// ImGui Platform Binding for: Windows (standard windows API for 32 and 64 bits applications)
// This needs to be used along with a Renderer (e.g. DirectX11, OpenGL3, Vulkan..)
#include "imgui.h"
#include "imgui_impl_win32.h"
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <tchar.h>
// CHANGELOG
// 2018-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
// 2018-03-20: Misc: Setup io.BackendFlags ImGuiBackendFlags_HasMouseCursors and ImGuiBackendFlags_HasSetMousePos flags + honor ImGuiConfigFlags_NoMouseCursorChange flag.
// 2018-02-20: Inputs: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling).
// 2018-02-06: Inputs: Added mapping for ImGuiKey_Space.
// 2018-02-06: Inputs: Honoring the io.WantSetMousePos by repositioning the mouse (when using navigation and ImGuiConfigFlags_NavMoveMouse is set).
// 2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
// 2018-01-20: Inputs: Added Horizontal Mouse Wheel support.
// 2018-01-08: Inputs: Added mapping for ImGuiKey_Insert.
// 2018-01-05: Inputs: Added WM_LBUTTONDBLCLK double-click handlers for window classes with the CS_DBLCLKS flag.
// 2017-10-23: Inputs: Added WM_SYSKEYDOWN / WM_SYSKEYUP handlers so e.g. the VK_MENU key can be read.
// 2017-10-23: Inputs: Using Win32 ::SetCapture/::GetCapture() to retrieve mouse positions outside the client area when dragging.
// 2016-11-12: Inputs: Only call Win32 ::SetCursor(NULL) when io.MouseDrawCursor is set.
// Win32 Data
static HWND g_hWnd = 0;
static INT64 g_Time = 0;
static INT64 g_TicksPerSecond = 0;
static ImGuiMouseCursor g_LastMouseCursor = ImGuiMouseCursor_Count_;
// Forward Declarations
static void ImGui_ImplWin32_InitPlatformInterface();
static void ImGui_ImplWin32_ShutdownPlatformInterface();
// Functions
bool ImGui_ImplWin32_Init(void* hwnd)
{
if (!::QueryPerformanceFrequency((LARGE_INTEGER *)&g_TicksPerSecond))
return false;
if (!::QueryPerformanceCounter((LARGE_INTEGER *)&g_Time))
return false;
// Setup back-end capabilities flags
ImGuiIO& io = ImGui::GetIO();
io.BackendFlags |= ImGuiBackendFlags_HasMouseCursors; // We can honor GetMouseCursor() values (optional)
io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos; // We can honor io.WantSetMousePos requests (optional, rarely used)
io.BackendFlags |= ImGuiBackendFlags_PlatformHasViewports; // We can create multi-viewports on the Platform side (optional)
io.BackendFlags |= ImGuiBackendFlags_HasMouseHoveredViewport; // We can set io.MouseHoveredViewport correctly (optional, not easy)
// Our mouse update function expect PlatformHandle to be filled for the main viewport
g_hWnd = (HWND)hwnd;
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
main_viewport->PlatformHandle = (void*)g_hWnd;
if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
ImGui_ImplWin32_InitPlatformInterface();
// Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array that we will update during the application lifetime.
