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pixi.js / src / pixi / renderers / WebGLRenderer.js
@Mat Groves Mat Groves on 20 Feb 2013 17 KB Documentation update
/**
 * @author Mat Groves http://matgroves.com/
 */

PIXI._defaultFrame = new PIXI.Rectangle(0,0,1,1);

/**
 * the WebGLRenderer is draws the stage and all its content onto a webGL enabled canvas. This renderer should be used for browsers support webGL. This Render works by automatically managing webGLBatchs. So no need for Sprite Batch's or Sprite Cloud's
 * Dont forget to add the view to your DOM or you will not see anything :)
 * @class WebGLRenderer
 * @param width {Number} the width of the canvas view
 * @default 0
 * @param height {Number} the height of the canvas view
 * @default 0
 */
PIXI.WebGLRenderer = function(width, height)
{
	this.width = width ? width : 800;
	this.height = height ? height : 600;
	
	this.view = document.createElement( 'canvas' ); 
    this.view.width = this.width;
	this.view.height = this.height;  
	this.view.background = "#FF0000";
	
	// deal with losing context..	
    var scope = this;
	this.view.addEventListener('webglcontextlost', function(event) { scope.handleContextLost(event); }, false)
	this.view.addEventListener('webglcontextrestored', function(event) { scope.handleContextRestored(event); }, false)

	this.batchs = [];
	
	try 
 	{
        this.gl = this.view.getContext("experimental-webgl",  {  	
    		 alpha: false
        });
    } 
    catch (e) 
    {
    	throw new Error(" This browser does not support webGL. Try using the canvas renderer" + this);
    }
    
    this.initShaders();
    
    
    var gl = this.gl;
    
    this.batch = new PIXI.WebGLBatch(gl);
   	gl.disable(gl.DEPTH_TEST);
    gl.enable(gl.BLEND);
    gl.colorMask(true, true, true, false); 
    
    this.projectionMatrix =  mat4.create();
    
    this.resize(this.width, this.height)
    this.contextLost = false;
}

// constructor
PIXI.WebGLRenderer.constructor = PIXI.WebGLRenderer;

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.initShaders = function() 
{
	var gl = this.gl;
	var fragmentShader = PIXI.CompileFragmentShader(gl, PIXI.shaderFragmentSrc);
	var vertexShader = PIXI.CompileVertexShader(gl, PIXI.shaderVertexSrc);
	
	this.shaderProgram = gl.createProgram();
	
	var shaderProgram = this.shaderProgram;
	
    gl.attachShader(shaderProgram, vertexShader);
    gl.attachShader(shaderProgram, fragmentShader);
    gl.linkProgram(shaderProgram);

    if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
        alert("Could not initialise shaders");
    }

    gl.useProgram(shaderProgram);

    shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
    gl.enableVertexAttribArray(shaderProgram.vertexPositionAttribute);

    shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
    gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);
	
	shaderProgram.colorAttribute = gl.getAttribLocation(shaderProgram, "aColor");
    gl.enableVertexAttribArray(shaderProgram.colorAttribute);


    shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
    shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
	
	PIXI.shaderProgram = this.shaderProgram;
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.checkVisibility = function(displayObject, globalVisible)
{
	var children = displayObject.children;
	
	
	for (var i=0; i < children.length; i++) 
	{
		var child = children[i];
		
		// TODO optimize... shouldt need to loop through everything all the time
		var actualVisibility = child.visible && globalVisible;
		
		// everything should have a batch!
		// time to see whats new!
		if(child.textureChange)
		{
			child.textureChange = false;
			if(actualVisibility)
			{
				this.removeDisplayObject(child)
				this.addDisplayObject(child)
			}
			// update texture!!
		}
		
