phaser/src/gameobjects/Graphics.js

/**
* @author       Richard Davey <rich@photonstorm.com>
* @copyright    2016 Photon Storm Ltd.
* @license      {@link https://github.com/photonstorm/phaser/blob/master/license.txt|MIT License}
*/

/**
* A Graphics object is a way to draw primitives to your game. Primitives include forms of geometry, such as Rectangles,
* Circles and Polygons. They also include lines, arcs and curves. When you initially create a Graphics object it will
* be empty. To 'draw' to it you first specify a lineStyle or fillStyle (or both), and then draw a shape. For example:
*
* ```
* graphics.beginFill(0xff0000);
* graphics.drawCircle(50, 50, 100);
* graphics.endFill();
* ```
* 
* This will draw a circle shape to the Graphics object, with a diameter of 100, located at x: 50, y: 50.
*
* When a Graphics object is rendered it will render differently based on if the game is running under Canvas or
* WebGL. Under Canvas it will use the HTML Canvas context drawing operations to draw the path. Under WebGL the
* graphics data is decomposed into polygons. Both of these are expensive processes, especially with complex shapes.
* 
* If your Graphics object doesn't change much (or at all) once you've drawn your shape to it, then you will help
* performance by calling `Graphics.generateTexture`. This will 'bake' the Graphics object into a Texture, and return it.
* You can then use this Texture for Sprites or other display objects. If your Graphics object updates frequently then
* you should avoid doing this, as it will constantly generate new textures, which will consume memory.
*
* As you can tell, Graphics objects are a bit of a trade-off. While they are extremely useful, you need to be careful
* in their complexity and quantity of them in your game.
*
* @class Phaser.Graphics
* @constructor
* @extends PIXI.DisplayObjectContainer
* @extends Phaser.Component.Core
* @extends Phaser.Component.Angle
* @extends Phaser.Component.AutoCull
* @extends Phaser.Component.Bounds
* @extends Phaser.Component.Destroy
* @extends Phaser.Component.FixedToCamera
* @extends Phaser.Component.InputEnabled
* @extends Phaser.Component.InWorld
* @extends Phaser.Component.LifeSpan
* @extends Phaser.Component.PhysicsBody
* @extends Phaser.Component.Reset
* @param {Phaser.Game} game - Current game instance.
* @param {number} [x=0] - X position of the new graphics object.
* @param {number} [y=0] - Y position of the new graphics object.
*/
Phaser.Graphics = function (game, x, y) {

    if (x === undefined) { x = 0; }
    if (y === undefined) { y = 0; }

    /**
    * @property {number} type - The const type of this object.
    * @default
    */
    this.type = Phaser.GRAPHICS;

    /**
    * @property {number} physicsType - The const physics body type of this object.
    * @readonly
    */
    this.physicsType = Phaser.SPRITE;

    /**
    * @property {Phaser.Point} anchor - Required for a Graphics shape to work as a Physics body, do not modify this value.
    * @private
    */
    this.anchor = new Phaser.Point();

    PIXI.DisplayObjectContainer.call(this);

    this.renderable = true;

    /**
     * The alpha value used when filling the Graphics object.
     *
     * @property fillAlpha
     * @type Number
     */
    this.fillAlpha = 1;

    /**
     * The width (thickness) of any lines drawn.
     *
     * @property lineWidth
     * @type Number
     */
    this.lineWidth = 0;

    /**
     * The color of any lines drawn.
     *
     * @property lineColor
     * @type String
     * @default 0
     */
    this.lineColor = 0;

    /**
     * Graphics data
     *
     * @property graphicsData
     * @type Array
     * @private
     */
    this.graphicsData = [];

    /**
     * The tint applied to the graphic shape. This is a hex value. Apply a value of 0xFFFFFF to reset the tint.
     *
     * @property tint
     * @type Number
     * @default 0xFFFFFF
     */
    this.tint = 0xFFFFFF;