io.KeyMap[ImGuiKey_Tab] = VK_TAB;
io.KeyMap[ImGuiKey_LeftArrow] = VK_LEFT;
io.KeyMap[ImGuiKey_RightArrow] = VK_RIGHT;
io.KeyMap[ImGuiKey_UpArrow] = VK_UP;
io.KeyMap[ImGuiKey_DownArrow] = VK_DOWN;
io.KeyMap[ImGuiKey_PageUp] = VK_PRIOR;
io.KeyMap[ImGuiKey_PageDown] = VK_NEXT;
io.KeyMap[ImGuiKey_Home] = VK_HOME;
io.KeyMap[ImGuiKey_End] = VK_END;
io.KeyMap[ImGuiKey_Insert] = VK_INSERT;
io.KeyMap[ImGuiKey_Delete] = VK_DELETE;
io.KeyMap[ImGuiKey_Backspace] = VK_BACK;
io.KeyMap[ImGuiKey_Space] = VK_SPACE;
io.KeyMap[ImGuiKey_Enter] = VK_RETURN;
io.KeyMap[ImGuiKey_Escape] = VK_ESCAPE;
io.KeyMap[ImGuiKey_A] = 'A';
io.KeyMap[ImGuiKey_C] = 'C';
io.KeyMap[ImGuiKey_V] = 'V';
io.KeyMap[ImGuiKey_X] = 'X';
io.KeyMap[ImGuiKey_Y] = 'Y';
io.KeyMap[ImGuiKey_Z] = 'Z';
io.ImeWindowHandle = g_hWnd;
return true;
}
void ImGui_ImplWin32_Shutdown()
{
ImGui_ImplWin32_ShutdownPlatformInterface();
g_hWnd = (HWND)0;
}
static bool ImGui_ImplWin32_UpdateMouseCursor()
{
ImGuiIO& io = ImGui::GetIO();
if (io.ConfigFlags & ImGuiConfigFlags_NoMouseCursorChange)
return false;
ImGuiMouseCursor imgui_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
if (imgui_cursor == ImGuiMouseCursor_None)
{
// Hide OS mouse cursor if imgui is drawing it or if it wants no cursor
::SetCursor(NULL);
}
else
{
// Hardware cursor type
LPTSTR win32_cursor = IDC_ARROW;
switch (imgui_cursor)
{
case ImGuiMouseCursor_Arrow: win32_cursor = IDC_ARROW; break;
case ImGuiMouseCursor_TextInput: win32_cursor = IDC_IBEAM; break;
case ImGuiMouseCursor_ResizeAll: win32_cursor = IDC_SIZEALL; break;
case ImGuiMouseCursor_ResizeEW: win32_cursor = IDC_SIZEWE; break;
case ImGuiMouseCursor_ResizeNS: win32_cursor = IDC_SIZENS; break;
case ImGuiMouseCursor_ResizeNESW: win32_cursor = IDC_SIZENESW; break;
case ImGuiMouseCursor_ResizeNWSE: win32_cursor = IDC_SIZENWSE; break;
}
::SetCursor(::LoadCursor(NULL, win32_cursor));
}
return true;
}
// This code supports multiple OS Windows mapped into different ImGui viewports,
// So it is a little more complicated than your typical binding code (which only needs to set io.MousePos in your WM_MOUSEMOVE handler)
// This is what imgui needs from the back-end to support multiple windows:
// - io.MousePos = mouse position (e.g. io.MousePos == viewport->Pos when we are on the upper-left of our viewport)
// - io.MousePosViewport = viewport which mouse position is based from (generally the focused/active/capturing viewport)
// - io.MouseHoveredWindow = viewport which mouse is hovering, **regardless of it being the active/focused window**, **regardless of another window holding mouse captured**. [Optional]
// This function overwrite the value of io.MousePos normally updated by the WM_MOUSEMOVE handler.
// We keep the WM_MOUSEMOVE handling code so that WndProc function can be copied as-in in applications which do not need multiple OS windows support.
