic resize
         const ImVec2 size_auto_fit = CalcSizeAutoFit(window);
@@ -4423,7 +4434,10 @@
         if (window->Collapsed)
         {
             // Title bar only
+            float backup_border_size = style.FrameBorderSize;
+            g.Style.FrameBorderSize = window->WindowBorderSize;
             RenderFrame(title_bar_rect.Min, title_bar_rect.Max, GetColorU32(ImGuiCol_TitleBgCollapsed), true, window_rounding);
+            g.Style.FrameBorderSize = backup_border_size;
         }
         else
         {
@@ -4477,9 +4491,9 @@
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                if (flags & ImGuiWindowFlags_ShowBorders)
-                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border));
                 window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
+                if (style.FrameBorderSize > 0.0f)
+                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
             }
 
             // Scrollbars
@@ -4493,20 +4507,17 @@
             if (!(flags & ImGuiWindowFlags_NoResize))
             {
                 const ImVec2 br = window->Rect().GetBR();
-                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window->WindowBorderSize));
-                window->DrawList->PathLineTo(br + ImVec2(-window->WindowBorderSize, -resize_corner_size));
-                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window->WindowBorderSize, br.y - window_rounding - window->WindowBorderSize), window_rounding, 0, 3);
+                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window_border_size));
+                window->DrawList->PathLineTo(br + ImVec2(-window_border_size, -resize_corner_size));
+                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window_border_size, br.y - window_rounding - window_border_size), window_rounding, 0, 3);
                 window->DrawList->PathFillConvex(resize_col);
             }
 
             // Borders
-            if (flags & ImGuiWindowFlags_ShowBorders)
-            {
-                window->DrawList->AddRect(window->Pos+ImVec2(1,1), window->Pos+window->Size+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), window_rounding);
-                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding);
-                if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                    window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,0), title_bar_rect.GetBR()-ImVec2(1,0), GetColorU32(ImGuiCol_Border));
-            }
+            if (window_border_size > 0.0f)
+                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding, ~0, window_border_size);
+            if (style.FrameBorderSize > 0 && !(flags & ImGuiWindowFlags_NoTitleBar))
+                window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,-1), title_bar_rect.GetBR()+ImVec2(-1,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
         // Update ContentsRegionMax. All the variable it depends on are set above in this function.
@@ -5060,11 +5071,15 @@
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, Alpha) },                // ImGuiStyleVar_Alpha
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowPadding) },        // ImGuiStyleVar_WindowPadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowRounding) },       // ImGuiStyleVar_WindowRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowBorderSize) },     // ImGuiStyleVar_WindowBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowMinSize) },        // ImGuiStyleVar_WindowMinSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildRounding) },        // ImGuiStyleVar_ChildRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildBorderSize) },      // ImGuiStyleVar_ChildBorderSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupRounding) },        // ImGuiStyleVar_PopupRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupBorderSize) },      // ImGuiStyleVar_PopupBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, FramePadding) },         // ImGuiStyleVar_FramePadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameRounding) },        // ImGuiStyleVar_FrameRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameBorderSize) },      // ImGuiStyleVar_FrameBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemSpacing) },          // ImGuiStyleVar_ItemSpacing
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemInnerSpacing) },     // ImGuiStyleVar_ItemInnerSpacing
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, IndentSpacing) },        // ImGuiStyleVar_IndentSpacing
@@ -5129,7 +5144,7 @@
     case ImGuiCol_Text: return "Text";
     case ImGuiCol_TextDisabled: return "TextDisabled";
     case ImGuiCol_WindowBg: return "WindowBg";
-    case ImGuiCol_ChildWindowBg: return "ChildWindowBg";
+    case ImGuiCol_ChildBg: return "ChildBg";
     case ImGuiCol_PopupBg: return "PopupBg";
     case ImGuiCol_Border: return "Border";
     case ImGuiCol_BorderShadow: return "BorderShadow";
@@ -7654,7 +7669,7 @@
     // Render
     fraction = ImSaturate(fraction);
     RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
-    bb.Expand(ImVec2(-window->WindowBorderSize, -window->WindowBorderSize));
+    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
     const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
     RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);
 
@@ -7777,10 +7792,10 @@
         window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
     }
 
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16);
+        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
     }
 
     if (g.LogEnabled)
@@ -8919,18 +8934,17 @@
         // Position our combo ABOVE because there's more space to fit! (FIXME: Handle in Begin() or use a shared helper. We have similar code in Begin() for popup placement)
         popup_y1 = ImClamp(frame_bb.Min.y - popup_size.y, style.DisplaySafeAreaPadding.y, frame_bb.Min.y);
         popup_y2 = frame_bb.Min.y;
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
     }
     else
     {
         // Position our combo below
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
     }
     SetNextWindowSize(ImVec2(popup_size.x, popup_y2 - popup_y1), ImGuiCond_Appearing);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
 
-    const ImGuiWindowFlags flags = ImGuiWindowFlags_ComboBox | ((window->Flags & ImGuiWindowFlags_ShowBorders) ? ImGuiWindowFlags_ShowBorders : 0);
-    if (!BeginPopupEx(id, flags))
+    if (!BeginPopupEx(id, ImGuiWindowFlags_ComboBox))
     {
         IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
         return false;
@@ -9396,7 +9410,7 @@
     if (menu_is_open)
     {
         SetNextWindowPos(popup_pos, ImGuiCond_Always);
-        ImGuiWindowFlags flags = ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
+        ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
         menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
     }
 
@@ -9541,7 +9555,7 @@
         else
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ~0);
     }
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (g.Style.FrameBorderSize > 0.0f)
         RenderFrameBorder(bb.Min, bb.Max, rounding);
     else
         window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border

diff --git a/imgui.cpp b/imgui.cpp
index 850ea24..2510fb7 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -214,7 +214,10 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.
+                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.
  - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.
+ - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.
  - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.
  - 2017/11/02 (1.53) - marked IsRootWindowOrAnyChildHovered() as obsolete is favor of using IsWindowHovered(ImGuiHoveredFlags_FlattenChilds);
  - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.
@@ -703,13 +706,17 @@
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
+    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
     ChildRounding           = 0.0f;             // Radius of child window corners rounding. Set to 0.0f to have rectangular child windows
+    ChildBorderSize         = 1.0f;             // Thickness of border around child windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     PopupRounding           = 0.0f;             // Radius of popup window corners rounding. Set to 0.0f to have rectangular child windows
+    PopupBorderSize         = 1.0f;             // Thickness of border around popup or tooltip windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     FramePadding            = ImVec2(4,3);      // Padding within a framed rectangle (used by most widgets)
     FrameRounding           = 0.0f;             // Radius of frame corners rounding. Set to 0.0f to have rectangular frames (used by most widgets).
+    FrameBorderSize         = 0.0f;             // Thickness of border around frames. Generally set to 0.0f or 1.0f. Other values not well tested.
     ItemSpacing             = ImVec2(8,4);      // Horizontal and vertical spacing between widgets/lines
     ItemInnerSpacing        = ImVec2(4,4);      // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     TouchExtraPadding       = ImVec2(0,0);      // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -734,8 +741,8 @@
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {
     WindowPadding = ImFloor(WindowPadding * scale_factor);
-    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     WindowRounding = ImFloor(WindowRounding * scale_factor);
+    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     ChildRounding = ImFloor(ChildRounding * scale_factor);
     PopupRounding = ImFloor(PopupRounding * scale_factor);
     FramePadding = ImFloor(FramePadding * scale_factor);
@@ -2215,12 +2222,14 @@
     ImGuiContext& g = *GImGui;
 
     // Check user data
-    IM_ASSERT(g.IO.DeltaTime >= 0.0f);               // Need a positive DeltaTime (zero is tolerated but will cause some timing issues)
-    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f);
-    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0);           // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded());     // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f);  // Invalid style setting
-    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f);  // Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)
+    // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
+    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
+    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting");
+    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)");
+    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
 
     // Initialize on first frame
     if (!g.Initialized)
@@ -2764,7 +2773,8 @@
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // ImGui::EndFrame() called multiple times, or forgot to call ImGui::NewFrame() again
+    if (g.FrameCountEnded == g.FrameCount)          // Don't process EndFrame() multiple times.
+        return;
 
     // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
     if (g.IO.ImeSetInputScreenPosFn && ImLengthSqr(g.OsImePosRequest - g.OsImePosSet) > 0.0001f)
@@ -3093,10 +3103,11 @@
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     window->DrawList->AddRectFilled(p_min, p_max, fill_col, rounding);
-    if (border && (window->Flags & ImGuiWindowFlags_ShowBorders))
+    const float border_size = g.Style.FrameBorderSize;
+    if (border && border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3104,10 +3115,11 @@
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    const float border_size = g.Style.FrameBorderSize;
+    if (border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3683,14 +3695,12 @@
 bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     if (!IsPopupOpen(id))
     {
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
 
-    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGuiWindowFlags flags = extra_flags|ImGuiWindowFlags_Popup|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings;
 
     char name[20];
@@ -3700,9 +3710,7 @@
         ImFormatString(name, IM_ARRAYSIZE(name), "##popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
     bool is_open = Begin(name, NULL, flags);
-    if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
-        g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
-    if (!is_open) // NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
+    if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
     return is_open;
@@ -3716,7 +3724,7 @@
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
-    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::IsPopupOpen(ImGuiID id)
@@ -3765,8 +3773,6 @@
     IM_ASSERT(window->Flags & ImGuiWindowFlags_Popup);  // Mismatched BeginPopup()/EndPopup() calls
     IM_ASSERT(GImGui->CurrentPopupStack.Size > 0);
     End();
-    if (!(window->Flags & ImGuiWindowFlags_Modal))
-        PopStyleVar();
 }
 
 bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
@@ -3792,7 +3798,7 @@
     IM_ASSERT(id != 0);                                                  // However, you cannot pass a NULL str_id if the last item has no identifier (e.g. a Text() item)
     if (IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
@@ -3804,7 +3810,7 @@
         if (IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
             if (also_over_items || !IsAnyItemHovered())
                 OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
@@ -3814,11 +3820,12 @@
     ImGuiID id = GImGui->CurrentWindow->GetID(str_id);
     if (!IsAnyWindowHovered() && IsMouseClicked(mouse_button))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 static bool BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags extra_flags)
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = ImGui::GetCurrentWindow();
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_ChildWindow;
     flags |= (parent_window->Flags & ImGuiWindowFlags_NoMove);  // Inherit the NoMove flag
@@ -3830,8 +3837,10 @@
         size.x = ImMax(content_avail.x, 4.0f) - fabsf(size.x); // Arbitrary minimum zero-ish child size of 4.0f (0.0f causing too much issues)
     if (size.y <= 0.0f)
         size.y = ImMax(content_avail.y, 4.0f) - fabsf(size.y);
-    if (border)
-        flags |= ImGuiWindowFlags_ShowBorders;
+
+    const float backup_border_size = g.Style.ChildBorderSize;
+    if (!border)
+        g.Style.ChildBorderSize = 0.0f;
     flags |= extra_flags;
 
     char title[256];
@@ -3844,8 +3853,7 @@
     bool ret = ImGui::Begin(title, NULL, flags);
     ImGuiWindow* child_window = ImGui::GetCurrentWindow();
     child_window->AutoFitChildAxises = auto_fit_axises;
-    if (!(parent_window->Flags & ImGuiWindowFlags_ShowBorders))
-        child_window->Flags &= ~ImGuiWindowFlags_ShowBorders;
+    g.Style.ChildBorderSize = backup_border_size;
 
     return ret;
 }
@@ -3892,16 +3900,17 @@
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    PushStyleColor(ImGuiCol_ChildWindowBg, style.Colors[ImGuiCol_FrameBg]);
+    PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
     PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+    PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
-    return BeginChild(id, size, (g.CurrentWindow->Flags & ImGuiWindowFlags_ShowBorders) ? true : false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
+    return BeginChild(id, size, true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
 }
 
 void ImGui::EndChildFrame()
 {
     EndChild();
-    PopStyleVar(2);
+    PopStyleVar(3);
     PopStyleColor();
 }
 
@@ -4099,7 +4108,7 @@
     if (flags & (ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup))
         return ImGuiCol_PopupBg;
     if (flags & ImGuiWindowFlags_ChildWindow)
-        return ImGuiCol_ChildWindowBg;
+        return ImGuiCol_ChildBg;
     return ImGuiCol_WindowBg;
 }
 
@@ -4283,13 +4292,15 @@
             }
         }
 
-        // Lock window padding so that altering the ShowBorders flag for children doesn't have side-effects.
+        // Lock window padding so that altering the border sizes for children doesn't have side-effects.
         window->WindowPadding = style.WindowPadding;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)))
+        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)) && style.WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->WindowBorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
+        window->WindowBorderSize = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildBorderSize : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;
+        const ImVec2 window_padding = window->WindowPadding;
         const float window_rounding = window->WindowRounding;
+        const float window_border_size = window->WindowBorderSize;
 
         // Calculate auto-fit size, handle automatic resize
         const ImVec2 size_auto_fit = CalcSizeAutoFit(window);
@@ -4423,7 +4434,10 @@
         if (window->Collapsed)
         {
             // Title bar only
+            float backup_border_size = style.FrameBorderSize;
+            g.Style.FrameBorderSize = window->WindowBorderSize;
             RenderFrame(title_bar_rect.Min, title_bar_rect.Max, GetColorU32(ImGuiCol_TitleBgCollapsed), true, window_rounding);
+            g.Style.FrameBorderSize = backup_border_size;
         }
         else
         {
@@ -4477,9 +4491,9 @@
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                if (flags & ImGuiWindowFlags_ShowBorders)
-                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border));
                 window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
+                if (style.FrameBorderSize > 0.0f)
+                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
             }
 
             // Scrollbars
@@ -4493,20 +4507,17 @@
             if (!(flags & ImGuiWindowFlags_NoResize))
             {
                 const ImVec2 br = window->Rect().GetBR();
-                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window->WindowBorderSize));
-                window->DrawList->PathLineTo(br + ImVec2(-window->WindowBorderSize, -resize_corner_size));
-                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window->WindowBorderSize, br.y - window_rounding - window->WindowBorderSize), window_rounding, 0, 3);
+                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window_border_size));
+                window->DrawList->PathLineTo(br + ImVec2(-window_border_size, -resize_corner_size));
+                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window_border_size, br.y - window_rounding - window_border_size), window_rounding, 0, 3);
                 window->DrawList->PathFillConvex(resize_col);
             }
 
