Babylon.js/Layer/babylon.layer.js

var BABYLON = BABYLON || {};

(function () {
    BABYLON.Layer = function (name, imgUrl, scene, isBackground) {
        this.name = name;
        this.texture = imgUrl ? new BABYLON.Texture(imgUrl, scene, true) : null;
        this.isBackground = isBackground === undefined ? true : isBackground;

        this._scene = scene;
        this._scene.layers.push(this);
        
        // VBO
        var vertices = [];
        vertices.push(1, 1);
        vertices.push(-1, 1);
        vertices.push(-1, -1);
        vertices.push(1, -1);
        this._vertexDeclaration = [2];
        this._vertexStrideSize = 2 * 4;
        this._vertexBuffer = scene.getEngine().createVertexBuffer(vertices);

        // Indices
        var indices = [];
        indices.push(0);
        indices.push(1);
        indices.push(2);

        indices.push(0);
        indices.push(2);
        indices.push(3);

        this._indexBuffer = scene.getEngine().createIndexBuffer(indices);
        
        // Effects
        this._effect = this._scene.getEngine().createEffect("layer",
                    ["position"],
                    ["textureMatrix"],
                    ["textureSampler"], "");
    };

    // Members
    BABYLON.Layer.prototype.onDispose = null;

    // Methods
    BABYLON.Layer.prototype.render = function () {
        // Check
        if (!this._effect.isReady() || !this.texture || !this.texture.isReady())
            return 0;

        var engine = this._scene.getEngine();
       
        // Render
        engine.enableEffect(this._effect);

        // Texture
        this._effect.setTexture("textureSampler", this.texture);
        this._effect.setMatrix("textureMatrix", this.texture._computeTextureMatrix());

        // VBOs
        engine.bindBuffers(this._vertexBuffer, this._indexBuffer, this._vertexDeclaration, this._vertexStrideSize, this._effect);

        // Draw order
        engine.setAlphaMode(BABYLON.Engine.ALPHA_COMBINE);
        engine.draw(true, 0, 6);
        engine.setAlphaMode(BABYLON.Engine.ALPHA_DISABLE);
    };
    
    BABYLON.Layer.prototype.dispose = function () {
        if (this._vertexBuffer) {
            //this._scene.getEngine()._releaseBuffer(this._vertexBuffer);
            this._vertexBuffer = null;
        }

        if (this._indexBuffer) {
            this._scene.getEngine()._releaseBuffer(this._indexBuffer);
            this._indexBuffer = null;
        }

        if (this.texture) {
            this.texture.dispose();
            this.texture = null;
        }

        // Remove from scene
        var index = this._scene.layers.indexOf(this);
        this._scene.layers.splice(index, 1);
        
        // Callback
        if (this.onDispose) {
            this.onDispose();
        }
    };
    
})();