		
		
		if(child.cacheVisible != actualVisibility)
		{
			child.cacheVisible = actualVisibility;
			
			if(child.cacheVisible)
			{
				this.addDisplayObject(child);
			}
			else
			{
				this.removeDisplayObject(child);
			}
		}
		
		if(child.children.length > 0)
		{
			this.checkVisibility(child, actualVisibility);
		}
		
		
	};
}


/**
 * Renders the stage to its webGL view
 * @method render
 * @param stage {Stage} the PIXI.Stage element to be rendered
 */
PIXI.WebGLRenderer.prototype.render = function(stage)
{
	if(this.contextLost)return;
	
	// update children if need be
	// best to remove first!
	for (var i=0; i < stage.__childrenRemoved.length; i++)
	{
		this.removeDisplayObject(stage.__childrenRemoved[i]);
	//	stage.__childrenRemoved[i].cacheVisible = false;
	}
	/*
	// no add all new sprites		
	for (var i=0; i < stage.__childrenAdded.length; i++) 
	{
		stage.__childrenAdded[i].cacheVisible = false;
//		this.addDisplayObject(stage.__childrenAdded[i]);
	}*/
	// update any textures	
	for (var i=0; i < PIXI.texturesToUpdate.length; i++) this.updateTexture(PIXI.texturesToUpdate[i]);
	
	// empty out the arrays
	stage.__childrenRemoved = [];
	stage.__childrenAdded = [];
	PIXI.texturesToUpdate = [];
	
	// recursivly loop through all items!
	this.checkVisibility(stage, true);
	
	// update the scen graph	
	stage.updateTransform();
	
	var gl = this.gl;
	
	gl.clear(gl.COLOR_BUFFER_BIT)

	gl.clearColor(0, 0, 0, 1.0);     
	
	// set the correct blend mode!
 	gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
    gl.uniformMatrix4fv(this.shaderProgram.mvMatrixUniform, false, this.projectionMatrix);
   
	// render all the batchs!	
	
	
	var renderable;
	for (var i=0; i < this.batchs.length; i++) 
	{
		renderable = this.batchs[i];
		if(renderable instanceof PIXI.WebGLBatch)
		{
			this.batchs[i].render();
		}
		else if(renderable instanceof PIXI.Strip)
		{
			if(renderable.visible)this.renderStrip(renderable);
		}
	}
	
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.updateTexture = function(texture)
{
	var gl = this.gl;
	
	if(!texture._glTexture)
	{
		texture._glTexture = gl.createTexture();
	}
	
	if(texture.hasLoaded)
	{
		gl.bindTexture(gl.TEXTURE_2D, texture._glTexture);
	 	gl.pixelStorei(gl.UNPACK_PREMULTIPLY_ALPHA_WEBGL, true);
		gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, texture.image);
		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
		gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);

	//	gl.generateMipmap(gl.TEXTURE_2D);
		gl.bindTexture(gl.TEXTURE_2D, null);
	}
	
	this.refreshBatchs = true;
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.addDisplayObject = function(displayObject)
{
	
	if(!displayObject.stage)return; // means it was removed 
	if(displayObject.__inWebGL)return; //means it is already in webgL
	
	//displayObject.cacheVisible = displayObject.visible;
	
	// TODO if objects parent is not visible then dont add to stage!!!!
	//if(!displayObject.visible)return;

	
	displayObject.batch = null;
	
	//displayObject.cacheVisible = true;
	if(!displayObject.renderable)return;

	// while looping below THE OBJECT MAY NOT HAVE BEEN ADDED
	displayObject.__inWebGL = true;

	/*
	 *  LOOK FOR THE PREVIOUS SPRITE
	 *  This part looks for the closest previous sprite that can go into a batch
	 *  It keeps going back until it finds a sprite or the stage
	 */
	var previousSprite = displayObject;
	do
	{
		if(previousSprite.childIndex == 0)
		{
			previousSprite = previousSprite.parent;
			
