WarpPI/desktop/src/main/java/ar/com/hjg/pngj/chunks/PngChunkBKGD.java

115 lines
2.7 KiB
Java

package ar.com.hjg.pngj.chunks;
import ar.com.hjg.pngj.ImageInfo;
import ar.com.hjg.pngj.PngHelperInternal;
import ar.com.hjg.pngj.PngjException;
/**
* bKGD Chunk.
* <p>
* see {@link http://www.w3.org/TR/PNG/#11bKGD}
* <p>
* This chunk structure depends on the image type
*/
public class PngChunkBKGD extends PngChunkSingle {
public final static String ID = ChunkHelper.bKGD;
// only one of these is meaningful
private int gray;
private int red;
private int green;
private int blue;
private int paletteIndex;
public PngChunkBKGD(ImageInfo info) {
super(ChunkHelper.bKGD, info);
}
@Override
public ChunkOrderingConstraint getOrderingConstraint() {
return ChunkOrderingConstraint.AFTER_PLTE_BEFORE_IDAT;
}
@Override
public ChunkRaw createRawChunk() {
ChunkRaw c = null;
if (imgInfo.greyscale) {
c = createEmptyChunk(2, true);
PngHelperInternal.writeInt2tobytes(gray, c.data, 0);
} else if (imgInfo.indexed) {
c = createEmptyChunk(1, true);
c.data[0] = (byte) paletteIndex;
} else {
c = createEmptyChunk(6, true);
PngHelperInternal.writeInt2tobytes(red, c.data, 0);
PngHelperInternal.writeInt2tobytes(green, c.data, 0);
PngHelperInternal.writeInt2tobytes(blue, c.data, 0);
}
return c;
}
@Override
public void parseFromRaw(ChunkRaw c) {
if (imgInfo.greyscale) {
gray = PngHelperInternal.readInt2fromBytes(c.data, 0);
} else if (imgInfo.indexed) {
paletteIndex = (int) (c.data[0] & 0xff);
} else {
red = PngHelperInternal.readInt2fromBytes(c.data, 0);
green = PngHelperInternal.readInt2fromBytes(c.data, 2);
blue = PngHelperInternal.readInt2fromBytes(c.data, 4);
}
}
/**
* Set gray value (0-255 if bitdept=8)
*
* @param gray
*/
public void setGray(int gray) {
if (!imgInfo.greyscale)
throw new PngjException("only gray images support this");
this.gray = gray;
}
public int getGray() {
if (!imgInfo.greyscale)
throw new PngjException("only gray images support this");
return gray;
}
/**
* Set pallette index
*
*/
public void setPaletteIndex(int i) {
if (!imgInfo.indexed)
throw new PngjException("only indexed (pallete) images support this");
this.paletteIndex = i;
}
public int getPaletteIndex() {
if (!imgInfo.indexed)
throw new PngjException("only indexed (pallete) images support this");
return paletteIndex;
}
/**
* Set rgb values
*
*/
public void setRGB(int r, int g, int b) {
if (imgInfo.greyscale || imgInfo.indexed)
throw new PngjException("only rgb or rgba images support this");
red = r;
green = g;
blue = b;
}
public int[] getRGB() {
if (imgInfo.greyscale || imgInfo.indexed)
throw new PngjException("only rgb or rgba images support this");
return new int[] { red, green, blue };
}
}