             // Borders
-            if (flags & ImGuiWindowFlags_ShowBorders)
-            {
-                window->DrawList->AddRect(window->Pos+ImVec2(1,1), window->Pos+window->Size+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), window_rounding);
-                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding);
-                if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                    window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,0), title_bar_rect.GetBR()-ImVec2(1,0), GetColorU32(ImGuiCol_Border));
-            }
+            if (window_border_size > 0.0f)
+                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding, ~0, window_border_size);
+            if (style.FrameBorderSize > 0 && !(flags & ImGuiWindowFlags_NoTitleBar))
+                window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,-1), title_bar_rect.GetBR()+ImVec2(-1,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
         // Update ContentsRegionMax. All the variable it depends on are set above in this function.
@@ -5060,11 +5071,15 @@
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, Alpha) },                // ImGuiStyleVar_Alpha
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowPadding) },        // ImGuiStyleVar_WindowPadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowRounding) },       // ImGuiStyleVar_WindowRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowBorderSize) },     // ImGuiStyleVar_WindowBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowMinSize) },        // ImGuiStyleVar_WindowMinSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildRounding) },        // ImGuiStyleVar_ChildRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildBorderSize) },      // ImGuiStyleVar_ChildBorderSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupRounding) },        // ImGuiStyleVar_PopupRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupBorderSize) },      // ImGuiStyleVar_PopupBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, FramePadding) },         // ImGuiStyleVar_FramePadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameRounding) },        // ImGuiStyleVar_FrameRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameBorderSize) },      // ImGuiStyleVar_FrameBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemSpacing) },          // ImGuiStyleVar_ItemSpacing
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemInnerSpacing) },     // ImGuiStyleVar_ItemInnerSpacing
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, IndentSpacing) },        // ImGuiStyleVar_IndentSpacing
@@ -5129,7 +5144,7 @@
     case ImGuiCol_Text: return "Text";
     case ImGuiCol_TextDisabled: return "TextDisabled";
     case ImGuiCol_WindowBg: return "WindowBg";
-    case ImGuiCol_ChildWindowBg: return "ChildWindowBg";
+    case ImGuiCol_ChildBg: return "ChildBg";
     case ImGuiCol_PopupBg: return "PopupBg";
     case ImGuiCol_Border: return "Border";
     case ImGuiCol_BorderShadow: return "BorderShadow";
@@ -7654,7 +7669,7 @@
     // Render
     fraction = ImSaturate(fraction);
     RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
-    bb.Expand(ImVec2(-window->WindowBorderSize, -window->WindowBorderSize));
+    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
     const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
     RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);
 
@@ -7777,10 +7792,10 @@
         window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
     }
 
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16);
+        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
     }
 
     if (g.LogEnabled)
@@ -8919,18 +8934,17 @@
         // Position our combo ABOVE because there's more space to fit! (FIXME: Handle in Begin() or use a shared helper. We have similar code in Begin() for popup placement)
         popup_y1 = ImClamp(frame_bb.Min.y - popup_size.y, style.DisplaySafeAreaPadding.y, frame_bb.Min.y);
         popup_y2 = frame_bb.Min.y;
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
     }
     else
     {
         // Position our combo below
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
     }
     SetNextWindowSize(ImVec2(popup_size.x, popup_y2 - popup_y1), ImGuiCond_Appearing);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
 
-    const ImGuiWindowFlags flags = ImGuiWindowFlags_ComboBox | ((window->Flags & ImGuiWindowFlags_ShowBorders) ? ImGuiWindowFlags_ShowBorders : 0);
-    if (!BeginPopupEx(id, flags))
+    if (!BeginPopupEx(id, ImGuiWindowFlags_ComboBox))
     {
         IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
         return false;
@@ -9396,7 +9410,7 @@
     if (menu_is_open)
     {
         SetNextWindowPos(popup_pos, ImGuiCond_Always);
-        ImGuiWindowFlags flags = ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
+        ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
         menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
     }
 
@@ -9541,7 +9555,7 @@
         else
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ~0);
     }
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (g.Style.FrameBorderSize > 0.0f)
         RenderFrameBorder(bb.Min, bb.Max, rounding);
     else
         window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
diff --git a/imgui.h b/imgui.h
index f00ed49..93bebe7 100644
--- a/imgui.h
+++ b/imgui.h
@@ -125,8 +125,9 @@
     IMGUI_API ImGuiIO&      GetIO();
     IMGUI_API ImGuiStyle&   GetStyle();
     IMGUI_API ImDrawData*   GetDrawData();                              // same value as passed to your io.RenderDrawListsFn() function. valid after Render() and until the next call to NewFrame()
-    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until NewFrame()/Render().
-    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize rendering data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until Render()/EndFrame().
+    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize the draw data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          EndFrame();                                 // ends the ImGui frame. automatically called by Render(), so most likely don't need to ever call that yourself directly. If you don't need to render you may call EndFrame() but you'll have wasted CPU already. If you don't need to render, better to not create any imgui windows instead!
     IMGUI_API void          Shutdown();
 
     // Demo/Debug/Info
@@ -352,7 +353,7 @@
     IMGUI_API bool          TreeNodeEx(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(3);
     IMGUI_API bool          TreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API bool          TreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
-    IMGUI_API void          TreePush(const char* str_id = NULL);                                    // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
+    IMGUI_API void          TreePush(const char* str_id);                                           // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
     IMGUI_API void          TreePush(const void* ptr_id = NULL);                                    // "
     IMGUI_API void          TreePop();                                                              // ~ Unindent()+PopId()
     IMGUI_API void          TreeAdvanceToLabelPos();                                                // advance cursor x position by GetTreeNodeToLabelSpacing()
@@ -511,7 +512,7 @@
     ImGuiWindowFlags_NoScrollWithMouse      = 1 << 4,   // Disable user vertically scrolling with mouse wheel
     ImGuiWindowFlags_NoCollapse             = 1 << 5,   // Disable user collapsing window by double-clicking on it
     ImGuiWindowFlags_AlwaysAutoResize       = 1 << 6,   // Resize every window to its content every frame
-    ImGuiWindowFlags_ShowBorders            = 1 << 7,   // Show borders around windows and items
+    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // Show borders around windows and items (OBSOLETE! Use e.g. style.FrameBorderSize=1.0f to enable borders).
     ImGuiWindowFlags_NoSavedSettings        = 1 << 8,   // Never load/save settings in .ini file
     ImGuiWindowFlags_NoInputs               = 1 << 9,   // Disable catching mouse or keyboard inputs, hovering test with pass through.
     ImGuiWindowFlags_MenuBar                = 1 << 10,  // Has a menu-bar
@@ -639,7 +640,7 @@
     ImGuiCol_Text,
     ImGuiCol_TextDisabled,
     ImGuiCol_WindowBg,              // Background of normal windows
-    ImGuiCol_ChildWindowBg,         // Background of child windows
+    ImGuiCol_ChildBg,               // Background of child windows
     ImGuiCol_PopupBg,               // Background of popups, menus, tooltips windows
     ImGuiCol_Border,
     ImGuiCol_BorderShadow,
@@ -682,7 +683,7 @@
 
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
+    , ImGuiCol_ChildWindowBg = ImGuiCol_ChildBg, ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
 #endif
 };
 
@@ -695,11 +696,15 @@
     ImGuiStyleVar_Alpha,               // float     Alpha
     ImGuiStyleVar_WindowPadding,       // ImVec2    WindowPadding
     ImGuiStyleVar_WindowRounding,      // float     WindowRounding
+    ImGuiStyleVar_WindowBorderSize,    // float     WindowBorderSize
     ImGuiStyleVar_WindowMinSize,       // ImVec2    WindowMinSize
     ImGuiStyleVar_ChildRounding,       // float     ChildRounding
+    ImGuiStyleVar_ChildBorderSize,     // float     ChildBorderSize
     ImGuiStyleVar_PopupRounding,       // float     PopupRounding
+    ImGuiStyleVar_PopupBorderSize,     // float     PopupBorderSize
     ImGuiStyleVar_FramePadding,        // ImVec2    FramePadding
     ImGuiStyleVar_FrameRounding,       // float     FrameRounding
+    ImGuiStyleVar_FrameBorderSize,     // float     FrameBorderSize
     ImGuiStyleVar_ItemSpacing,         // ImVec2    ItemSpacing
     ImGuiStyleVar_ItemInnerSpacing,    // ImVec2    ItemInnerSpacing
     ImGuiStyleVar_IndentSpacing,       // float     IndentSpacing
@@ -776,13 +781,17 @@
 {
     float       Alpha;                      // Global alpha applies to everything in ImGui
     ImVec2      WindowPadding;              // Padding within a window
-    ImVec2      WindowMinSize;              // Minimum window size
     float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
+    ImVec2      WindowMinSize;              // Minimum window size
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.
     float       ChildRounding;              // Radius of child window corners rounding. Set to 0.0f to have rectangular windows.
+    float       ChildBorderSize;            // Thickness of border around child windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     float       PopupRounding;              // Radius of popup window corners rounding.
+    float       PopupBorderSize;            // Thickness of border around popup windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      FramePadding;               // Padding within a framed rectangle (used by most widgets)
     float       FrameRounding;              // Radius of frame corners rounding. Set to 0.0f to have rectangular frame (used by most widgets).
+    float       FrameBorderSize;            // Thickness of border around frames. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      ItemSpacing;                // Horizontal and vertical spacing between widgets/lines
     ImVec2      ItemInnerSpacing;           // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     ImVec2      TouchExtraPadding;          // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -1042,12 +1051,11 @@
     int                 CountGrep;
 
     IMGUI_API           ImGuiTextFilter(const char* default_filter = "");
-                        ~ImGuiTextFilter() {}
-    void                Clear() { InputBuf[0] = 0; Build(); }
     IMGUI_API bool      Draw(const char* label = "Filter (inc,-exc)", float width = 0.0f);    // Helper calling InputText+Build
     IMGUI_API bool      PassFilter(const char* text, const char* text_end = NULL) const;
-    bool                IsActive() const { return !Filters.empty(); }
     IMGUI_API void      Build();
+    void                Clear() { InputBuf[0] = 0; Build(); }
+    bool                IsActive() const { return !Filters.empty(); }
 };
 
 // Helper: Text buffer for logging/accumulating text
@@ -1138,7 +1146,7 @@
     // NB: Helper functions for text manipulation. Calling those function loses selection.
     IMGUI_API void    DeleteChars(int pos, int bytes_count);
     IMGUI_API void    InsertChars(int pos, const char* text, const char* text_end = NULL);
-    bool    HasSelection() const { return SelectionStart != SelectionEnd; }
+    bool              HasSelection() const { return SelectionStart != SelectionEnd; }
 };
 
 // Resizing callback data to apply custom constraint. As enabled by SetNextWindowSizeConstraints(). Callback is called during the next Begin().

diff --git a/imgui.cpp b/imgui.cpp
index 850ea24..2510fb7 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -214,7 +214,10 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.
+                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.
  - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.
+ - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.
  - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.
  - 2017/11/02 (1.53) - marked IsRootWindowOrAnyChildHovered() as obsolete is favor of using IsWindowHovered(ImGuiHoveredFlags_FlattenChilds);
  - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.
@@ -703,13 +706,17 @@
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
+    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
     ChildRounding           = 0.0f;             // Radius of child window corners rounding. Set to 0.0f to have rectangular child windows
+    ChildBorderSize         = 1.0f;             // Thickness of border around child windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     PopupRounding           = 0.0f;             // Radius of popup window corners rounding. Set to 0.0f to have rectangular child windows
+    PopupBorderSize         = 1.0f;             // Thickness of border around popup or tooltip windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     FramePadding            = ImVec2(4,3);      // Padding within a framed rectangle (used by most widgets)
     FrameRounding           = 0.0f;             // Radius of frame corners rounding. Set to 0.0f to have rectangular frames (used by most widgets).
+    FrameBorderSize         = 0.0f;             // Thickness of border around frames. Generally set to 0.0f or 1.0f. Other values not well tested.
     ItemSpacing             = ImVec2(8,4);      // Horizontal and vertical spacing between widgets/lines
     ItemInnerSpacing        = ImVec2(4,4);      // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     TouchExtraPadding       = ImVec2(0,0);      // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -734,8 +741,8 @@
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {
     WindowPadding = ImFloor(WindowPadding * scale_factor);
-    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     WindowRounding = ImFloor(WindowRounding * scale_factor);
+    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     ChildRounding = ImFloor(ChildRounding * scale_factor);
     PopupRounding = ImFloor(PopupRounding * scale_factor);
     FramePadding = ImFloor(FramePadding * scale_factor);
@@ -2215,12 +2222,14 @@
     ImGuiContext& g = *GImGui;
 
     // Check user data
-    IM_ASSERT(g.IO.DeltaTime >= 0.0f);               // Need a positive DeltaTime (zero is tolerated but will cause some timing issues)
-    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f);
-    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0);           // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded());     // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f);  // Invalid style setting
-    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f);  // Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)
+    // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
+    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
+    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting");
+    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)");
+    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
 
     // Initialize on first frame
     if (!g.Initialized)
@@ -2764,7 +2773,8 @@
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // ImGui::EndFrame() called multiple times, or forgot to call ImGui::NewFrame() again
+    if (g.FrameCountEnded == g.FrameCount)          // Don't process EndFrame() multiple times.
+        return;
 
     // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
     if (g.IO.ImeSetInputScreenPosFn && ImLengthSqr(g.OsImePosRequest - g.OsImePosSet) > 0.0001f)
@@ -3093,10 +3103,11 @@
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     window->DrawList->AddRectFilled(p_min, p_max, fill_col, rounding);
-    if (border && (window->Flags & ImGuiWindowFlags_ShowBorders))
+    const float border_size = g.Style.FrameBorderSize;
+    if (border && border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3104,10 +3115,11 @@
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    const float border_size = g.Style.FrameBorderSize;
+    if (border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3683,14 +3695,12 @@
 bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     if (!IsPopupOpen(id))
     {
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
 
