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:  *
  50:  * @author C. Brian Jones (cbj@gnu.org) 
  51:  */
  52: public class ReplicateScaleFilter extends ImageFilter
  53: {
  54:     public ReplicateScaleFilter(int width, int height) {
  55:     destHeight = height;
  56:     destWidth = width;
  57:     }
  58: 
  59:     /**
  60:      * The height of the destination image.
  61:      */
  62:     protected int destHeight;
  63: 
  64:     /**
  65:      * The width of the destination image.
  66:      */
  67:     protected int destWidth;
  68: 
  69:     /**
  70:      * The height of the source image.
  71:      */
  72:     protected int srcHeight;
  73: 
  74:     /**
  75:      * The width of the source image.
  76:      */
  77:     protected int srcWidth;
  78: 
  79:     /**
  80:      *
  81:      */
  82:     protected int srcrows[];
  83: 
  84:     /**
  85:      *
  86:      */
  87:     protected int srccols[];
  88: 
  89:     /**
  90:      *
  91:      */
  92:     protected Object outpixbuf;
  93: 
  94:     /**
  95:      * An <code>ImageProducer</code> indicates the size of the image
  96:      * being produced using this method.  A filter can override this 
  97:      * method to intercept these calls from the producer in order to
  98:      * change either the width or the height before in turn calling
  99:      * the consumer's <code>setDimensions</code> method.
 100:      * 
 101:      * @param width the width of the image
 102:      * @param height the height of the image 
 103:      */
 104:     public void setDimensions(int width, int height)
 105:     {
 106:     srcWidth = width;
 107:     srcHeight = height;
 108: 
 109:     /* If either destHeight or destWidth is < 0, the image should
 110:        maintain its original aspect ratio.  When both are < 0,
 111:        just maintain the original width and height. */
 112:     if (destWidth < 0 && destHeight < 0)
 113:         {
 114:         destWidth = width;
 115:         destHeight = height;
 116:     }
 117:     else if (destWidth < 0)
 118:     {
 119:         destWidth = (int) (width * ((double) destHeight / srcHeight));
 120:     }
 121:     else if (destHeight < 0)
 122:     {
 123:         destHeight = (int) (height * ((double) destWidth / srcWidth));
 124:     }
 125: 
 126:     if (consumer != null)
 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:     if (consumer != null)
 140:       consumer.setProperties(props);
 141:     }
 142: 
 143:     /**
 144:      * This function delivers a rectangle of pixels where any
 145:      * pixel(m,n) is stored in the array as a <code>byte</code> at
 146:      * index (n * scansize + m + offset).  
 147:      *
 148:      * @param x the x coordinate of the rectangle
 149:      * @param y the y coordinate of the rectangle
 150:      * @param w the width of the rectangle
 151:      * @param h the height of the rectangle
 152:      * @param model the <code>ColorModel</code> used to translate the pixels
 153:      * @param pixels the array of pixel values
 154:      * @param offset the index of the first pixels in the <code>pixels</code> array
 155:      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
 156:      */
 157:     public void setPixels(int x, int y, int w, int h, 
 158:        ColorModel model, byte[] pixels, int offset, int scansize)
 159:     {
 160:     double rx = ((double) srcWidth) / destWidth;
 161:     double ry = ((double) srcHeight) / destHeight;
 162: 
 163:     int destScansize = (int) Math.round(scansize / rx);
 164: 
 165:     byte[] destPixels = replicatePixels(x, y, w, h,
 166:                                            model, pixels, offset, scansize,
 167:                                        rx, ry, destScansize);
 168: 
 169:     if (consumer != null)
 170:       consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry),
 171:                  (int) Math.ceil(w/rx), (int) Math.ceil(h/ry),
 172:                  model, destPixels, 0, destScansize);
 173:     }
 174: 
 175:     /**
 176:      * This function delivers a rectangle of pixels where any
 177:      * pixel(m,n) is stored in the array as an <code>int</code> at
 178:      * index (n * scansize + m + offset).  
 179:      *
 180:      * @param x the x coordinate of the rectangle
 181:      * @param y the y coordinate of the rectangle
 182:      * @param w the width of the rectangle
 183:      * @param h the height of the rectangle
 184:      * @param model the <code>ColorModel</code> used to translate the pixels
 185:      * @param pixels the array of pixel values
 186:      * @param offset the index of the first pixels in the <code>pixels</code> array
 187:      * @param scansize the width to use in extracting pixels from the <code>pixels</code> array
 188:      */
 189:     public void setPixels(int x, int y, int w, int h, 
 190:            ColorModel model, int[] pixels, int offset, int scansize)
 191:     {
 192:     double rx = ((double) srcWidth) / destWidth;
 193:     double ry = ((double) srcHeight) / destHeight;
 194: 
 195:     int destScansize = (int) Math.round(scansize / rx);
 196: 
 197:     int[] destPixels = replicatePixels(x, y, w, h,
 198:                                            model, pixels, offset, scansize,
 199:                                        rx, ry, destScansize);
 200: 
 201:     if (consumer != null)
 202:       consumer.setPixels((int) Math.floor(x/rx), (int) Math.floor(y/ry),
 203:                  (int) Math.ceil(w/rx), (int) Math.ceil(h/ry),
 204:                  model, destPixels, 0, destScansize);
 205:     }
 206: 
 207:     private byte[] replicatePixels(int srcx, int srcy, int srcw, int srch,
 208:                                    ColorModel model, byte[] srcPixels,
 209:                                    int srcOffset, int srcScansize,
 210:                                    double rx, double ry, int destScansize)
 211:     {
 212:     byte[] destPixels =
 213:       new byte[(int) Math.ceil(srcw/rx) * (int) Math.ceil(srch/ry)];
 214: 
 215:     int a, b;
 216:     for (int i = 0; i < destPixels.length; i++)
 217:     {
 218:         a = (int) ((int) ( ((double) i) / destScansize) * ry) * srcScansize;
 219:         b = (int) ((i % destScansize) * rx);
 220:         if ((a + b + srcOffset) < srcPixels.length)
 221:         destPixels[i] = srcPixels[a + b + srcOffset];
 222:     }
 223: 
 224:     return destPixels;
 225:     }
 226: 
 227:     private int[] replicatePixels(int srcx, int srcy, int srcw, int srch,
 228:                                   ColorModel model, int[] srcPixels,
 229:                                   int srcOffset, int srcScansize,
 230:                                   double rx, double ry, int destScansize)
 231:     {
 232:     int[] destPixels =
 233:       new int[(int) Math.ceil(srcw/rx) * (int) Math.ceil(srch/ry)];
 234: 
 235:     int a, b;
 236:     for (int i = 0; i < destPixels.length; i++)
 237:     {
 238:         a = (int) ((int) ( ((double) i) / destScansize) * ry) * srcScansize;
 239:         b = (int) ((i % destScansize) * rx);
 240:         if ((a + b + srcOffset) < srcPixels.length)
 241:         destPixels[i] = srcPixels[a + b + srcOffset];
 242:     }
 243: 
 244:     return destPixels;
 245:     }
 246: }