libjava/classpath/java/awt/image/RGBImageFilter.java

   1 /* RGBImageFilter.java -- Java class for filtering Pixels by RGB values
   2    Copyright (C) 1999, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19 02110-1301 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.awt.image;
  40
  41 /**
  42  * A filter designed to filter images in the default RGBColorModel regardless of
  43  * the ImageProducer's ColorModel.
  44  *
  45  * @author Mark Benvenuto (mcb54@columbia.edu)
  46  */
  47 public abstract class RGBImageFilter extends ImageFilter
  48 {
  49   protected ColorModel origmodel;
  50
  51   protected ColorModel newmodel;
  52
  53   /**
  54    * Specifies whether to apply the filter to the index entries of the
  55    * IndexColorModel. Subclasses should set this to true if the filter
  56    * does not depend on the pixel's coordinate.
  57    */
  58   protected boolean canFilterIndexColorModel = false;
  59
  60   /**
  61    * Construct new RGBImageFilter.
  62    */
  63   public RGBImageFilter()
  64   {
  65   }
  66
  67   /**
  68    * Sets the ColorModel used to filter with. If the specified ColorModel is
  69    * IndexColorModel and canFilterIndexColorModel is true, we subsitute the
  70    * ColorModel for a filtered one here and in setPixels whenever the original
  71    * one appears. Otherwise overrides the default ColorModel of ImageProducer
  72    * and specifies the default RGBColorModel
  73    *
  74    * @param model the color model to be used most often by setPixels
  75    *
  76    * @see ColorModel
  77    */
  78   public void setColorModel(ColorModel model)
  79   {
  80     if ((model instanceof IndexColorModel) && canFilterIndexColorModel)
  81       {
  82         ColorModel newCM = filterIndexColorModel((IndexColorModel) model);
  83         substituteColorModel(model, newCM);
  84         consumer.setColorModel(newmodel);
  85       }
  86     else
  87       {
  88         consumer.setColorModel(ColorModel.getRGBdefault());
  89       }
  90   }
  91
  92   /**
  93    * Registers a new ColorModel to subsitute for the old ColorModel when
  94    * setPixels encounters the a pixel with the old ColorModel. The pixel
  95    * remains unchanged except for a new ColorModel.
  96    *
  97    * @param oldcm the old ColorModel
  98    * @param newcm the new ColorModel
  99    */
 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 }