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

/**
 * the CanvasRenderer is draws the stage and all its content onto a 2d canvas. This renderer should be used for browsers that do not support webGL.
 * Dont forget to add the view to your DOM or you will not see anything :)
 * @class CanvasRenderer
 * @param width {Number} the width of the canvas view
 * @param height {Number} the height of the canvas view
 */
PIXI.CanvasRenderer = function(width, height)
{
	/**
	 * The width of the canvas view
	 * @property width
	 * @type Number
	 * @default 800
	 */
	this.width = width ? width : 800;
	/**
	 * The height of the canvas view
	 * @property height
	 * @type Number
	 * @default 600
	 */
	this.height = height ? height : 600;
	
	this.refresh = true;
	
	/**
	 * The canvas element that the everything is drawn to
	 * @property view
	 * @type Canvas
	 */
	this.view = document.createElement( 'canvas' ); 
	
    this.view.width = this.width;
	this.view.height = this.height;  
	this.view.background = "#FF0000";
	this.count = 0;
	
	/**
	 * The canvas context that the everything is drawn to
	 * @property context
	 * @type Canvas 2d Context
	 */
	this.context = this.view.getContext("2d");
}

// constructor
PIXI.CanvasRenderer.constructor = PIXI.CanvasRenderer;

/**
 * Renders the stage to its canvas view
 * @method render
 * @param stage {Stage} the Stage element to be rendered
 */
PIXI.CanvasRenderer.prototype.render = function(stage)
{
	// update children if need be
	
	stage.__childrenAdded = [];
	stage.__childrenRemoved = [];
	
	// update textures if need be
	PIXI.texturesToUpdate = [];
	
	
	this.context.setTransform(1,0,0,1,0,0); 
	stage.updateTransform();
	  
	this.context.setTransform(1,0,0,1,0,0); 
	this.context.clearRect(0, 0, this.width, this.height)
    this.renderDisplayObject(stage);
}

/**
 * resizes the canvas view to the specified width and height
 * @param the new width of the canvas view
 * @param the new height of the canvas view
 */
PIXI.CanvasRenderer.prototype.resize = function(width, height)
{
	this.width = width;
	this.height = height;
	
	this.view.width = width;
	this.view.height = height;
}

/**
 * @private
 */
PIXI.CanvasRenderer.prototype.renderDisplayObject = function(displayObject)
{
	var transform = displayObject.worldTransform;
	var context = this.context;
	context.globalCompositeOperation = "source-over"
	var blit = false;
	
	if(!displayObject.visible)return;
		
	if(displayObject instanceof PIXI.Sprite)
	{
		var frame = displayObject.texture.frame;
		
		if(frame)
		{
			context.globalAlpha = displayObject.worldAlpha;
			
			// BLITZ!!!
			/*
			 * if the rotation is 0 then we can blitz it
			 * meaning we dont need to do a transform and also we
			 * can round to the nearest round number for a little extra speed!
			 */
			if(displayObject.rotation == 0)
			{
				if(!blit)this.context.setTransform(1,0,0,1,0,0); 
				blit = true;
				context.drawImage(displayObject.texture.baseTexture.image, 
								   frame.x,
								   frame.y,
								   frame.width,
								   frame.height,
								   (transform[2]+ ((displayObject.anchor.x - displayObject.texture.trim.x) * -frame.width) * transform[0]),
								   (transform[5]+ ((displayObject.anchor.y - displayObject.texture.trim.y) * -frame.height)* transform[4]),
								   (displayObject.width * transform[0]),
								   (displayObject.height * transform[4]));
				
			}	
			else
			{
				blit = false;
				context.setTransform(transform[0], transform[3], transform[1], transform[4], transform[2], transform[5])
				context.drawImage(displayObject.texture.baseTexture.image, 
								   frame.x,
								   frame.y,
								   frame.width,
								   frame.height,
								   (displayObject.anchor.x - displayObject.texture.trim.x) * -frame.width, 
								   (displayObject.anchor.y - displayObject.texture.trim.y) * -frame.height,
								   displayObject.width,
								   displayObject.height);
			}
		}					   
   	}
   	else if(displayObject instanceof PIXI.Strip)
	{
		context.setTransform(transform[0], transform[3], transform[1], transform[4], transform[2], transform[5])
		this.renderStrip(displayObject);
	}
	
