1 files changed, 93 insertions, 0 deletions
diff --git a/src/jogl/classes/jogamp/opengl/util/pngj/chunks/PngChunkPLTE.java b/src/jogl/classes/jogamp/opengl/util/pngj/chunks/PngChunkPLTE.java
new file mode 100644
index 000000000..123080bb3
--- /dev/null
+++ b/src/jogl/classes/jogamp/opengl/util/pngj/chunks/PngChunkPLTE.java
@@ -0,0 +1,93 @@
+package jogamp.opengl.util.pngj.chunks;
+
+import jogamp.opengl.util.pngj.ImageInfo;
+import jogamp.opengl.util.pngj.PngjException;
+
+/*
+ * Palette chunk *this is critical*
+ */
+public class PngChunkPLTE extends PngChunk {
+	// http://www.w3.org/TR/PNG/#11PLTE
+	private int nentries = 0;
+	/**
+	 * RGB8 packed in one integer
+	 */
+	private int[] entries;
+
+	public PngChunkPLTE(ImageInfo info) {
+		super(ChunkHelper.PLTE, info);
+	}
+
+	@Override
+	public ChunkRaw createChunk() {
+		int len = 3 * nentries;
+		int[] rgb = new int[3];
+		ChunkRaw c = createEmptyChunk(len, true);
+		for (int n = 0, i = 0; n < nentries; n++) {
+			getEntryRgb(n, rgb);
+			c.data[i++] = (byte) rgb[0];
+			c.data[i++] = (byte) rgb[1];
+			c.data[i++] = (byte) rgb[2];
+		}
+		return c;
+	}
+
+	@Override
+	public void parseFromChunk(ChunkRaw chunk) {
+		setNentries(chunk.len / 3);
+		for (int n = 0, i = 0; n < nentries; n++) {
+			setEntry(n, (int) (chunk.data[i++] & 0xff), (int) (chunk.data[i++] & 0xff), (int) (chunk.data[i++] & 0xff));
+		}
+	}
+
+	@Override
+	public void cloneDataFromRead(PngChunk other) {
+		PngChunkPLTE otherx = (PngChunkPLTE) other;
+		this.setNentries(otherx.getNentries());
+		System.arraycopy(otherx.entries, 0, entries, 0, nentries);
+	}
+
+	public void setNentries(int n) {
+		nentries = n;
+		if (nentries < 1 || nentries > 256)
+			throw new PngjException("invalid pallette - nentries=" + nentries);
+		if (entries == null || entries.length != nentries) { // alloc
+			entries = new int[nentries];
+		}
+	}
+
+	public int getNentries() {
+		return nentries;
+	}
+
+	public void setEntry(int n, int r, int g, int b) {
+		entries[n] = ((r << 16) | (g << 8) | b);
+	}
+
+	public int getEntry(int n) {
+		return entries[n];
+	}
+
+	public void getEntryRgb(int n, int[] rgb) {
+		getEntryRgb(n, rgb, 0);
+	}
+
+	public void getEntryRgb(int n, int[] rgb, int offset) {
+		int v = entries[n];
+		rgb[offset + 0] = ((v & 0xff0000) >> 16);
+		rgb[offset + 1] = ((v & 0xff00) >> 8);
+		rgb[offset + 2] = (v & 0xff);
+	}
+
+	public int minBitDepth() {
+		if (nentries <= 2)
+			return 1;
+		else if (nentries <= 4)
+			return 2;
+		else if (nentries <= 16)
+			return 4;
+		else
+			return 8;
+	}
+
+}