static void ImGui_ImplWin32_UpdateMousePos()
{
ImGuiIO& io = ImGui::GetIO();
io.MousePos = ImVec2(-FLT_MAX, -FLT_MAX);
io.MousePosViewport = 0;
io.MouseHoveredViewport = 0;
POINT pos;
if (!::GetCursorPos(&pos))
return;
// Our back-end can tell which window is under the mouse cursor (not every back-end can), so pass that info to imgui
HWND hovered_hwnd = ::WindowFromPoint(pos);
if (hovered_hwnd)
if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hovered_hwnd))
io.MouseHoveredViewport = viewport->ID;
// Convert mouse from screen position to window client position
HWND focused_hwnd = ::GetActiveWindow();
if (focused_hwnd != 0 && ::ScreenToClient(focused_hwnd, &pos))
if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)focused_hwnd))
{
io.MousePos = ImVec2(viewport->Pos.x + (float)pos.x, viewport->Pos.y + (float)pos.y);
io.MousePosViewport = viewport->ID;
}
}
void ImGui_ImplWin32_NewFrame()
{
ImGuiIO& io = ImGui::GetIO();
// Setup display size (every frame to accommodate for window resizing)
RECT rect;
::GetClientRect(g_hWnd, &rect);
io.DisplaySize = ImVec2((float)(rect.right - rect.left), (float)(rect.bottom - rect.top));
// Setup time step
INT64 current_time;
::QueryPerformanceCounter((LARGE_INTEGER *)¤t_time);
io.DeltaTime = (float)(current_time - g_Time) / g_TicksPerSecond;
g_Time = current_time;
// Read keyboard modifiers inputs
io.KeyCtrl = (::GetKeyState(VK_CONTROL) & 0x8000) != 0;
io.KeyShift = (::GetKeyState(VK_SHIFT) & 0x8000) != 0;
io.KeyAlt = (::GetKeyState(VK_MENU) & 0x8000) != 0;
io.KeySuper = false;
// io.KeysDown : filled by WM_KEYDOWN/WM_KEYUP events
// io.MousePos : filled by WM_MOUSEMOVE events
// io.MouseDown : filled by WM_*BUTTON* events
// io.MouseWheel : filled by WM_MOUSEWHEEL events
// Set OS mouse position if requested (only used when ImGuiConfigFlags_NavEnableSetMousePos is enabled by user)
if (io.WantSetMousePos)
{
POINT pos = { (int)io.MousePos.x, (int)io.MousePos.y };
::ClientToScreen(g_hWnd, &pos);
::SetCursorPos(pos.x, pos.y);
}
// Update OS mouse cursor with the cursor requested by imgui
ImGuiMouseCursor mouse_cursor = io.MouseDrawCursor ? ImGuiMouseCursor_None : ImGui::GetMouseCursor();
if (g_LastMouseCursor != mouse_cursor)
{
g_LastMouseCursor = mouse_cursor;
ImGui_ImplWin32_UpdateMouseCursor();
}
ImGui_ImplWin32_UpdateMousePos();
// Start the frame. This call will update the io.WantCaptureMouse, io.WantCaptureKeyboard flag that you can use to dispatch inputs (or not) to your application.
ImGui::NewFrame();
}
// Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
#ifndef WM_MOUSEHWHEEL
#define WM_MOUSEHWHEEL 0x020E
#endif
// Process Win32 mouse/keyboard inputs.
// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
// PS: In this Win32 handler, we use the capture API (GetCapture/SetCapture/ReleaseCapture) to be able to read mouse coordinations when dragging mouse outside of our window bounds.
// PS: We treat DBLCLK messages as regular mouse down messages, so this code will work on windows classes that have the CS_DBLCLKS flag set. Our own example app code doesn't set this flag.
IMGUI_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui::GetCurrentContext() == NULL)
return 0;
ImGuiIO& io = ImGui::GetIO();
switch (msg)
{
case WM_LBUTTONDOWN: case WM_LBUTTONDBLCLK:
case WM_RBUTTONDOWN: case WM_RBUTTONDBLCLK:
case WM_MBUTTONDOWN: case WM_MBUTTONDBLCLK:
{
int button = 0;
if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK) button = 0;
if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK) button = 1;
if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK) button = 2;
if (!ImGui::IsAnyMouseDown() && ::GetCapture() == NULL)
::SetCapture(hwnd);
io.MouseDown[button] = true;
return 0;
}
case WM_LBUTTONUP:
case WM_RBUTTONUP:
case WM_MBUTTONUP:
{
int button = 0;
if (msg == WM_LBUTTONUP) button = 0;
if (msg == WM_RBUTTONUP) button = 1;
if (msg == WM_MBUTTONUP) button = 2;
io.MouseDown[button] = false;
if (!ImGui::IsAnyMouseDown() && ::GetCapture() == hwnd)
::ReleaseCapture();
return 0;
}
case WM_MOUSEWHEEL:
io.MouseWheel += GET_WHEEL_DELTA_WPARAM(wParam) > 0 ? +1.0f : -1.0f;
return 0;
case WM_MOUSEHWHEEL:
io.MouseWheelH += GET_WHEEL_DELTA_WPARAM(wParam) > 0 ? +1.0f : -1.0f;
return 0;
case WM_MOUSEMOVE:
io.MousePos.x = (signed short)(lParam);
io.MousePos.y = (signed short)(lParam >> 16);
return 0;
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
if (wParam < 256)
io.KeysDown[wParam] = 1;
return 0;
case WM_KEYUP:
case WM_SYSKEYUP:
if (wParam < 256)
io.KeysDown[wParam] = 0;
return 0;
case WM_CHAR:
// You can also use ToAscii()+GetKeyboardState() to retrieve characters.
