// Note: Our source will always have either one or two bands
// since we insert an Any2Lum transform before ourself in the
// rendering chain.
Raster srcRas = srcRed.getData(wr.getBounds());
PixelInterleavedSampleModel srcSM;
srcSM = (PixelInterleavedSampleModel)srcRas.getSampleModel();
DataBufferByte srcDB = (DataBufferByte)srcRas.getDataBuffer();
byte [] src = srcDB.getData();
PixelInterleavedSampleModel dstSM;
dstSM = (PixelInterleavedSampleModel)wr.getSampleModel();
DataBufferByte dstDB = (DataBufferByte)wr.getDataBuffer();
byte [] dst = dstDB.getData();
int srcX0 = srcRas.getMinX()-srcRas.getSampleModelTranslateX();
int srcY0 = srcRas.getMinY()-srcRas.getSampleModelTranslateY();
int dstX0 = wr.getMinX()-wr.getSampleModelTranslateX();
int dstX1 = dstX0+wr.getWidth()-1;
int dstY0 = wr.getMinY()-wr.getSampleModelTranslateY();
int srcStep = srcSM.getPixelStride();
int [] offsets = srcSM.getBandOffsets();
int srcLOff = offsets[0];
int srcAOff = offsets[1];
if (srcRed.getColorModel().isAlphaPremultiplied()) {
// Lum is already multiplied by alpha so we just copy lum channel.
for (int y=0; y<srcRas.getHeight(); y++) {
int srcI = srcDB.getOffset() + srcSM.getOffset(srcX0, srcY0);
int dstI = dstDB.getOffset() + dstSM.getOffset(dstX0, dstY0);
int dstE = dstDB.getOffset() + dstSM.getOffset(dstX1+1,dstY0);
srcI += srcLOff; // Go to Lum Channel (already mult by alpha).
while (dstI < dstE) {
dst[dstI++] = src[srcI];
srcI += srcStep; // Go to next pixel
}
srcY0++;
dstY0++;
}
}
else {
// This allows me to pre-adjust my index by srcLOff
// Then only add the offset for srcAOff
srcAOff = srcAOff-srcLOff;
for (int y=0; y<srcRas.getHeight(); y++) {
int srcI = srcDB.getOffset() + srcSM.getOffset(srcX0, srcY0);
int dstI = dstDB.getOffset() + dstSM.getOffset(dstX0, dstY0);
int dstE = dstDB.getOffset() + dstSM.getOffset(dstX1+1,dstY0);
srcI += srcLOff;
while (dstI < dstE) {
int sl = (src[srcI])&0xFF; // LOff already included