    /**
     * The blend mode to be applied to the graphic shape. Apply a value of PIXI.blendModes.NORMAL to reset the blend mode.
     *
     * @property blendMode
     * @type Number
     * @default PIXI.blendModes.NORMAL;
     */
    this.blendMode = PIXI.blendModes.NORMAL;
    
    /**
     * Current path
     *
     * @property currentPath
     * @type Object
     * @private
     */
    this.currentPath = null;
    
    /**
     * Array containing some WebGL-related properties used by the WebGL renderer.
     *
     * @property _webGL
     * @type Array
     * @private
     */
    this._webGL = [];

    /**
     * Whether this shape is being used as a mask.
     *
     * @property isMask
     * @type Boolean
     */
    this.isMask = false;

    /**
     * The bounds' padding used for bounds calculation.
     *
     * @property boundsPadding
     * @type Number
     */
    this.boundsPadding = 0;

    this._localBounds = new Phaser.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.
     * 
     * @property dirty
     * @type Boolean
     * @private
     */
    this.dirty = true;

    /**
     * Used to detect if the bounds have been invalidated, by this Graphics being cleared or drawn to.
     * If this is set to true then the updateLocalBounds is called once in the postUpdate method.
     * 
     * @property _boundsDirty
     * @type Boolean
     * @private
     */
    this._boundsDirty = false;

    /**
     * Used to detect if the webgl graphics object has changed. If this is set to true then the graphics object will be recalculated.
     * 
     * @property webGLDirty
     * @type Boolean
     * @private
     */
    this.webGLDirty = false;

    /**
     * Used to detect if the cached sprite object needs to be updated.
     * 
     * @property cachedSpriteDirty
     * @type Boolean
     * @private
     */
    this.cachedSpriteDirty = false;

    Phaser.Component.Core.init.call(this, game, x, y, '', null);

};

Phaser.Graphics.prototype = Object.create(PIXI.DisplayObjectContainer.prototype);
Phaser.Graphics.prototype.constructor = Phaser.Graphics;

Phaser.Component.Core.install.call(Phaser.Graphics.prototype, [
    'Angle',
    'AutoCull',
    'Bounds',
    'Destroy',
    'FixedToCamera',
    'InputEnabled',
    'InWorld',
    'LifeSpan',
    'PhysicsBody',
    'Reset'
]);

Phaser.Graphics.prototype.preUpdatePhysics = Phaser.Component.PhysicsBody.preUpdate;
Phaser.Graphics.prototype.preUpdateLifeSpan = Phaser.Component.LifeSpan.preUpdate;
Phaser.Graphics.prototype.preUpdateInWorld = Phaser.Component.InWorld.preUpdate;
Phaser.Graphics.prototype.preUpdateCore = Phaser.Component.Core.preUpdate;

/**
* Automatically called by World.preUpdate.
* 
* @method
* @memberof Phaser.Graphics
*/
Phaser.Graphics.prototype.preUpdate = function () {

    if (!this.preUpdatePhysics() || !this.preUpdateLifeSpan() || !this.preUpdateInWorld())
    {
        return false;
    }

    return this.preUpdateCore();

};

/**
* Automatically called by World
* @method Phaser.Graphics.prototype.postUpdate
*/
Phaser.Graphics.prototype.postUpdate = function () {

    Phaser.Component.PhysicsBody.postUpdate.call(this);
    Phaser.Component.FixedToCamera.postUpdate.call(this);

    if (this._boundsDirty)
    {
        this.updateLocalBounds();
        this._boundsDirty = false;
    }

    for (var i = 0; i < this.children.length; i++)
    {
        this.children[i].postUpdate();
    }

};

/**
* Destroy this Graphics instance.
*
* @method Phaser.Graphics.prototype.destroy
* @param {boolean} [destroyChildren=true] - Should every child of this object have its destroy method called?
*/
Phaser.Graphics.prototype.destroy = function (destroyChildren) {

    this.clear();

    Phaser.Component.Destroy.prototype.destroy.call(this, destroyChildren);

};