-    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGuiWindowFlags flags = extra_flags|ImGuiWindowFlags_Popup|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings;
 
     char name[20];
@@ -3700,9 +3710,7 @@
         ImFormatString(name, IM_ARRAYSIZE(name), "##popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
     bool is_open = Begin(name, NULL, flags);
-    if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
-        g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
-    if (!is_open) // NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
+    if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
     return is_open;
@@ -3716,7 +3724,7 @@
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
-    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::IsPopupOpen(ImGuiID id)
@@ -3765,8 +3773,6 @@
     IM_ASSERT(window->Flags & ImGuiWindowFlags_Popup);  // Mismatched BeginPopup()/EndPopup() calls
     IM_ASSERT(GImGui->CurrentPopupStack.Size > 0);
     End();
-    if (!(window->Flags & ImGuiWindowFlags_Modal))
-        PopStyleVar();
 }
 
 bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
@@ -3792,7 +3798,7 @@
     IM_ASSERT(id != 0);                                                  // However, you cannot pass a NULL str_id if the last item has no identifier (e.g. a Text() item)
     if (IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
@@ -3804,7 +3810,7 @@
         if (IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
             if (also_over_items || !IsAnyItemHovered())
                 OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
@@ -3814,11 +3820,12 @@
     ImGuiID id = GImGui->CurrentWindow->GetID(str_id);
     if (!IsAnyWindowHovered() && IsMouseClicked(mouse_button))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 static bool BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags extra_flags)
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = ImGui::GetCurrentWindow();
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_ChildWindow;
     flags |= (parent_window->Flags & ImGuiWindowFlags_NoMove);  // Inherit the NoMove flag
@@ -3830,8 +3837,10 @@
         size.x = ImMax(content_avail.x, 4.0f) - fabsf(size.x); // Arbitrary minimum zero-ish child size of 4.0f (0.0f causing too much issues)
     if (size.y <= 0.0f)
         size.y = ImMax(content_avail.y, 4.0f) - fabsf(size.y);
-    if (border)
-        flags |= ImGuiWindowFlags_ShowBorders;
+
+    const float backup_border_size = g.Style.ChildBorderSize;
+    if (!border)
+        g.Style.ChildBorderSize = 0.0f;
     flags |= extra_flags;
 
     char title[256];
@@ -3844,8 +3853,7 @@
     bool ret = ImGui::Begin(title, NULL, flags);
     ImGuiWindow* child_window = ImGui::GetCurrentWindow();
     child_window->AutoFitChildAxises = auto_fit_axises;
-    if (!(parent_window->Flags & ImGuiWindowFlags_ShowBorders))
-        child_window->Flags &= ~ImGuiWindowFlags_ShowBorders;
+    g.Style.ChildBorderSize = backup_border_size;
 
     return ret;
 }
@@ -3892,16 +3900,17 @@
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    PushStyleColor(ImGuiCol_ChildWindowBg, style.Colors[ImGuiCol_FrameBg]);
+    PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
     PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+    PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
-    return BeginChild(id, size, (g.CurrentWindow->Flags & ImGuiWindowFlags_ShowBorders) ? true : false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
+    return BeginChild(id, size, true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
 }
 
 void ImGui::EndChildFrame()
 {
     EndChild();
-    PopStyleVar(2);
+    PopStyleVar(3);
     PopStyleColor();
 }
 
@@ -4099,7 +4108,7 @@
     if (flags & (ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup))
         return ImGuiCol_PopupBg;
     if (flags & ImGuiWindowFlags_ChildWindow)
-        return ImGuiCol_ChildWindowBg;
+        return ImGuiCol_ChildBg;
     return ImGuiCol_WindowBg;
 }
 
@@ -4283,13 +4292,15 @@
             }
         }
 
-        // Lock window padding so that altering the ShowBorders flag for children doesn't have side-effects.
+        // Lock window padding so that altering the border sizes for children doesn't have side-effects.
         window->WindowPadding = style.WindowPadding;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)))
+        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)) && style.WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->WindowBorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
+        window->WindowBorderSize = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildBorderSize : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;
+        const ImVec2 window_padding = window->WindowPadding;
         const float window_rounding = window->WindowRounding;
+        const float window_border_size = window->WindowBorderSize;
 
         // Calculate auto-fit size, handle automatic resize
         const ImVec2 size_auto_fit = CalcSizeAutoFit(window);
@@ -4423,7 +4434,10 @@
         if (window->Collapsed)
         {
             // Title bar only
+            float backup_border_size = style.FrameBorderSize;
+            g.Style.FrameBorderSize = window->WindowBorderSize;
             RenderFrame(title_bar_rect.Min, title_bar_rect.Max, GetColorU32(ImGuiCol_TitleBgCollapsed), true, window_rounding);
+            g.Style.FrameBorderSize = backup_border_size;
         }
         else
         {
@@ -4477,9 +4491,9 @@
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                if (flags & ImGuiWindowFlags_ShowBorders)
-                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border));
                 window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
+                if (style.FrameBorderSize > 0.0f)
+                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
             }
 
             // Scrollbars
@@ -4493,20 +4507,17 @@
             if (!(flags & ImGuiWindowFlags_NoResize))
             {
                 const ImVec2 br = window->Rect().GetBR();
-                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window->WindowBorderSize));
-                window->DrawList->PathLineTo(br + ImVec2(-window->WindowBorderSize, -resize_corner_size));
-                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window->WindowBorderSize, br.y - window_rounding - window->WindowBorderSize), window_rounding, 0, 3);
+                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window_border_size));
+                window->DrawList->PathLineTo(br + ImVec2(-window_border_size, -resize_corner_size));
+                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window_border_size, br.y - window_rounding - window_border_size), window_rounding, 0, 3);
                 window->DrawList->PathFillConvex(resize_col);
             }
 
             // Borders
-            if (flags & ImGuiWindowFlags_ShowBorders)
-            {
-                window->DrawList->AddRect(window->Pos+ImVec2(1,1), window->Pos+window->Size+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), window_rounding);
-                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding);
-                if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                    window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,0), title_bar_rect.GetBR()-ImVec2(1,0), GetColorU32(ImGuiCol_Border));
-            }
+            if (window_border_size > 0.0f)
+                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding, ~0, window_border_size);
+            if (style.FrameBorderSize > 0 && !(flags & ImGuiWindowFlags_NoTitleBar))
+                window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,-1), title_bar_rect.GetBR()+ImVec2(-1,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
         // Update ContentsRegionMax. All the variable it depends on are set above in this function.
@@ -5060,11 +5071,15 @@
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, Alpha) },                // ImGuiStyleVar_Alpha
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowPadding) },        // ImGuiStyleVar_WindowPadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowRounding) },       // ImGuiStyleVar_WindowRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowBorderSize) },     // ImGuiStyleVar_WindowBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowMinSize) },        // ImGuiStyleVar_WindowMinSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildRounding) },        // ImGuiStyleVar_ChildRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildBorderSize) },      // ImGuiStyleVar_ChildBorderSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupRounding) },        // ImGuiStyleVar_PopupRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupBorderSize) },      // ImGuiStyleVar_PopupBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, FramePadding) },         // ImGuiStyleVar_FramePadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameRounding) },        // ImGuiStyleVar_FrameRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameBorderSize) },      // ImGuiStyleVar_FrameBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemSpacing) },          // ImGuiStyleVar_ItemSpacing
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemInnerSpacing) },     // ImGuiStyleVar_ItemInnerSpacing
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, IndentSpacing) },        // ImGuiStyleVar_IndentSpacing
@@ -5129,7 +5144,7 @@
     case ImGuiCol_Text: return "Text";
     case ImGuiCol_TextDisabled: return "TextDisabled";
     case ImGuiCol_WindowBg: return "WindowBg";
-    case ImGuiCol_ChildWindowBg: return "ChildWindowBg";
+    case ImGuiCol_ChildBg: return "ChildBg";
     case ImGuiCol_PopupBg: return "PopupBg";
     case ImGuiCol_Border: return "Border";
     case ImGuiCol_BorderShadow: return "BorderShadow";
@@ -7654,7 +7669,7 @@
     // Render
     fraction = ImSaturate(fraction);
     RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
-    bb.Expand(ImVec2(-window->WindowBorderSize, -window->WindowBorderSize));
+    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
     const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
     RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);
 
@@ -7777,10 +7792,10 @@
         window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
     }
 
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16);
+        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
     }
 
     if (g.LogEnabled)
@@ -8919,18 +8934,17 @@
         // Position our combo ABOVE because there's more space to fit! (FIXME: Handle in Begin() or use a shared helper. We have similar code in Begin() for popup placement)
         popup_y1 = ImClamp(frame_bb.Min.y - popup_size.y, style.DisplaySafeAreaPadding.y, frame_bb.Min.y);
         popup_y2 = frame_bb.Min.y;
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
     }
     else
     {
         // Position our combo below
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
     }
     SetNextWindowSize(ImVec2(popup_size.x, popup_y2 - popup_y1), ImGuiCond_Appearing);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
 
-    const ImGuiWindowFlags flags = ImGuiWindowFlags_ComboBox | ((window->Flags & ImGuiWindowFlags_ShowBorders) ? ImGuiWindowFlags_ShowBorders : 0);
-    if (!BeginPopupEx(id, flags))
+    if (!BeginPopupEx(id, ImGuiWindowFlags_ComboBox))
     {
         IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
         return false;
@@ -9396,7 +9410,7 @@
     if (menu_is_open)
     {
         SetNextWindowPos(popup_pos, ImGuiCond_Always);
-        ImGuiWindowFlags flags = ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
+        ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
         menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
     }
 
@@ -9541,7 +9555,7 @@
         else
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ~0);
     }
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (g.Style.FrameBorderSize > 0.0f)
         RenderFrameBorder(bb.Min, bb.Max, rounding);
     else
         window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
diff --git a/imgui.h b/imgui.h
index f00ed49..93bebe7 100644
--- a/imgui.h
+++ b/imgui.h
@@ -125,8 +125,9 @@
     IMGUI_API ImGuiIO&      GetIO();
     IMGUI_API ImGuiStyle&   GetStyle();
     IMGUI_API ImDrawData*   GetDrawData();                              // same value as passed to your io.RenderDrawListsFn() function. valid after Render() and until the next call to NewFrame()
-    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until NewFrame()/Render().
-    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize rendering data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until Render()/EndFrame().
+    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize the draw data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          EndFrame();                                 // ends the ImGui frame. automatically called by Render(), so most likely don't need to ever call that yourself directly. If you don't need to render you may call EndFrame() but you'll have wasted CPU already. If you don't need to render, better to not create any imgui windows instead!
     IMGUI_API void          Shutdown();
 
     // Demo/Debug/Info
@@ -352,7 +353,7 @@
     IMGUI_API bool          TreeNodeEx(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(3);
     IMGUI_API bool          TreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API bool          TreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
-    IMGUI_API void          TreePush(const char* str_id = NULL);                                    // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
+    IMGUI_API void          TreePush(const char* str_id);                                           // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
     IMGUI_API void          TreePush(const void* ptr_id = NULL);                                    // "
     IMGUI_API void          TreePop();                                                              // ~ Unindent()+PopId()
     IMGUI_API void          TreeAdvanceToLabelPos();                                                // advance cursor x position by GetTreeNodeToLabelSpacing()
@@ -511,7 +512,7 @@
     ImGuiWindowFlags_NoScrollWithMouse      = 1 << 4,   // Disable user vertically scrolling with mouse wheel
     ImGuiWindowFlags_NoCollapse             = 1 << 5,   // Disable user collapsing window by double-clicking on it
     ImGuiWindowFlags_AlwaysAutoResize       = 1 << 6,   // Resize every window to its content every frame
-    ImGuiWindowFlags_ShowBorders            = 1 << 7,   // Show borders around windows and items
+    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // Show borders around windows and items (OBSOLETE! Use e.g. style.FrameBorderSize=1.0f to enable borders).
     ImGuiWindowFlags_NoSavedSettings        = 1 << 8,   // Never load/save settings in .ini file
     ImGuiWindowFlags_NoInputs               = 1 << 9,   // Disable catching mouse or keyboard inputs, hovering test with pass through.
     ImGuiWindowFlags_MenuBar                = 1 << 10,  // Has a menu-bar
@@ -639,7 +640,7 @@
     ImGuiCol_Text,
     ImGuiCol_TextDisabled,
     ImGuiCol_WindowBg,              // Background of normal windows
-    ImGuiCol_ChildWindowBg,         // Background of child windows
+    ImGuiCol_ChildBg,               // Background of child windows
     ImGuiCol_PopupBg,               // Background of popups, menus, tooltips windows
     ImGuiCol_Border,
     ImGuiCol_BorderShadow,
@@ -682,7 +683,7 @@
 
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
+    , ImGuiCol_ChildWindowBg = ImGuiCol_ChildBg, ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
 #endif
 };
 
@@ -695,11 +696,15 @@
     ImGuiStyleVar_Alpha,               // float     Alpha
     ImGuiStyleVar_WindowPadding,       // ImVec2    WindowPadding
     ImGuiStyleVar_WindowRounding,      // float     WindowRounding
+    ImGuiStyleVar_WindowBorderSize,    // float     WindowBorderSize
     ImGuiStyleVar_WindowMinSize,       // ImVec2    WindowMinSize
     ImGuiStyleVar_ChildRounding,       // float     ChildRounding
+    ImGuiStyleVar_ChildBorderSize,     // float     ChildBorderSize
     ImGuiStyleVar_PopupRounding,       // float     PopupRounding
+    ImGuiStyleVar_PopupBorderSize,     // float     PopupBorderSize
     ImGuiStyleVar_FramePadding,        // ImVec2    FramePadding
     ImGuiStyleVar_FrameRounding,       // float     FrameRounding
+    ImGuiStyleVar_FrameBorderSize,     // float     FrameBorderSize
     ImGuiStyleVar_ItemSpacing,         // ImVec2    ItemSpacing
     ImGuiStyleVar_ItemInnerSpacing,    // ImVec2    ItemInnerSpacing
     ImGuiStyleVar_IndentSpacing,       // float     IndentSpacing
@@ -776,13 +781,17 @@
 {
     float       Alpha;                      // Global alpha applies to everything in ImGui
     ImVec2      WindowPadding;              // Padding within a window
-    ImVec2      WindowMinSize;              // Minimum window size
     float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
+    ImVec2      WindowMinSize;              // Minimum window size
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.
     float       ChildRounding;              // Radius of child window corners rounding. Set to 0.0f to have rectangular windows.
+    float       ChildBorderSize;            // Thickness of border around child windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     float       PopupRounding;              // Radius of popup window corners rounding.
+    float       PopupBorderSize;            // Thickness of border around popup windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      FramePadding;               // Padding within a framed rectangle (used by most widgets)
     float       FrameRounding;              // Radius of frame corners rounding. Set to 0.0f to have rectangular frame (used by most widgets).
+    float       FrameBorderSize;            // Thickness of border around frames. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      ItemSpacing;                // Horizontal and vertical spacing between widgets/lines
     ImVec2      ItemInnerSpacing;           // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     ImVec2      TouchExtraPadding;          // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -1042,12 +1051,11 @@
     int                 CountGrep;
 
     IMGUI_API           ImGuiTextFilter(const char* default_filter = "");
-                        ~ImGuiTextFilter() {}
-    void                Clear() { InputBuf[0] = 0; Build(); }
     IMGUI_API bool      Draw(const char* label = "Filter (inc,-exc)", float width = 0.0f);    // Helper calling InputText+Build
     IMGUI_API bool      PassFilter(const char* text, const char* text_end = NULL) const;
-    bool                IsActive() const { return !Filters.empty(); }
     IMGUI_API void      Build();
+    void                Clear() { InputBuf[0] = 0; Build(); }
+    bool                IsActive() const { return !Filters.empty(); }
 };
 
 // Helper: Text buffer for logging/accumulating text
@@ -1138,7 +1146,7 @@
     // NB: Helper functions for text manipulation. Calling those function loses selection.
     IMGUI_API void    DeleteChars(int pos, int bytes_count);
     IMGUI_API void    InsertChars(int pos, const char* text, const char* text_end = NULL);
-    bool    HasSelection() const { return SelectionStart != SelectionEnd; }
+    bool              HasSelection() const { return SelectionStart != SelectionEnd; }
 };
 
