Graphics.js

/**
 * @author Mat Groves http://matgroves.com/ @Doormat23
 */


/**
 * The Graphics class contains a set of methods that you can use to create primitive shapes and lines.
 * It is important to know that with the webGL renderer only simple polys can be filled at this stage
 * Complex polys will not be filled. Heres an example of a complex poly: http://www.goodboydigital.com/wp-content/uploads/2013/06/complexPolygon.png
 *
 * @class Graphics
 * @extends DisplayObjectContainer
 * @constructor
 */
PIXI.Graphics = function()
{
    PIXI.DisplayObjectContainer.call( this );

    this.renderable = true;

    /**
     * The alpha of the fill of this graphics object
     *
     * @property fillAlpha
     * @type Number
     */
    this.fillAlpha = 1;

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

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

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

    this.tint = 0xFFFFFF;// * Math.random();

    this.blendMode = PIXI.blendModes.NORMAL;
    
    /**
     * Current path
     *
     * @property currentPath
     * @type Object
     * @private
     */
    this.currentPath = {points:[]};

    this._webGL = [];

    this.isMask = false;

    this.bounds = null;

    this.boundsPadding = 10;
};

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

/**
 * If cacheAsBitmap is true the graphics object will then 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
 * It is also usful as the graphics object will always be aliased because it will be rendered using canvas
 * Not recommended if you are conastanly redrawing the graphics element.
 *
 * @property cacheAsBitmap
 * @default false
 * @type Boolean
 * @private
 */
Object.defineProperty(PIXI.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;
        }

    }
});


/**
 * Specifies a 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 object's stored style
 * @param color {Number} color of the line to draw, will update the object's stored style
 * @param alpha {Number} alpha of the line to draw, will update the object's stored style
 */
PIXI.Graphics.prototype.lineStyle = function(lineWidth, color, alpha)
{
    if (!this.currentPath.points.length) this.graphicsData.pop();

    this.lineWidth = lineWidth || 0;
    this.lineColor = color || 0;
    this.lineAlpha = (arguments.length < 3) ? 1 : alpha;

    this.currentPath = {lineWidth:this.lineWidth, lineColor:this.lineColor, lineAlpha:this.lineAlpha,
                        fillColor:this.fillColor, fillAlpha:this.fillAlpha, fill:this.filling, points:[], type:PIXI.Graphics.POLY};

    this.graphicsData.push(this.currentPath);
};

/**
 * Moves the current drawing position to (x, y).
 *
 * @method moveTo
 * @param x {Number} the X coord to move to
 * @param y {Number} the Y coord to move to
 */
PIXI.Graphics.prototype.moveTo = function(x, y)
{
    if (!this.currentPath.points.length) this.graphicsData.pop();

    this.currentPath = this.currentPath = {lineWidth:this.lineWidth, lineColor:this.lineColor, lineAlpha:this.lineAlpha,
                        fillColor:this.fillColor, fillAlpha:this.fillAlpha, fill:this.filling, points:[], type:PIXI.Graphics.POLY};

    this.currentPath.points.push(x, y);

    this.graphicsData.push(this.currentPath);
};

/**
 * 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 coord to draw to
 * @param y {Number} the Y coord to draw to
 */
PIXI.Graphics.prototype.lineTo = function(x, y)
{
    this.currentPath.points.push(x, y);
    this.dirty = true;
};

/**
 * 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 {uint} the color of the fill
 * @param alpha {Number} the alpha
 */
PIXI.Graphics.prototype.beginFill = function(color, alpha)
{

    this.filling = true;
    this.fillColor = color || 0;
    this.fillAlpha = (arguments.length < 2) ? 1 : alpha;
};

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

/**
 * @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
 */
PIXI.Graphics.prototype.drawRect = function( x, y, width, height )
{
    if (!this.currentPath.points.length) this.graphicsData.pop();

    this.currentPath = {lineWidth:this.lineWidth, lineColor:this.lineColor, lineAlpha:this.lineAlpha,
                        fillColor:this.fillColor, fillAlpha:this.fillAlpha, fill:this.filling,
                        points:[x, y, width, height], type:PIXI.Graphics.RECT};

    this.graphicsData.push(this.currentPath);
    this.dirty = true;
};

/**
 * Draws a circle.
 *
 * @method drawCircle
 * @param x {Number} The X coord of the center of the circle
 * @param y {Number} The Y coord of the center of the circle
 * @param radius {Number} The radius of the circle
 */
PIXI.Graphics.prototype.drawCircle = function( x, y, radius)
{

    if (!this.currentPath.points.length) this.graphicsData.pop();

    this.currentPath = {lineWidth:this.lineWidth, lineColor:this.lineColor, lineAlpha:this.lineAlpha,
                        fillColor:this.fillColor, fillAlpha:this.fillAlpha, fill:this.filling,
                        points:[x, y, radius, radius], type:PIXI.Graphics.CIRC};

    this.graphicsData.push(this.currentPath);
    this.dirty = true;
};

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

    if (!this.currentPath.points.length) this.graphicsData.pop();

    this.currentPath = {lineWidth:this.lineWidth, lineColor:this.lineColor, lineAlpha:this.lineAlpha,
                        fillColor:this.fillColor, fillAlpha:this.fillAlpha, fill:this.filling,
                        points:[x, y, width, height], type:PIXI.Graphics.ELIP};

    this.graphicsData.push(this.currentPath);
    this.dirty = true;
};