	// render!
	for (var i=0; i < displayObject.children.length; i++) 
	{
		this.renderDisplayObject(displayObject.children[i]);
	}
}

/**
 * @private
 */
PIXI.CanvasRenderer.prototype.renderStripFlat = function(strip)
{
	var context = this.context;
	var verticies = strip.verticies;
	var uvs = strip.uvs;
	
	var length = verticies.length/2;
	this.count++;
	
	context.beginPath();
	for (var i=1; i < length-2; i++) 
	{
		
		// draw some triangles!
		var index = i*2;
		
		 var x0 = verticies[index],   x1 = verticies[index+2], x2 = verticies[index+4];
 		 var y0 = verticies[index+1], y1 = verticies[index+3], y2 = verticies[index+5];
 		 
		context.moveTo(x0, y0);
		context.lineTo(x1, y1);
		context.lineTo(x2, y2);
		
	};	
	
//	context.globalCompositeOperation = 'lighter';
	context.fillStyle = "#FF0000";
	context.fill();
	context.closePath();
	//context.globalCompositeOperation = 'source-over';	
}

/**
 * @private
 */
PIXI.CanvasRenderer.prototype.renderStrip = function(strip)
{
	var context = this.context;
	//context.globalCompositeOperation = 'lighter';
	// draw triangles!!
	var verticies = strip.verticies;
	var uvs = strip.uvs;
	
	var length = verticies.length/2;
	this.count++;
	for (var i=1; i < length-2; i++) 
	{
		
		// draw some triangles!
		var index = i*2;
		
		 var x0 = verticies[index],   x1 = verticies[index+2], x2 = verticies[index+4];
 		 var y0 = verticies[index+1], y1 = verticies[index+3], y2 = verticies[index+5];
 		 
  		 var u0 = uvs[index] * strip.texture.width,   u1 = uvs[index+2]* strip.texture.width, u2 = uvs[index+4]* strip.texture.width;
   		 var v0 = uvs[index+1]* strip.texture.height, v1 = uvs[index+3]* strip.texture.height, v2 = uvs[index+5]* strip.texture.height;


		context.save();
		context.beginPath();
		context.moveTo(x0, y0);
		context.lineTo(x1, y1);
		context.lineTo(x2, y2);
		context.closePath();
		
	//	context.fillStyle = "white"//rgb(1, 1, 1,1));
	//	context.fill();
		context.clip();
		
		
        // Compute matrix transform
        var delta = u0*v1 + v0*u2 + u1*v2 - v1*u2 - v0*u1 - u0*v2;
        var delta_a = x0*v1 + v0*x2 + x1*v2 - v1*x2 - v0*x1 - x0*v2;
        var delta_b = u0*x1 + x0*u2 + u1*x2 - x1*u2 - x0*u1 - u0*x2;
        var delta_c = u0*v1*x2 + v0*x1*u2 + x0*u1*v2 - x0*v1*u2 - v0*u1*x2 - u0*x1*v2;
        var delta_d = y0*v1 + v0*y2 + y1*v2 - v1*y2 - v0*y1 - y0*v2;
        var delta_e = u0*y1 + y0*u2 + u1*y2 - y1*u2 - y0*u1 - u0*y2;
        var delta_f = u0*v1*y2 + v0*y1*u2 + y0*u1*v2 - y0*v1*u2 - v0*u1*y2 - u0*y1*v2;
		
		
		
		    
        context.transform(delta_a/delta, delta_d/delta,
                      delta_b/delta, delta_e/delta,
                      delta_c/delta, delta_f/delta);
                 
		context.drawImage(strip.texture.baseTexture.image, 0, 0);
	  	context.restore();
	};
	
//	context.globalCompositeOperation = 'source-over';	
}