module BABYLON {
    export class SpriteManager {
        public sprites = new Array<Sprite>();
        public renderingGroupId = 0;
        public layerMask: number = 0x0FFFFFFF;
        public onDispose: () => void;
        public fogEnabled = true;

        private _capacity: number;
        private _spriteTexture: Texture;
        private _epsilon: number;

        private _scene: Scene;

        private _vertexDeclaration = [4, 4, 4, 4];
        private _vertexStrideSize = 16 * 4; // 15 floats per sprite (x, y, z, angle, sizeX, sizeY, offsetX, offsetY, invertU, invertV, cellIndexX, cellIndexY, color)
        private _vertexBuffer: WebGLBuffer;
        private _indexBuffer: WebGLBuffer;
        private _vertices: Float32Array;
        private _effectBase: Effect;
        private _effectFog: Effect;

        constructor(public name: string, imgUrl: string, capacity: number, public cellSize: number, scene: Scene, epsilon?: number, samplingMode: number = Texture.TRILINEAR_SAMPLINGMODE) {
            this._capacity = capacity;
            this._spriteTexture = new Texture(imgUrl, scene, true, false, samplingMode);
            this._spriteTexture.wrapU = Texture.CLAMP_ADDRESSMODE;
            this._spriteTexture.wrapV = Texture.CLAMP_ADDRESSMODE;

            this._epsilon = epsilon === undefined ? 0.01 : epsilon;

            this._scene = scene;
            this._scene.spriteManagers.push(this);

            // VBO
            this._vertexBuffer = scene.getEngine().createDynamicVertexBuffer(capacity * this._vertexStrideSize * 4);

            var indices = [];
            var index = 0;
            for (var count = 0; count < capacity; count++) {
                indices.push(index);
                indices.push(index + 1);
                indices.push(index + 2);
                indices.push(index);
                indices.push(index + 2);
                indices.push(index + 3);
                index += 4;
            }

            this._indexBuffer = scene.getEngine().createIndexBuffer(indices);
            this._vertices = new Float32Array(capacity * this._vertexStrideSize);

            // Effects
            this._effectBase = this._scene.getEngine().createEffect("sprites",
                ["position", "options", "cellInfo", "color"],
                ["view", "projection", "textureInfos", "alphaTest"],
                ["diffuseSampler"], "");

            this._effectFog = this._scene.getEngine().createEffect("sprites",
                ["position", "options", "cellInfo", "color"],
                ["view", "projection", "textureInfos", "alphaTest", "vFogInfos", "vFogColor"],
                ["diffuseSampler"], "#define FOG");
        }

        private _appendSpriteVertex(index: number, sprite: Sprite, offsetX: number, offsetY: number, rowSize: number): void {
            var arrayOffset = index * 16;

            if (offsetX === 0)
                offsetX = this._epsilon;
            else if (offsetX === 1)
                offsetX = 1 - this._epsilon;

            if (offsetY === 0)
                offsetY = this._epsilon;
            else if (offsetY === 1)
                offsetY = 1 - this._epsilon;

            this._vertices[arrayOffset] = sprite.position.x;
            this._vertices[arrayOffset + 1] = sprite.position.y;
            this._vertices[arrayOffset + 2] = sprite.position.z;
            this._vertices[arrayOffset + 3] = sprite.angle;
            this._vertices[arrayOffset + 4] = sprite.width;
            this._vertices[arrayOffset + 5] = sprite.height;
            this._vertices[arrayOffset + 6] = offsetX;
            this._vertices[arrayOffset + 7] = offsetY;
            this._vertices[arrayOffset + 8] = sprite.invertU ? 1 : 0;
            this._vertices[arrayOffset + 9] = sprite.invertV ? 1 : 0;
            var offset = (sprite.cellIndex / rowSize) >> 0;
            this._vertices[arrayOffset + 10] = sprite.cellIndex - offset * rowSize;
            this._vertices[arrayOffset + 11] = offset;
            // Color
            this._vertices[arrayOffset + 12] = sprite.color.r;
            this._vertices[arrayOffset + 13] = sprite.color.g;
            this._vertices[arrayOffset + 14] = sprite.color.b;
            this._vertices[arrayOffset + 15] = sprite.color.a;
        }

        public render(): void {
            // Check
            if (!this._effectBase.isReady() || !this._effectFog.isReady() || !this._spriteTexture || !this._spriteTexture.isReady())
                return;

            var engine = this._scene.getEngine();
            var baseSize = this._spriteTexture.getBaseSize();

            // Sprites
            var deltaTime = engine.getDeltaTime();
            var max = Math.min(this._capacity, this.sprites.length);
            var rowSize = baseSize.width / this.cellSize;

            var offset = 0;
            for (var index = 0; index < max; index++) {
                var sprite = this.sprites[index];
                if (!sprite) {
                    continue;
                }

                sprite._animate(deltaTime);

                this._appendSpriteVertex(offset++, sprite, 0, 0, rowSize);
                this._appendSpriteVertex(offset++, sprite, 1, 0, rowSize);
                this._appendSpriteVertex(offset++, sprite, 1, 1, rowSize);
                this._appendSpriteVertex(offset++, sprite, 0, 1, rowSize);
            }
            engine.updateDynamicVertexBuffer(this._vertexBuffer, this._vertices);

            // Render
            var effect = this._effectBase;

            if (this._scene.fogEnabled && this._scene.fogMode !== Scene.FOGMODE_NONE && this.fogEnabled) {
                effect = this._effectFog;
            }

            engine.enableEffect(effect);

            var viewMatrix = this._scene.getViewMatrix();
            effect.setTexture("diffuseSampler", this._spriteTexture);
            effect.setMatrix("view", viewMatrix);
            effect.setMatrix("projection", this._scene.getProjectionMatrix());

            effect.setFloat2("textureInfos", this.cellSize / baseSize.width, this.cellSize / baseSize.height);

            // Fog
            if (this._scene.fogEnabled && this._scene.fogMode !== Scene.FOGMODE_NONE && this.fogEnabled) {
                effect.setFloat4("vFogInfos", this._scene.fogMode, this._scene.fogStart, this._scene.fogEnd, this._scene.fogDensity);
                effect.setColor3("vFogColor", this._scene.fogColor);
            }

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

            // Draw order
            engine.setDepthFunctionToLessOrEqual();
            effect.setBool("alphaTest", true);
            engine.setColorWrite(false);
            engine.draw(true, 0, max * 6);
            engine.setColorWrite(true);
            effect.setBool("alphaTest", false);

            engine.setAlphaMode(Engine.ALPHA_COMBINE);
            engine.draw(true, 0, max * 6);
            engine.setAlphaMode(Engine.ALPHA_DISABLE);
        }

        public dispose(): void {
            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._spriteTexture) {
                this._spriteTexture.dispose();
                this._spriteTexture = null;
            }

            // Remove from scene
            var index = this._scene.spriteManagers.indexOf(this);
            this._scene.spriteManagers.splice(index, 1);

            // Callback
            if (this.onDispose) {
                this.onDispose();
            }
        }
    }
}