		}
		else
		{
			previousSprite = previousSprite.parent.children[previousSprite.childIndex-1];
			// what if the bloop has children???
			while(previousSprite.children.length != 0)
			{
				// keep diggin till we get to the last child
				previousSprite = previousSprite.children[previousSprite.children.length-1];
			}
		}
		
		if(previousSprite == displayObject.stage)break;
	}
	while(!previousSprite.renderable || !previousSprite.__inWebGL)
	//while(!(previousSprite instanceof PIXI.Sprite))

	/*
	 *  LOOK FOR THE NEXT SPRITE
	 *  This part looks for the closest next sprite that can go into a batch
	 *  it keeps looking until it finds a sprite or gets to the end of the display
	 *  scene graph
	 * 
	 *  These look a lot scarier than the actually are...
	 */
	var nextSprite = displayObject;
	do
	{
		// moving forward!
		// if it has no children.. 
		if(nextSprite.children.length == 0)
		{
			// go along to the parent..
			while(nextSprite.childIndex == nextSprite.parent.children.length-1)
			{
				nextSprite = nextSprite.parent;
				if(nextSprite == displayObject.stage)
				{
					nextSprite = null
					break;
				}
			}
			
			if(nextSprite)nextSprite = nextSprite.parent.children[nextSprite.childIndex+1];
			
		}
		else
		{
			nextSprite = nextSprite.children[0];
		}

		if(!nextSprite)break;
	}
	while(!nextSprite.renderable || !nextSprite.__inWebGL)
	
	/*
	 * so now we have the next renderable and the previous renderable
	 * 
	 */
	
	if(displayObject instanceof PIXI.Sprite)
	{
		var previousBatch
		var nextBatch
		
		if(previousSprite instanceof PIXI.Sprite)
		{
			previousBatch = previousSprite.batch;
			
			if(previousBatch)
			{
				if(previousBatch.texture == displayObject.texture.baseTexture && previousBatch.blendMode == displayObject.blendMode)
				{
					previousBatch.insertAfter(displayObject, previousSprite);
					return;
				}
			}
		}
		else
		{
			// TODO reword!
			previousBatch = previousSprite;
		}
	
		if(nextSprite)
		{
			if(nextSprite instanceof PIXI.Sprite)
			{
				nextBatch = nextSprite.batch;
			
				//batch may not exist if item was added to the display list but not to the webGL
				if(nextBatch)
				{
					if(nextBatch.texture == displayObject.texture.baseTexture && nextBatch.blendMode == displayObject.blendMode)
					{
						nextBatch.insertBefore(displayObject, nextSprite);
						return;
					}
					else
					{
						if(nextBatch == previousBatch)
						{
							// THERE IS A SPLIT IN THIS BATCH! //
							var splitBatch = previousBatch.split(nextSprite);
							// COOL!
							// add it back into the array	
							/*
							 * OOPS!
							 * seems the new sprite is in the middle of a batch
							 * lets split it.. 
							 */
							var batch = PIXI._getBatch(this.gl);

							var index = this.batchs.indexOf( previousBatch );
							batch.init(displayObject);
							this.batchs.splice(index+1, 0, batch, splitBatch);
							
							return;
						}
					}
				}
			}
			else
			{
				// TODO re-word!
				nextBatch = nextSprite;
			}
		}
		
		/*
		 * looks like it does not belong to any batch!
		 * but is also not intersecting one..
		 * time to create anew one!
		 */
		
		var batch = PIXI._getBatch(this.gl);
		batch.init(displayObject);

		if(previousBatch) // if this is invalid it means 
		{
			var index = this.batchs.indexOf( previousBatch );
			this.batchs.splice(index+1, 0, batch);
		}
		else
		{
			this.batchs.push(batch);
		}
	
	}
	else if(displayObject instanceof PIXI.Strip)
	{
		// add to a batch!!
		this.initStrip(displayObject);
		this.batchs.push(displayObject);
		