if (wParam > 0 && wParam < 0x10000)
io.AddInputCharacter((unsigned short)wParam);
return 0;
case WM_SETCURSOR:
if (LOWORD(lParam) == HTCLIENT && ImGui_ImplWin32_UpdateMouseCursor())
return 1;
return 0;
}
return 0;
}
// --------------------------------------------------------------------------------------------------------
// DPI handling
// Those in theory should be simple calls but Windows has multiple ways to handle DPI, and most of them
// require recent Windows versions at runtime or recent Windows SDK at compile-time. Neither we want to depend on.
// So we dynamically select and load those functions to avoid dependencies. This is the scheme successfully
// used by GLFW (from which we borrowed some of the code here) and other applications aiming to be portable.
//---------------------------------------------------------------------------------------------------------
// FIXME-DPI: For now we just call SetProcessDpiAwareness(PROCESS_PER_MONITOR_AWARE) without requiring SDK 8.1 or 10.
// We may allow/aim calling the most-recent-available version, e.g. Windows 10 Creators Update has SetThreadDpiAwarenessContext(DPI_AWARENESS_CONTEXT_PER_MONITOR_AWARE_V2);
// At this point ImGui_ImplWin32_EnableDpiAwareness() is just a helper called by main.cpp, we don't call it ourselves.
//---------------------------------------------------------------------------------------------------------
static BOOL IsWindowsVersionOrGreater(WORD major, WORD minor, WORD sp)
{
OSVERSIONINFOEXW osvi = { sizeof(osvi), major, minor, 0, 0,{ 0 }, sp };
DWORD mask = VER_MAJORVERSION | VER_MINORVERSION | VER_SERVICEPACKMAJOR;
ULONGLONG cond = VerSetConditionMask(0, VER_MAJORVERSION, VER_GREATER_EQUAL);
cond = VerSetConditionMask(cond, VER_MINORVERSION, VER_GREATER_EQUAL);
cond = VerSetConditionMask(cond, VER_SERVICEPACKMAJOR, VER_GREATER_EQUAL);
return VerifyVersionInfoW(&osvi, mask, cond);
}
#define IsWindows8Point1OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0602), LOBYTE(0x0602), 0) // _WIN32_WINNT_WINBLUE
#define IsWindows10OrGreater() IsWindowsVersionOrGreater(HIBYTE(0x0A00), LOBYTE(0x0A00), 0) // _WIN32_WINNT_WIN10
#ifndef DPI_ENUMS_DECLARED
typedef enum { PROCESS_DPI_UNAWARE = 0, PROCESS_SYSTEM_DPI_AWARE = 1, PROCESS_PER_MONITOR_DPI_AWARE = 2 } PROCESS_DPI_AWARENESS;
typedef enum { MDT_EFFECTIVE_DPI = 0, MDT_ANGULAR_DPI = 1, MDT_RAW_DPI = 2, MDT_DEFAULT = MDT_EFFECTIVE_DPI } MONITOR_DPI_TYPE;
#endif
typedef HRESULT(WINAPI * PFN_SetProcessDpiAwareness)(PROCESS_DPI_AWARENESS); // Shcore.lib+dll, Windows 8.1
typedef HRESULT(WINAPI * PFN_GetDpiForMonitor)(HMONITOR, MONITOR_DPI_TYPE, UINT*, UINT*); // Shcore.lib+dll, Windows 8.1
void ImGui_ImplWin32_EnableDpiAwareness()
{
if (IsWindows8Point1OrGreater())
{
static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
if (PFN_SetProcessDpiAwareness SetProcessDpiAwarenessFn = (PFN_SetProcessDpiAwareness)::GetProcAddress(shcore_dll, "SetProcessDpiAwareness"))
SetProcessDpiAwarenessFn(PROCESS_PER_MONITOR_DPI_AWARE);
}
else
{
SetProcessDPIAware();
}
}
float ImGui_ImplWin32_GetDpiScaleForMonitor(void* monitor)
{
UINT xdpi = 96, ydpi = 96;
if (IsWindows8Point1OrGreater())
{
static HINSTANCE shcore_dll = ::LoadLibraryA("shcore.dll"); // Reference counted per-process
if (PFN_GetDpiForMonitor GetDpiForMonitorFn = (PFN_GetDpiForMonitor)::GetProcAddress(shcore_dll, "GetDpiForMonitor"))
GetDpiForMonitorFn((HMONITOR)monitor, MDT_EFFECTIVE_DPI, &xdpi, &ydpi);
}
else
{
const HDC dc = ::GetDC(NULL);
xdpi = ::GetDeviceCaps(dc, LOGPIXELSX);
ydpi = ::GetDeviceCaps(dc, LOGPIXELSY);
::ReleaseDC(NULL, dc);
}
IM_ASSERT(xdpi == ydpi); // Please contact me if you hit this assert!