/*
* Draws a single {Phaser.Polygon} triangle from a {Phaser.Point} array
*
* @method Phaser.Graphics.prototype.drawTriangle
* @param {Array<Phaser.Point>} points - An array of Phaser.Points that make up the three vertices of this triangle
* @param {boolean} [cull=false] - Should we check if the triangle is back-facing
*/
Phaser.Graphics.prototype.drawTriangle = function (points, cull) {

    if (cull === undefined) { cull = false; }

    var triangle = new Phaser.Polygon(points);

    if (cull)
    {
        var cameraToFace = new Phaser.Point(this.game.camera.x - points[0].x, this.game.camera.y - points[0].y);
        var ab = new Phaser.Point(points[1].x - points[0].x, points[1].y - points[0].y);
        var cb = new Phaser.Point(points[1].x - points[2].x, points[1].y - points[2].y);
        var faceNormal = cb.cross(ab);

        if (cameraToFace.dot(faceNormal) > 0)
        {
            this.drawPolygon(triangle);
        }
    }
    else
    {
        this.drawPolygon(triangle);
    }

};

/*
* Draws {Phaser.Polygon} triangles
*
* @method Phaser.Graphics.prototype.drawTriangles
* @param {Array<Phaser.Point>|Array<number>} vertices - An array of Phaser.Points or numbers that make up the vertices of the triangles
* @param {Array<number>} {indices=null} - An array of numbers that describe what order to draw the vertices in
* @param {boolean} [cull=false] - Should we check if the triangle is back-facing
*/
Phaser.Graphics.prototype.drawTriangles = function (vertices, indices, cull) {

    if (cull === undefined) { cull = false; }

    var point1 = new Phaser.Point();
    var point2 = new Phaser.Point();
    var point3 = new Phaser.Point();
    var points = [];
    var i;

    if (!indices)
    {
        if (vertices[0] instanceof Phaser.Point)
        {
            for (i = 0; i < vertices.length / 3; i++)
            {
                this.drawTriangle([vertices[i * 3], vertices[i * 3 + 1], vertices[i * 3 + 2]], cull);
            }
        }
        else
        {
            for (i = 0; i < vertices.length / 6; i++)
            {
                point1.x = vertices[i * 6 + 0];
                point1.y = vertices[i * 6 + 1];
                point2.x = vertices[i * 6 + 2];
                point2.y = vertices[i * 6 + 3];
                point3.x = vertices[i * 6 + 4];
                point3.y = vertices[i * 6 + 5];
                this.drawTriangle([point1, point2, point3], cull);
            }
        }
    }
    else
    {
        if (vertices[0] instanceof Phaser.Point)
        {
            for (i = 0; i < indices.length /3; i++)
            {
                points.push(vertices[indices[i * 3 ]]);
                points.push(vertices[indices[i * 3 + 1]]);
                points.push(vertices[indices[i * 3 + 2]]);

                if (points.length === 3)
                {
                    this.drawTriangle(points, cull);
                    points = [];
                }
            }
        }
        else
        {
            for (i = 0; i < indices.length; i++)
            {
                point1.x = vertices[indices[i] * 2];
                point1.y = vertices[indices[i] * 2 + 1];
                points.push(point1.copyTo({}));

                if (points.length === 3)
                {
                    this.drawTriangle(points, cull);
                    points = [];
                }
            }
        }
    }
};

/**
 * Specifies the line style used for subsequent calls to Graphics methods such as the lineTo() method or the drawCircle() method.
 *
 * @method lineStyle
 * @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}
 */
Phaser.Graphics.prototype.lineStyle = function (lineWidth, color, alpha) {

    this.lineWidth = lineWidth || 0;
    this.lineColor = color || 0;
    this.lineAlpha = (alpha === undefined) ? 1 : alpha;

    if (this.currentPath)
    {
        if (this.currentPath.shape.points.length)
        {
            // halfway through a line? start a new one!
            this.drawShape(new Phaser.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.
 *
 * @method moveTo
 * @param x {Number} the X coordinate to move to
 * @param y {Number} the Y coordinate to move to
 * @return {Graphics}
  */
Phaser.Graphics.prototype.moveTo = function (x, y) {

    this.drawShape(new Phaser.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).
 *
 * @method lineTo
 * @param x {Number} the X coordinate to draw to
 * @param y {Number} the Y coordinate to draw to
 * @return {Graphics}
 */
Phaser.Graphics.prototype.lineTo = function (x, y) {

    if (!this.currentPath)
    {
        this.moveTo(0, 0);
    }

    this.currentPath.shape.points.push(x, y);
    this.dirty = true;
    this._boundsDirty = 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
 *
 * @method quadraticCurveTo
 * @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}
 */
Phaser.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;
    this._boundsDirty = true;

    return this;

