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pixi.js / src / primitives / Graphics.js
@Chad Engler Chad Engler on 28 Dec 2014 28 KB initial move to new module folders
var core = require('../core'),
    GraphicsData = require('./GraphicsData');

/**
 * The Graphics class contains methods used to draw primitive shapes such as lines, circles and
 * rectangles to the display, and color and fill them.
 *
 * @class
 * @extends DisplayObjectContainer
 * @namespace PIXI
 */
function Graphics() {
    core.DisplayObjectContainer.call(this);

    this.renderable = true;

    /**
     * The alpha value used when filling the Graphics object.
     *
     * @member {number}
     * @default 1
     */
    this.fillAlpha = 1;

    /**
     * The width (thickness) of any lines drawn.
     *
     * @member {number}
     * @default 0
     */
    this.lineWidth = 0;

    /**
     * The color of any lines drawn.
     *
     * @member {string}
     * @default 0
     */
    this.lineColor = 0;

    /**
     * Graphics data
     *
     * @member {object[]}
     * @private
     */
    this.graphicsData = [];

    /**
     * The tint applied to the graphic shape. This is a hex value. Apply a value of 0xFFFFFF to reset the tint.
     *
     * @member {number}
     * @default 0xFFFFFF
     */
    this.tint = 0xFFFFFF;

    /**
     * The blend mode to be applied to the graphic shape. Apply a value of blendModes.NORMAL to reset the blend mode.
     *
     * @member {number}
     * @default CONST.blendModes.NORMAL;
     */
    this.blendMode = core.CONST.blendModes.NORMAL;

    /**
     * Current path
     *
     * @member {object}
     * @private
     */
    this.currentPath = null;

    /**
     * Array containing some WebGL-related properties used by the WebGL renderer.
     *
     * @member {object[]}
     * @private
     */
    this._webGL = [];

    /**
     * Whether this shape is being used as a mask.
     *
     * @member {boolean}
     */
    this.isMask = false;

    /**
     * The bounds' padding used for bounds calculation.
     *
     * @member {number}
     */
    this.boundsPadding = 0;

    /**
     * A cache of the local bounds to prevent recalculation.
     *
     * @member {REctangle}
     * @private
     */
    this._localBounds = new core.math.Rectangle(0,0,1,1);

    /**
     * Used to detect if the graphics object has changed. If this is set to true then the graphics
     * object will be recalculated.
     *
     * @member {boolean}
     * @private
     */
    this.dirty = true;

    /**
     * Used to detect if the WebGL graphics object has changed. If this is set to true then the
     * graphics object will be recalculated.
     *
     * @member {boolean}
     * @private
     */
    this.glDirty = false;

    /**
     * Used to detect if the cached sprite object needs to be updated.
     *
     * @member {boolean}
     * @private
     */
    this.cachedSpriteDirty = false;
}

// constructor
Graphics.prototype = Object.create(core.DisplayObjectContainer.prototype);
Graphics.prototype.constructor = Graphics;
module.exports = Graphics;

Object.defineProperties(Graphics.prototype, {
    /**
     * When cacheAsBitmap is set to true the graphics object will be rendered as if it was a sprite.
     * This is useful if your graphics element does not change often, as it will speed up the rendering
     * of the object in exchange for taking up texture memory. It is also useful if you need the graphics
     * object to be anti-aliased, because it will be rendered using canvas. This is not recommended if
     * you are constantly redrawing the graphics element.
     *
     * @member {boolean}
     * @memberof Graphics#
     * @default false
     * @private
     */
    cacheAsBitmap: {
        get: function () {
            return this._cacheAsBitmap;
        },
        set: function (value) {
            this._cacheAsBitmap = value;

            if (this._cacheAsBitmap) {
                this._generateCachedSprite();
            }
            else {
                this.destroyCachedSprite();
                this.dirty = true;
            }
        }
    }
});