return xdpi / 96.0f;
}
float ImGui_ImplWin32_GetDpiScaleForHwnd(void* hwnd)
{
HMONITOR monitor = ::MonitorFromWindow((HWND)hwnd, MONITOR_DEFAULTTONEAREST);
return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
}
float ImGui_ImplWin32_GetDpiScaleForRect(int x1, int y1, int x2, int y2)
{
RECT viewport_rect = { (LONG)x1, (LONG)y1, (LONG)x2, (LONG)y2 };
HMONITOR monitor = ::MonitorFromRect(&viewport_rect, MONITOR_DEFAULTTONEAREST);
return ImGui_ImplWin32_GetDpiScaleForMonitor(monitor);
}
// --------------------------------------------------------------------------------------------------------
// Platform Windows
// --------------------------------------------------------------------------------------------------------
struct ImGuiViewportDataWin32
{
HWND Hwnd;
bool HwndOwned;
DWORD DwStyle;
DWORD DwExStyle;
ImGuiViewportDataWin32() { Hwnd = NULL; HwndOwned = false; DwStyle = DwExStyle = 0; }
~ImGuiViewportDataWin32() { IM_ASSERT(Hwnd == NULL); }
};
static void ImGui_ImplWin32_CreateWindow(ImGuiViewport* viewport)
{
ImGuiViewportDataWin32* data = IM_NEW(ImGuiViewportDataWin32)();
viewport->PlatformUserData = data;
bool no_decoration = (viewport->Flags & ImGuiViewportFlags_NoDecoration) != 0;
bool no_task_bar_icon = (viewport->Flags & ImGuiViewportFlags_NoTaskBarIcon) != 0;
if (no_decoration)
{
data->DwStyle = WS_POPUP;
data->DwExStyle = no_task_bar_icon ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW;
}
else
{
data->DwStyle = WS_OVERLAPPEDWINDOW;
data->DwExStyle = no_task_bar_icon ? WS_EX_TOOLWINDOW : WS_EX_APPWINDOW;
}
// Create window
RECT rect = { (LONG)viewport->PlatformPos.x, (LONG)viewport->PlatformPos.y, (LONG)(viewport->PlatformPos.x + viewport->Size.x), (LONG)(viewport->PlatformPos.y + viewport->Size.y) };
::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle);
data->Hwnd = ::CreateWindowEx(
data->DwExStyle, _T("ImGui Platform"), _T("No Title Yet"), data->DwStyle, // Style, class name, window name
rect.left, rect.top, rect.right - rect.left, rect.bottom - rect.top, // Window area
g_hWnd, NULL, ::GetModuleHandle(NULL), NULL); // Parent window, Menu, Instance, Param
data->HwndOwned = true;
viewport->PlatformRequestResize = false;
viewport->PlatformHandle = data->Hwnd;
}
static void ImGui_ImplWin32_DestroyWindow(ImGuiViewport* viewport)
{
if (ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData)
{
if (::GetCapture() == data->Hwnd)
{
// Transfer capture so if we started dragging from a window that later disappears, we'll still receive the MOUSEUP event.
