/**
* Unload the given image's data into the given byte stream using the given compression strategy.
* Answer the number of bytes written. Method modified to use the passed data if it is not null.
*/
int unloadData(ImageData image, byte[] data, OutputStream out, int comp) {
int totalSize = 0;
try {
if (comp == 0) return unloadDataNoCompression(image, data, out);
int bpl = (image.width * image.depth + 7) / 8;
int bmpBpl = (bpl + 3) / 4 * 4; // BMP pads scanlines to multiples of 4 bytes
int imageBpl = image.bytesPerLine;
// Compression can actually take twice as much space, in worst case
byte[] buf = new byte[bmpBpl * 2];
int srcOffset = imageBpl * (image.height - 1); // Start at last line
if (data == null) data = image.data;
totalSize = 0;
byte[] buf2 = new byte[32768];
int buf2Offset = 0;
for (int y = image.height - 1; y >= 0; y--) {
int lineSize = compress(comp, data, srcOffset, bpl, buf, y == 0);
if (buf2Offset + lineSize > buf2.length) {
out.write(buf2, 0, buf2Offset);
buf2Offset = 0;
}
System.arraycopy(buf, 0, buf2, buf2Offset, lineSize);
buf2Offset += lineSize;
totalSize += lineSize;
srcOffset -= imageBpl;
}
if (buf2Offset > 0) out.write(buf2, 0, buf2Offset);
} catch (IOException e) {
SWT.error(SWT.ERROR_IO, e);
}
return totalSize;
}
/**
* Prepare the given image's data for unloading into a byte stream using no compression strategy.
* Answer the number of bytes written. Method modified to use the passed data if it is not null.
*/
int unloadDataNoCompression(ImageData image, byte[] data, OutputStream out) {
int bmpBpl = 0;
try {
int bpl = (image.width * image.depth + 7) / 8;
bmpBpl = (bpl + 3) / 4 * 4; // BMP pads scanlines to multiples of 4 bytes
int linesPerBuf = 32678 / bmpBpl;
byte[] buf = new byte[linesPerBuf * bmpBpl];
if (data == null) data = image.data;
int imageBpl = image.bytesPerLine;
int dataIndex = imageBpl * (image.height - 1); // Start at last line
if (image.depth == 16) {
for (int y = 0; y < image.height; y += linesPerBuf) {
int count = image.height - y;
if (linesPerBuf < count) count = linesPerBuf;
int bufOffset = 0;
for (int i = 0; i < count; i++) {
for (int wIndex = 0; wIndex < bpl; wIndex += 2) {
buf[bufOffset + wIndex + 1] = data[dataIndex + wIndex + 1];
buf[bufOffset + wIndex] = data[dataIndex + wIndex];
}
bufOffset += bmpBpl;
dataIndex -= imageBpl;
}
out.write(buf, 0, bufOffset);
}
} else {
for (int y = 0; y < image.height; y += linesPerBuf) {
int tmp = image.height - y;
int count = tmp < linesPerBuf ? tmp : linesPerBuf;
int bufOffset = 0;
for (int i = 0; i < count; i++) {
System.arraycopy(data, dataIndex, buf, bufOffset, bpl);
bufOffset += bmpBpl;
dataIndex -= imageBpl;
}
out.write(buf, 0, bufOffset);
}
}
} catch (IOException e) {
SWT.error(SWT.ERROR_IO, e);
}
return bmpBpl * image.height;
}