/**
 * Specifies the line style used for subsequent calls to Graphics methods such as the lineTo() method or the drawCircle() method.
 *
 * @param lineWidth {number} width of the line to draw, will update the objects stored style
 * @param color {number} color of the line to draw, will update the objects stored style
 * @param alpha {number} alpha of the line to draw, will update the objects stored style
 * @return {Graphics}
 */
Graphics.prototype.lineStyle = function (lineWidth, color, alpha) {
    this.lineWidth = lineWidth || 0;
    this.lineColor = color || 0;
    this.lineAlpha = (arguments.length < 3) ? 1 : alpha;

    if (this.currentPath) {
        if (this.currentPath.shape.points.length) {
            // halfway through a line? start a new one!
            this.drawShape( new core.math.Polygon( this.currentPath.shape.points.slice(-2) ));
        }
        else {
            // otherwise its empty so lets just set the line properties
            this.currentPath.lineWidth = this.lineWidth;
            this.currentPath.lineColor = this.lineColor;
            this.currentPath.lineAlpha = this.lineAlpha;
        }
    }

    return this;
};

/**
 * Moves the current drawing position to x, y.
 *
 * @param x {number} the X coordinate to move to
 * @param y {number} the Y coordinate to move to
 * @return {Graphics}
  */
Graphics.prototype.moveTo = function (x, y) {
    this.drawShape(new core.math.Polygon([x,y]));

    return this;
};

/**
 * Draws a line using the current line style from the current drawing position to (x, y);
 * The current drawing position is then set to (x, y).
 *
 * @param x {number} the X coordinate to draw to
 * @param y {number} the Y coordinate to draw to
 * @return {Graphics}
 */
Graphics.prototype.lineTo = function (x, y) {
    this.currentPath.shape.points.push(x, y);
    this.dirty = true;

    return this;
};

/**
 * Calculate the points for a quadratic bezier curve and then draws it.
 * Based on: https://stackoverflow.com/questions/785097/how-do-i-implement-a-bezier-curve-in-c
 *
 * @param cpX {number} Control point x
 * @param cpY {number} Control point y
 * @param toX {number} Destination point x
 * @param toY {number} Destination point y
 * @return {Graphics}
 */
Graphics.prototype.quadraticCurveTo = function (cpX, cpY, toX, toY) {
    if (this.currentPath) {
        if (this.currentPath.shape.points.length === 0) {
            this.currentPath.shape.points = [0, 0];
        }
    }
    else {
        this.moveTo(0,0);
    }

    var xa,
        ya,
        n = 20,
        points = this.currentPath.shape.points;

    if (points.length === 0) {
        this.moveTo(0, 0);
    }

    var fromX = points[points.length-2];
    var fromY = points[points.length-1];

    var j = 0;
    for (var i = 1; i <= n; ++i) {
        j = i / n;

        xa = fromX + ( (cpX - fromX) * j );
        ya = fromY + ( (cpY - fromY) * j );

        points.push( xa + ( ((cpX + ( (toX - cpX) * j )) - xa) * j ),
                     ya + ( ((cpY + ( (toY - cpY) * j )) - ya) * j ) );
    }

    this.dirty = true;

    return this;
};

/**
 * Calculate the points for a bezier curve and then draws it.
 *
 * @param cpX {number} Control point x
 * @param cpY {number} Control point y
 * @param cpX2 {number} Second Control point x
 * @param cpY2 {number} Second Control point y
 * @param toX {number} Destination point x
 * @param toY {number} Destination point y
 * @return {Graphics}
 */
Graphics.prototype.bezierCurveTo = function (cpX, cpY, cpX2, cpY2, toX, toY) {
    if (this.currentPath) {
        if (this.currentPath.shape.points.length === 0) {
            this.currentPath.shape.points = [0, 0];
        }
    }
    else {
        this.moveTo(0,0);
    }

    var n = 20,
        dt,
        dt2,
        dt3,
        t2,
        t3,
        points = this.currentPath.shape.points;

    var fromX = points[points.length-2];
    var fromY = points[points.length-1];

    var j = 0;

    for (var i = 1; i <= n; ++i) {
        j = i / n;

        dt = (1 - j);
        dt2 = dt * dt;
        dt3 = dt2 * dt;

        t2 = j * j;
        t3 = t2 * j;

        points.push( dt3 * fromX + 3 * dt2 * j * cpX + 3 * dt * t2 * cpX2 + t3 * toX,
                     dt3 * fromY + 3 * dt2 * j * cpY + 3 * dt * t2 * cpY2 + t3 * toY);
    }

    this.dirty = true;

    return this;
};

