module BABYLON {
    export class LensRenderingPipeline extends PostProcessRenderPipeline {

    	// Lens effects can be of the following:
    	// - chromatic aberration (slight shift of RGB colors)
    	// - blur on the edge of the lens
    	// - lens distortion
    	// - depth-of-field 'bokeh' effect (shapes appearing in blured areas, stronger highlights)
    	// - grain/dust-on-lens effect

    	// Two additional texture samplers are needed:
    	// - depth map (for depth-of-field)
    	// - grain texture

        /**
        * The chromatic aberration PostProcess id in the pipeline
        * @type {string}
        */
        public LensChromaticAberrationEffect: string = "LensChromaticAberrationEffect";
        /**
        * The depth-of-field PostProcess id in the pipeline
        * @type {string}
        */
        public LensDepthOfFieldEffect: string = "LensDepthOfFieldEffect";

        private _scene: Scene;
        private _depthTexture: RenderTargetTexture;
        private _grainTexture: Texture;

        private _chromaticAberrationPostProcess: PostProcess;
        private _depthOfFieldPostProcess: PostProcess;

        private _edgeBlur: number;
        private _grainAmount: number;
        private _chromaticAberration: number;
        private _distortion: number;
        private _highlightsGain: number;
        private _highlightsThreshold: number;
        private _dofDepth: number;
        private _dofAperture: number;
        private _dofPentagon: boolean;
        private _blurNoise: boolean;

        /**
         * @constructor
         * @param {string} name - The rendering pipeline name
         * @param {object} parameters - An object containing all parameters (see below)
         * @param {BABYLON.Scene} scene - The scene linked to this pipeline
         * @param {number} ratio - The size of the postprocesses (0.5 means that your postprocess will have a width = canvas.width 0.5 and a height = canvas.height 0.5)
         * @param {BABYLON.Camera[]} cameras - The array of cameras that the rendering pipeline will be attached to

         	Effect parameters are as follow:
		 	{
				chromatic_aberration: number;		// from 0 to x (1 for realism)
				edge_blur: number;					// from 0 to x (1 for realism)
				distortion: number;					// from 0 to x (1 for realism)
				grain_amount: number;				// from 0 to 1
				grain_texture: BABYLON.Texture;		// texture to use for grain effect; if unset, use random B&W noise
				dof_focus_depth: number;			// depth-of-field: focus depth; unset to disable
				dof_aperture: number;				// depth-of-field: focus blur bias (default: 1)
				dof_pentagon: boolean;				// depth-of-field: makes a pentagon-like "bokeh" effect
				dof_gain: boolean;					// depth-of-field: depthOfField gain (default: 1)
				dof_threshold: boolean;				// depth-of-field: depthOfField threshold (default: 1)
				blur_noise: boolean;				// add a little bit of noise to the blur (default: true)
			}

			Note: if an effect parameter is unset, effect is disabled
         */
        constructor(name: string, parameters: any, scene: Scene, ratio: number = 1.0, cameras?: Camera[]) {
			super(scene.getEngine(), name);

			this._scene = scene;

			// Fetch texture samplers
			this._depthTexture = scene.enableDepthRenderer().getDepthMap(); // Force depth renderer "on"
			if(parameters.grain_texture) { this._grainTexture = parameters.grain_texture; }
			else { this._createGrainTexture(); }

			// save parameters
			this._edgeBlur = parameters.edge_blur ? parameters.edge_blur : 0;
			this._grainAmount = parameters.grain_amount ? parameters.grain_amount : 0;
			this._chromaticAberration = parameters.chromatic_aberration ? parameters.chromatic_aberration : 0;
			this._distortion = parameters.distortion ? parameters.distortion : 0;
			this._highlightsGain = parameters.dof_gain ? parameters.dof_gain : 1;
			this._highlightsThreshold = parameters.dof_threshold ? parameters.dof_threshold : 1;
			this._dofDepth = parameters.dof_focus_depth !== undefined ? parameters.dof_focus_depth : -1;
			this._dofAperture = parameters.dof_aperture ? parameters.dof_aperture : 1;
			this._dofPentagon = parameters.dof_pentagon !== undefined ? parameters.dof_pentagon : true;
			this._blurNoise = parameters.blur_noise !== undefined ? parameters.blur_noise : true;

			// Create effects
            this._createChromaticAberrationPostProcess(ratio);
            this._createDepthOfFieldPostProcess(ratio);

            // Set up pipeline
            this.addEffect(new PostProcessRenderEffect(scene.getEngine(), this.LensChromaticAberrationEffect, () => { return this._chromaticAberrationPostProcess; }, true));
            this.addEffect(new PostProcessRenderEffect(scene.getEngine(), this.LensDepthOfFieldEffect, () => { return this._depthOfFieldPostProcess; }, true));

            // Finish
            scene.postProcessRenderPipelineManager.addPipeline(this);
            if(cameras) {
                scene.postProcessRenderPipelineManager.attachCamerasToRenderPipeline(name, cameras);
            }
        }

