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diff --git a/libjava/classpath/gnu/javax/imageio/bmp/DecodeRLE4.java b/libjava/classpath/gnu/javax/imageio/bmp/DecodeRLE4.java
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+/* DecodeRLE4.java --
+ Copyright (C) 2005 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING. If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library. Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module. An independent module is a module which is not derived from
+or based on this library. If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so. If you do not wish to do so, delete this
+exception statement from your version. */
+
+package gnu.javax.imageio.bmp;
+
+import java.io.IOException;
+import javax.imageio.stream.ImageInputStream;
+import java.awt.image.BufferedImage;
+import java.awt.image.IndexColorModel;
+import java.awt.image.Raster;
+import java.awt.image.WritableRaster;
+import java.awt.image.DataBuffer;
+import java.awt.image.DataBufferByte;
+import java.awt.image.MultiPixelPackedSampleModel;
+import java.awt.image.SampleModel;
+import java.awt.Dimension;
+
+public class DecodeRLE4 extends BMPDecoder {
+
+ public DecodeRLE4(BMPFileHeader fh, BMPInfoHeader ih){
+ super(fh, ih);
+ }
+
+ /**
+ * RLE control codes
+ */
+ private static final byte ESCAPE = (byte)0;
+ private static final byte EOL = (byte)0; // end of line
+ private static final byte EOB = (byte)1; // end of bitmap
+ private static final byte DELTA = (byte)2; // delta
+
+ public BufferedImage decode(ImageInputStream in) throws IOException, BMPException {
+ IndexColorModel palette = readPalette(in);
+ skipToImage(in);
+
+ Dimension d = infoHeader.getSize();
+ int h = (int)d.getHeight();
+ int w = (int)d.getWidth();
+
+ byte[] data = uncompress(w, h, in);
+ SampleModel sm = new MultiPixelPackedSampleModel(DataBuffer.TYPE_BYTE,
+ w, h, 4);
+
+ DataBuffer db = new DataBufferByte(data, w*h, 0);
+ WritableRaster raster = Raster.createWritableRaster(sm, db, null);
+
+ return new BufferedImage(palette, raster, false, null);
+ }
+
+ private byte[] uncompress(int w, int h, ImageInputStream in)
+ throws BMPException, IOException {
+ byte[] cmd = new byte[2];
+ byte[] data = new byte[w*h>>1];
+ int offIn = 0;
+ int x=0,y=0;
+
+ // width in bytes
+ w += (w&1);
+ w = w >> 1;
+
+ try {
+ while(((x>>1) + y*w) < w*h){
+ if(in.read(cmd) != 2)
+ throw new IOException("Error reading compressed data.");
+
+ if(cmd[0] == ESCAPE){
+ switch(cmd[1]){
+ case EOB: // end of bitmap
+ return data;
+ case EOL: // end of line
+ x = 0;
+ y++;
+ break;
+ case DELTA: // delta
+ if(in.read(cmd) != 2)
+ throw new IOException("Error reading compressed data.");
+ int dx = cmd[0] & (0xFF);
+ int dy = cmd[1] & (0xFF);
+ x += dx;
+ y += dy;
+ break;
+
+ default:
+ // decode a literal run
+ int length = cmd[1] & (0xFF);
+
+ // size of run, which is word aligned.
+ int bytesize = length;
+ bytesize += (bytesize & 1);
+ bytesize >>= 1;
+ bytesize += (bytesize & 1);
+
+ byte[] run = new byte[bytesize];
+ if(in.read(run) != bytesize)
+ throw new IOException("Error reading compressed data.");
+
+ if((x&1) == 0){
+ length += (length&1);
+ length >>= 1;
+ System.arraycopy(run, 0, data, ((x>>1) + w*(h-y-1)),
+ length);
+ } else {
+ for(int i=0;i<length;i++){
+ if((i&1) == 0) // copy high to low
+ data[((x+i)>>1) + w*(h-y-1)]
+ |= ((run[i>>1]&0xF0) >> 4);
+ else // copy low to high
+ data[((x+i)>>1) + w*(h-y-1)]
+ |= ((run[i>>1]&0x0F) << 4);
+ }
+ }
+ x += cmd[1] & (0xFF);
+ break;
+ }
+ } else {
+ // decode a byte run
+ int length = cmd[0] & (0xFF);
+ if((x&1) == 0){
+ length += (length&1);
+ length >>= 1;
+ for(int i=0;i<length;i++)
+ data[(h-y-1)*w + i + (x >> 1)] = cmd[1];
+ } else {
+ for(int i=0;i<length;i++){
+ if((i&1) == 0) // copy high to low
+ data[((x+i)>>1) + w*(h-y-1)]
+ |= ((cmd[1]&0xF0) >> 4);
+ else // copy low to high
+ data[((x+i)>>1) + w*(h-y-1)]
+ |= ((cmd[1]&0x0F) << 4);
+ }
+ }
+ x += cmd[0] & (0xFF);
+ }
+ }
+ return data;
+ } catch(ArrayIndexOutOfBoundsException e){
+ throw new BMPException("Invalid RLE data.");
+ }
+ }
+}
+