	}

	// if its somthing else... then custom codes!
	this.batchUpdate = true;
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.removeDisplayObject = function(displayObject)
{
	//if(displayObject.stage)return;
	displayObject.cacheVisible = false;//displayObject.visible;
	
	if(!displayObject.renderable)return;
	
	displayObject.__inWebGL = false;
		
	/*
	 * removing is a lot quicker..
	 * 
	 */
	var batchToRemove;
	
	if(displayObject instanceof PIXI.Sprite)
	{
		// should always have a batch!
		var batch = displayObject.batch;
		if(!batch)return; // this means the display list has been altered befre rendering
		
		batch.remove(displayObject);
		
		
		if(batch.size==0)
		{
			batchToRemove = batch
		}
	}
	else
	{
		batchToRemove = displayObject;
	}
	
	/*
	 * Looks like there is somthing that needs removing!
	 */
	if(batchToRemove)	
	{
		var index = this.batchs.indexOf( batchToRemove );
		if(index == -1)return;// this means it was added then removed before rendered
		
		// ok so.. check to see if you adjacent batchs should be joined.
		// TODO may optimise?
		if(index == 0 || index == this.batchs.length-1)
		{
			// wha - eva! just get of the empty batch!
			this.batchs.splice(index, 1);
			if(batchToRemove instanceof PIXI.WebGLBatch)PIXI._returnBatch(batchToRemove);
		
			return;
		}
		
		if(this.batchs[index-1] instanceof PIXI.WebGLBatch && this.batchs[index+1] instanceof PIXI.WebGLBatch)
		{
			if(this.batchs[index-1].texture == this.batchs[index+1].texture)
			{
				//console.log("MERGE")
				this.batchs[index-1].merge(this.batchs[index+1]);
				
				if(batchToRemove instanceof PIXI.WebGLBatch)PIXI._returnBatch(batchToRemove);
				PIXI._returnBatch(this.batchs[index+1]);
				this.batchs.splice(index, 2);
				return;
			}
		}
		
		
		this.batchs.splice(index, 1);
		if(batchToRemove instanceof PIXI.WebGLBatch)PIXI._returnBatch(batchToRemove);
	}
	
	
}

/**
 * resizes the webGL view to the specified width and height
 * @method resize
 * @param width {Number} the new width of the webGL view
 * @param height {Number} the new height of the webGL view
 */
PIXI.WebGLRenderer.prototype.resize = function(width, height)
{
	this.width = width;
	this.height = height;
	
	this.view.width = width;
	this.view.height = height;
	
	this.gl.viewport(0, 0, this.width, this.height);	

	mat4.identity(this.projectionMatrix);
	mat4.scale(this.projectionMatrix, [2/this.width, -2/this.height, 1]);
	mat4.translate(this.projectionMatrix, [-this.width/2, -this.height/2, 0]);	
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.initStrip = function(strip)
{
	// build the strip!
	var gl = this.gl;
	var shaderProgram = this.shaderProgram;
	
	strip._vertexBuffer = gl.createBuffer();
	strip._indexBuffer = gl.createBuffer();
	strip._uvBuffer = gl.createBuffer();
	strip._colorBuffer = gl.createBuffer();
	
	gl.bindBuffer(gl.ARRAY_BUFFER, strip._vertexBuffer);
	gl.bufferData(gl.ARRAY_BUFFER, strip.verticies, gl.DYNAMIC_DRAW);

	gl.bindBuffer(gl.ARRAY_BUFFER, strip._uvBuffer);
    gl.bufferData(gl.ARRAY_BUFFER,  strip.uvs, gl.STATIC_DRAW);

    gl.bindBuffer(gl.ARRAY_BUFFER, strip._colorBuffer);
	gl.bufferData(gl.ARRAY_BUFFER, strip.colors, gl.STATIC_DRAW);