/**
 * The arcTo() method creates an arc/curve between two tangents on the canvas.
 *
 * "borrowed" from https://code.google.com/p/fxcanvas/ - thanks google!
 *
 * @param x1 {number} The x-coordinate of the beginning of the arc
 * @param y1 {number} The y-coordinate of the beginning of the arc
 * @param x2 {number} The x-coordinate of the end of the arc
 * @param y2 {number} The y-coordinate of the end of the arc
 * @param radius {number} The radius of the arc
 * @return {Graphics}
 */
Graphics.prototype.arcTo = function (x1, y1, x2, y2, radius) {
    if (this.currentPath) {
        if (this.currentPath.shape.points.length === 0) {
            this.currentPath.shape.points.push(x1, y1);
        }
    }
    else {
        this.moveTo(x1, y1);
    }

    var points = this.currentPath.shape.points,
        fromX = points[points.length-2],
        fromY = points[points.length-1],
        a1 = fromY - y1,
        b1 = fromX - x1,
        a2 = y2   - y1,
        b2 = x2   - x1,
        mm = Math.abs(a1 * b2 - b1 * a2);

    if (mm < 1.0e-8 || radius === 0) {
        if (points[points.length-2] !== x1 || points[points.length-1] !== y1) {
            points.push(x1, y1);
        }
    }
    else {
        var dd = a1 * a1 + b1 * b1,
            cc = a2 * a2 + b2 * b2,
            tt = a1 * a2 + b1 * b2,
            k1 = radius * Math.sqrt(dd) / mm,
            k2 = radius * Math.sqrt(cc) / mm,
            j1 = k1 * tt / dd,
            j2 = k2 * tt / cc,
            cx = k1 * b2 + k2 * b1,
            cy = k1 * a2 + k2 * a1,
            px = b1 * (k2 + j1),
            py = a1 * (k2 + j1),
            qx = b2 * (k1 + j2),
            qy = a2 * (k1 + j2),
            startAngle = Math.atan2(py - cy, px - cx),
            endAngle   = Math.atan2(qy - cy, qx - cx);

        this.arc(cx + x1, cy + y1, radius, startAngle, endAngle, b1 * a2 > b2 * a1);
    }

    this.dirty = true;

    return this;
};

/**
 * The arc method creates an arc/curve (used to create circles, or parts of circles).
 *
 * @param cx {number} The x-coordinate of the center of the circle
 * @param cy {number} The y-coordinate of the center of the circle
 * @param radius {number} The radius of the circle
 * @param startAngle {number} The starting angle, in radians (0 is at the 3 o'clock position of the arc's circle)
 * @param endAngle {number} The ending angle, in radians
 * @param anticlockwise {boolean} Optional. Specifies whether the drawing should be counterclockwise or clockwise. False is default, and indicates clockwise, while true indicates counter-clockwise.
 * @return {Graphics}
 */
Graphics.prototype.arc = function (cx, cy, radius, startAngle, endAngle, anticlockwise) {
    var startX = cx + Math.cos(startAngle) * radius;
    var startY = cy + Math.sin(startAngle) * radius;
    var points;

    if (this.currentPath) {
        points = this.currentPath.shape.points;

        if (points.length === 0) {
            points.push(startX, startY);
        }
        else if (points[points.length-2] !== startX || points[points.length-1] !== startY) {
            points.push(startX, startY);
        }
    }
    else {
        this.moveTo(startX, startY);
        points = this.currentPath.shape.points;
    }

    if (startAngle === endAngle) {
        return this;
    }

    if (!anticlockwise && endAngle <= startAngle) {
        endAngle += Math.PI * 2;
    }
    else if (anticlockwise && startAngle <= endAngle) {
        startAngle += Math.PI * 2;
    }

    var sweep = anticlockwise ? (startAngle - endAngle) *-1 : (endAngle - startAngle);
    var segs = (Math.abs(sweep)/ (Math.PI * 2)) * 40;

    if (sweep === 0) {
        return this;
    }

    var theta = sweep/(segs*2);
    var theta2 = theta*2;

    var cTheta = Math.cos(theta);
    var sTheta = Math.sin(theta);

    var segMinus = segs - 1;

    var remainder = ( segMinus % 1 ) / segMinus;

    for (var i = 0; i <= segMinus; ++i) {
        var real =  i + remainder * i;
        var angle = ((theta) + startAngle + (theta2 * real));

        var c = Math.cos(angle);
        var s = -Math.sin(angle);

        points.push(( (cTheta *  c) + (sTheta * s) ) * radius + cx,
                    ( (cTheta * -s) + (sTheta * c) ) * radius + cy);
    }

    this.dirty = true;

    return this;
};

