001/* RGBImageFilter.java -- Java class for filtering Pixels by RGB values 002 Copyright (C) 1999, 2005 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.awt.image; 040 041/** 042 * A filter designed to filter images in the default RGBColorModel regardless of 043 * the ImageProducer's ColorModel. 044 * 045 * @author Mark Benvenuto (mcb54@columbia.edu) 046 */ 047public abstract class RGBImageFilter extends ImageFilter 048{ 049 protected ColorModel origmodel; 050 051 protected ColorModel newmodel; 052 053 /** 054 * Specifies whether to apply the filter to the index entries of the 055 * IndexColorModel. Subclasses should set this to true if the filter 056 * does not depend on the pixel's coordinate. 057 */ 058 protected boolean canFilterIndexColorModel = false; 059 060 /** 061 * Construct new RGBImageFilter. 062 */ 063 public RGBImageFilter() 064 { 065 } 066 067 /** 068 * Sets the ColorModel used to filter with. If the specified ColorModel is 069 * IndexColorModel and canFilterIndexColorModel is true, we subsitute the 070 * ColorModel for a filtered one here and in setPixels whenever the original 071 * one appears. Otherwise overrides the default ColorModel of ImageProducer 072 * and specifies the default RGBColorModel 073 * 074 * @param model the color model to be used most often by setPixels 075 * 076 * @see ColorModel 077 */ 078 public void setColorModel(ColorModel model) 079 { 080 if ((model instanceof IndexColorModel) && canFilterIndexColorModel) 081 { 082 ColorModel newCM = filterIndexColorModel((IndexColorModel) model); 083 substituteColorModel(model, newCM); 084 consumer.setColorModel(newmodel); 085 } 086 else 087 { 088 consumer.setColorModel(ColorModel.getRGBdefault()); 089 } 090 } 091 092 /** 093 * Registers a new ColorModel to subsitute for the old ColorModel when 094 * setPixels encounters the a pixel with the old ColorModel. The pixel 095 * remains unchanged except for a new ColorModel. 096 * 097 * @param oldcm the old ColorModel 098 * @param newcm the new ColorModel 099 */ 100 public void substituteColorModel(ColorModel oldcm, ColorModel newcm) 101 { 102 origmodel = oldcm; 103 newmodel = newcm; 104 } 105 106 /** 107 * Filters an IndexColorModel through the filterRGB function. Uses 108 * coordinates of -1 to indicate its filtering an index and not a pixel. 109 * 110 * @param icm an IndexColorModel to filter 111 */ 112 public IndexColorModel filterIndexColorModel(IndexColorModel icm) 113 { 114 int len = icm.getMapSize(); 115 byte[] reds = new byte[len]; 116 byte[] greens = new byte[len]; 117 byte[] blues = new byte[len]; 118 byte[] alphas = new byte[len]; 119 120 icm.getAlphas( alphas ); 121 icm.getReds( reds ); 122 icm.getGreens( greens ); 123 icm.getBlues( blues ); 124 125 int transparent = icm.getTransparentPixel(); 126 boolean needAlpha = false; 127 for( int i = 0; i < len; i++ ) 128 { 129 int rgb = filterRGB(-1, -1, icm.getRGB(i)); 130 alphas[i] = (byte) (rgb >> 24); 131 if (alphas[i] != ((byte) 0xff) && i != transparent) 132 needAlpha = true; 133 reds[i] = (byte) (rgb >> 16); 134 greens[i] = (byte) (rgb >> 8); 135 blues[i] = (byte) (rgb); 136 } 137 IndexColorModel newIcm; 138 if (needAlpha) 139 newIcm = new IndexColorModel(icm.getPixelSize(), len, reds, greens, 140 blues, alphas); 141 else 142 newIcm = new IndexColorModel(icm.getPixelSize(), len, reds, greens, 143 blues, transparent); 144 return newIcm; 145 } 146 147 /** 148 * This functions filters a set of RGB pixels through filterRGB. 