	
    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, strip._indexBuffer);
    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, strip.indices, gl.STATIC_DRAW);
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.renderStrip = function(strip)
{
	var gl = this.gl;
	var shaderProgram = this.shaderProgram;
//	mat
	var mat4Real = mat3.toMat4(strip.worldTransform);
	mat4.transpose(mat4Real);
	
	mat4.multiply(this.projectionMatrix, mat4Real, mat4Real )

	gl.uniformMatrix4fv(this.shaderProgram.mvMatrixUniform, false, mat4Real);
  
	if(strip.blendMode == PIXI.blendModes.NORMAL)
	{
		gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
	}
	else
	{
		gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_COLOR);
	}
	
	if(!strip.dirty)
	{
		
		gl.bindBuffer(gl.ARRAY_BUFFER, strip._vertexBuffer);
		gl.bufferSubData(gl.ARRAY_BUFFER, 0, strip.verticies)
	    gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, 2, gl.FLOAT, false, 0, 0);
		
		// update the uvs
	   	gl.bindBuffer(gl.ARRAY_BUFFER, strip._uvBuffer);
	    gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, 2, gl.FLOAT, false, 0, 0);
			
	    gl.activeTexture(gl.TEXTURE0);
	    gl.bindTexture(gl.TEXTURE_2D, strip.texture.baseTexture._glTexture);
		
		gl.bindBuffer(gl.ARRAY_BUFFER, strip._colorBuffer);
	    gl.vertexAttribPointer(shaderProgram.colorAttribute, 1, gl.FLOAT, false, 0, 0);
		
		// dont need to upload!
	    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, strip._indexBuffer);
    
	
	}
	else
	{
		strip.dirty = false;
		gl.bindBuffer(gl.ARRAY_BUFFER, strip._vertexBuffer);
		gl.bufferData(gl.ARRAY_BUFFER, strip.verticies, gl.STATIC_DRAW)
	    gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, 2, gl.FLOAT, false, 0, 0);
		
		// update the uvs
	   	gl.bindBuffer(gl.ARRAY_BUFFER, strip._uvBuffer);
	   	gl.bufferData(gl.ARRAY_BUFFER, strip.uvs, gl.STATIC_DRAW)
	    gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, 2, gl.FLOAT, false, 0, 0);
			
	    gl.activeTexture(gl.TEXTURE0);
	    gl.bindTexture(gl.TEXTURE_2D, strip.texture.baseTexture._glTexture);
		
		gl.bindBuffer(gl.ARRAY_BUFFER, strip._colorBuffer);
		gl.bufferData(gl.ARRAY_BUFFER, strip.colors, gl.STATIC_DRAW)
	    gl.vertexAttribPointer(shaderProgram.colorAttribute, 1, gl.FLOAT, false, 0, 0);
		
		// dont need to upload!
	    gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, strip._indexBuffer);
	    gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, strip.indices, gl.STATIC_DRAW);
	    
	}
	
	gl.drawElements(gl.TRIANGLE_STRIP, strip.indices.length, gl.UNSIGNED_SHORT, 0);
    
    gl.uniformMatrix4fv(this.shaderProgram.mvMatrixUniform, false, this.projectionMatrix);
  
  //  console.log("!!!")
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.handleContextLost = function(event)
{
	event.preventDefault();
	this.contextLost = true;
}

/**
 * @private
 */
PIXI.WebGLRenderer.prototype.handleContextRestored = function(event)
{
	this.gl = this.view.getContext("experimental-webgl",  {  	
		alpha: true
    });
        
	this.initShaders();	
	
	for (var i=0; i < PIXI.TextureCache.length; i++) 
	{
		this.updateTexture(PIXI.TextureCache[i]);
	};
	
	for (var i=0; i <  this.batchs.length; i++) 
	{
		this.batchs[i].restoreLostContext(this.gl)//
		this.batchs[i].dirty = true;
	};
	
	PIXI._restoreBatchs(this.gl);
	
	this.contextLost = false;
}