001/* Copyright (C) 2000, 2002, 2004  Free Software Foundation
002
003This file is part of GNU Classpath.
004
005GNU Classpath is free software; you can redistribute it and/or modify
006it under the terms of the GNU General Public License as published by
007the Free Software Foundation; either version 2, or (at your option)
008any later version.
009
010GNU Classpath is distributed in the hope that it will be useful, but
011WITHOUT ANY WARRANTY; without even the implied warranty of
012MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013General Public License for more details.
014
015You should have received a copy of the GNU General Public License
016along with GNU Classpath; see the file COPYING.  If not, write to the
017Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
01802110-1301 USA.
019
020Linking this library statically or dynamically with other modules is
021making a combined work based on this library.  Thus, the terms and
022conditions of the GNU General Public License cover the whole
023combination.
024
025As a special exception, the copyright holders of this library give you
026permission to link this library with independent modules to produce an
027executable, regardless of the license terms of these independent
028modules, and to copy and distribute the resulting executable under
029terms of your choice, provided that you also meet, for each linked
030independent module, the terms and conditions of the license of that
031module.  An independent module is a module which is not derived from
032or based on this library.  If you modify this library, you may extend
033this exception to your version of the library, but you are not
034obligated to do so.  If you do not wish to do so, delete this
035exception statement from your version. */
036
037
038package java.awt.image;
039
040import gnu.java.awt.BitMaskExtent;
041
042import java.awt.Point;
043import java.awt.color.ColorSpace;
044
045/**
046 * @author Rolf W. Rasmussen (rolfwr@ii.uib.no)
047 */
048public abstract class PackedColorModel extends ColorModel
049{
050  private int masks[];
051
052  /* Package accessibility, the DirectColorModel needs this array */
053  int shifts[];
054
055  public PackedColorModel(ColorSpace cspace, int pixelBits,
056                          int[] colorMaskArray, int alphaMask,
057                          boolean isAlphaPremultiplied,
058                          int transparency,
059                          int transferType)
060  {
061    super(pixelBits, calcBitsPerComponent(colorMaskArray, alphaMask),
062          cspace, (alphaMask != 0), isAlphaPremultiplied, transparency,
063          transferType);
064    initMasks(colorMaskArray, alphaMask);
065    if ((pixelBits<1) || (pixelBits>32)) {
066      throw new IllegalArgumentException("pixels per bits must be " +
067                                         "in the range [1, 32]");
068    }
069  }
070
071  private static int[] calcBitsPerComponent(int[] colorMaskArray,
072                                            int alphaMask)
073  {
074    int numComponents = colorMaskArray.length;
075    if (alphaMask != 0) numComponents++;
076
077    int[] bitsPerComponent = new int[numComponents];
078
079    BitMaskExtent extent = new BitMaskExtent();
080    for (int b=0; b<colorMaskArray.length; b++)
081      {
082        extent.setMask(colorMaskArray[b]);
083        bitsPerComponent[b] = extent.bitWidth;
084      }
085    if (alphaMask != 0)
086      {
087        extent.setMask(alphaMask);
088        bitsPerComponent[numComponents-1] = extent.bitWidth;
089      }
090    return bitsPerComponent;
091  }
092
093  /** Initializes the masks.  */
094  private void initMasks(int[] colorMaskArray, int alphaMask)
095  {
096    int numComponents = colorMaskArray.length;
097    if (alphaMask == 0)
098      {
099        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}