/**
 * Specifies a simple one-color fill that subsequent calls to other Graphics methods
 * (such as lineTo() or drawCircle()) use when drawing.
 *
 * @param color {number} the color of the fill
 * @param alpha {number} the alpha of the fill
 * @return {Graphics}
 */
Graphics.prototype.beginFill = function (color, alpha) {
    this.filling = true;
    this.fillColor = color || 0;
    this.fillAlpha = (alpha === undefined) ? 1 : alpha;

    if (this.currentPath) {
        if (this.currentPath.shape.points.length <= 2) {
            this.currentPath.fill = this.filling;
            this.currentPath.fillColor = this.fillColor;
            this.currentPath.fillAlpha = this.fillAlpha;
        }
    }
    return this;
};

/**
 * Applies a fill to the lines and shapes that were added since the last call to the beginFill() method.
 *
 * @return {Graphics}
 */
Graphics.prototype.endFill = function () {
    this.filling = false;
    this.fillColor = null;
    this.fillAlpha = 1;

    return this;
};

/**
 *
 * @param x {number} The X coord of the top-left of the rectangle
 * @param y {number} The Y coord of the top-left of the rectangle
 * @param width {number} The width of the rectangle
 * @param height {number} The height of the rectangle
 * @return {Graphics}
 */
Graphics.prototype.drawRect = function ( x, y, width, height ) {
    this.drawShape(new core.math.Rectangle(x,y, width, height));

    return this;
};

/**
 *
 * @param x {number} The X coord of the top-left of the rectangle
 * @param y {number} The Y coord of the top-left of the rectangle
 * @param width {number} The width of the rectangle
 * @param height {number} The height of the rectangle
 * @param radius {number} Radius of the rectangle corners
 */
Graphics.prototype.drawRoundedRect = function ( x, y, width, height, radius ) {
    this.drawShape(new core.math.RoundedRectangle(x, y, width, height, radius));

    return this;
};

/**
 * Draws a circle.
 *
 * @param x {number} The X coordinate of the center of the circle
 * @param y {number} The Y coordinate of the center of the circle
 * @param radius {number} The radius of the circle
 * @return {Graphics}
 */
Graphics.prototype.drawCircle = function (x, y, radius) {
    this.drawShape(new core.math.Circle(x,y, radius));

    return this;
};

/**
 * Draws an ellipse.
 *
 * @param x {number} The X coordinate of the center of the ellipse
 * @param y {number} The Y coordinate of the center of the ellipse
 * @param width {number} The half width of the ellipse
 * @param height {number} The half height of the ellipse
 * @return {Graphics}
 */
Graphics.prototype.drawEllipse = function (x, y, width, height) {
    this.drawShape(new core.math.Ellipse(x, y, width, height));

    return this;
};

/**
 * Draws a polygon using the given path.
 *
 * @param path {Array} The path data used to construct the polygon.
 * @return {Graphics}
 */
Graphics.prototype.drawPolygon = function (path) {
    if (!(path instanceof Array)) {
        path = Array.prototype.slice.call(arguments);
    }

    this.drawShape(new core.math.Polygon(path));

    return this;
};

/**
 * Clears the graphics that were drawn to this Graphics object, and resets fill and line style settings.
 *
 * @return {Graphics}
 */
Graphics.prototype.clear = function () {
    this.lineWidth = 0;
    this.filling = false;

    this.dirty = true;
    this.clearDirty = true;
    this.graphicsData = [];

    return this;
};

/**
 * Useful function that returns a texture of the graphics object that can then be used to create sprites
 * This can be quite useful if your geometry is complicated and needs to be reused multiple times.
 *
 * @param resolution {number} The resolution of the texture being generated
 * @param scaleMode {number} Should be one of the scaleMode consts
 * @return {Texture} a texture of the graphics object
 */
Graphics.prototype.generateTexture = function (resolution, scaleMode) {
    resolution = resolution || 1;

    var bounds = this.getBounds();

    var canvasBuffer = new core.CanvasBuffer(bounds.width * resolution, bounds.height * resolution);

    var texture = core.Texture.fromCanvas(canvasBuffer.canvas, scaleMode);
    texture.baseTexture.resolution = resolution;

    canvasBuffer.context.scale(resolution, resolution);

    canvasBuffer.context.translate(-bounds.x,-bounds.y);

    core.CanvasGraphics.renderGraphics(this, canvasBuffer.context);

    return texture;
};