 // Resizing callback data to apply custom constraint. As enabled by SetNextWindowSizeConstraints(). Callback is called during the next Begin().
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 9ac07b7..7bf92e3 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -165,22 +165,20 @@
     }
 
     static bool no_titlebar = false;
-    static bool no_border = true;
-    static bool no_resize = false;
-    static bool no_move = false;
     static bool no_scrollbar = false;
-    static bool no_collapse = false;
     static bool no_menu = false;
+    static bool no_move = false;
+    static bool no_resize = false;
+    static bool no_collapse = false;
 
     // Demonstrate the various window flags. Typically you would just use the default.
     ImGuiWindowFlags window_flags = 0;
     if (no_titlebar)  window_flags |= ImGuiWindowFlags_NoTitleBar;
-    if (!no_border)   window_flags |= ImGuiWindowFlags_ShowBorders;
-    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
-    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
     if (no_scrollbar) window_flags |= ImGuiWindowFlags_NoScrollbar;
-    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     if (!no_menu)     window_flags |= ImGuiWindowFlags_MenuBar;
+    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
+    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
+    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     ImGui::SetNextWindowSize(ImVec2(550,680), ImGuiCond_FirstUseEver);
     if (!ImGui::Begin("ImGui Demo", p_open, window_flags))
     {
@@ -238,12 +236,11 @@
     if (ImGui::CollapsingHeader("Window options"))
     {
         ImGui::Checkbox("No titlebar", &no_titlebar); ImGui::SameLine(150);
-        ImGui::Checkbox("No border", &no_border); ImGui::SameLine(300);
-        ImGui::Checkbox("No resize", &no_resize);
-        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
         ImGui::Checkbox("No scrollbar", &no_scrollbar); ImGui::SameLine(300);
-        ImGui::Checkbox("No collapse", &no_collapse);
         ImGui::Checkbox("No menu", &no_menu);
+        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
+        ImGui::Checkbox("No resize", &no_resize); ImGui::SameLine(300);
+        ImGui::Checkbox("No collapse", &no_collapse);
 
         if (ImGui::TreeNode("Style"))
         {
@@ -685,7 +682,6 @@
             ImGui::TreePop();
         }
 
-
         if (ImGui::TreeNode("Plots widgets"))
         {
             static bool animate = true;
@@ -1341,7 +1337,7 @@
             if (ImGui::Button("Select.."))
                 ImGui::OpenPopup("select");
             ImGui::SameLine();
-            ImGui::Text(selected_fish == -1 ? "<None>" : names[selected_fish]);
+            ImGui::TextUnformatted(selected_fish == -1 ? "<None>" : names[selected_fish]);
             if (ImGui::BeginPopup("select"))
             {
                 ImGui::Text("Aquarium");
@@ -1878,6 +1874,15 @@
         ref_saved_style = style;
     }
 
+    // Simplified Settings
+    if (ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f")) 
+        style.GrabRounding = style.FrameRounding; // Make GrabRounding always the same value as FrameRounding
+    { bool window_border = (style.WindowBorderSize > 0.0f); if (ImGui::Checkbox("WindowBorder", &window_border)) style.WindowBorderSize = window_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool frame_border = (style.FrameBorderSize > 0.0f); if (ImGui::Checkbox("FrameBorder", &frame_border)) style.FrameBorderSize = frame_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool popup_border = (style.PopupBorderSize > 0.0f); if (ImGui::Checkbox("PopupBorder", &popup_border)) style.PopupBorderSize = popup_border ? 1.0f : 0.0f; }
+
     // Save/Revert button
     if (ImGui::Button("Save Ref"))
         *ref = ref_saved_style = style;
@@ -1902,19 +1907,25 @@
     if (ImGui::TreeNode("Settings"))
     {
         ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 16.0f, "%.0f");
-        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("ItemSpacing", (float*)&style.ItemSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("ItemInnerSpacing", (float*)&style.ItemInnerSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("TouchExtraPadding", (float*)&style.TouchExtraPadding, 0.0f, 10.0f, "%.0f");
         ImGui::SliderFloat("IndentSpacing", &style.IndentSpacing, 0.0f, 30.0f, "%.0f");
         ImGui::SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("GrabMinSize", &style.GrabMinSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::Text("BorderSize");
+        ImGui::SliderFloat("WindowBorderSize", &style.WindowBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("ChildBorderSize", &style.ChildBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("PopupBorderSize", &style.PopupBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("FrameBorderSize", &style.FrameBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::Text("Rounding");
+        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 14.0f, "%.0f");
+        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
         ImGui::Text("Alignment");
         ImGui::SliderFloat2("WindowTitleAlign", (float*)&style.WindowTitleAlign, 0.0f, 1.0f, "%.2f");
         ImGui::SliderFloat2("ButtonTextAlign", (float*)&style.ButtonTextAlign, 0.0f, 1.0f, "%.2f"); ImGui::SameLine(); ShowHelpMarker("Alignment applies when a button is larger than its text content.");

diff --git a/imgui.cpp b/imgui.cpp
index 850ea24..2510fb7 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -214,7 +214,10 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.
+                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.
  - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.
+ - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.
  - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.
  - 2017/11/02 (1.53) - marked IsRootWindowOrAnyChildHovered() as obsolete is favor of using IsWindowHovered(ImGuiHoveredFlags_FlattenChilds);
  - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.
@@ -703,13 +706,17 @@
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
+    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
     ChildRounding           = 0.0f;             // Radius of child window corners rounding. Set to 0.0f to have rectangular child windows
+    ChildBorderSize         = 1.0f;             // Thickness of border around child windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     PopupRounding           = 0.0f;             // Radius of popup window corners rounding. Set to 0.0f to have rectangular child windows
+    PopupBorderSize         = 1.0f;             // Thickness of border around popup or tooltip windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     FramePadding            = ImVec2(4,3);      // Padding within a framed rectangle (used by most widgets)
     FrameRounding           = 0.0f;             // Radius of frame corners rounding. Set to 0.0f to have rectangular frames (used by most widgets).
+    FrameBorderSize         = 0.0f;             // Thickness of border around frames. Generally set to 0.0f or 1.0f. Other values not well tested.
     ItemSpacing             = ImVec2(8,4);      // Horizontal and vertical spacing between widgets/lines
     ItemInnerSpacing        = ImVec2(4,4);      // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     TouchExtraPadding       = ImVec2(0,0);      // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -734,8 +741,8 @@
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {
     WindowPadding = ImFloor(WindowPadding * scale_factor);
-    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     WindowRounding = ImFloor(WindowRounding * scale_factor);
+    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     ChildRounding = ImFloor(ChildRounding * scale_factor);
     PopupRounding = ImFloor(PopupRounding * scale_factor);
     FramePadding = ImFloor(FramePadding * scale_factor);
@@ -2215,12 +2222,14 @@
     ImGuiContext& g = *GImGui;
 
     // Check user data
-    IM_ASSERT(g.IO.DeltaTime >= 0.0f);               // Need a positive DeltaTime (zero is tolerated but will cause some timing issues)
-    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f);
-    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0);           // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded());     // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f);  // Invalid style setting
-    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f);  // Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)
+    // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
+    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
+    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting");
+    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)");
+    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
 
     // Initialize on first frame
     if (!g.Initialized)
@@ -2764,7 +2773,8 @@
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // ImGui::EndFrame() called multiple times, or forgot to call ImGui::NewFrame() again
+    if (g.FrameCountEnded == g.FrameCount)          // Don't process EndFrame() multiple times.
+        return;
 
     // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
     if (g.IO.ImeSetInputScreenPosFn && ImLengthSqr(g.OsImePosRequest - g.OsImePosSet) > 0.0001f)
@@ -3093,10 +3103,11 @@
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     window->DrawList->AddRectFilled(p_min, p_max, fill_col, rounding);
-    if (border && (window->Flags & ImGuiWindowFlags_ShowBorders))
+    const float border_size = g.Style.FrameBorderSize;
+    if (border && border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3104,10 +3115,11 @@
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    const float border_size = g.Style.FrameBorderSize;
+    if (border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3683,14 +3695,12 @@
 bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     if (!IsPopupOpen(id))
     {
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
 
-    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGuiWindowFlags flags = extra_flags|ImGuiWindowFlags_Popup|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings;
 
     char name[20];
@@ -3700,9 +3710,7 @@
         ImFormatString(name, IM_ARRAYSIZE(name), "##popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
     bool is_open = Begin(name, NULL, flags);
-    if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
-        g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
-    if (!is_open) // NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
+    if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
     return is_open;
@@ -3716,7 +3724,7 @@
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
-    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::IsPopupOpen(ImGuiID id)
@@ -3765,8 +3773,6 @@
     IM_ASSERT(window->Flags & ImGuiWindowFlags_Popup);  // Mismatched BeginPopup()/EndPopup() calls
     IM_ASSERT(GImGui->CurrentPopupStack.Size > 0);
     End();
-    if (!(window->Flags & ImGuiWindowFlags_Modal))
-        PopStyleVar();
 }
 
 bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
@@ -3792,7 +3798,7 @@
     IM_ASSERT(id != 0);                                                  // However, you cannot pass a NULL str_id if the last item has no identifier (e.g. a Text() item)
     if (IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
@@ -3804,7 +3810,7 @@
         if (IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
             if (also_over_items || !IsAnyItemHovered())
                 OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
@@ -3814,11 +3820,12 @@
     ImGuiID id = GImGui->CurrentWindow->GetID(str_id);
     if (!IsAnyWindowHovered() && IsMouseClicked(mouse_button))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 static bool BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags extra_flags)
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = ImGui::GetCurrentWindow();
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_ChildWindow;
     flags |= (parent_window->Flags & ImGuiWindowFlags_NoMove);  // Inherit the NoMove flag
@@ -3830,8 +3837,10 @@
         size.x = ImMax(content_avail.x, 4.0f) - fabsf(size.x); // Arbitrary minimum zero-ish child size of 4.0f (0.0f causing too much issues)
     if (size.y <= 0.0f)
         size.y = ImMax(content_avail.y, 4.0f) - fabsf(size.y);
-    if (border)
-        flags |= ImGuiWindowFlags_ShowBorders;
+
+    const float backup_border_size = g.Style.ChildBorderSize;
+    if (!border)
+        g.Style.ChildBorderSize = 0.0f;
     flags |= extra_flags;
 
     char title[256];
@@ -3844,8 +3853,7 @@
     bool ret = ImGui::Begin(title, NULL, flags);
     ImGuiWindow* child_window = ImGui::GetCurrentWindow();
     child_window->AutoFitChildAxises = auto_fit_axises;
-    if (!(parent_window->Flags & ImGuiWindowFlags_ShowBorders))
-        child_window->Flags &= ~ImGuiWindowFlags_ShowBorders;
+    g.Style.ChildBorderSize = backup_border_size;
 
     return ret;
 }
@@ -3892,16 +3900,17 @@
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    PushStyleColor(ImGuiCol_ChildWindowBg, style.Colors[ImGuiCol_FrameBg]);
+    PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
     PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+    PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
-    return BeginChild(id, size, (g.CurrentWindow->Flags & ImGuiWindowFlags_ShowBorders) ? true : false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
+    return BeginChild(id, size, true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
 }
 
 void ImGui::EndChildFrame()
 {
     EndChild();
-    PopStyleVar(2);
+    PopStyleVar(3);
     PopStyleColor();
 }
 
@@ -4099,7 +4108,7 @@
     if (flags & (ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup))
         return ImGuiCol_PopupBg;
     if (flags & ImGuiWindowFlags_ChildWindow)
-        return ImGuiCol_ChildWindowBg;
+        return ImGuiCol_ChildBg;
     return ImGuiCol_WindowBg;
 }
 
@@ -4283,13 +4292,15 @@
             }
         }
 
-        // Lock window padding so that altering the ShowBorders flag for children doesn't have side-effects.
+        // Lock window padding so that altering the border sizes for children doesn't have side-effects.
         window->WindowPadding = style.WindowPadding;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)))
+        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)) && style.WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->WindowBorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
+        window->WindowBorderSize = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildBorderSize : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;
+        const ImVec2 window_padding = window->WindowPadding;
         const float window_rounding = window->WindowRounding;
+        const float window_border_size = window->WindowBorderSize;
 
         // Calculate auto-fit size, handle automatic resize
         const ImVec2 size_auto_fit = CalcSizeAutoFit(window);
@@ -4423,7 +4434,10 @@
         if (window->Collapsed)
         {
             // Title bar only
+            float backup_border_size = style.FrameBorderSize;
+            g.Style.FrameBorderSize = window->WindowBorderSize;
             RenderFrame(title_bar_rect.Min, title_bar_rect.Max, GetColorU32(ImGuiCol_TitleBgCollapsed), true, window_rounding);
+            g.Style.FrameBorderSize = backup_border_size;
         }
         else
         {
@@ -4477,9 +4491,9 @@
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                if (flags & ImGuiWindowFlags_ShowBorders)
-                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border));
                 window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
+                if (style.FrameBorderSize > 0.0f)
+                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
             }
 
             // Scrollbars
@@ -4493,20 +4507,17 @@
             if (!(flags & ImGuiWindowFlags_NoResize))
             {
                 const ImVec2 br = window->Rect().GetBR();
-                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window->WindowBorderSize));
-                window->DrawList->PathLineTo(br + ImVec2(-window->WindowBorderSize, -resize_corner_size));
-                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window->WindowBorderSize, br.y - window_rounding - window->WindowBorderSize), window_rounding, 0, 3);
+                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window_border_size));
+                window->DrawList->PathLineTo(br + ImVec2(-window_border_size, -resize_corner_size));
+                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window_border_size, br.y - window_rounding - window_border_size), window_rounding, 0, 3);
                 window->DrawList->PathFillConvex(resize_col);
             }
 