        // public methods
        public setEdgeBlur(amount: number) { this._edgeBlur = amount; }
        public disableEdgeBlur() { this._edgeBlur = 0; }
        public setGrainAmount(amount: number) { this._grainAmount = amount; }
        public disableGrain() { this._grainAmount = 0; }
        public setChromaticAberration(amount: number) { this._chromaticAberration = amount; }
        public disableChromaticAberration() { this._chromaticAberration = 0; }
        public setEdgeDistortion(amount: number) { this._distortion = amount; }
        public disableEdgeDistortion() { this._distortion = 0; }
        public setHighlightsGain(amount: number) { this._highlightsGain = amount; }
        public setHighlightsThreshold(amount: number) { this._highlightsThreshold = amount; }
        public setFocusDepth(amount: number) { this._dofDepth = amount; }
        public disableDepthOfField() { this._dofDepth = -1; }
        public setAperture(amount: number) { this._dofAperture = amount; }
        public enablePentagonBokeh() { this._dofPentagon = true; }
        public disablePentagonBokeh() { this._dofPentagon = false; }
        public enableNoiseBlur() { this._blurNoise = true; }
        public disableNoiseBlur() { this._blurNoise = false; }

        /**
         * Removes the internal pipeline assets and detaches the pipeline from the scene cameras
         */
        public dispose(disableDepthRender: boolean = false): void {
            this._scene.postProcessRenderPipelineManager.detachCamerasFromRenderPipeline(this._name, this._scene.cameras);

            // this._originalColorPostProcess = undefined;
            this._chromaticAberrationPostProcess = undefined;
            this._depthOfFieldPostProcess = undefined;

            this._grainTexture.dispose();

            if (disableDepthRender)
                this._scene.disableDepthRenderer();
        }

        // colors shifting and distortion
        private _createChromaticAberrationPostProcess(ratio: number): void {
            this._chromaticAberrationPostProcess = new PostProcess("LensChromaticAberration", "./chromaticAberration",
            	["chromatic_aberration", "screen_width", "screen_height"],		// uniforms
            	[],											// samplers
                ratio, null, Texture.TRILINEAR_SAMPLINGMODE,
                this._scene.getEngine(), false);

            this._chromaticAberrationPostProcess.onApply = (effect: Effect) => {
            	effect.setFloat('chromatic_aberration', this._chromaticAberration);
                effect.setFloat('screen_width', this._scene.getEngine().getRenderWidth());
                effect.setFloat('screen_height', this._scene.getEngine().getRenderHeight());
            };
        }

        // colors shifting and distortion
        private _createDepthOfFieldPostProcess(ratio: number): void {
            this._depthOfFieldPostProcess = new PostProcess("LensDepthOfField", "./depthOfField",
            	[
            		"gain", "threshold", "focus_depth", "aperture", "pentagon", "maxZ", "edge_blur",
            		"chromatic_aberration", "distortion", "blur_noise", "grain_amount", "screen_width", "screen_height"
            	],
            	["depthSampler", "grainSampler"],
                ratio, null, Texture.TRILINEAR_SAMPLINGMODE,
                this._scene.getEngine(), false);

            this._depthOfFieldPostProcess.onApply = (effect: Effect) => {
	            effect.setBool('pentagon', this._dofPentagon);
            	effect.setBool('blur_noise', this._blurNoise);
            	effect.setFloat('maxZ', this._scene.activeCamera.maxZ);
            	effect.setFloat('grain_amount', this._grainAmount);

            	effect.setTexture("depthSampler", this._depthTexture);
            	effect.setTexture("grainSampler", this._grainTexture);

            	effect.setFloat('screen_width', this._scene.getEngine().getRenderWidth());
            	effect.setFloat('screen_height', this._scene.getEngine().getRenderHeight());

            	effect.setFloat('distortion', this._distortion);

	            effect.setFloat('focus_depth', this._dofDepth);
	            effect.setFloat('aperture', this._dofAperture);
            	effect.setFloat('gain', this._highlightsGain);
            	effect.setFloat('threshold', this._highlightsThreshold);

            	effect.setFloat('edge_blur', this._edgeBlur);
            };
        }

        // creates a black and white random noise texture, 512x512
        private _createGrainTexture(): void {
            var size = 512;

            this._grainTexture = new DynamicTexture("LensNoiseTexture", size, this._scene, false, Texture.BILINEAR_SAMPLINGMODE);
            this._grainTexture.wrapU = Texture.WRAP_ADDRESSMODE;
            this._grainTexture.wrapV = Texture.WRAP_ADDRESSMODE;

            var context = (<DynamicTexture>this._grainTexture).getContext();

            var rand = (min, max) => {
                return Math.random() * (max - min) + min;
            }

            var value;
            for (var x = 0; x < size; x++) {
                for (var y = 0; y < size; y++) {
                    value = Math.floor(rand(0.42,0.58)*255);
                    context.fillStyle = 'rgb(' + value + ', ' + value + ', ' + value + ')';
                    context.fillRect(x, y, 1, 1);
                }
            }
            (<DynamicTexture>this._grainTexture).update(false);
        }

    }
}