};

/**
 * Calculate the points for a bezier curve and then draws it.
 *
 * @method bezierCurveTo
 * @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}
 */
Phaser.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;
    this._boundsDirty = 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!
 *
 * @method arcTo
 * @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}
 */
Phaser.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;
    this._boundsDirty = true;

    return this;

};

/**
 * The arc method creates an arc/curve (used to create circles, or parts of circles).
 *
 * @method arc
 * @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.
 * @param segments {Number} Optional. The number of segments to use when calculating the arc. The default is 40. If you need more fidelity use a higher number.
 * @return {Graphics}
 */
Phaser.Graphics.prototype.arc = function (cx, cy, radius, startAngle, endAngle, anticlockwise, segments) {

    //  If we do this we can never draw a full circle
    if (startAngle === endAngle)
    {
        return this;
    }

    if (anticlockwise === undefined) { anticlockwise = false; }
    if (segments === undefined) { segments = 40; }

    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.ceil(Math.abs(sweep) / (Math.PI * 2)) * segments;

    //  Sweep check - moved here because we don't want to do the moveTo below if the arc fails
    if (sweep === 0)
    {
        return this;
    }

    var startX = cx + Math.cos(startAngle) * radius;
    var startY = cy + Math.sin(startAngle) * radius;

    if (anticlockwise && this.filling)
    {
        this.moveTo(cx, cy);
    }
    else
    {
        this.moveTo(startX, startY);
    }

    //  currentPath will always exist after calling a moveTo
    var points = this.currentPath.shape.points;

    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;
    this._boundsDirty = true;

    return this;

};

/**
 * Specifies a simple one-color fill that subsequent calls to other Graphics methods
 * (such as lineTo() or drawCircle()) use when drawing.
 *
 * @method beginFill
 * @param color {Number} the color of the fill
 * @param alpha {Number} the alpha of the fill
 * @return {Graphics}
 */
Phaser.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.
 *
 * @method endFill
 * @return {Graphics}
 */
Phaser.Graphics.prototype.endFill = function () {

    this.filling = false;
    this.fillColor = null;
    this.fillAlpha = 1;

    return this;

};

/**
 * @method drawRect
 *
 * @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}
 */
Phaser.Graphics.prototype.drawRect = function (x, y, width, height) {

    this.drawShape(new Phaser.Rectangle(x, y, width, height));

    return this;

};

/**
 * @method drawRoundedRect
 * @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. In WebGL this must be a value between 0 and 9.
 */
Phaser.Graphics.prototype.drawRoundedRect = function (x, y, width, height, radius) {

    this.drawShape(new Phaser.RoundedRectangle(x, y, width, height, radius));

    return this;

};

/**
 * Draws a circle.
 *
 * @method drawCircle
 * @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 diameter {Number} The diameter of the circle
 * @return {Graphics}
 */
Phaser.Graphics.prototype.drawCircle = function (x, y, diameter) {

    this.drawShape(new Phaser.Circle(x, y, diameter));

    return this;

};

/**
 * Draws an ellipse.
 *
 * @method drawEllipse
 * @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}
 */
Phaser.Graphics.prototype.drawEllipse = function (x, y, width, height) {

    this.drawShape(new Phaser.Ellipse(x, y, width, height));

    return this;

};

