old-autovect-branch/libjava/classpath/java/awt/image/PackedColorModel.java

   1 /* Copyright (C) 2000, 2002, 2004  Free Software Foundation
   2
   3 This file is part of GNU Classpath.
   4
   5 GNU Classpath is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 GNU Classpath is distributed in the hope that it will be useful, but
  11 WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with GNU Classpath; see the file COPYING.  If not, write to the
  17 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18 02110-1301 USA.
  19
  20 Linking this library statically or dynamically with other modules is
  21 making a combined work based on this library.  Thus, the terms and
  22 conditions of the GNU General Public License cover the whole
  23 combination.
  24
  25 As a special exception, the copyright holders of this library give you
  26 permission to link this library with independent modules to produce an
  27 executable, regardless of the license terms of these independent
  28 modules, and to copy and distribute the resulting executable under
  29 terms of your choice, provided that you also meet, for each linked
  30 independent module, the terms and conditions of the license of that
  31 module.  An independent module is a module which is not derived from
  32 or based on this library.  If you modify this library, you may extend
  33 this exception to your version of the library, but you are not
  34 obligated to do so.  If you do not wish to do so, delete this
  35 exception statement from your version. */
  36
  37
  38 package java.awt.image;
  39
  40 import gnu.java.awt.BitMaskExtent;
  41
  42 import java.awt.Point;
  43 import java.awt.color.ColorSpace;
  44
  45 /**
  46  * @author Rolf W. Rasmussen (rolfwr@ii.uib.no)
  47  */
  48 public abstract class PackedColorModel extends ColorModel
  49 {
  50   private int masks[];
  51
  52   /* Package accessibility, the DirectColorModel needs this array */
  53   int shifts[];
  54
  55   public PackedColorModel(ColorSpace cspace, int pixelBits,
  56                           int[] colorMaskArray, int alphaMask,
  57                           boolean isAlphaPremultiplied,
  58                           int transparency,
  59                           int transferType)
  60   {
  61     super(pixelBits, calcBitsPerComponent(colorMaskArray, alphaMask),
  62           cspace, (alphaMask != 0), isAlphaPremultiplied, transparency,
  63           transferType);
  64     initMasks(colorMaskArray, alphaMask);
  65     if ((pixelBits<1) || (pixelBits>32)) {
  66       throw new IllegalArgumentException("pixels per bits must be " +
  67                                          "in the range [1, 32]");
  68     }
  69   }
  70
  71   private static int[] calcBitsPerComponent(int[] colorMaskArray,
  72                                             int alphaMask)
  73   {
  74     int numComponents = colorMaskArray.length;
  75     if (alphaMask != 0) numComponents++;
  76
  77     int[] bitsPerComponent = new int[numComponents];
  78
  79     BitMaskExtent extent = new BitMaskExtent();
  80     for (int b=0; b<colorMaskArray.length; b++)
  81       {
  82         extent.setMask(colorMaskArray[b]);
  83         bitsPerComponent[b] = extent.bitWidth;
  84       }
  85     if (alphaMask != 0)
  86       {
  87         extent.setMask(alphaMask);
  88         bitsPerComponent[numComponents-1] = extent.bitWidth;
  89       }
  90     return bitsPerComponent;
  91   }
  92
  93   /** Initializes the masks.  */
  94   private void initMasks(int[] colorMaskArray, int alphaMask)
  95   {
  96     int numComponents = colorMaskArray.length;
  97     if (alphaMask == 0)
  98       {
  99         masks = colorMaskArray;
 100       }
 101     else
 102       {
 103         masks = new int[numComponents+1];
 104         System.arraycopy(colorMaskArray, 0,
 105                          masks, 0,
 106                          numComponents);
 107         masks[numComponents++] = alphaMask;
 108       }
 109
 110     shifts = new int[numComponents];
 111
 112     // Bit field handling have been moved to a utility class
 113     BitMaskExtent extent = new BitMaskExtent();
 114     for (int b=0; b<numComponents; b++)
 115       {
 116         extent.setMask(masks[b]);
 117         shifts[b] = extent.leastSignificantBit;
 118       }
 119   }
 120
 121   public PackedColorModel(ColorSpace cspace, int pixelBits,
 122                           int rmask, int gmask, int bmask,
 123                           int amask, boolean isAlphaPremultiplied,
 124                           int transparency,
 125                           int transferType)
 126   {
 127     this(cspace, pixelBits, makeColorMaskArray(rmask, gmask, bmask),
 128          amask, isAlphaPremultiplied, transparency, transferType);
 129   }
 130
 131   /* TODO: If there is a alpha mask, it is inefficient to create a
 132      color mask array that will be discarded when the alpha mask is
 133      appended. We should probably create a private constructor that
 134      takes a complete array of masks (color+alpha) as an
 135      argument. */
 136
 137   private static int[] makeColorMaskArray(int rmask, int gmask, int bmask)
 138   {
 139     int[] colorMaskArray = { rmask, gmask, bmask };
 140     return colorMaskArray;
 141   }
 142
 143   public final int getMask(int index)
 144   {
 145     return masks[index];
 146   }
 147
 148   public final int[] getMasks()
 149   {
 150     return masks;
 151   }
 152
 153   public SampleModel createCompatibleSampleModel(int w, int h)
 154   {
 155     return new SinglePixelPackedSampleModel(transferType, w, h, masks);
 156   }
 157
 158   public boolean isCompatibleSampleModel(SampleModel sm)
 159   {
 160     if (!super.isCompatibleSampleModel(sm)) return false;
 161     if (!(sm instanceof SinglePixelPackedSampleModel)) return false;
 162
 163     SinglePixelPackedSampleModel sppsm =
 164       (SinglePixelPackedSampleModel) sm;
 165     return java.util.Arrays.equals(sppsm.getBitMasks(), masks);
 166   }
 167
 168   public WritableRaster getAlphaRaster(WritableRaster raster) {
 169     if (!hasAlpha()) return null;
 170
 171     SampleModel sm = raster.getSampleModel();
 172     int[] alphaBand = { sm.getNumBands() - 1 };
 173     SampleModel alphaModel = sm.createSubsetSampleModel(alphaBand);
 174     DataBuffer buffer = raster.getDataBuffer();
 175     Point origin = new Point(0, 0);
 176     return Raster.createWritableRaster(alphaModel, buffer, origin);
 177   }
 178
 179   public boolean equals(Object obj)
 180   {
 181     if (!super.equals(obj)) return false;
 182     if (!(obj instanceof PackedColorModel)) return false;
 183
 184     PackedColorModel other = (PackedColorModel) obj;
 185
 186     return java.util.Arrays.equals(masks, other.masks);
 187   }
 188 }