/**
 * Renders the object using the WebGL renderer
 *
 * @method _renderWebGL
 * @param renderSession {RenderSession}
 * @private
 */
Graphics.prototype._renderWebGL = function (renderSession) {
    // if the sprite is not visible or the alpha is 0 then no need to render this element
    if (!this.visible || this.alpha <= 0 || this.isMask === true) {
        return;
    }

    if (this._cacheAsBitmap) {
        if (this.dirty || this.cachedSpriteDirty) {
            this._generateCachedSprite();

            // we will also need to update the texture on the gpu too!
            this.updateCachedSpriteTexture();

            this.cachedSpriteDirty = false;
            this.dirty = false;
        }

        this._cachedSprite.worldAlpha = this.worldAlpha;

        core.Sprite.prototype._renderWebGL.call(this._cachedSprite, renderSession);

        return;
    }
    else {
        renderSession.spriteBatch.stop();
        renderSession.blendModeManager.setBlendMode(this.blendMode);

        if (this._mask) {
            renderSession.maskManager.pushMask(this._mask, renderSession);
        }

        if (this._filters) {
            renderSession.filterManager.pushFilter(this._filterBlock);
        }

        // check blend mode
        if (this.blendMode !== renderSession.spriteBatch.currentBlendMode) {
            renderSession.spriteBatch.currentBlendMode = this.blendMode;

            var blendModeWebGL = blendModesWebGL[renderSession.spriteBatch.currentBlendMode];

            renderSession.spriteBatch.gl.blendFunc(blendModeWebGL[0], blendModeWebGL[1]);
        }

        // check if the webgl graphic needs to be updated
        if (this.glDirty) {
            this.dirty = true;
            this.glDirty = false;
        }

        core.WebGLGraphics.renderGraphics(this, renderSession);

        // only render if it has children!
        if (this.children.length) {
            renderSession.spriteBatch.start();

             // simple render children!
            for (var i = 0, j = this.children.length; i < j; ++i) {
                this.children[i]._renderWebGL(renderSession);
            }

            renderSession.spriteBatch.stop();
        }

        if (this._filters) {
            renderSession.filterManager.popFilter();
        }

        if (this._mask) {
            renderSession.maskManager.popMask(this.mask, renderSession);
        }

        renderSession.drawCount++;

        renderSession.spriteBatch.start();
    }
};

/**
 * Renders the object using the Canvas renderer
 *
 * @method _renderCanvas
 * @param renderSession {RenderSession}
 * @private
 */
Graphics.prototype._renderCanvas = function (renderSession) {
    // if the sprite is not visible or the alpha is 0 then no need to render this element
    if (!this.visible || this.alpha <= 0 || this.isMask === true) {
        return;
    }

    if (this._cacheAsBitmap) {
        if (this.dirty || this.cachedSpriteDirty) {
            this._generateCachedSprite();

            // we will also need to update the texture
            this.updateCachedSpriteTexture();

            this.cachedSpriteDirty = false;
            this.dirty = false;
        }

        this._cachedSprite.alpha = this.alpha;

        core.Sprite.prototype._renderCanvas.call(this._cachedSprite, renderSession);

        return;
    }
    else {
        var context = renderSession.context;
        var transform = this.worldTransform;

        if (this.blendMode !== renderSession.currentBlendMode) {
            renderSession.currentBlendMode = this.blendMode;
            context.globalCompositeOperation = blendModesCanvas[renderSession.currentBlendMode];
        }

        if (this._mask) {
            renderSession.maskManager.pushMask(this._mask, renderSession);
        }

        var resolution = renderSession.resolution;
        context.setTransform(
            transform.a * resolution,
            transform.b * resolution,
            transform.c * resolution,
            transform.d * resolution,
            transform.tx * resolution,
            transform.ty * resolution
        );

        core.CanvasGraphics.renderGraphics(this, context);

        for (var i = 0, j = this.children.length; i < j; ++i) {
            this.children[i]._renderCanvas(renderSession);
        }

        if (this._mask) {
            renderSession.maskManager.popMask(renderSession);
        }
    }
};