             // Borders
-            if (flags & ImGuiWindowFlags_ShowBorders)
-            {
-                window->DrawList->AddRect(window->Pos+ImVec2(1,1), window->Pos+window->Size+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), window_rounding);
-                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding);
-                if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                    window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,0), title_bar_rect.GetBR()-ImVec2(1,0), GetColorU32(ImGuiCol_Border));
-            }
+            if (window_border_size > 0.0f)
+                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding, ~0, window_border_size);
+            if (style.FrameBorderSize > 0 && !(flags & ImGuiWindowFlags_NoTitleBar))
+                window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,-1), title_bar_rect.GetBR()+ImVec2(-1,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
         // Update ContentsRegionMax. All the variable it depends on are set above in this function.
@@ -5060,11 +5071,15 @@
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, Alpha) },                // ImGuiStyleVar_Alpha
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowPadding) },        // ImGuiStyleVar_WindowPadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowRounding) },       // ImGuiStyleVar_WindowRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowBorderSize) },     // ImGuiStyleVar_WindowBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowMinSize) },        // ImGuiStyleVar_WindowMinSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildRounding) },        // ImGuiStyleVar_ChildRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildBorderSize) },      // ImGuiStyleVar_ChildBorderSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupRounding) },        // ImGuiStyleVar_PopupRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupBorderSize) },      // ImGuiStyleVar_PopupBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, FramePadding) },         // ImGuiStyleVar_FramePadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameRounding) },        // ImGuiStyleVar_FrameRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameBorderSize) },      // ImGuiStyleVar_FrameBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemSpacing) },          // ImGuiStyleVar_ItemSpacing
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemInnerSpacing) },     // ImGuiStyleVar_ItemInnerSpacing
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, IndentSpacing) },        // ImGuiStyleVar_IndentSpacing
@@ -5129,7 +5144,7 @@
     case ImGuiCol_Text: return "Text";
     case ImGuiCol_TextDisabled: return "TextDisabled";
     case ImGuiCol_WindowBg: return "WindowBg";
-    case ImGuiCol_ChildWindowBg: return "ChildWindowBg";
+    case ImGuiCol_ChildBg: return "ChildBg";
     case ImGuiCol_PopupBg: return "PopupBg";
     case ImGuiCol_Border: return "Border";
     case ImGuiCol_BorderShadow: return "BorderShadow";
@@ -7654,7 +7669,7 @@
     // Render
     fraction = ImSaturate(fraction);
     RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
-    bb.Expand(ImVec2(-window->WindowBorderSize, -window->WindowBorderSize));
+    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
     const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
     RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);
 
@@ -7777,10 +7792,10 @@
         window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
     }
 
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16);
+        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
     }
 
     if (g.LogEnabled)
@@ -8919,18 +8934,17 @@
         // Position our combo ABOVE because there's more space to fit! (FIXME: Handle in Begin() or use a shared helper. We have similar code in Begin() for popup placement)
         popup_y1 = ImClamp(frame_bb.Min.y - popup_size.y, style.DisplaySafeAreaPadding.y, frame_bb.Min.y);
         popup_y2 = frame_bb.Min.y;
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
     }
     else
     {
         // Position our combo below
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
     }
     SetNextWindowSize(ImVec2(popup_size.x, popup_y2 - popup_y1), ImGuiCond_Appearing);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
 
-    const ImGuiWindowFlags flags = ImGuiWindowFlags_ComboBox | ((window->Flags & ImGuiWindowFlags_ShowBorders) ? ImGuiWindowFlags_ShowBorders : 0);
-    if (!BeginPopupEx(id, flags))
+    if (!BeginPopupEx(id, ImGuiWindowFlags_ComboBox))
     {
         IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
         return false;
@@ -9396,7 +9410,7 @@
     if (menu_is_open)
     {
         SetNextWindowPos(popup_pos, ImGuiCond_Always);
-        ImGuiWindowFlags flags = ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
+        ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
         menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
     }
 
@@ -9541,7 +9555,7 @@
         else
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ~0);
     }
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (g.Style.FrameBorderSize > 0.0f)
         RenderFrameBorder(bb.Min, bb.Max, rounding);
     else
         window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
diff --git a/imgui.h b/imgui.h
index f00ed49..93bebe7 100644
--- a/imgui.h
+++ b/imgui.h
@@ -125,8 +125,9 @@
     IMGUI_API ImGuiIO&      GetIO();
     IMGUI_API ImGuiStyle&   GetStyle();
     IMGUI_API ImDrawData*   GetDrawData();                              // same value as passed to your io.RenderDrawListsFn() function. valid after Render() and until the next call to NewFrame()
-    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until NewFrame()/Render().
-    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize rendering data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until Render()/EndFrame().
+    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize the draw data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          EndFrame();                                 // ends the ImGui frame. automatically called by Render(), so most likely don't need to ever call that yourself directly. If you don't need to render you may call EndFrame() but you'll have wasted CPU already. If you don't need to render, better to not create any imgui windows instead!
     IMGUI_API void          Shutdown();
 
     // Demo/Debug/Info
@@ -352,7 +353,7 @@
     IMGUI_API bool          TreeNodeEx(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(3);
     IMGUI_API bool          TreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API bool          TreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
-    IMGUI_API void          TreePush(const char* str_id = NULL);                                    // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
+    IMGUI_API void          TreePush(const char* str_id);                                           // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
     IMGUI_API void          TreePush(const void* ptr_id = NULL);                                    // "
     IMGUI_API void          TreePop();                                                              // ~ Unindent()+PopId()
     IMGUI_API void          TreeAdvanceToLabelPos();                                                // advance cursor x position by GetTreeNodeToLabelSpacing()
@@ -511,7 +512,7 @@
     ImGuiWindowFlags_NoScrollWithMouse      = 1 << 4,   // Disable user vertically scrolling with mouse wheel
     ImGuiWindowFlags_NoCollapse             = 1 << 5,   // Disable user collapsing window by double-clicking on it
     ImGuiWindowFlags_AlwaysAutoResize       = 1 << 6,   // Resize every window to its content every frame
-    ImGuiWindowFlags_ShowBorders            = 1 << 7,   // Show borders around windows and items
+    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // Show borders around windows and items (OBSOLETE! Use e.g. style.FrameBorderSize=1.0f to enable borders).
     ImGuiWindowFlags_NoSavedSettings        = 1 << 8,   // Never load/save settings in .ini file
     ImGuiWindowFlags_NoInputs               = 1 << 9,   // Disable catching mouse or keyboard inputs, hovering test with pass through.
     ImGuiWindowFlags_MenuBar                = 1 << 10,  // Has a menu-bar
@@ -639,7 +640,7 @@
     ImGuiCol_Text,
     ImGuiCol_TextDisabled,
     ImGuiCol_WindowBg,              // Background of normal windows
-    ImGuiCol_ChildWindowBg,         // Background of child windows
+    ImGuiCol_ChildBg,               // Background of child windows
     ImGuiCol_PopupBg,               // Background of popups, menus, tooltips windows
     ImGuiCol_Border,
     ImGuiCol_BorderShadow,
@@ -682,7 +683,7 @@
 
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
+    , ImGuiCol_ChildWindowBg = ImGuiCol_ChildBg, ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
 #endif
 };
 
@@ -695,11 +696,15 @@
     ImGuiStyleVar_Alpha,               // float     Alpha
     ImGuiStyleVar_WindowPadding,       // ImVec2    WindowPadding
     ImGuiStyleVar_WindowRounding,      // float     WindowRounding
+    ImGuiStyleVar_WindowBorderSize,    // float     WindowBorderSize
     ImGuiStyleVar_WindowMinSize,       // ImVec2    WindowMinSize
     ImGuiStyleVar_ChildRounding,       // float     ChildRounding
+    ImGuiStyleVar_ChildBorderSize,     // float     ChildBorderSize
     ImGuiStyleVar_PopupRounding,       // float     PopupRounding
+    ImGuiStyleVar_PopupBorderSize,     // float     PopupBorderSize
     ImGuiStyleVar_FramePadding,        // ImVec2    FramePadding
     ImGuiStyleVar_FrameRounding,       // float     FrameRounding
+    ImGuiStyleVar_FrameBorderSize,     // float     FrameBorderSize
     ImGuiStyleVar_ItemSpacing,         // ImVec2    ItemSpacing
     ImGuiStyleVar_ItemInnerSpacing,    // ImVec2    ItemInnerSpacing
     ImGuiStyleVar_IndentSpacing,       // float     IndentSpacing
@@ -776,13 +781,17 @@
 {
     float       Alpha;                      // Global alpha applies to everything in ImGui
     ImVec2      WindowPadding;              // Padding within a window
-    ImVec2      WindowMinSize;              // Minimum window size
     float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
+    ImVec2      WindowMinSize;              // Minimum window size
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.
     float       ChildRounding;              // Radius of child window corners rounding. Set to 0.0f to have rectangular windows.
+    float       ChildBorderSize;            // Thickness of border around child windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     float       PopupRounding;              // Radius of popup window corners rounding.
+    float       PopupBorderSize;            // Thickness of border around popup windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      FramePadding;               // Padding within a framed rectangle (used by most widgets)
     float       FrameRounding;              // Radius of frame corners rounding. Set to 0.0f to have rectangular frame (used by most widgets).
+    float       FrameBorderSize;            // Thickness of border around frames. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      ItemSpacing;                // Horizontal and vertical spacing between widgets/lines
     ImVec2      ItemInnerSpacing;           // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     ImVec2      TouchExtraPadding;          // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -1042,12 +1051,11 @@
     int                 CountGrep;
 
     IMGUI_API           ImGuiTextFilter(const char* default_filter = "");
-                        ~ImGuiTextFilter() {}
-    void                Clear() { InputBuf[0] = 0; Build(); }
     IMGUI_API bool      Draw(const char* label = "Filter (inc,-exc)", float width = 0.0f);    // Helper calling InputText+Build
     IMGUI_API bool      PassFilter(const char* text, const char* text_end = NULL) const;
-    bool                IsActive() const { return !Filters.empty(); }
     IMGUI_API void      Build();
+    void                Clear() { InputBuf[0] = 0; Build(); }
+    bool                IsActive() const { return !Filters.empty(); }
 };
 
 // Helper: Text buffer for logging/accumulating text
@@ -1138,7 +1146,7 @@
     // NB: Helper functions for text manipulation. Calling those function loses selection.
     IMGUI_API void    DeleteChars(int pos, int bytes_count);
     IMGUI_API void    InsertChars(int pos, const char* text, const char* text_end = NULL);
-    bool    HasSelection() const { return SelectionStart != SelectionEnd; }
+    bool              HasSelection() const { return SelectionStart != SelectionEnd; }
 };
 
 // Resizing callback data to apply custom constraint. As enabled by SetNextWindowSizeConstraints(). Callback is called during the next Begin().
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 9ac07b7..7bf92e3 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -165,22 +165,20 @@
     }
 
     static bool no_titlebar = false;
-    static bool no_border = true;
-    static bool no_resize = false;
-    static bool no_move = false;
     static bool no_scrollbar = false;
-    static bool no_collapse = false;
     static bool no_menu = false;
+    static bool no_move = false;
+    static bool no_resize = false;
+    static bool no_collapse = false;
 
     // Demonstrate the various window flags. Typically you would just use the default.
     ImGuiWindowFlags window_flags = 0;
     if (no_titlebar)  window_flags |= ImGuiWindowFlags_NoTitleBar;
-    if (!no_border)   window_flags |= ImGuiWindowFlags_ShowBorders;
-    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
-    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
     if (no_scrollbar) window_flags |= ImGuiWindowFlags_NoScrollbar;
-    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     if (!no_menu)     window_flags |= ImGuiWindowFlags_MenuBar;
+    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
+    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
+    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     ImGui::SetNextWindowSize(ImVec2(550,680), ImGuiCond_FirstUseEver);
     if (!ImGui::Begin("ImGui Demo", p_open, window_flags))
     {
@@ -238,12 +236,11 @@
     if (ImGui::CollapsingHeader("Window options"))
     {
         ImGui::Checkbox("No titlebar", &no_titlebar); ImGui::SameLine(150);
-        ImGui::Checkbox("No border", &no_border); ImGui::SameLine(300);
-        ImGui::Checkbox("No resize", &no_resize);
-        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
         ImGui::Checkbox("No scrollbar", &no_scrollbar); ImGui::SameLine(300);
-        ImGui::Checkbox("No collapse", &no_collapse);
         ImGui::Checkbox("No menu", &no_menu);
+        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
+        ImGui::Checkbox("No resize", &no_resize); ImGui::SameLine(300);
+        ImGui::Checkbox("No collapse", &no_collapse);
 
         if (ImGui::TreeNode("Style"))
         {
@@ -685,7 +682,6 @@
             ImGui::TreePop();
         }
 
-
         if (ImGui::TreeNode("Plots widgets"))
         {
             static bool animate = true;
@@ -1341,7 +1337,7 @@
             if (ImGui::Button("Select.."))
                 ImGui::OpenPopup("select");
             ImGui::SameLine();
-            ImGui::Text(selected_fish == -1 ? "<None>" : names[selected_fish]);
+            ImGui::TextUnformatted(selected_fish == -1 ? "<None>" : names[selected_fish]);
             if (ImGui::BeginPopup("select"))
             {
                 ImGui::Text("Aquarium");
@@ -1878,6 +1874,15 @@
         ref_saved_style = style;
     }
 
+    // Simplified Settings
+    if (ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f")) 
+        style.GrabRounding = style.FrameRounding; // Make GrabRounding always the same value as FrameRounding
+    { bool window_border = (style.WindowBorderSize > 0.0f); if (ImGui::Checkbox("WindowBorder", &window_border)) style.WindowBorderSize = window_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool frame_border = (style.FrameBorderSize > 0.0f); if (ImGui::Checkbox("FrameBorder", &frame_border)) style.FrameBorderSize = frame_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool popup_border = (style.PopupBorderSize > 0.0f); if (ImGui::Checkbox("PopupBorder", &popup_border)) style.PopupBorderSize = popup_border ? 1.0f : 0.0f; }
+
     // Save/Revert button
     if (ImGui::Button("Save Ref"))
         *ref = ref_saved_style = style;
@@ -1902,19 +1907,25 @@
     if (ImGui::TreeNode("Settings"))
     {
         ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 16.0f, "%.0f");
-        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("ItemSpacing", (float*)&style.ItemSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("ItemInnerSpacing", (float*)&style.ItemInnerSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("TouchExtraPadding", (float*)&style.TouchExtraPadding, 0.0f, 10.0f, "%.0f");
         ImGui::SliderFloat("IndentSpacing", &style.IndentSpacing, 0.0f, 30.0f, "%.0f");
         ImGui::SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("GrabMinSize", &style.GrabMinSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::Text("BorderSize");
+        ImGui::SliderFloat("WindowBorderSize", &style.WindowBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("ChildBorderSize", &style.ChildBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("PopupBorderSize", &style.PopupBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("FrameBorderSize", &style.FrameBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::Text("Rounding");
+        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 14.0f, "%.0f");
+        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
         ImGui::Text("Alignment");
         ImGui::SliderFloat2("WindowTitleAlign", (float*)&style.WindowTitleAlign, 0.0f, 1.0f, "%.2f");
         ImGui::SliderFloat2("ButtonTextAlign", (float*)&style.ButtonTextAlign, 0.0f, 1.0f, "%.2f"); ImGui::SameLine(); ShowHelpMarker("Alignment applies when a button is larger than its text content.");
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 3a934ea..8718e97 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -129,9 +129,9 @@
     colors[ImGuiCol_Text]                   = ImVec4(0.90f, 0.90f, 0.90f, 1.00f);
     colors[ImGuiCol_TextDisabled]           = ImVec4(0.60f, 0.60f, 0.60f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.00f, 0.00f, 0.00f, 0.70f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(0.11f, 0.11f, 0.14f, 0.92f);
-    colors[ImGuiCol_Border]                 = ImVec4(0.70f, 0.70f, 0.70f, 0.27f);
+    colors[ImGuiCol_Border]                 = ImVec4(0.50f, 0.50f, 0.50f, 0.50f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_FrameBg]                = ImVec4(0.43f, 0.43f, 0.43f, 0.39f);
     colors[ImGuiCol_FrameBgHovered]         = ImVec4(0.47f, 0.47f, 0.69f, 0.40f);
@@ -178,9 +178,9 @@
     colors[ImGuiCol_Text]                   = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_TextDisabled]           = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.06f, 0.06f, 0.06f, 0.94f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(1.00f, 1.00f, 1.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(1.00f, 1.00f, 1.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(0.08f, 0.08f, 0.08f, 0.94f);
-    colors[ImGuiCol_Border]                 = ImVec4(0.86f, 0.86f, 1.00f, 0.20f);
+    colors[ImGuiCol_Border]                 = ImVec4(0.43f, 0.43f, 0.50f, 0.50f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_FrameBg]                = ImVec4(0.16f, 0.29f, 0.48f, 0.54f);
     colors[ImGuiCol_FrameBgHovered]         = ImVec4(0.26f, 0.59f, 0.98f, 0.40f);
@@ -229,7 +229,7 @@
     //colors[ImGuiCol_TextHovered]          = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     //colors[ImGuiCol_TextActive]           = ImVec4(1.00f, 1.00f, 0.00f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.94f, 0.94f, 0.94f, 1.00f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(1.00f, 1.00f, 1.00f, 0.94f);
     colors[ImGuiCol_Border]                 = ImVec4(0.00f, 0.00f, 0.00f, 0.30f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
@@ -1617,7 +1617,7 @@
 