/**
 * Draws a polygon using the given path.
 *
 * @method drawPolygon
 * @param path {Array|Phaser.Polygon} The path data used to construct the polygon. Can either be an array of points or a Phaser.Polygon object.
 * @return {Graphics}
 */
Phaser.Graphics.prototype.drawPolygon = function (path) {

    if (path instanceof Phaser.Polygon)
    {
        path = path.points;
    }

    // prevents an argument assignment deopt
    // see section 3.1: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#3-managing-arguments
    var points = path;

    if (!Array.isArray(points))
    {
        // prevents an argument leak deopt
        // see section 3.2: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#3-managing-arguments
        points = new Array(arguments.length);

        for (var i = 0; i < points.length; ++i)
        {
            points[i] = arguments[i];
        }
    }

    this.drawShape(new Phaser.Polygon(points));

    return this;

};

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

    this.lineWidth = 0;
    this.filling = false;

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

    this.updateLocalBounds();

    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.
 *
 * @method generateTexture
 * @param [resolution=1] {Number} The resolution of the texture being generated
 * @param [scaleMode=0] {Number} Should be one of the PIXI.scaleMode consts
 * @param [padding=0] {Number} Add optional extra padding to the generated texture (default 0)
 * @return {Texture} a texture of the graphics object
 */
Phaser.Graphics.prototype.generateTexture = function (resolution, scaleMode, padding) {

    if (resolution === undefined) { resolution = 1; }
    if (scaleMode === undefined) { scaleMode = PIXI.scaleModes.DEFAULT; }
    if (padding === undefined) { padding = 0; }

    var bounds = this.getBounds();

    bounds.width += padding;
    bounds.height += padding;
   
    var canvasBuffer = new PIXI.CanvasBuffer(bounds.width * resolution, bounds.height * resolution);
    
    var texture = PIXI.Texture.fromCanvas(canvasBuffer.canvas, scaleMode);

    texture.baseTexture.resolution = resolution;

    canvasBuffer.context.scale(resolution, resolution);

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

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

    return texture;

};

/**
* Renders the object using the WebGL renderer
*
* @method _renderWebGL
* @param renderSession {RenderSession} 
* @private
*/
Phaser.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 === false || 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;

        PIXI.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 = PIXI.blendModesWebGL[renderSession.spriteBatch.currentBlendMode];
            renderSession.spriteBatch.gl.blendFunc(blendModeWebGL[0], blendModeWebGL[1]);
        }
        
        // check if the webgl graphic needs to be updated
        if (this.webGLDirty)
        {
            this.dirty = true;
            this.webGLDirty = false;
        }
        
        PIXI.WebGLGraphics.renderGraphics(this, renderSession);
        
        // only render if it has children!
        if (this.children.length)
        {
            renderSession.spriteBatch.start();

            // simple render children!
            for (var i = 0; i < this.children.length; 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
*/
Phaser.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 === false || this.alpha === 0 || this.isMask === true)
    {
        return;
    }

    // if the tint has changed, set the graphics object to dirty.
    if (this._prevTint !== this.tint)
    {
        this.dirty = true;
        this._prevTint = this.tint;
    }

    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;

        PIXI.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 = PIXI.blendModesCanvas[renderSession.currentBlendMode];
        }

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

        var resolution = renderSession.resolution;
        var tx = (transform.tx * renderSession.resolution) + renderSession.shakeX;
        var ty = (transform.ty * renderSession.resolution) + renderSession.shakeY;

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

        PIXI.CanvasGraphics.renderGraphics(this, context);

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

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

};

/**
 * Retrieves the bounds of the graphic shape as a rectangle object
 *
 * @method getBounds
 * @return {Rectangle} the rectangular bounding area
 */
Phaser.Graphics.prototype.getBounds = function (matrix) {

    if (this._currentBounds)
    {
        return this._currentBounds;
    }

    //  Return an empty object if the item is a mask!
    if (!this.renderable)
    {
        return Phaser.EmptyRectangle;
    }

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

    this._currentBounds = this._bounds;

    return this._currentBounds;

};

