package jogamp.opengl.util.pngj.chunks; import jogamp.opengl.util.pngj.ImageInfo; import jogamp.opengl.util.pngj.PngHelperInternal; import jogamp.opengl.util.pngj.PngjException; /** * hIST chunk. *
* see http://www.w3.org/TR/PNG/#11hIST
* only for palette images
*/
public class PngChunkHIST extends PngChunkSingle {
public final static String ID = ChunkHelper.hIST;
private int[] hist = new int[0]; // should have same lenght as palette
public PngChunkHIST(ImageInfo info) {
super(ID, info);
}
@Override
public ChunkOrderingConstraint getOrderingConstraint() {
return ChunkOrderingConstraint.AFTER_PLTE_BEFORE_IDAT;
}
@Override
public void parseFromRaw(ChunkRaw c) {
if (!imgInfo.indexed)
throw new PngjException("only indexed images accept a HIST chunk");
int nentries = c.data.length / 2;
hist = new int[nentries];
for (int i = 0; i < hist.length; i++) {
hist[i] = PngHelperInternal.readInt2fromBytes(c.data, i * 2);
}
}
@Override
public ChunkRaw createRawChunk() {
if (!imgInfo.indexed)
throw new PngjException("only indexed images accept a HIST chunk");
ChunkRaw c = null;
c = createEmptyChunk(hist.length * 2, true);
for (int i = 0; i < hist.length; i++) {
PngHelperInternal.writeInt2tobytes(hist[i], c.data, i * 2);
}
return c;
}
@Override
public void cloneDataFromRead(PngChunk other) {
PngChunkHIST otherx = (PngChunkHIST) other;
hist = new int[otherx.hist.length];
System.arraycopy(otherx.hist, 0, hist, 0, otherx.hist.length);
}
public int[] getHist() {
return hist;
}
public void setHist(int[] hist) {
this.hist = hist;
}
}