::ReleaseCapture();
::SetCapture(g_hWnd);
}
if (data->Hwnd && data->HwndOwned)
::DestroyWindow(data->Hwnd);
data->Hwnd = NULL;
IM_DELETE(data);
}
viewport->PlatformUserData = viewport->PlatformHandle = NULL;
}
static void ImGui_ImplWin32_ShowWindow(ImGuiViewport* viewport)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
if (viewport->Flags & ImGuiViewportFlags_NoFocusOnAppearing)
::ShowWindow(data->Hwnd, SW_SHOWNA);
else
::ShowWindow(data->Hwnd, SW_SHOW);
}
static ImVec2 ImGui_ImplWin32_GetWindowPos(ImGuiViewport* viewport)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
POINT pos = { 0, 0 };
::ClientToScreen(data->Hwnd, &pos);
return ImVec2((float)pos.x, (float)pos.y);
}
static void ImGui_ImplWin32_SetWindowPos(ImGuiViewport* viewport, ImVec2 pos)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
RECT rect = { (LONG)pos.x, (LONG)pos.y, (LONG)pos.x, (LONG)pos.y };
::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle);
::SetWindowPos(data->Hwnd, NULL, rect.left, rect.top, 0, 0, SWP_NOZORDER | SWP_NOSIZE | SWP_NOACTIVATE);
}
static ImVec2 ImGui_ImplWin32_GetWindowSize(ImGuiViewport* viewport)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
RECT rect;
::GetClientRect(data->Hwnd, &rect);
return ImVec2(float(rect.right - rect.left), float(rect.bottom - rect.top));
}
static void ImGui_ImplWin32_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
RECT rect = { 0, 0, (LONG)size.x, (LONG)size.y };
::AdjustWindowRectEx(&rect, data->DwStyle, FALSE, data->DwExStyle); // Client to Screen
::SetWindowPos(data->Hwnd, NULL, 0, 0, rect.right - rect.left, rect.bottom - rect.top, SWP_NOZORDER | SWP_NOMOVE | SWP_NOACTIVATE);
}
static void ImGui_ImplWin32_SetWindowTitle(ImGuiViewport* viewport, const char* title)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
::SetWindowTextA(data->Hwnd, title);
}
static void ImGui_ImplWin32_SetWindowAlpha(ImGuiViewport* viewport, float alpha)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
IM_ASSERT(data->Hwnd != 0);
IM_ASSERT(alpha >= 0.0f && alpha <= 1.0f);
if (alpha < 1.0f)
{
DWORD style = ::GetWindowLongW(data->Hwnd, GWL_EXSTYLE) | WS_EX_LAYERED;
::SetWindowLongW(data->Hwnd, GWL_EXSTYLE, style);
::SetLayeredWindowAttributes(data->Hwnd, 0, (BYTE)(255 * alpha), LWA_ALPHA);
}
else
{
DWORD style = ::GetWindowLongW(data->Hwnd, GWL_EXSTYLE) & ~WS_EX_LAYERED;
::SetWindowLongW(data->Hwnd, GWL_EXSTYLE, style);
}
}
static float ImGui_ImplWin32_GetWindowDpiScale(ImGuiViewport* viewport)
{
ImGuiViewportDataWin32* data = (ImGuiViewportDataWin32*)viewport->PlatformUserData;
if (data && data->Hwnd)
return ImGui_ImplWin32_GetDpiScaleForHwnd(data->Hwnd);
// The first frame a viewport is created we don't have a window yet
return ImGui_ImplWin32_GetDpiScaleForRect(
(int)(viewport->PlatformPos.x), (int)(viewport->PlatformPos.y),
(int)(viewport->PlatformPos.x + viewport->Size.x), (int)(viewport->PlatformPos.y + viewport->Size.y));
}
static LRESULT CALLBACK ImGui_ImplWin32_WndProcHandler_PlatformWindow(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
return true;
if (ImGuiViewport* viewport = ImGui::FindViewportByPlatformHandle((void*)hWnd))
{
switch (msg)
{
case WM_CLOSE:
viewport->PlatformRequestClose = true;
return 0;
case WM_MOVE:
viewport->PlatformRequestMove = true;
break;
case WM_SIZE:
viewport->PlatformRequestResize = true;
break;
case WM_NCHITTEST:
// Let mouse pass-through the window. This will allow the back-end to set io.MouseHoveredViewport properly (which is OPTIONAL).