/**
 * Retrieves the non-global local bounds of the graphic shape as a rectangle. The calculation takes all visible children into consideration.
 *
 * @method getLocalBounds
 * @return {Rectangle} The rectangular bounding area
 */
Phaser.Graphics.prototype.getLocalBounds = function () {

    var matrixCache = this.worldTransform;

    this.worldTransform = Phaser.identityMatrix;

    for (var i = 0; i < this.children.length; i++)
    {
        this.children[i].updateTransform();
    }

    var bounds = this.getBounds();

    this.worldTransform = matrixCache;

    for (i = 0; i < this.children.length; i++)
    {
        this.children[i].updateTransform();
    }

    return bounds;

};

/**
* Tests if a point is inside this graphics object
*
* @param point {Point} the point to test
* @return {boolean} the result of the test
*/
Phaser.Graphics.prototype.containsPoint = function (point) {

    this.worldTransform.applyInverse(point, tempPoint);

    var graphicsData = this.graphicsData;

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

        if (!data.fill)
        {
            continue;
        }

        // only deal with fills..
        if (data.shape)
        {
            if (data.shape.contains(tempPoint.x, tempPoint.y))
            {
                return true;
            }
        }
    }

    return false;

};

/**
 * Update the bounds of the object
 *
 * @method updateLocalBounds
 */
Phaser.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 === Phaser.RECTANGLE || type === Phaser.ROUNDEDRECTANGLE)
            {
                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 === Phaser.CIRCLE)
            {
                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 === Phaser.ELLIPSE)
            {
                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 - assumes points are sequential, not Point objects
                points = shape.points;

                for (var j = 0; j < points.length; j++)
                {
                    if (points[j] instanceof Phaser.Point)
                    {
                        x = points[j].x;
                        y = points[j].y;
                    }
                    else
                    {
                        x = points[j];
                        y = points[j + 1];

                        if (j < points.length - 1)
                        {
                            j++;
                        }
                    }

                    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
 *
 * @method _generateCachedSprite
 * @private
 */
Phaser.Graphics.prototype._generateCachedSprite = function () {

    var bounds = this.getLocalBounds();

    if (!this._cachedSprite)
    {
        var canvasBuffer = new PIXI.CanvasBuffer(bounds.width, bounds.height);
        var texture = PIXI.Texture.fromCanvas(canvasBuffer.canvas);
        
        this._cachedSprite = new PIXI.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..
    PIXI.CanvasGraphics.renderGraphics(this, this._cachedSprite.buffer.context);
    this._cachedSprite.alpha = this.alpha;

};

/**
 * Updates texture size based on canvas size
 *
 * @method updateCachedSpriteTexture
 * @private
 */
Phaser.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.
 *
 * @method destroyCachedSprite
 */
Phaser.Graphics.prototype.destroyCachedSprite = function () {

    this._cachedSprite.texture.destroy(true);
    this._cachedSprite = null;

};

/**
 * Draws the given shape to this Graphics object. Can be any of Circle, Rectangle, Ellipse, Line or Polygon.
 *
 * @method drawShape
 * @param {Circle|Rectangle|Ellipse|Line|Polygon} shape The Shape object to draw.
 * @return {GraphicsData} The generated GraphicsData object.
 */
Phaser.Graphics.prototype.drawShape = function (shape) {

    if (this.currentPath)
    {
        // check current path!
        if (this.currentPath.shape.points.length <= 2)
        {
            this.graphicsData.pop();
        }
    }

    this.currentPath = null;

    //  Handle mixed-type polygons
    if (shape instanceof Phaser.Polygon)
    {
        shape = shape.clone();
        shape.flatten();
    }

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

    if (data.type === Phaser.POLYGON)
    {
        data.shape.closed = this.filling;
        this.currentPath = data;
    }

    this.dirty = true;
    this._boundsDirty = true;

    return data;

};

/**
 * 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.
 *
 * @property cacheAsBitmap
 * @type Boolean
 * @default false
 * @private
 */
Object.defineProperty(Phaser.Graphics.prototype, 'cacheAsBitmap', {

    get: function () {

        return  this._cacheAsBitmap;

    },

    set: function (value) {

        this._cacheAsBitmap = value;

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

        this.dirty = true;
        this.webGLDirty = true;

    }
});