ColorUtil

/*
    CASA Lib for ActionScript 3.0
    Copyright (c) 2011, Aaron Clinger & Contributors of CASA Lib
    All rights reserved.
    
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      this list of conditions and the following disclaimer.
    
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      this list of conditions and the following disclaimer in the documentation
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    - Neither the name of the CASA Lib nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.
    
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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*/
package org.casalib.util {
    import flash.geom.ColorTransform;
    import org.casalib.math.Percent;
    import org.casalib.util.NumberUtil;
    
    /**
        Provides utility functions for dealing with color.
        
        @author Aaron Clinger
        @version 03/29/10
    */
    public class ColorUtil {
        
        /**
            Interpolates (tints) between two colors.
            
            @param begin: The start color.
            @param end: The finish color.
            @param amount: The level of interpolation between the two colors.
            @return The new interpolated color.
            @example
                
                    var myColor:ColorTransform = new ColorTransform();
                    myColor.color              = 0xFF0000;
                    
                    var box:Sprite = new Sprite();
                    box.graphics.beginFill(0x0000FF);
                    box.graphics.drawRect(10, 10, 250, 250);
                    box.graphics.endFill();
                    
                    box.transform.colorTransform = ColorUtil.interpolateColor(new ColorTransform(), myColor, new Percent(0.5));
                    
                    this.addChild(box);
                
        */
        public static function interpolateColor(begin:ColorTransform, end:ColorTransform, amount:Percent):ColorTransform {
            var interpolation:ColorTransform = new ColorTransform();
            
            interpolation.redMultiplier   = NumberUtil.interpolate(amount, begin.redMultiplier, end.redMultiplier);
            interpolation.greenMultiplier = NumberUtil.interpolate(amount, begin.greenMultiplier, end.greenMultiplier);
            interpolation.blueMultiplier  = NumberUtil.interpolate(amount, begin.blueMultiplier, end.blueMultiplier);
            interpolation.alphaMultiplier = NumberUtil.interpolate(amount, begin.alphaMultiplier, end.alphaMultiplier);
            interpolation.redOffset       = NumberUtil.interpolate(amount, begin.redOffset, end.redOffset);
            interpolation.greenOffset     = NumberUtil.interpolate(amount, begin.greenOffset, end.greenOffset);
            interpolation.blueOffset      = NumberUtil.interpolate(amount, begin.blueOffset, end.blueOffset);
            interpolation.alphaOffset     = NumberUtil.interpolate(amount, begin.alphaOffset, end.alphaOffset);
            
            return interpolation;
        }
        
        /**
            Converts a series of individual RGB(A) values to a 32-bit ARGB color value.
            
            @param r: A uint from 0 to 255 representing the red color value.
            @param g: A uint from 0 to 255 representing the green color value.
            @param b: A uint from 0 to 255 representing the blue color value.
            @param a: A uint from 0 to 255 representing the alpha value. Default is 255.
            @return Returns a hexidecimal color as a String.
            @example
                
                    var hexColor : String = ColorUtil.getHexStringFromARGB(128, 255, 0, 255);
                    trace(hexColor); // Traces 80FF00FF
                
        */
        public static function getColor(r : uint, g : uint, b : uint, a : uint = 255) : uint {
            return (a << 24) | (r << 16) | (g << 8) | b;
        }
        
        /**
            Converts a 32-bit ARGB color value into an ARGB object.
            
            @param color: The 32-bit ARGB color value.
            @return Returns an object with the properties a, r, g, and b defined.
            @example
                
                    var myRGB:Object = ColorUtil.getARGB(0xCCFF00FF);
                    trace("Alpha = " + myRGB.a);
                    trace("Red = " + myRGB.r);
                    trace("Green = " + myRGB.g);
                    trace("Blue = " + myRGB.b);
                
        */
        public static function getARGB(color : uint) : Object {
            var c : Object = {};
            c.a = color >> 24 & 0xFF;
            c.r = color >> 16 & 0xFF;
            c.g = color >> 8 & 0xFF;
            c.b = color & 0xFF;
            return c;
        }
        
        /**
            Converts a 24-bit RGB color value into an RGB object.
            
            @param color: The 24-bit RGB color value.
            @return Returns an object with the properties r, g, and b defined.
            @example
                
                    var myRGB:Object = ColorUtil.getRGB(0xFF00FF);
                    trace("Red = " + myRGB.r);
                    trace("Green = " + myRGB.g);
                    trace("Blue = " + myRGB.b);
                
        */
        public static function getRGB(color : uint) : Object {
            var c : Object = {};
            c.r = color >> 16 & 0xFF;
            c.g = color >> 8 & 0xFF;
            c.b = color & 0xFF;
            return c;
        }
        
        /**
            Converts a 32-bit ARGB color value into a hexidecimal String representation.
            
            @param a: A uint from 0 to 255 representing the alpha value.
            @param r: A uint from 0 to 255 representing the red color value.
            @param g: A uint from 0 to 255 representing the green color value.
            @param b: A uint from 0 to 255 representing the blue color value.
            @return Returns a hexidecimal color as a String.
            @example
                
                    var hexColor : String = ColorUtil.getHexStringFromARGB(128, 255, 0, 255);
                    trace(hexColor); // Traces 80FF00FF
                
        */
        public static function getHexStringFromARGB(a : uint, r : uint, g : uint, b : uint) : String {
            var aa : String = a.toString(16);
            var rr : String = r.toString(16);
            var gg : String = g.toString(16);
            var bb : String = b.toString(16);
            aa = (aa.length == 1) ? '0' + aa : aa;
            rr = (rr.length == 1) ? '0' + rr : rr;
            gg = (gg.length == 1) ? '0' + gg : gg;
            bb = (bb.length == 1) ? '0' + bb : bb;
            return (aa + rr + gg + bb).toUpperCase();
        }
        
        /**
            Converts an RGB color value into a hexidecimal String representation.
            
            @param r: A uint from 0 to 255 representing the red color value.
            @param g: A uint from 0 to 255 representing the green color value.
            @param b: A uint from 0 to 255 representing the blue color value.
            @return Returns a hexidecimal color as a String.
            @example
                
                    var hexColor : String = ColorUtil.getHexStringFromRGB(255, 0, 255);
                    trace(hexColor); // Traces FF00FF
                
        */
        public static function getHexStringFromRGB(r : uint, g : uint, b : uint) : String {
            var rr : String = r.toString(16);
            var gg : String = g.toString(16);
            var bb : String = b.toString(16);
            rr = (rr.length == 1) ? '0' + rr : rr;
            gg = (gg.length == 1) ? '0' + gg : gg;
            bb = (bb.length == 1) ? '0' + bb : bb;
            return (rr + gg + bb).toUpperCase();
        }
    }
}