     // Start packing
     const int max_tex_height = 1024*32;
-    stbtt_pack_context spc;
+    stbtt_pack_context spc = {};
     stbtt_PackBegin(&spc, NULL, atlas->TexWidth, max_tex_height, 0, atlas->TexGlyphPadding, NULL);
     stbtt_PackSetOversampling(&spc, 1, 1);
 
@@ -2183,7 +2183,7 @@
     IndexAdvanceX[dst] = (src < index_size) ? IndexAdvanceX.Data[src] : 1.0f;
 }
 
-const ImFontGlyph* ImFont::FindGlyph(unsigned short c) const
+const ImFontGlyph* ImFont::FindGlyph(ImWchar c) const
 {
     if (c < IndexLookup.Size)
     {

diff --git a/imgui.cpp b/imgui.cpp
index 850ea24..2510fb7 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -214,7 +214,10 @@
  Here is a change-log of API breaking changes, if you are using one of the functions listed, expect to have to fix some code.
  Also read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2017/11/18 (1.53) - Style, Begin: removed ImGuiWindowFlags_ShowBorders window flag. Borders are now fully set up in the ImGuiStyle structure (see e.g. style.FrameBorderSize, style.WindowBorderSize). Use ImGui::ShowStyleEditor() to look them up.
+                       Please note that the style system will keep evolving (hopefully stabilizing in Q1 2018), and so custom styles will probably subtly break over time. It is recommended you use the StyleColorsClassic(), StyleColorsDark(), StyleColorsLight() functions.
  - 2017/11/18 (1.53) - Style: removed ImGuiCol_ComboBg in favor of combo boxes using ImGuiCol_PopupBg for consistency.
+ - 2017/11/18 (1.53) - Style: renamed ImGuiCol_ChildWindowBg to ImGuiCol_ChildBg.
  - 2017/11/18 (1.53) - Style: renamed style.ChildWindowRounding to style.ChildRounding, ImGuiStyleVar_ChildWindowRounding to ImGuiStyleVar_ChildRounding.
  - 2017/11/02 (1.53) - marked IsRootWindowOrAnyChildHovered() as obsolete is favor of using IsWindowHovered(ImGuiHoveredFlags_FlattenChilds);
  - 2017/10/24 (1.52) - renamed IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCS to IMGUI_DISABLE_WIN32_DEFAULT_CLIPBOARD_FUNCTIONS/IMGUI_DISABLE_WIN32_DEFAULT_IME_FUNCTIONS for consistency.
@@ -703,13 +706,17 @@
 {
     Alpha                   = 1.0f;             // Global alpha applies to everything in ImGui
     WindowPadding           = ImVec2(8,8);      // Padding within a window
-    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowRounding          = 9.0f;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    WindowBorderSize        = 0.0f;             // Thickness of border around windows. Generally set to 0.0f or 1.0f. Other values not well tested.
+    WindowMinSize           = ImVec2(32,32);    // Minimum window size
     WindowTitleAlign        = ImVec2(0.0f,0.5f);// Alignment for title bar text
     ChildRounding           = 0.0f;             // Radius of child window corners rounding. Set to 0.0f to have rectangular child windows
+    ChildBorderSize         = 1.0f;             // Thickness of border around child windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     PopupRounding           = 0.0f;             // Radius of popup window corners rounding. Set to 0.0f to have rectangular child windows
+    PopupBorderSize         = 1.0f;             // Thickness of border around popup or tooltip windows. Generally set to 0.0f or 1.0f. Other values not well tested.
     FramePadding            = ImVec2(4,3);      // Padding within a framed rectangle (used by most widgets)
     FrameRounding           = 0.0f;             // Radius of frame corners rounding. Set to 0.0f to have rectangular frames (used by most widgets).
+    FrameBorderSize         = 0.0f;             // Thickness of border around frames. Generally set to 0.0f or 1.0f. Other values not well tested.
     ItemSpacing             = ImVec2(8,4);      // Horizontal and vertical spacing between widgets/lines
     ItemInnerSpacing        = ImVec2(4,4);      // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     TouchExtraPadding       = ImVec2(0,0);      // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -734,8 +741,8 @@
 void ImGuiStyle::ScaleAllSizes(float scale_factor)
 {
     WindowPadding = ImFloor(WindowPadding * scale_factor);
-    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     WindowRounding = ImFloor(WindowRounding * scale_factor);
+    WindowMinSize = ImFloor(WindowMinSize * scale_factor);
     ChildRounding = ImFloor(ChildRounding * scale_factor);
     PopupRounding = ImFloor(PopupRounding * scale_factor);
     FramePadding = ImFloor(FramePadding * scale_factor);
@@ -2215,12 +2222,14 @@
     ImGuiContext& g = *GImGui;
 
     // Check user data
-    IM_ASSERT(g.IO.DeltaTime >= 0.0f);               // Need a positive DeltaTime (zero is tolerated but will cause some timing issues)
-    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f);
-    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0);           // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded());     // Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?
-    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f);  // Invalid style setting
-    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f);  // Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)
+    // (We pass an error message in the assert expression as a trick to get it visible to programmers who are not using a debugger, as most assert handlers display their argument)
+    IM_ASSERT(g.IO.DeltaTime >= 0.0f                                    && "Need a positive DeltaTime (zero is tolerated but will cause some timing issues)");
+    IM_ASSERT(g.IO.DisplaySize.x >= 0.0f && g.IO.DisplaySize.y >= 0.0f  && "Invalid DisplaySize value");
+    IM_ASSERT(g.IO.Fonts->Fonts.Size > 0                                && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.IO.Fonts->Fonts[0]->IsLoaded()                          && "Font Atlas not created. Did you call io.Fonts->GetTexDataAsRGBA32 / GetTexDataAsAlpha8 ?");
+    IM_ASSERT(g.Style.CurveTessellationTol > 0.0f                       && "Invalid style setting");
+    IM_ASSERT(g.Style.Alpha >= 0.0f && g.Style.Alpha <= 1.0f            && "Invalid style setting. Alpha cannot be negative (allows us to avoid a few clamps in color computations)");
+    IM_ASSERT((g.FrameCount == 0 || g.FrameCountEnded == g.FrameCount)  && "Forgot to call Render() or EndFrame() at the end of the previous frame?");
 
     // Initialize on first frame
     if (!g.Initialized)
@@ -2764,7 +2773,8 @@
 {
     ImGuiContext& g = *GImGui;
     IM_ASSERT(g.Initialized);                       // Forgot to call ImGui::NewFrame()
-    IM_ASSERT(g.FrameCountEnded != g.FrameCount);   // ImGui::EndFrame() called multiple times, or forgot to call ImGui::NewFrame() again
+    if (g.FrameCountEnded == g.FrameCount)          // Don't process EndFrame() multiple times.
+        return;
 
     // Notify OS when our Input Method Editor cursor has moved (e.g. CJK inputs using Microsoft IME)
     if (g.IO.ImeSetInputScreenPosFn && ImLengthSqr(g.OsImePosRequest - g.OsImePosSet) > 0.0001f)
@@ -3093,10 +3103,11 @@
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
     window->DrawList->AddRectFilled(p_min, p_max, fill_col, rounding);
-    if (border && (window->Flags & ImGuiWindowFlags_ShowBorders))
+    const float border_size = g.Style.FrameBorderSize;
+    if (border && border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3104,10 +3115,11 @@
 {
     ImGuiContext& g = *GImGui;
     ImGuiWindow* window = g.CurrentWindow;
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    const float border_size = g.Style.FrameBorderSize;
+    if (border_size > 0.0f)
     {
-        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding);
-        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding);
+        window->DrawList->AddRect(p_min+ImVec2(1,1), p_max+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), rounding, ~0, border_size);
+        window->DrawList->AddRect(p_min, p_max, GetColorU32(ImGuiCol_Border), rounding, ~0, border_size);
     }
 }
 
@@ -3683,14 +3695,12 @@
 bool ImGui::BeginPopupEx(ImGuiID id, ImGuiWindowFlags extra_flags)
 {
     ImGuiContext& g = *GImGui;
-    ImGuiWindow* window = g.CurrentWindow;
     if (!IsPopupOpen(id))
     {
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
 
-    PushStyleVar(ImGuiStyleVar_WindowRounding, 0.0f);
     ImGuiWindowFlags flags = extra_flags|ImGuiWindowFlags_Popup|ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings;
 
     char name[20];
@@ -3700,9 +3710,7 @@
         ImFormatString(name, IM_ARRAYSIZE(name), "##popup_%08x", id); // Not recycling, so we can close/open during the same frame
 
     bool is_open = Begin(name, NULL, flags);
-    if (!(window->Flags & ImGuiWindowFlags_ShowBorders))
-        g.CurrentWindow->Flags &= ~ImGuiWindowFlags_ShowBorders;
-    if (!is_open) // NB: is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
+    if (!is_open) // NB: Begin can return false when the popup is completely clipped (e.g. zero size display)
         EndPopup();
 
     return is_open;
@@ -3716,7 +3724,7 @@
         ClearSetNextWindowData(); // We behave like Begin() and need to consume those values
         return false;
     }
-    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(g.CurrentWindow->GetID(str_id), ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::IsPopupOpen(ImGuiID id)
@@ -3765,8 +3773,6 @@
     IM_ASSERT(window->Flags & ImGuiWindowFlags_Popup);  // Mismatched BeginPopup()/EndPopup() calls
     IM_ASSERT(GImGui->CurrentPopupStack.Size > 0);
     End();
-    if (!(window->Flags & ImGuiWindowFlags_Modal))
-        PopStyleVar();
 }
 
 bool ImGui::OpenPopupOnItemClick(const char* str_id, int mouse_button)
@@ -3792,7 +3798,7 @@
     IM_ASSERT(id != 0);                                                  // However, you cannot pass a NULL str_id if the last item has no identifier (e.g. a Text() item)
     if (IsMouseClicked(mouse_button) && IsItemHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextWindow(const char* str_id, int mouse_button, bool also_over_items)
@@ -3804,7 +3810,7 @@
         if (IsWindowHovered(ImGuiHoveredFlags_AllowWhenBlockedByPopup))
             if (also_over_items || !IsAnyItemHovered())
                 OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 bool ImGui::BeginPopupContextVoid(const char* str_id, int mouse_button)
@@ -3814,11 +3820,12 @@
     ImGuiID id = GImGui->CurrentWindow->GetID(str_id);
     if (!IsAnyWindowHovered() && IsMouseClicked(mouse_button))
         OpenPopupEx(id, true);
-    return BeginPopupEx(id, ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize);
+    return BeginPopupEx(id, ImGuiWindowFlags_AlwaysAutoResize);
 }
 
 static bool BeginChildEx(const char* name, ImGuiID id, const ImVec2& size_arg, bool border, ImGuiWindowFlags extra_flags)
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* parent_window = ImGui::GetCurrentWindow();
     ImGuiWindowFlags flags = ImGuiWindowFlags_NoTitleBar|ImGuiWindowFlags_NoResize|ImGuiWindowFlags_NoSavedSettings|ImGuiWindowFlags_ChildWindow;
     flags |= (parent_window->Flags & ImGuiWindowFlags_NoMove);  // Inherit the NoMove flag
@@ -3830,8 +3837,10 @@
         size.x = ImMax(content_avail.x, 4.0f) - fabsf(size.x); // Arbitrary minimum zero-ish child size of 4.0f (0.0f causing too much issues)
     if (size.y <= 0.0f)
         size.y = ImMax(content_avail.y, 4.0f) - fabsf(size.y);
-    if (border)
-        flags |= ImGuiWindowFlags_ShowBorders;
+
+    const float backup_border_size = g.Style.ChildBorderSize;
+    if (!border)
+        g.Style.ChildBorderSize = 0.0f;
     flags |= extra_flags;
 
     char title[256];
@@ -3844,8 +3853,7 @@
     bool ret = ImGui::Begin(title, NULL, flags);
     ImGuiWindow* child_window = ImGui::GetCurrentWindow();
     child_window->AutoFitChildAxises = auto_fit_axises;
-    if (!(parent_window->Flags & ImGuiWindowFlags_ShowBorders))
-        child_window->Flags &= ~ImGuiWindowFlags_ShowBorders;
+    g.Style.ChildBorderSize = backup_border_size;
 
     return ret;
 }
@@ -3892,16 +3900,17 @@
 {
     ImGuiContext& g = *GImGui;
     const ImGuiStyle& style = g.Style;
-    PushStyleColor(ImGuiCol_ChildWindowBg, style.Colors[ImGuiCol_FrameBg]);
+    PushStyleColor(ImGuiCol_ChildBg, style.Colors[ImGuiCol_FrameBg]);
     PushStyleVar(ImGuiStyleVar_ChildRounding, style.FrameRounding);
+    PushStyleVar(ImGuiStyleVar_ChildBorderSize, style.FrameBorderSize);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
-    return BeginChild(id, size, (g.CurrentWindow->Flags & ImGuiWindowFlags_ShowBorders) ? true : false, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
+    return BeginChild(id, size, true, ImGuiWindowFlags_NoMove | ImGuiWindowFlags_AlwaysUseWindowPadding | extra_flags);
 }
 
 void ImGui::EndChildFrame()
 {
     EndChild();
-    PopStyleVar(2);
+    PopStyleVar(3);
     PopStyleColor();
 }
 
