libjava/classpath/java/awt/image/RescaleOp.java

   1 /* Copyright (C) 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 java.awt.RenderingHints;
  41 import java.awt.geom.Point2D;
  42 import java.awt.geom.Rectangle2D;
  43 import java.util.Arrays;
  44
  45 /**
  46  * @author Jerry Quinn (jlquinn@optonline.net)
  47  */
  48 public class RescaleOp implements BufferedImageOp, RasterOp
  49 {
  50   private float[] scale;
  51   private float[] offsets;
  52   private RenderingHints hints = null;
  53
  54   public RescaleOp(float[] scaleFactors,
  55                    float[] offsets,
  56                    RenderingHints hints)
  57   {
  58     this.scale = scaleFactors;
  59     this.offsets = offsets;
  60     this.hints = hints;
  61   }
  62
  63   public RescaleOp(float scaleFactor,
  64                    float offset,
  65                    RenderingHints hints)
  66   {
  67     scale = new float[]{ scaleFactor };
  68     offsets = new float[]{offset};
  69     this.hints = hints;
  70   }
  71
  72   public final float[] getScaleFactors(float[] scaleFactors)
  73   {
  74     if (scaleFactors == null)
  75       scaleFactors = new float[scale.length];
  76     System.arraycopy(scale, 0, scaleFactors, 0, scale.length);
  77     return scaleFactors;
  78   }
  79
  80   public final float[] getOffsets(float[] offsets)
  81   {
  82     if (offsets == null)
  83       offsets = new float[this.offsets.length];
  84     System.arraycopy(this.offsets, 0, offsets, 0, this.offsets.length);
  85     return offsets;
  86   }
  87
  88   public final int getNumFactors()
  89   {
  90     return scale.length;
  91   }
  92
  93   /* (non-Javadoc)
  94    * @see java.awt.image.BufferedImageOp#getRenderingHints()
  95    */
  96   public final RenderingHints getRenderingHints()
  97   {
  98     return hints;
  99   }
 100
 101   /* (non-Javadoc)
 102    * @see java.awt.image.BufferedImageOp#filter(java.awt.image.BufferedImage, java.awt.image.BufferedImage)
 103    */
 104   public final BufferedImage filter(BufferedImage src, BufferedImage dst)
 105   {
 106     // TODO Make sure premultiplied alpha is handled correctly.
 107     // TODO See that color conversion is handled.
 108     // TODO figure out how to use rendering hints.
 109     if (scale.length != offsets.length)
 110       throw new IllegalArgumentException();
 111
 112     ColorModel scm = src.getColorModel();
 113     if (dst == null) dst = createCompatibleDestImage(src, null);
 114
 115     WritableRaster wsrc = src.getRaster();
 116     WritableRaster wdst = dst.getRaster();
 117
 118     // Share constant across colors except alpha
 119     if (scale.length == 1 || scale.length == scm.getNumColorComponents())
 120       {
 121         // Construct a raster that doesn't include an alpha band.
 122         int[] subbands = new int[scm.getNumColorComponents()];
 123         for (int i=0; i < subbands.length; i++) subbands[i] = i;
 124         wsrc =
 125           wsrc.createWritableChild(wsrc.minX, wsrc.minY, wsrc.width, wsrc.height,
 126                                    wsrc.minX, wsrc.minY, subbands);
 127       }
 128     // else all color bands
 129
 130     filter(wsrc, wdst);
 131     return dst;
 132   }
 133
 134   /* (non-Javadoc)
 135    * @see java.awt.image.RasterOp#filter(java.awt.image.Raster, java.awt.image.WritableRaster)
 136    */
 137   public final WritableRaster filter(Raster src, WritableRaster dest)
 138   {
 139     if (dest == null) dest = src.createCompatibleWritableRaster();
 140
 141     // Required sanity checks
 142     if (src.numBands != dest.numBands || scale.length != offsets.length)
 143       throw new IllegalArgumentException();
 144     if (scale.length != 1 && scale.length != src.numBands)
 145       throw new IllegalArgumentException();
 146
 147     // Create scaling arrays if needed
 148     float[] lscale = scale;
 149     float[] loff = offsets;
 150     if (scale.length == 1)
 151       {
 152         lscale = new float[src.numBands];
 153         Arrays.fill(lscale, scale[0]);
 154         loff = new float[src.numBands];
 155         Arrays.fill(loff, offsets[0]);
 156       }
 157
 158     // TODO The efficiency here can be improved for various data storage
 159     // patterns, aka SampleModels.
 160     float[] pixel = new float[src.numBands];
 161     for (int y = src.minY; y < src.height + src.minY; y++)
 162       for (int x = src.minX; x < src.width + src.minX; x++)
 163         {
 164           src.getPixel(x, y, pixel);
 165           for (int b = 0; b < src.numBands; b++)
 166             pixel[b] = pixel[b] * lscale[b] + loff[b];
 167           dest.setPixel(x, y, pixel);
 168         }
 169     return dest;
 170   }
 171
 172   /* (non-Javadoc)
 173    * @see java.awt.image.BufferedImageOp#createCompatibleDestImage(java.awt.image.BufferedImage, java.awt.image.ColorModel)
 174    */
 175   public BufferedImage createCompatibleDestImage(BufferedImage src,
 176                                                  ColorModel dstCM)
 177   {
 178     if (dstCM == null) dstCM = src.getColorModel();
 179     WritableRaster wr = src.getRaster().createCompatibleWritableRaster();
 180     BufferedImage image
 181       = new BufferedImage(dstCM, wr, src.isPremultiplied, null);
 182     return image;
 183   }
 184
 185   /* (non-Javadoc)
 186    * @see java.awt.image.RasterOp#createCompatibleDestRaster(java.awt.image.Raster)
 187    */
 188   public WritableRaster createCompatibleDestRaster(Raster src)
 189   {
 190     return src.createCompatibleWritableRaster();
 191   }
 192
 193   /* (non-Javadoc)
 194    * @see java.awt.image.BufferedImageOp#getBounds2D(java.awt.image.BufferedImage)
 195    */
 196   public final Rectangle2D getBounds2D(BufferedImage src)
 197   {
 198     return src.getRaster().getBounds();
 199   }
 200
 201   /* (non-Javadoc)
 202    * @see java.awt.image.RasterOp#getBounds2D(java.awt.image.Raster)
 203    */
 204   public final Rectangle2D getBounds2D(Raster src)
 205   {
 206     return src.getBounds();
 207   }
 208
 209   /* (non-Javadoc)
 210    * @see java.awt.image.BufferedImageOp#getPoint2D(java.awt.geom.Point2D, java.awt.geom.Point2D)
 211    */
 212   public final Point2D getPoint2D(Point2D src, Point2D dst) {
 213     if (dst == null) dst = (Point2D) src.clone();
 214     else dst.setLocation(src);
 215     return dst;
 216   }
 217
 218 }