libjava/java/awt/image/ReplicateScaleFilter.java

   1 /* ReplicateScaleFilter.java -- Java class for filtering images
   2    Copyright (C) 1999 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., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 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 import java.util.Hashtable;
  42
  43 /**
  44  * This filter should be used for fast scaling of images where the result
  45  * does not need to ensure straight lines are still straight, etc.  The
  46  * exact method is not defined by Sun but some sort of fast Box filter should
  47  * probably be correct.
  48  * <br>
  49  * Currently this filter does nothing and needs to be implemented.
  50  *
  51  * @author C. Brian Jones (cbj@gnu.org)
  52  */
  53 public class ReplicateScaleFilter extends ImageFilter
  54 {
  55     public ReplicateScaleFilter(int width, int height) {
  56         destHeight = height;
  57         destWidth = width;
  58     }
  59
  60     /**
  61      * The height of the destination image.
  62      */
  63     protected int destHeight;
  64
  65     /**
  66      * The width of the destination image.
  67      */
  68     protected int destWidth;
  69
  70     /**
  71      * The height of the source image.
  72      */
  73     protected int srcHeight;
  74
  75     /**
  76      * The width of the source image.
  77      */
  78     protected int srcWidth;
  79
  80     /**
  81      *
  82      */
  83     protected int srcrows[];
  84
  85     /**
  86      *
  87      */
  88     protected int srccols[];
  89
  90     /**
  91      *
  92      */
  93     protected Object outpixbuf;
  94
  95     /**
  96      * An <code>ImageProducer</code> indicates the size of the image
  97      * being produced using this method.  A filter can override this
  98      * method to intercept these calls from the producer in order to
  99      * change either the width or the height before in turn calling
 100      * the consumer's <code>setDimensions</code> method.
 101      *
 102      * @param width the width of the image
 103      * @param height the height of the image
 104      */
 105     public void setDimensions(int width, int height)
 106     {
 107         srcWidth = width;
 108         srcHeight = height;
 109
 110         /* If either destHeight or destWidth is < 0, the image should
 111            maintain its original aspect ratio.  When both are < 0,
 112            just maintain the original width and height. */
 113         if (destWidth < 0 && destHeight < 0)
 114         {
 115             destWidth = width;
 116             destHeight = height;
 117         }
 118         else if (destWidth < 0)
 119         {
 120             destWidth = (int) (width * ((double) destHeight / srcHeight));
 121         }
 122         else if (destHeight < 0)
 123         {
 124             destHeight = (int) (height * ((double) destWidth / srcWidth));
 125         }
 126
 127         consumer.setDimensions(destWidth, destHeight);
 128     }
 129
 130     /**
 131      * An <code>ImageProducer</code> can set a list of properties
 132      * associated with this image by using this method.
 133      *
 134      * @param props the list of properties associated with this image
 135      */
 136     public void setProperties(Hashtable props)
 137     {
 138         props.put("filters", "ReplicateScaleFilter");
 139         consumer.setProperties(props);
 140     }
 141
 142     /**
 143      * This function delivers a rectangle of pixels where any
 144      * pixel(m,n) is stored in the array as a <code>byte</code> at
 145      * index (n * scansize + m + offset).
 146      *
 147      * @param x the x coordinate of the rectangle
 148      * @param y the y coordinate of the rectangle
 149      * @param w the width of the rectangle
 150      * @param h the height of the rectangle
 151      * @param model the <code>ColorModel</code> used to translate the pixels
 152      * @param pixels the array of pixel values
 153      * @param offset the index of the first pixels in the <code>pixels</code> array
 154      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
 155      */
 156     public void setPixels(int x, int y, int w, int h,
 157            ColorModel model, byte[] pixels, int offset, int scansize)
 158     {
 159         double rx = ((double) srcWidth) / destWidth;
 160         double ry = ((double) srcHeight) / destHeight;
 161
 162         int destScansize = (int) Math.round(scansize / rx);
 163
 164         byte[] destPixels = replicatePixels(x, y, w, h,
 165                                            model, pixels, offset, scansize,
 166                                            rx, ry, destScansize);
 167
 168         consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry),
 169                            (int) Math.ceil(w/rx), (int) Math.ceil(h/ry),
 170                            model, destPixels, 0, destScansize);
 171     }
 172
 173     /**
 174      * This function delivers a rectangle of pixels where any
 175      * pixel(m,n) is stored in the array as an <code>int</code> at
 176      * index (n * scansize + m + offset).
 177      *
 178      * @param x the x coordinate of the rectangle
 179      * @param y the y coordinate of the rectangle
 180      * @param w the width of the rectangle
 181      * @param h the height of the rectangle
 182      * @param model the <code>ColorModel</code> used to translate the pixels
 183      * @param pixels the array of pixel values
 184      * @param offset the index of the first pixels in the <code>pixels</code> array
 185      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
 186      */
 187     public void setPixels(int x, int y, int w, int h,
 188            ColorModel model, int[] pixels, int offset, int scansize)
 189     {
 190         double rx = ((double) srcWidth) / destWidth;
 191         double ry = ((double) srcHeight) / destHeight;
 192
 193         int destScansize = (int) Math.round(scansize / rx);
 194
 195         int[] destPixels = replicatePixels(x, y, w, h,
 196                                            model, pixels, offset, scansize,
 197                                            rx, ry, destScansize);
 198
 199         consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry),
 200                            (int) Math.ceil(w/rx), (int) Math.ceil(h/ry),
 201                            model, destPixels, 0, destScansize);
 202     }
 203
 204     private byte[] replicatePixels(int srcx, int srcy, int srcw, int srch,
 205                                    ColorModel model, byte[] srcPixels,
 206                                    int srcOffset, int srcScansize,
 207                                    double rx, double ry, int destScansize)
 208     {
 209         byte[] destPixels =
 210           new byte[(int) Math.ceil(srcw/rx) * (int) Math.ceil(srch/ry)];
 211
 212         int a, b;
 213         for (int i = 0; i < destPixels.length; i++)
 214         {
 215             a = (int) ((int) ( ((double) i) / destScansize) * ry) * srcScansize;
 216             b = (int) ((i % destScansize) * rx);
 217             if ((a + b + srcOffset) < srcPixels.length)
 218                 destPixels[i] = srcPixels[a + b + srcOffset];
 219         }
 220
 221         return destPixels;
 222     }
 223
 224     private int[] replicatePixels(int srcx, int srcy, int srcw, int srch,
 225                                   ColorModel model, int[] srcPixels,
 226                                   int srcOffset, int srcScansize,
 227                                   double rx, double ry, int destScansize)
 228     {
 229         int[] destPixels =
 230           new int[(int) Math.ceil(srcw/rx) * (int) Math.ceil(srch/ry)];
 231
 232         int a, b;
 233         for (int i = 0; i < destPixels.length; i++)
 234         {
 235             a = (int) ((int) ( ((double) i) / destScansize) * ry) * srcScansize;
 236             b = (int) ((i % destScansize) * rx);
 237             if ((a + b + srcOffset) < srcPixels.length)
 238                 destPixels[i] = srcPixels[a + b + srcOffset];
 239         }
 240
 241         return destPixels;
 242     }
 243 }
 244