149 * 150 * @param x the x coordinate of the rectangle 151 * @param y the y coordinate of the rectangle 152 * @param w the width of the rectangle 153 * @param h the height of the rectangle 154 * @param pixels the array of pixel values 155 * @param offset the index of the first pixels in the 156 * <code>pixels</code> array 157 * @param scansize the width to use in extracting pixels from the 158 * <code>pixels</code> array 159 */ 160 public void filterRGBPixels(int x, int y, int w, int h, int[] pixels, 161 int offset, int scansize) 162 { 163 int index = offset; 164 for (int yp = 0; yp < h; yp++) 165 { 166 for (int xp = 0; xp < w; xp++) 167 { 168 pixels[index] = filterRGB(xp + x, yp + y, pixels[index]); 169 index++; 170 } 171 index += scansize - w; 172 } 173 consumer.setPixels(x, y, w, h, ColorModel.getRGBdefault(), pixels, offset, 174 scansize); 175 } 176 177 /** 178 * If the ColorModel is the same ColorModel which as already converted 179 * then it converts it the converted ColorModel. Otherwise it passes the 180 * array of pixels through filterRGBpixels. 181 * 182 * @param x the x coordinate of the rectangle 183 * @param y the y coordinate of the rectangle 184 * @param w the width of the rectangle 185 * @param h the height of the rectangle 186 * @param model the <code>ColorModel</code> used to translate the pixels 187 * @param pixels the array of pixel values 188 * @param offset the index of the first pixels in the <code>pixels</code> 189 * array 190 * @param scansize the width to use in extracting pixels from the 191 * <code>pixels</code> array 192 */ 193 public void setPixels(int x, int y, int w, int h, ColorModel model, 194 byte[] pixels, int offset, int scansize) 195 { 196 if (model == origmodel) 197 { 198 consumer.setPixels(x, y, w, h, newmodel, pixels, offset, scansize); 199 } 200 else 201 { 202 int[] filtered = new int[w]; 203 int index = offset; 204 for (int yp = 0; yp < h; yp++) 205 { 206 for (int xp = 0; xp < w; xp++) 207 { 208 filtered[xp] = model.getRGB((pixels[index] & 0xff)); 209 index++; 210 } 211 index += scansize - w; 212 filterRGBPixels(x, y + yp, w, 1, filtered, 0, w); 213 } 214 } 215 } 216 217 /** 218 * This function delivers a rectangle of pixels where any 219 * pixel(m,n) is stored in the array as an <code>int</code> at 220 * index (n * scansize + m + offset). 221 * 222 * @param x the x coordinate of the rectangle 223 * @param y the y coordinate of the rectangle 224 * @param w the width of the rectangle 225 * @param h the height of the rectangle 226 * @param model the <code>ColorModel</code> used to translate the pixels 227 * @param pixels the array of pixel values 228 * @param offset the index of the first pixels in the <code>pixels</code> 229 * array 230 * @param scansize the width to use in extracting pixels from the 231 * <code>pixels</code> array 232 */ 233 public void setPixels(int x, int y, int w, int h, ColorModel model, 234 int[] pixels, int offset, int scansize) 235 { 236 if (model == origmodel) 237 { 238 consumer.setPixels(x, y, w, h, newmodel, pixels, offset, scansize); 239 } 240 else 241 { 242 int[] filtered = new int[w]; 243 int index = offset; 244 for (int yp = 0; yp < h; yp++) 245 { 246 for (int xp = 0; xp < w; xp++) 247 { 248 filtered[xp] = model.getRGB((pixels[index])); 249 index++; 250 } 251 index += scansize - w; 252 filterRGBPixels(x, y + yp, w, 1, filtered, 0, w); 253 } 254 } 255 } 256 257 /** 258 * Filters a single pixel from the default ColorModel. 259 * 260 * @param x x-coordinate 261 * @param y y-coordinate 262 * @param rgb color 263 */ 264 public abstract int filterRGB(int x, int y, int rgb); 265}