Source for java.awt.image.ReplicateScaleFilter

   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., 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: 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: }