// Copyright (C) 1998, 1999, 2001 Chris Nokleberg// Please see included LICENSE.TXTpackage com.sixlegs.image.png;import java.awt.image.ColorModel;import java.awt.image.DirectColorModel;import java.io.IOException;final class Chunk_IHDRextends Chunk{    /* package */ int width;    /* package */ int height;    /* package */ int depth;    /* package */ int outputDepth;    /* package */ int compress;    /* package */ int filter;    /* package */ int interlace;    /* package */ Interlacer interlacer;    /* package */ int samples = 1;    /* package */ int colorType;    /* package */ int cmBits;    /* package */ boolean paletteUsed = false;    /* package */ boolean colorUsed = false;    /* package */ boolean alphaUsed = false;      /* package */ ColorModel alphaModel;    /* package */ ColorModel model;    Chunk_IHDR()    {        super(IHDR);    }    protected boolean multipleOK()    {        return false;    }    // TODO: shorten    protected void readData()    throws IOException    {        img.data.header = this;         if (length != 13) badLength(13);        width = in_data.readInt();        height = in_data.readInt();        if (width <= 0 || height <= 0) {            throw new PngException("Bad image size: " + in_data.unsign(width) +                                   "x" + in_data.unsign(height));        }        depth = in_data.readUnsignedByte();        outputDepth = (depth == 16 ? 8 : depth);        int blue = 0;        switch (outputDepth) {        case 1:  blue = 0x01; break;        case 2:  blue = 0x03; break;        case 4:  blue = 0x0F; break;        case 8:  blue = 0xFF; break;        default:            throw new PngException("Bad bit depth: " + depth);        }        byte[] sbit = null;        int green = blue  << outputDepth;        int red   = green << outputDepth;        int alpha = red   << outputDepth;            byte b_depth = (byte)depth;        colorType = in_data.readUnsignedByte();        switch (colorType) {        case PngImage.COLOR_TYPE_GRAY:             sbit = new byte[]{b_depth, b_depth, b_depth};            cmBits = 3 * outputDepth;            break;        case PngImage.COLOR_TYPE_RGB:             sbit = new byte[]{b_depth, b_depth, b_depth};            cmBits = 3 * outputDepth;            samples = 3;            colorUsed = true;            break;        case PngImage.COLOR_TYPE_PALETTE:             sbit = new byte[]{8, 8, 8};            cmBits = outputDepth;            colorUsed = paletteUsed = true;            break;        case PngImage.COLOR_TYPE_GRAY_ALPHA:             sbit = new byte[]{b_depth, b_depth, b_depth, b_depth};            cmBits = 4 * outputDepth;            samples = 2;            alphaUsed = true;             break;        case PngImage.COLOR_TYPE_RGB_ALPHA:             sbit = new byte[]{b_depth, b_depth, b_depth, b_depth};            cmBits = 4 * outputDepth;            samples = 4;            alphaUsed = colorUsed = true;             break;        default:            cmBits = 0;            throw new PngException("Bad color type: " + colorType);        }        img.data.properties.put("significant bits", sbit);        if (paletteUsed) {            // set later when we see the PLTE chunk        } else {            if (alphaUsed) {                model = alphaModel = new DirectColorModel(cmBits, red, green, blue, alpha);            } else {                 // we may switch to alphaModel if a tRNS chunk is found later                alphaModel = ColorModel.getRGBdefault();                model = new DirectColorModel(24, 0xFF0000, 0x00FF00, 0x0000FF);            }        }        switch (colorType) {        case PngImage.COLOR_TYPE_GRAY:             break;        case PngImage.COLOR_TYPE_PALETTE:            if (depth == 16)                throw new PngException("Bad bit depth for color type " + colorType + ": " + depth);            break;        default:            if (depth <= 4)                throw new PngException("Bad bit depth for color type " + colorType + ": " + depth);        }        if ((compress = in_data.readUnsignedByte()) != PngImage.COMPRESSION_TYPE_BASE)             throw new PngException("Unrecognized compression method: " + compress);        if ((filter = in_data.readUnsignedByte()) != PngImage.FILTER_TYPE_BASE)            throw new PngException("Unrecognized filter method: " + filter);        interlace = in_data.readUnsignedByte();        switch (interlace) {        case PngImage.INTERLACE_TYPE_NONE:            interlacer = new NullInterlacer(width, height);            break;        case PngImage.INTERLACE_TYPE_ADAM7:            interlacer = new Adam7Interlacer(width, height);            break;        default:            throw new PngException("Unrecognized interlace method: " + interlace);        }        img.data.properties.put("width", new Integer(width));        img.data.properties.put("height", new Integer(height));        img.data.properties.put("bit depth", new Integer(depth));        img.data.properties.put("interlace type", new Integer(interlace));        img.data.properties.put("compression type", new Integer(compress));        img.data.properties.put("filter type", new Integer(filter));        img.data.properties.put("color type", new Integer(colorType));    }}