root/as3/FLARToolKit/trunk/libs/Papervision3D/src/org/papervision3d/materials/utils/BumpmapGenerator.as

package org.papervision3d.materials.utils
{
        import flash.display.BitmapData;
        import flash.filters.ConvolutionFilter;
        import flash.geom.Point;

        public class BumpmapGenerator
        {
                public static function generateBumpmapFrom(bitmapData : BitmapData) : BitmapData
                {
                        var tempMap : BitmapData;
                        var p : Point = new Point();
                        var convolve : ConvolutionFilter = new ConvolutionFilter();
                        convolve.matrixX = 3;
                        convolve.matrixY = 3;
                        convolve.divisor = 1;
                        convolve.bias = 127;
                        
                        var outputData : BitmapData = new BitmapData(bitmapData.width, bitmapData.height, false, 0x000080);
                        
                        convolve.matrix = new Array(0, 0, 0, -1, 0, 1, 0, 0, 0);
                        tempMap = bitmapData.clone();
                        tempMap.applyFilter(bitmapData, tempMap.rect, p, convolve);
                        outputData.copyChannel(tempMap, tempMap.rect, p, 1, 1);
                        convolve.matrix = new Array(0, -1, 0, 0, 0, 0, 0, 1, 0);
                        tempMap = bitmapData.clone();
                        tempMap.applyFilter(bitmapData, tempMap.rect, p, convolve);
                        outputData.copyChannel(tempMap, tempMap.rect, p, 1, 2);
                
                        tempMap.dispose();
                        return outputData;
                }
        }
}