package com.zehfernando.display {
	import flash.display.MovieClip;
	import flash.events.Event;
	import flash.filters.ColorMatrixFilter;	

	/**
	 * @author Zeh Fernando
	 */
	public class DesignerMovieClip extends MovieClip {

		// Sources:
		//
		// http://www.graficaobscura.com/matrix/index.html
		//
		// And specially Mario Klingemann's ColorMatrix class 2.1:
		// http://www.quasimondo.com/archives/000565.php
		// http://www.quasimondo.com/colormatrix/ColorMatrix.as
		// http://www.quasimondo.com
		// His code is licensed under MIT license:
		// http://www.opensource.org/licenses/mit-license.php
		

		// Static constants -------------------------------------------------------------------
		
		// Defines luminance using sRGB luminance
		protected static const LUMINANCE_R:Number = 0.212671;
		protected static const LUMINANCE_G:Number = 0.715160;
		protected static const LUMINANCE_B:Number = 0.072169;

		// Instance properties ----------------------------------------------------------------
		
		protected var setToUpdate:Boolean;		// Whether this instance is already set to update on the next Event.RENDER
		
		// Color properties interface
		protected var _saturation:Number;		// Saturation: 0 (grayscale) -> 1 (normal, default) -> 2+ (highly saturated)
		protected var _contrast:Number;			// Contrast: 0 (grey) -> 1 (normal) -> 2 (high contrast) 
		protected var _brightness:Number;		// Brightness offset: -1 (black) -> 0 (normal) -> 1 (full white) 
		protected var _exposure:Number;			// Brightness multiplier: 0 (black) -> 1 (normal) -> 2 (super bright)
		protected var _hue:Number;				// Hue offset in degrees: -180 -> 0 (normal) -> 180 
		
		// Matrices
		protected var saturationMatrix:Array;
		protected var contrastMatrix:Array;
		protected var brightnessMatrix:Array;
		protected var exposureMatrix:Array;
		protected var hueMatrix:Array;
		
		// Overridden properties
		protected var _filters:Array;

		// ================================================================================================================
		// CONSTRUCTOR ----------------------------------------------------------------------------------------------------

		public function DesignerMovieClip() {
			super();
			setToUpdate = false;
			filters = [];
			saturation = 1;
			contrast = 1;
			brightness = 0;
			exposure = 1;
			hue = 0;
		}

		// ================================================================================================================
		// INTERNAL INSTANCE functions ------------------------------------------------------------------------------------

		protected function updateSaturationMatrix(): void {
			// Create the pre-calculated saturation matrix
			
			var nc:Number = 1-_saturation;
			var nr:Number = LUMINANCE_R * nc;
			var ng:Number = LUMINANCE_G * nc;
			var nb:Number = LUMINANCE_B * nc;

			saturationMatrix = [
				nr+_saturation,	ng,				nb,				0,	0,
				nr,				ng+_saturation,	nb,				0,	0,
				nr,				ng,				nb+_saturation,	0,	0,
				0,  			0, 				0,  			1,  0
			];
			
			requestVisualUpdate();
		}

		protected function updateContrastMatrix(): void {
			// Create the pre-calculated contrast matrix
			
			var co:Number = 128 * (1-_contrast);
			
			contrastMatrix = [
				_contrast,	0,	0, 	0, 	co,
				0,	_contrast,	0, 	0, 	co,
				0,	0,	_contrast, 	0, 	co,
				0,	0,	0, 	1, 	0
			];
			
			requestVisualUpdate();
		}

		protected function updateBrightnessMatrix(): void {
			// Create the pre-calculated brightness matrix
			
			var co:Number = 255 * _brightness;
			
			brightnessMatrix = [
				1,	0,	0, 	0, 	co,
				0,	1,	0, 	0, 	co,
				0,	0,	1, 	0, 	co,
				0,	0,	0, 	1, 	0
			];
			
			requestVisualUpdate();
		}

		protected function updateExposureMatrix(): void {
			// Create the pre-calculated exposture matrix
			
			exposureMatrix = [
				_exposure,	0,	0, 	0, 	0,
				0,	_exposure,	0, 	0, 	0,
				0,	0,	_exposure, 	0, 	0,
				0,	0,	0, 	1, 	0
			];
			
			requestVisualUpdate();
		}

		protected function updateHueMatrix(): void {
			// Create the pre-calculated hue matrix
			