/**
 * Retrieves the bounds of the graphic shape as a rectangle object
 *
 * @return {Rectangle} the rectangular bounding area
 */
Graphics.prototype.getBounds = function (matrix) {
    // return an empty object if the item is a mask!
    if (this.isMask) {
        return core.math.Rectangle.EMPTY;
    }

    if (this.dirty) {
        this.updateLocalBounds();

        this.glDirty = true;
        this.cachedSpriteDirty = true;
        this.dirty = false;
    }

    var bounds = this._localBounds;

    var w0 = bounds.x;
    var w1 = bounds.width + bounds.x;

    var h0 = bounds.y;
    var h1 = bounds.height + bounds.y;

    var worldTransform = matrix || this.worldTransform;

    var a = worldTransform.a;
    var b = worldTransform.b;
    var c = worldTransform.c;
    var d = worldTransform.d;
    var tx = worldTransform.tx;
    var ty = worldTransform.ty;

    var x1 = a * w1 + c * h1 + tx;
    var y1 = d * h1 + b * w1 + ty;

    var x2 = a * w0 + c * h1 + tx;
    var y2 = d * h1 + b * w0 + ty;

    var x3 = a * w0 + c * h0 + tx;
    var y3 = d * h0 + b * w0 + ty;

    var x4 =  a * w1 + c * h0 + tx;
    var y4 =  d * h0 + b * w1 + ty;

    var maxX = x1;
    var maxY = y1;

    var minX = x1;
    var minY = y1;

    minX = x2 < minX ? x2 : minX;
    minX = x3 < minX ? x3 : minX;
    minX = x4 < minX ? x4 : minX;

    minY = y2 < minY ? y2 : minY;
    minY = y3 < minY ? y3 : minY;
    minY = y4 < minY ? y4 : minY;

    maxX = x2 > maxX ? x2 : maxX;
    maxX = x3 > maxX ? x3 : maxX;
    maxX = x4 > maxX ? x4 : maxX;

    maxY = y2 > maxY ? y2 : maxY;
    maxY = y3 > maxY ? y3 : maxY;
    maxY = y4 > maxY ? y4 : maxY;

    this._bounds.x = minX;
    this._bounds.width = maxX - minX;

    this._bounds.y = minY;
    this._bounds.height = maxY - minY;

    return this._bounds;
};

/**
 * Update the bounds of the object
 *
 */
Graphics.prototype.updateLocalBounds = function () {
    var minX = Infinity;
    var maxX = -Infinity;

    var minY = Infinity;
    var maxY = -Infinity;

    if (this.graphicsData.length) {
        var shape, points, x, y, w, h;

        for (var i = 0; i < this.graphicsData.length; i++) {
            var data = this.graphicsData[i];
            var type = data.type;
            var lineWidth = data.lineWidth;
            shape = data.shape;

            if (type === Graphics.RECT || type === Graphics.RREC) {
                x = shape.x - lineWidth/2;
                y = shape.y - lineWidth/2;
                w = shape.width + lineWidth;
                h = shape.height + lineWidth;

                minX = x < minX ? x : minX;
                maxX = x + w > maxX ? x + w : maxX;

                minY = y < minY ? y : minY;
                maxY = y + h > maxY ? y + h : maxY;
            }
            else if (type === Graphics.CIRC) {
                x = shape.x;
                y = shape.y;
                w = shape.radius + lineWidth/2;
                h = shape.radius + lineWidth/2;

                minX = x - w < minX ? x - w : minX;
                maxX = x + w > maxX ? x + w : maxX;

                minY = y - h < minY ? y - h : minY;
                maxY = y + h > maxY ? y + h : maxY;
            }
            else if (type === Graphics.ELIP) {
                x = shape.x;
                y = shape.y;
                w = shape.width + lineWidth/2;
                h = shape.height + lineWidth/2;

                minX = x - w < minX ? x - w : minX;
                maxX = x + w > maxX ? x + w : maxX;

                minY = y - h < minY ? y - h : minY;
                maxY = y + h > maxY ? y + h : maxY;
            }
            else {
                // POLY
                points = shape.points;

                for (var j = 0; j < points.length; j += 2) {
                    x = points[j];
                    y = points[j+1];

                    minX = x-lineWidth < minX ? x-lineWidth : minX;
                    maxX = x+lineWidth > maxX ? x+lineWidth : maxX;

                    minY = y-lineWidth < minY ? y-lineWidth : minY;
                    maxY = y+lineWidth > maxY ? y+lineWidth : maxY;
                }
            }
        }
    }
    else {
        minX = 0;
        maxX = 0;
        minY = 0;
        maxY = 0;
    }

    var padding = this.boundsPadding;

    this._localBounds.x = minX - padding;
    this._localBounds.width = (maxX - minX) + padding * 2;

    this._localBounds.y = minY - padding;
    this._localBounds.height = (maxY - minY) + padding * 2;
};

