protected boolean saveTGA(OutputStream output) {
byte header[] = new byte[18];
if (format == ALPHA) { // save ALPHA images as 8bit grayscale
header[2] = 0x0B;
header[16] = 0x08;
header[17] = 0x28;
} else if (format == RGB) {
header[2] = 0x0A;
header[16] = 24;
header[17] = 0x20;
} else if (format == ARGB) {
header[2] = 0x0A;
header[16] = 32;
header[17] = 0x28;
} else {
throw new RuntimeException("Image format not recognized inside save()");
}
// set image dimensions lo-hi byte order
header[12] = (byte) (width & 0xff);
header[13] = (byte) (width >> 8);
header[14] = (byte) (height & 0xff);
header[15] = (byte) (height >> 8);
try {
output.write(header);
int maxLen = height * width;
int index = 0;
int col; //, prevCol;
int[] currChunk = new int[128];
// 8bit image exporter is in separate loop
// to avoid excessive conditionals...
if (format == ALPHA) {
while (index < maxLen) {
boolean isRLE = false;
int rle = 1;
currChunk[0] = col = pixels[index] & 0xff;
while (index + rle < maxLen) {
if (col != (pixels[index + rle]&0xff) || rle == 128) {
isRLE = (rle > 1);
break;
}
rle++;
}
if (isRLE) {
output.write(0x80 | (rle - 1));
output.write(col);
} else {
rle = 1;
while (index + rle < maxLen) {
int cscan = pixels[index + rle] & 0xff;
if ((col != cscan && rle < 128) || rle < 3) {
currChunk[rle] = col = cscan;
} else {
if (col == cscan) rle -= 2;
break;
}
rle++;
}
output.write(rle - 1);
for (int i = 0; i < rle; i++) output.write(currChunk[i]);
}
index += rle;
}
} else { // export 24/32 bit TARGA
while (index < maxLen) {
boolean isRLE = false;
currChunk[0] = col = pixels[index];
int rle = 1;
// try to find repeating bytes (min. len = 2 pixels)
// maximum chunk size is 128 pixels
while (index + rle < maxLen) {
if (col != pixels[index + rle] || rle == 128) {
isRLE = (rle > 1); // set flag for RLE chunk
break;
}
rle++;
}
if (isRLE) {
output.write(128 | (rle - 1));
output.write(col & 0xff);
output.write(col >> 8 & 0xff);
output.write(col >> 16 & 0xff);
if (format == ARGB) output.write(col >>> 24 & 0xff);
} else { // not RLE
rle = 1;
while (index + rle < maxLen) {
if ((col != pixels[index + rle] && rle < 128) || rle < 3) {
currChunk[rle] = col = pixels[index + rle];
} else {
// check if the exit condition was the start of
// a repeating colour
if (col == pixels[index + rle]) rle -= 2;
break;
}
rle++;
}
// write uncompressed chunk
output.write(rle - 1);
if (format == ARGB) {
for (int i = 0; i < rle; i++) {
col = currChunk[i];
output.write(col & 0xff);
output.write(col >> 8 & 0xff);
output.write(col >> 16 & 0xff);
output.write(col >>> 24 & 0xff);
}
} else {
for (int i = 0; i < rle; i++) {
col = currChunk[i];
output.write(col & 0xff);
output.write(col >> 8 & 0xff);
output.write(col >> 16 & 0xff);
}
}
}
index += rle;
}
}
output.flush();
return true;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}