			var hAngle:Number = _hue / 180 * Math.PI;
			var hCos:Number = Math.cos(hAngle);
			var hSin:Number = Math.sin(hAngle);
			
			hueMatrix = [
				((LUMINANCE_R + (hCos * (1 - LUMINANCE_R))) + (hSin * -(LUMINANCE_R))), ((LUMINANCE_G + (hCos * -(LUMINANCE_G))) + (hSin * -(LUMINANCE_G))), ((LUMINANCE_B + (hCos * -(LUMINANCE_B))) + (hSin * (1 - LUMINANCE_B))), 0, 0, 
				((LUMINANCE_R + (hCos * -(LUMINANCE_R))) + (hSin * 0.143)), ((LUMINANCE_G + (hCos * (1 - LUMINANCE_G))) + (hSin * 0.14)), ((LUMINANCE_B + (hCos * -(LUMINANCE_B))) + (hSin * -0.283)), 0, 0, 
				((LUMINANCE_R + (hCos * -(LUMINANCE_R))) + (hSin * -((1 - LUMINANCE_R)))), ((LUMINANCE_G + (hCos * -(LUMINANCE_G))) + (hSin * LUMINANCE_G)), ((LUMINANCE_B + (hCos * (1 - LUMINANCE_B))) + (hSin * LUMINANCE_B)), 0, 0, 
				0, 0, 0, 1, 0
           	];
			
			requestVisualUpdate();
		}
		
		protected function requestVisualUpdate(): void {
			if (Boolean(stage) && !setToUpdate) {
				setToUpdate = true;
				stage.addEventListener(Event.RENDER, onRender, false, 0, true);
				stage.invalidate();
			}
		}
		
		protected function doVisualUpdate(): void {
		 	// Create empty maytix
		 	var mtx:Array = [
		 		1,0,0,0,0,
				0,1,0,0,0,
				0,0,1,0,0,
				0,0,0,1,0
			];
			var temp:Array = [];

		 	// Precalculate a single matrix from all matrices by multiplication
		 	// The order the final matrix is calculated can change the way it looks
		 	var matrices:Array = [saturationMatrix, contrastMatrix, brightnessMatrix, exposureMatrix, hueMatrix];
		 	
		 	var i:int, j:int, mat:Array;
			var x:int, y:int;
			
			for (j = 0; j < matrices.length; j++) {
				i = 0;
				mat = matrices[j];
				for (y = 0; y < 4; y++ ) {
					
					for (x = 0; x < 5; x++ ) {
						temp[ int( i + x) ] =  Number(mat[i  ])      * Number(mtx[x]) + 
									   		   Number(mat[int(i+1)]) * Number(mtx[int(x +  5)]) + 
									   		   Number(mat[int(i+2)]) * Number(mtx[int(x + 10)]) + 
									   		   Number(mat[int(i+3)]) * Number(mtx[int(x + 15)]) +
									   		   (x == 4 ? Number(mat[int(i+4)]) : 0);
					}
					i+=5;
				}
				mtx = temp;
			}
			
			// Update object filters
			var newFilters:Array = [new ColorMatrixFilter(mtx)];
			super.filters = newFilters.concat(_filters);
		}
		
		// ================================================================================================================
		// EVENT functions ------------------------------------------------------------------------------------------------

		protected function onRender(e:Event): void {
			stage.removeEventListener(Event.RENDER, onRender);
			setToUpdate = false;
			
			doVisualUpdate();
		}

		// ================================================================================================================
		// ACCESSOR functions ---------------------------------------------------------------------------------------------

		public function get saturation(): Number {
			return _saturation;
		}
		public function set saturation(__value:Number): void {
			_saturation = __value;
			updateSaturationMatrix();
		}

		public function get contrast(): Number {
			return _contrast;
		}
		public function set contrast(__value:Number): void {
			_contrast = __value;
			updateContrastMatrix();
		}

		public function get brightness(): Number {
			return _brightness;
		}
		public function set brightness(__value:Number): void {
			_brightness = __value;
			updateBrightnessMatrix();
		}

		public function get exposure(): Number {
			return _exposure;
		}
		public function set exposure(__value:Number): void {
			_exposure = __value;
			updateExposureMatrix();
		}

		public function get hue(): Number {
			return _hue;
		}
		public function set hue(__value:Number): void {
			_hue = __value;
			updateHueMatrix();
		}

		override public function get filters(): Array {
			return _filters;
		}
		override public function set filters(__value:Array): void {
			_filters = __value;
			requestVisualUpdate();
		}
	}
}