// The ImGuiViewportFlags_NoInputs flag is set while dragging a viewport, as want to detect the window behind the one we are dragging.
// If you cannot easily access those viewport flags from your windowing/event code: you may manually synchronize its state e.g. in
// your main loop after calling UpdatePlatformWindows(). Iterate all viewports/platform windows and pass the flag to your windowing system.
if (viewport->Flags & ImGuiViewportFlags_NoInputs)
return HTTRANSPARENT;
break;
}
}
return DefWindowProc(hWnd, msg, wParam, lParam);
}
static BOOL CALLBACK ImGui_ImplWin32_UpdateMonitors_EnumFunc(HMONITOR, HDC, LPRECT rect, LPARAM)
{
ImGuiPlatformMonitor imgui_monitor;
imgui_monitor.Pos = ImVec2((float)rect->left, (float)rect->top);
imgui_monitor.Size = ImVec2((float)(rect->right - rect->left), (float)(rect->bottom - rect->top));
ImGui::GetPlatformIO().Monitors.push_back(imgui_monitor);
return TRUE;
}
// FIXME-PLATFORM: Update list when changed (WM_DISPLAYCHANGE?)
static void ImGui_ImplWin32_UpdateMonitors()
{
ImGui::GetPlatformIO().Monitors.resize(0);
::EnumDisplayMonitors(NULL, NULL, ImGui_ImplWin32_UpdateMonitors_EnumFunc, NULL);
}
static void ImGui_ImplWin32_InitPlatformInterface()
{
WNDCLASSEX wcex;
wcex.cbSize = sizeof(WNDCLASSEX);
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = ImGui_ImplWin32_WndProcHandler_PlatformWindow;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = 0;
wcex.hInstance = ::GetModuleHandle(NULL);
wcex.hIcon = NULL;
wcex.hCursor = NULL;
wcex.hbrBackground = (HBRUSH)(COLOR_BACKGROUND + 1);
wcex.lpszMenuName = NULL;
wcex.lpszClassName = _T("ImGui Platform");
wcex.hIconSm = NULL;
::RegisterClassEx(&wcex);
ImGui_ImplWin32_UpdateMonitors();
// Register platform interface (will be coupled with a renderer interface)
ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
platform_io.Platform_CreateWindow = ImGui_ImplWin32_CreateWindow;
platform_io.Platform_DestroyWindow = ImGui_ImplWin32_DestroyWindow;
platform_io.Platform_ShowWindow = ImGui_ImplWin32_ShowWindow;
platform_io.Platform_SetWindowPos = ImGui_ImplWin32_SetWindowPos;
platform_io.Platform_GetWindowPos = ImGui_ImplWin32_GetWindowPos;
platform_io.Platform_SetWindowSize = ImGui_ImplWin32_SetWindowSize;
platform_io.Platform_GetWindowSize = ImGui_ImplWin32_GetWindowSize;
platform_io.Platform_SetWindowTitle = ImGui_ImplWin32_SetWindowTitle;
platform_io.Platform_SetWindowAlpha = ImGui_ImplWin32_SetWindowAlpha;
platform_io.Platform_GetWindowDpiScale = ImGui_ImplWin32_GetWindowDpiScale;
// Register main window handle (which is owned by the main application, not by us)
ImGuiViewport* main_viewport = ImGui::GetMainViewport();
ImGuiViewportDataWin32* data = IM_NEW(ImGuiViewportDataWin32)();
data->Hwnd = g_hWnd;
data->HwndOwned = false;
main_viewport->PlatformUserData = data;
main_viewport->PlatformHandle = (void*)g_hWnd;
}
static void ImGui_ImplWin32_ShutdownPlatformInterface()
{
::UnregisterClass(_T("ImGui Platform"), ::GetModuleHandle(NULL));
}