@@ -4099,7 +4108,7 @@
     if (flags & (ImGuiWindowFlags_Tooltip | ImGuiWindowFlags_Popup))
         return ImGuiCol_PopupBg;
     if (flags & ImGuiWindowFlags_ChildWindow)
-        return ImGuiCol_ChildWindowBg;
+        return ImGuiCol_ChildBg;
     return ImGuiCol_WindowBg;
 }
 
@@ -4283,13 +4292,15 @@
             }
         }
 
-        // Lock window padding so that altering the ShowBorders flag for children doesn't have side-effects.
+        // Lock window padding so that altering the border sizes for children doesn't have side-effects.
         window->WindowPadding = style.WindowPadding;
-        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)))
+        if ((flags & ImGuiWindowFlags_ChildWindow) && !(flags & (ImGuiWindowFlags_AlwaysUseWindowPadding | ImGuiWindowFlags_ComboBox | ImGuiWindowFlags_Popup)) && style.WindowBorderSize == 0.0f)
             window->WindowPadding = ImVec2(0.0f, (flags & ImGuiWindowFlags_MenuBar) ? style.WindowPadding.y : 0.0f);
-        window->WindowBorderSize = (flags & ImGuiWindowFlags_ShowBorders) ? 1.0f : 0.0f;
         window->WindowRounding = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildRounding : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupRounding : style.WindowRounding;
+        window->WindowBorderSize = (flags & ImGuiWindowFlags_ChildWindow) ? style.ChildBorderSize : ((flags & ImGuiWindowFlags_Popup) && !(flags & ImGuiWindowFlags_Modal)) ? style.PopupBorderSize : style.WindowBorderSize;
+        const ImVec2 window_padding = window->WindowPadding;
         const float window_rounding = window->WindowRounding;
+        const float window_border_size = window->WindowBorderSize;
 
         // Calculate auto-fit size, handle automatic resize
         const ImVec2 size_auto_fit = CalcSizeAutoFit(window);
@@ -4423,7 +4434,10 @@
         if (window->Collapsed)
         {
             // Title bar only
+            float backup_border_size = style.FrameBorderSize;
+            g.Style.FrameBorderSize = window->WindowBorderSize;
             RenderFrame(title_bar_rect.Min, title_bar_rect.Max, GetColorU32(ImGuiCol_TitleBgCollapsed), true, window_rounding);
+            g.Style.FrameBorderSize = backup_border_size;
         }
         else
         {
@@ -4477,9 +4491,9 @@
             if (flags & ImGuiWindowFlags_MenuBar)
             {
                 ImRect menu_bar_rect = window->MenuBarRect();
-                if (flags & ImGuiWindowFlags_ShowBorders)
-                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border));
                 window->DrawList->AddRectFilled(menu_bar_rect.GetTL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_MenuBarBg), (flags & ImGuiWindowFlags_NoTitleBar) ? window_rounding : 0.0f, ImGuiCorner_TopLeft|ImGuiCorner_TopRight);
+                if (style.FrameBorderSize > 0.0f)
+                    window->DrawList->AddLine(menu_bar_rect.GetBL(), menu_bar_rect.GetBR(), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
             }
 
             // Scrollbars
@@ -4493,20 +4507,17 @@
             if (!(flags & ImGuiWindowFlags_NoResize))
             {
                 const ImVec2 br = window->Rect().GetBR();
-                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window->WindowBorderSize));
-                window->DrawList->PathLineTo(br + ImVec2(-window->WindowBorderSize, -resize_corner_size));
-                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window->WindowBorderSize, br.y - window_rounding - window->WindowBorderSize), window_rounding, 0, 3);
+                window->DrawList->PathLineTo(br + ImVec2(-resize_corner_size, -window_border_size));
+                window->DrawList->PathLineTo(br + ImVec2(-window_border_size, -resize_corner_size));
+                window->DrawList->PathArcToFast(ImVec2(br.x - window_rounding - window_border_size, br.y - window_rounding - window_border_size), window_rounding, 0, 3);
                 window->DrawList->PathFillConvex(resize_col);
             }
 
             // Borders
-            if (flags & ImGuiWindowFlags_ShowBorders)
-            {
-                window->DrawList->AddRect(window->Pos+ImVec2(1,1), window->Pos+window->Size+ImVec2(1,1), GetColorU32(ImGuiCol_BorderShadow), window_rounding);
-                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding);
-                if (!(flags & ImGuiWindowFlags_NoTitleBar))
-                    window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,0), title_bar_rect.GetBR()-ImVec2(1,0), GetColorU32(ImGuiCol_Border));
-            }
+            if (window_border_size > 0.0f)
+                window->DrawList->AddRect(window->Pos, window->Pos+window->Size, GetColorU32(ImGuiCol_Border), window_rounding, ~0, window_border_size);
+            if (style.FrameBorderSize > 0 && !(flags & ImGuiWindowFlags_NoTitleBar))
+                window->DrawList->AddLine(title_bar_rect.GetBL()+ImVec2(1,-1), title_bar_rect.GetBR()+ImVec2(-1,-1), GetColorU32(ImGuiCol_Border), style.FrameBorderSize);
         }
 
         // Update ContentsRegionMax. All the variable it depends on are set above in this function.
@@ -5060,11 +5071,15 @@
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, Alpha) },                // ImGuiStyleVar_Alpha
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowPadding) },        // ImGuiStyleVar_WindowPadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowRounding) },       // ImGuiStyleVar_WindowRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, WindowBorderSize) },     // ImGuiStyleVar_WindowBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, WindowMinSize) },        // ImGuiStyleVar_WindowMinSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildRounding) },        // ImGuiStyleVar_ChildRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, ChildBorderSize) },      // ImGuiStyleVar_ChildBorderSize
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupRounding) },        // ImGuiStyleVar_PopupRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, PopupBorderSize) },      // ImGuiStyleVar_PopupBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, FramePadding) },         // ImGuiStyleVar_FramePadding
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameRounding) },        // ImGuiStyleVar_FrameRounding
+    { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, FrameBorderSize) },      // ImGuiStyleVar_FrameBorderSize
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemSpacing) },          // ImGuiStyleVar_ItemSpacing
     { ImGuiDataType_Float2, (ImU32)IM_OFFSETOF(ImGuiStyle, ItemInnerSpacing) },     // ImGuiStyleVar_ItemInnerSpacing
     { ImGuiDataType_Float,  (ImU32)IM_OFFSETOF(ImGuiStyle, IndentSpacing) },        // ImGuiStyleVar_IndentSpacing
@@ -5129,7 +5144,7 @@
     case ImGuiCol_Text: return "Text";
     case ImGuiCol_TextDisabled: return "TextDisabled";
     case ImGuiCol_WindowBg: return "WindowBg";
-    case ImGuiCol_ChildWindowBg: return "ChildWindowBg";
+    case ImGuiCol_ChildBg: return "ChildBg";
     case ImGuiCol_PopupBg: return "PopupBg";
     case ImGuiCol_Border: return "Border";
     case ImGuiCol_BorderShadow: return "BorderShadow";
@@ -7654,7 +7669,7 @@
     // Render
     fraction = ImSaturate(fraction);
     RenderFrame(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), true, style.FrameRounding);
-    bb.Expand(ImVec2(-window->WindowBorderSize, -window->WindowBorderSize));
+    bb.Expand(ImVec2(-style.FrameBorderSize, -style.FrameBorderSize));
     const ImVec2 fill_br = ImVec2(ImLerp(bb.Min.x, bb.Max.x, fraction), bb.Max.y);
     RenderRectFilledRangeH(window->DrawList, bb, GetColorU32(ImGuiCol_PlotHistogram), 0.0f, fraction, style.FrameRounding);
 
@@ -7777,10 +7792,10 @@
         window->DrawList->AddCircleFilled(center, radius-pad, GetColorU32(ImGuiCol_CheckMark), 16);
     }
 
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (style.FrameBorderSize > 0.0f)
     {
-        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16);
-        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16);
+        window->DrawList->AddCircle(center+ImVec2(1,1), radius, GetColorU32(ImGuiCol_BorderShadow), 16, style.FrameBorderSize);
+        window->DrawList->AddCircle(center, radius, GetColorU32(ImGuiCol_Border), 16, style.FrameBorderSize);
     }
 
     if (g.LogEnabled)
@@ -8919,18 +8934,17 @@
         // Position our combo ABOVE because there's more space to fit! (FIXME: Handle in Begin() or use a shared helper. We have similar code in Begin() for popup placement)
         popup_y1 = ImClamp(frame_bb.Min.y - popup_size.y, style.DisplaySafeAreaPadding.y, frame_bb.Min.y);
         popup_y2 = frame_bb.Min.y;
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Min.y + style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 1.0f));
     }
     else
     {
         // Position our combo below
-        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - window->WindowBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
+        SetNextWindowPos(ImVec2(frame_bb.Min.x, frame_bb.Max.y - style.FrameBorderSize), ImGuiCond_Always, ImVec2(0.0f, 0.0f));
     }
     SetNextWindowSize(ImVec2(popup_size.x, popup_y2 - popup_y1), ImGuiCond_Appearing);
     PushStyleVar(ImGuiStyleVar_WindowPadding, style.FramePadding);
 
-    const ImGuiWindowFlags flags = ImGuiWindowFlags_ComboBox | ((window->Flags & ImGuiWindowFlags_ShowBorders) ? ImGuiWindowFlags_ShowBorders : 0);
-    if (!BeginPopupEx(id, flags))
+    if (!BeginPopupEx(id, ImGuiWindowFlags_ComboBox))
     {
         IM_ASSERT(0);   // This should never happen as we tested for IsPopupOpen() above
         return false;
@@ -9396,7 +9410,7 @@
     if (menu_is_open)
     {
         SetNextWindowPos(popup_pos, ImGuiCond_Always);
-        ImGuiWindowFlags flags = ImGuiWindowFlags_ShowBorders | ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
+        ImGuiWindowFlags flags = ImGuiWindowFlags_AlwaysAutoResize | ((window->Flags & (ImGuiWindowFlags_Popup|ImGuiWindowFlags_ChildMenu)) ? ImGuiWindowFlags_ChildMenu|ImGuiWindowFlags_ChildWindow : ImGuiWindowFlags_ChildMenu);
         menu_is_open = BeginPopupEx(id, flags); // menu_is_open can be 'false' when the popup is completely clipped (e.g. zero size display)
     }
 
@@ -9541,7 +9555,7 @@
         else
             window->DrawList->AddRectFilled(bb_inner.Min, bb_inner.Max, GetColorU32(col_source), rounding, ~0);
     }
-    if (window->Flags & ImGuiWindowFlags_ShowBorders)
+    if (g.Style.FrameBorderSize > 0.0f)
         RenderFrameBorder(bb.Min, bb.Max, rounding);
     else
         window->DrawList->AddRect(bb.Min, bb.Max, GetColorU32(ImGuiCol_FrameBg), rounding); // Color button are often in need of some sort of border
diff --git a/imgui.h b/imgui.h
index f00ed49..93bebe7 100644
--- a/imgui.h
+++ b/imgui.h
@@ -125,8 +125,9 @@
     IMGUI_API ImGuiIO&      GetIO();
     IMGUI_API ImGuiStyle&   GetStyle();
     IMGUI_API ImDrawData*   GetDrawData();                              // same value as passed to your io.RenderDrawListsFn() function. valid after Render() and until the next call to NewFrame()
-    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until NewFrame()/Render().
-    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize rendering data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          NewFrame();                                 // start a new ImGui frame, you can submit any command from this point until Render()/EndFrame().
+    IMGUI_API void          Render();                                   // ends the ImGui frame, finalize the draw data, then call your io.RenderDrawListsFn() function if set.
+    IMGUI_API void          EndFrame();                                 // ends the ImGui frame. automatically called by Render(), so most likely don't need to ever call that yourself directly. If you don't need to render you may call EndFrame() but you'll have wasted CPU already. If you don't need to render, better to not create any imgui windows instead!
     IMGUI_API void          Shutdown();
 
     // Demo/Debug/Info
@@ -352,7 +353,7 @@
     IMGUI_API bool          TreeNodeEx(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, ...) IM_FMTARGS(3);
     IMGUI_API bool          TreeNodeExV(const char* str_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
     IMGUI_API bool          TreeNodeExV(const void* ptr_id, ImGuiTreeNodeFlags flags, const char* fmt, va_list args) IM_FMTLIST(3);
-    IMGUI_API void          TreePush(const char* str_id = NULL);                                    // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
+    IMGUI_API void          TreePush(const char* str_id);                                           // ~ Indent()+PushId(). Already called by TreeNode() when returning true, but you can call Push/Pop yourself for layout purpose
     IMGUI_API void          TreePush(const void* ptr_id = NULL);                                    // "
     IMGUI_API void          TreePop();                                                              // ~ Unindent()+PopId()
     IMGUI_API void          TreeAdvanceToLabelPos();                                                // advance cursor x position by GetTreeNodeToLabelSpacing()
@@ -511,7 +512,7 @@
     ImGuiWindowFlags_NoScrollWithMouse      = 1 << 4,   // Disable user vertically scrolling with mouse wheel
     ImGuiWindowFlags_NoCollapse             = 1 << 5,   // Disable user collapsing window by double-clicking on it
     ImGuiWindowFlags_AlwaysAutoResize       = 1 << 6,   // Resize every window to its content every frame
-    ImGuiWindowFlags_ShowBorders            = 1 << 7,   // Show borders around windows and items
+    //ImGuiWindowFlags_ShowBorders          = 1 << 7,   // Show borders around windows and items (OBSOLETE! Use e.g. style.FrameBorderSize=1.0f to enable borders).
     ImGuiWindowFlags_NoSavedSettings        = 1 << 8,   // Never load/save settings in .ini file
     ImGuiWindowFlags_NoInputs               = 1 << 9,   // Disable catching mouse or keyboard inputs, hovering test with pass through.
     ImGuiWindowFlags_MenuBar                = 1 << 10,  // Has a menu-bar
@@ -639,7 +640,7 @@
     ImGuiCol_Text,
     ImGuiCol_TextDisabled,
     ImGuiCol_WindowBg,              // Background of normal windows
-    ImGuiCol_ChildWindowBg,         // Background of child windows
+    ImGuiCol_ChildBg,               // Background of child windows
     ImGuiCol_PopupBg,               // Background of popups, menus, tooltips windows
     ImGuiCol_Border,
     ImGuiCol_BorderShadow,
@@ -682,7 +683,7 @@
 
     // Obsolete names (will be removed)
 #ifndef IMGUI_DISABLE_OBSOLETE_FUNCTIONS
-    , ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
+    , ImGuiCol_ChildWindowBg = ImGuiCol_ChildBg, ImGuiCol_Column = ImGuiCol_Separator, ImGuiCol_ColumnHovered = ImGuiCol_SeparatorHovered, ImGuiCol_ColumnActive = ImGuiCol_SeparatorActive
 #endif
 };
 