/**
 * Generates the cached sprite when the sprite has cacheAsBitmap = true
 *
 * @private
 */
Graphics.prototype._generateCachedSprite = function () {
    var bounds = this.getLocalBounds();

    if (!this._cachedSprite) {
        var canvasBuffer = new core.CanvasBuffer(bounds.width, bounds.height);
        var texture = core.Texture.fromCanvas(canvasBuffer.canvas);

        this._cachedSprite = new core.Sprite(texture);
        this._cachedSprite.buffer = canvasBuffer;

        this._cachedSprite.worldTransform = this.worldTransform;
    }
    else {
        this._cachedSprite.buffer.resize(bounds.width, bounds.height);
    }

    // leverage the anchor to account for the offset of the element
    this._cachedSprite.anchor.x = -( bounds.x / bounds.width );
    this._cachedSprite.anchor.y = -( bounds.y / bounds.height );

    // this._cachedSprite.buffer.context.save();
    this._cachedSprite.buffer.context.translate(-bounds.x,-bounds.y);

    // make sure we set the alpha of the graphics to 1 for the render..
    this.worldAlpha = 1;

    // now render the graphic..
    core.CanvasGraphics.renderGraphics(this, this._cachedSprite.buffer.context);

    this._cachedSprite.alpha = this.alpha;
};

/**
 * Updates texture size based on canvas size
 *
 * @private
 */
Graphics.prototype.updateCachedSpriteTexture = function () {
    var cachedSprite = this._cachedSprite;
    var texture = cachedSprite.texture;
    var canvas = cachedSprite.buffer.canvas;

    texture.baseTexture.width = canvas.width;
    texture.baseTexture.height = canvas.height;
    texture.crop.width = texture.frame.width = canvas.width;
    texture.crop.height = texture.frame.height = canvas.height;

    cachedSprite._width = canvas.width;
    cachedSprite._height = canvas.height;

    // update the dirty base textures
    texture.baseTexture.dirty();
};

/**
 * Destroys a previous cached sprite.
 *
 */
Graphics.prototype.destroyCachedSprite = function () {
    this._cachedSprite.texture.destroy(true);

    // let the gc collect the unused sprite
    // TODO could be object pooled!
    this._cachedSprite = null;
};

/**
 * Draws the given shape to this Graphics object. Can be any of Circle, Rectangle, Ellipse, Line or Polygon.
 *
 * @param {Circle|Rectangle|Ellipse|Line|Polygon} shape The Shape object to draw.
 * @return {GraphicsData} The generated GraphicsData object.
 */
Graphics.prototype.drawShape = function (shape) {
    if (this.currentPath) {
        // check current path!
        if (this.currentPath.shape.points.length <= 2) {
            this.graphicsData.pop();
        }
    }

    this.currentPath = null;

    var data = new GraphicsData(this.lineWidth, this.lineColor, this.lineAlpha, this.fillColor, this.fillAlpha, this.filling, shape);

    this.graphicsData.push(data);

    if (data.type === Graphics.POLY) {
        data.shape.closed = this.filling;
        this.currentPath = data;
    }

    this.dirty = true;

    return data;
};

/**
 * @static
 * @constant
 */
Graphics.POLY = 0;

/**
 * @static
 * @constant
 */
Graphics.RECT = 1;

/**
 * @static
 * @constant
 */
Graphics.CIRC = 2;

/**
 * @static
 * @constant
 */
Graphics.ELIP = 3;

/**
 * @static
 * @constant
 */
Graphics.RREC = 4;

// REFACTOR: Move these to their classes, move types to central location.
core.math.Polygon.prototype.type = Graphics.POLY;
core.math.Rectangle.prototype.type = Graphics.RECT;
core.math.Circle.prototype.type = Graphics.CIRC;
core.math.Ellipse.prototype.type = Graphics.ELIP;
core.math.RoundedRectangle.prototype.type = Graphics.RREC;