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

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

    this.bounds = null; //new PIXI.Rectangle();
};

/**
 * 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
 * @return {Texture} a texture of the graphics object
 */
PIXI.Graphics.prototype.generateTexture = function()
{
    var bounds = this.getBounds();

    var canvasBuffer = new PIXI.CanvasBuffer(bounds.width, bounds.height);
    var texture = PIXI.Texture.fromCanvas(canvasBuffer.canvas);

    canvasBuffer.context.translate(-bounds.x,-bounds.y);
    
    PIXI.CanvasGraphics.renderGraphics(this, canvasBuffer.context);

    return texture;
};

PIXI.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._generateCachedSprite();
            // we will also need to update the texture on the gpu too!
            PIXI.updateWebGLTexture(this._cachedSprite.texture.baseTexture, renderSession.gl);
            
            this.dirty =  false;
        }

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

        return;
    }
    else
    {
        renderSession.spriteBatch.stop();

        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)
        {
            this.spriteBatch.currentBlendMode = this.blendMode;
            var blendModeWebGL = PIXI.blendModesWebGL[renderSession.spriteBatch.currentBlendMode];
            this.spriteBatch.gl.blendFunc(blendModeWebGL[0], blendModeWebGL[1]);
        }
     
        PIXI.WebGLGraphics.renderGraphics(this, renderSession);
        
        if(this._filters)renderSession.filterManager.popFilter();
        if(this._mask)renderSession.maskManager.popMask(renderSession);
          
        renderSession.drawCount++;

        renderSession.spriteBatch.start();
    }
};

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

    context.setTransform(transform[0], transform[3], transform[1], transform[4], transform[2], transform[5]);
    PIXI.CanvasGraphics.renderGraphics(this, context);
};

PIXI.Graphics.prototype.getBounds = function()
{
    if(!this.bounds)this.updateBounds();

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

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

    var worldTransform = this.worldTransform;

    var a = worldTransform[0];
    var b = worldTransform[3];
    var c = worldTransform[1];
    var d = worldTransform[4];
    var tx = worldTransform[2];
    var ty = worldTransform[5];

    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 = -Infinity;
    var maxY = -Infinity;

    var minX = Infinity;
    var minY = Infinity;

    minX = x1 < minX ? x1 : minX;
    minX = x2 < minX ? x2 : minX;
    minX = x3 < minX ? x3 : minX;
    minX = x4 < minX ? x4 : minX;

    minY = y1 < minY ? y1 : minY;
    minY = y2 < minY ? y2 : minY;
    minY = y3 < minY ? y3 : minY;
    minY = y4 < minY ? y4 : minY;

    maxX = x1 > maxX ? x1 : maxX;
    maxX = x2 > maxX ? x2 : maxX;
    maxX = x3 > maxX ? x3 : maxX;
    maxX = x4 > maxX ? x4 : maxX;

    maxY = y1 > maxY ? y1 : maxY;
    maxY = y2 > maxY ? y2 : maxY;
    maxY = y3 > maxY ? y3 : maxY;
    maxY = y4 > maxY ? y4 : maxY;

    var bounds = this._bounds;

    bounds.x = minX;
    bounds.width = maxX - minX;

    bounds.y = minY;
    bounds.height = maxY - minY;

    return bounds;
};

PIXI.Graphics.prototype.updateBounds = function()
{
    
    var minX = Infinity;
    var maxX = -Infinity;

    var minY = Infinity;
    var maxY = -Infinity;

    var points, x, y;

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

        points = data.points;

        if(type === PIXI.Graphics.RECT)
        {
            x = points.x - lineWidth/2;
            y = points.y - lineWidth/2;
            var width = points.width + lineWidth;
            var height = points.height + lineWidth;

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

            minY = y < minY ? x : minY;
            maxY = y + height > maxY ? y + height : maxY;
        }
        else if(type === PIXI.Graphics.CIRC || type === PIXI.Graphics.ELIP)
        {
            x = points.x;
            y = points.y;
            var radius = points.radius + lineWidth/2;

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

            minY = y - radius < minY ? y - radius : minY;
            maxY = y + radius > maxY ? y + radius : maxY;
        }
        else
        {
            // POLY
            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;
            }
        }
    }

    var padding = this.boundsPadding;
    this.bounds = new PIXI.Rectangle(minX - padding, minY - padding, (maxX - minX) + padding * 2, (maxY - minY) + padding * 2);
};

PIXI.Graphics.prototype._generateCachedSprite = function()
{
    var bounds = this.getBounds();

    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 offest 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);
    
    PIXI.CanvasGraphics.renderGraphics(this, this._cachedSprite.buffer.context);
   // this._cachedSprite.buffer.context.restore();
};

PIXI.Graphics.prototype.destroyCachedSprite = function()
{
    this._cachedSprite.texture.destroy(true);

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


// SOME TYPES:
PIXI.Graphics.POLY = 0;
PIXI.Graphics.RECT = 1;
PIXI.Graphics.CIRC = 2;
PIXI.Graphics.ELIP = 3;