@@ -695,11 +696,15 @@
     ImGuiStyleVar_Alpha,               // float     Alpha
     ImGuiStyleVar_WindowPadding,       // ImVec2    WindowPadding
     ImGuiStyleVar_WindowRounding,      // float     WindowRounding
+    ImGuiStyleVar_WindowBorderSize,    // float     WindowBorderSize
     ImGuiStyleVar_WindowMinSize,       // ImVec2    WindowMinSize
     ImGuiStyleVar_ChildRounding,       // float     ChildRounding
+    ImGuiStyleVar_ChildBorderSize,     // float     ChildBorderSize
     ImGuiStyleVar_PopupRounding,       // float     PopupRounding
+    ImGuiStyleVar_PopupBorderSize,     // float     PopupBorderSize
     ImGuiStyleVar_FramePadding,        // ImVec2    FramePadding
     ImGuiStyleVar_FrameRounding,       // float     FrameRounding
+    ImGuiStyleVar_FrameBorderSize,     // float     FrameBorderSize
     ImGuiStyleVar_ItemSpacing,         // ImVec2    ItemSpacing
     ImGuiStyleVar_ItemInnerSpacing,    // ImVec2    ItemInnerSpacing
     ImGuiStyleVar_IndentSpacing,       // float     IndentSpacing
@@ -776,13 +781,17 @@
 {
     float       Alpha;                      // Global alpha applies to everything in ImGui
     ImVec2      WindowPadding;              // Padding within a window
-    ImVec2      WindowMinSize;              // Minimum window size
     float       WindowRounding;             // Radius of window corners rounding. Set to 0.0f to have rectangular windows
+    float       WindowBorderSize;           // Thickness of border around windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
+    ImVec2      WindowMinSize;              // Minimum window size
     ImVec2      WindowTitleAlign;           // Alignment for title bar text. Defaults to (0.0f,0.5f) for left-aligned,vertically centered.
     float       ChildRounding;              // Radius of child window corners rounding. Set to 0.0f to have rectangular windows.
+    float       ChildBorderSize;            // Thickness of border around child windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     float       PopupRounding;              // Radius of popup window corners rounding.
+    float       PopupBorderSize;            // Thickness of border around popup windows. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      FramePadding;               // Padding within a framed rectangle (used by most widgets)
     float       FrameRounding;              // Radius of frame corners rounding. Set to 0.0f to have rectangular frame (used by most widgets).
+    float       FrameBorderSize;            // Thickness of border around frames. Generally set to 0.0f or 1.0f. (Other values are not well tested and more CPU/GPU costly)
     ImVec2      ItemSpacing;                // Horizontal and vertical spacing between widgets/lines
     ImVec2      ItemInnerSpacing;           // Horizontal and vertical spacing between within elements of a composed widget (e.g. a slider and its label)
     ImVec2      TouchExtraPadding;          // Expand reactive bounding box for touch-based system where touch position is not accurate enough. Unfortunately we don't sort widgets so priority on overlap will always be given to the first widget. So don't grow this too much!
@@ -1042,12 +1051,11 @@
     int                 CountGrep;
 
     IMGUI_API           ImGuiTextFilter(const char* default_filter = "");
-                        ~ImGuiTextFilter() {}
-    void                Clear() { InputBuf[0] = 0; Build(); }
     IMGUI_API bool      Draw(const char* label = "Filter (inc,-exc)", float width = 0.0f);    // Helper calling InputText+Build
     IMGUI_API bool      PassFilter(const char* text, const char* text_end = NULL) const;
-    bool                IsActive() const { return !Filters.empty(); }
     IMGUI_API void      Build();
+    void                Clear() { InputBuf[0] = 0; Build(); }
+    bool                IsActive() const { return !Filters.empty(); }
 };
 
 // Helper: Text buffer for logging/accumulating text
@@ -1138,7 +1146,7 @@
     // NB: Helper functions for text manipulation. Calling those function loses selection.
     IMGUI_API void    DeleteChars(int pos, int bytes_count);
     IMGUI_API void    InsertChars(int pos, const char* text, const char* text_end = NULL);
-    bool    HasSelection() const { return SelectionStart != SelectionEnd; }
+    bool              HasSelection() const { return SelectionStart != SelectionEnd; }
 };
 
 // Resizing callback data to apply custom constraint. As enabled by SetNextWindowSizeConstraints(). Callback is called during the next Begin().
diff --git a/imgui_demo.cpp b/imgui_demo.cpp
index 9ac07b7..7bf92e3 100644
--- a/imgui_demo.cpp
+++ b/imgui_demo.cpp
@@ -165,22 +165,20 @@
     }
 
     static bool no_titlebar = false;
-    static bool no_border = true;
-    static bool no_resize = false;
-    static bool no_move = false;
     static bool no_scrollbar = false;
-    static bool no_collapse = false;
     static bool no_menu = false;
+    static bool no_move = false;
+    static bool no_resize = false;
+    static bool no_collapse = false;
 
     // Demonstrate the various window flags. Typically you would just use the default.
     ImGuiWindowFlags window_flags = 0;
     if (no_titlebar)  window_flags |= ImGuiWindowFlags_NoTitleBar;
-    if (!no_border)   window_flags |= ImGuiWindowFlags_ShowBorders;
-    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
-    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
     if (no_scrollbar) window_flags |= ImGuiWindowFlags_NoScrollbar;
-    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     if (!no_menu)     window_flags |= ImGuiWindowFlags_MenuBar;
+    if (no_move)      window_flags |= ImGuiWindowFlags_NoMove;
+    if (no_resize)    window_flags |= ImGuiWindowFlags_NoResize;
+    if (no_collapse)  window_flags |= ImGuiWindowFlags_NoCollapse;
     ImGui::SetNextWindowSize(ImVec2(550,680), ImGuiCond_FirstUseEver);
     if (!ImGui::Begin("ImGui Demo", p_open, window_flags))
     {
@@ -238,12 +236,11 @@
     if (ImGui::CollapsingHeader("Window options"))
     {
         ImGui::Checkbox("No titlebar", &no_titlebar); ImGui::SameLine(150);
-        ImGui::Checkbox("No border", &no_border); ImGui::SameLine(300);
-        ImGui::Checkbox("No resize", &no_resize);
-        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
         ImGui::Checkbox("No scrollbar", &no_scrollbar); ImGui::SameLine(300);
-        ImGui::Checkbox("No collapse", &no_collapse);
         ImGui::Checkbox("No menu", &no_menu);
+        ImGui::Checkbox("No move", &no_move); ImGui::SameLine(150);
+        ImGui::Checkbox("No resize", &no_resize); ImGui::SameLine(300);
+        ImGui::Checkbox("No collapse", &no_collapse);
 
         if (ImGui::TreeNode("Style"))
         {
@@ -685,7 +682,6 @@
             ImGui::TreePop();
         }
 
-
         if (ImGui::TreeNode("Plots widgets"))
         {
             static bool animate = true;
@@ -1341,7 +1337,7 @@
             if (ImGui::Button("Select.."))
                 ImGui::OpenPopup("select");
             ImGui::SameLine();
-            ImGui::Text(selected_fish == -1 ? "<None>" : names[selected_fish]);
+            ImGui::TextUnformatted(selected_fish == -1 ? "<None>" : names[selected_fish]);
             if (ImGui::BeginPopup("select"))
             {
                 ImGui::Text("Aquarium");
@@ -1878,6 +1874,15 @@
         ref_saved_style = style;
     }
 
+    // Simplified Settings
+    if (ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f")) 
+        style.GrabRounding = style.FrameRounding; // Make GrabRounding always the same value as FrameRounding
+    { bool window_border = (style.WindowBorderSize > 0.0f); if (ImGui::Checkbox("WindowBorder", &window_border)) style.WindowBorderSize = window_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool frame_border = (style.FrameBorderSize > 0.0f); if (ImGui::Checkbox("FrameBorder", &frame_border)) style.FrameBorderSize = frame_border ? 1.0f : 0.0f; }
+    ImGui::SameLine();
+    { bool popup_border = (style.PopupBorderSize > 0.0f); if (ImGui::Checkbox("PopupBorder", &popup_border)) style.PopupBorderSize = popup_border ? 1.0f : 0.0f; }
+
     // Save/Revert button
     if (ImGui::Button("Save Ref"))
         *ref = ref_saved_style = style;
@@ -1902,19 +1907,25 @@
     if (ImGui::TreeNode("Settings"))
     {
         ImGui::SliderFloat2("WindowPadding", (float*)&style.WindowPadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 16.0f, "%.0f");
-        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("PopupRounding", &style.PopupRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("FramePadding", (float*)&style.FramePadding, 0.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat2("ItemSpacing", (float*)&style.ItemSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("ItemInnerSpacing", (float*)&style.ItemInnerSpacing, 0.0f, 20.0f, "%.0f");
         ImGui::SliderFloat2("TouchExtraPadding", (float*)&style.TouchExtraPadding, 0.0f, 10.0f, "%.0f");
         ImGui::SliderFloat("IndentSpacing", &style.IndentSpacing, 0.0f, 30.0f, "%.0f");
         ImGui::SliderFloat("ScrollbarSize", &style.ScrollbarSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 16.0f, "%.0f");
         ImGui::SliderFloat("GrabMinSize", &style.GrabMinSize, 1.0f, 20.0f, "%.0f");
-        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::Text("BorderSize");
+        ImGui::SliderFloat("WindowBorderSize", &style.WindowBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("ChildBorderSize", &style.ChildBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("PopupBorderSize", &style.PopupBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::SliderFloat("FrameBorderSize", &style.FrameBorderSize, 0.0f, 1.0f, "%.0f");
+        ImGui::Text("Rounding");
+        ImGui::SliderFloat("WindowRounding", &style.WindowRounding, 0.0f, 14.0f, "%.0f");
+        ImGui::SliderFloat("ChildRounding", &style.ChildRounding, 0.0f, 16.0f, "%.0f");
+        ImGui::SliderFloat("FrameRounding", &style.FrameRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("ScrollbarRounding", &style.ScrollbarRounding, 0.0f, 12.0f, "%.0f");
+        ImGui::SliderFloat("GrabRounding", &style.GrabRounding, 0.0f, 12.0f, "%.0f");
         ImGui::Text("Alignment");
         ImGui::SliderFloat2("WindowTitleAlign", (float*)&style.WindowTitleAlign, 0.0f, 1.0f, "%.2f");
         ImGui::SliderFloat2("ButtonTextAlign", (float*)&style.ButtonTextAlign, 0.0f, 1.0f, "%.2f"); ImGui::SameLine(); ShowHelpMarker("Alignment applies when a button is larger than its text content.");
diff --git a/imgui_draw.cpp b/imgui_draw.cpp
index 3a934ea..8718e97 100644
--- a/imgui_draw.cpp
+++ b/imgui_draw.cpp
@@ -129,9 +129,9 @@
     colors[ImGuiCol_Text]                   = ImVec4(0.90f, 0.90f, 0.90f, 1.00f);
     colors[ImGuiCol_TextDisabled]           = ImVec4(0.60f, 0.60f, 0.60f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.00f, 0.00f, 0.00f, 0.70f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(0.11f, 0.11f, 0.14f, 0.92f);
-    colors[ImGuiCol_Border]                 = ImVec4(0.70f, 0.70f, 0.70f, 0.27f);
+    colors[ImGuiCol_Border]                 = ImVec4(0.50f, 0.50f, 0.50f, 0.50f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_FrameBg]                = ImVec4(0.43f, 0.43f, 0.43f, 0.39f);
     colors[ImGuiCol_FrameBgHovered]         = ImVec4(0.47f, 0.47f, 0.69f, 0.40f);
@@ -178,9 +178,9 @@
     colors[ImGuiCol_Text]                   = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     colors[ImGuiCol_TextDisabled]           = ImVec4(0.50f, 0.50f, 0.50f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.06f, 0.06f, 0.06f, 0.94f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(1.00f, 1.00f, 1.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(1.00f, 1.00f, 1.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(0.08f, 0.08f, 0.08f, 0.94f);
-    colors[ImGuiCol_Border]                 = ImVec4(0.86f, 0.86f, 1.00f, 0.20f);
+    colors[ImGuiCol_Border]                 = ImVec4(0.43f, 0.43f, 0.50f, 0.50f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_FrameBg]                = ImVec4(0.16f, 0.29f, 0.48f, 0.54f);
     colors[ImGuiCol_FrameBgHovered]         = ImVec4(0.26f, 0.59f, 0.98f, 0.40f);
@@ -229,7 +229,7 @@
     //colors[ImGuiCol_TextHovered]          = ImVec4(1.00f, 1.00f, 1.00f, 1.00f);
     //colors[ImGuiCol_TextActive]           = ImVec4(1.00f, 1.00f, 0.00f, 1.00f);
     colors[ImGuiCol_WindowBg]               = ImVec4(0.94f, 0.94f, 0.94f, 1.00f);
-    colors[ImGuiCol_ChildWindowBg]          = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
+    colors[ImGuiCol_ChildBg]                = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
     colors[ImGuiCol_PopupBg]                = ImVec4(1.00f, 1.00f, 1.00f, 0.94f);
     colors[ImGuiCol_Border]                 = ImVec4(0.00f, 0.00f, 0.00f, 0.30f);
     colors[ImGuiCol_BorderShadow]           = ImVec4(0.00f, 0.00f, 0.00f, 0.00f);
@@ -1617,7 +1617,7 @@
 
     // Start packing
     const int max_tex_height = 1024*32;
-    stbtt_pack_context spc;
+    stbtt_pack_context spc = {};
     stbtt_PackBegin(&spc, NULL, atlas->TexWidth, max_tex_height, 0, atlas->TexGlyphPadding, NULL);
     stbtt_PackSetOversampling(&spc, 1, 1);
 
@@ -2183,7 +2183,7 @@
     IndexAdvanceX[dst] = (src < index_size) ? IndexAdvanceX.Data[src] : 1.0f;
 }
 
-const ImFontGlyph* ImFont::FindGlyph(unsigned short c) const
+const ImFontGlyph* ImFont::FindGlyph(ImWchar c) const
 {
     if (c < IndexLookup.Size)
     {
diff --git a/imgui_internal.h b/imgui_internal.h
index ba8aecd..f4c531c 100644
--- a/imgui_internal.h
+++ b/imgui_internal.h
@@ -815,7 +815,6 @@
     IMGUI_API void          BringWindowToBack(ImGuiWindow* window);
 
     IMGUI_API void          Initialize();
-    IMGUI_API void          EndFrame();                 // Ends the ImGui frame. Automatically called by Render()! you most likely don't need to ever call that yourself directly. If you don't need to render you can call EndFrame() but you'll have wasted CPU already. If you don't need to render, don't create any windows instead!
 
     IMGUI_API void          SetActiveID(ImGuiID id, ImGuiWindow* window);
     IMGUI_API void          ClearActiveID();