/*
 * @(#)DirectColorModel.java	1.69 00/02/02
 *
 * Copyright 1995-2000 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */

package java.awt.image;

import java.awt.color.ColorSpace;
import java.awt.Transparency;

/**
 * The <code>DirectColorModel</code> class is a <code>ColorModel</code>
 * class that works with pixel values that represent RGB
 * color and alpha information as separate samples and that pack all
 * samples for a single pixel into a single int, short, or byte quantity.
 * This class can be used only with ColorSpaces of type ColorSpace.TYPE_RGB.
 * There must be three color samples in the pixel values and there can
 * be a single alpha sample.  For those methods that use a primitive array
 * pixel representation of type <code>transferType</code>, the array 
 * length is always one.  The transfer 
 * types supported are DataBuffer.TYPE_BYTE,
 * DataBuffer.TYPE_USHORT, and DataBuffer.TYPE_INT.
 * Color and alpha samples are stored in the single 
 * element of the array in bits indicated by bit masks.  Each bit mask 
 * must be contiguous and masks must not overlap.  The same masks apply to 
 * the single int pixel representation used by other methods.  The 
 * correspondence of masks and color/alpha samples is as follows:
 * <ul>
 * <li> Masks are identified by indices running from 0 through 2  
 * if no alpha is present, or 3 if an alpha is present.  
 * <li> The first three indices refer to color samples; 
 * index 0 corresponds to red, index 1 to green, and index 2 to blue.  
 * <li> Index 3 corresponds to the alpha sample, if present. 
 * </ul>
 * <p>
 * The translation from pixel values to color/alpha components for
 * display or processing purposes is a one-to-one correspondence of
 * samples to components.  A <code>DirectColorModel</code> is 
 * typically used with image data which uses masks to define packed 
 * samples.  For example, a <code>DirectColorModel</code> can be used in
 * conjunction with a <code>SinglePixelPackedSampleModel</code> to 
 * construct a {@link BufferedImage}.  Normally the masks used by the 
 * {@link SampleModel} and the <code>ColorModel</code> would be the 
 * same.  However, if they are different, the color interpretation 
 * of pixel data will be done according to the masks of the 
 * <code>ColorModel</code>.
 * <p>
 * A single int pixel representation is valid for all objects of this
 * class, since it is always possible to represent pixel values used with
 * this class in a single int.  Therefore, methods which use this
 * representation will not throw an <code>IllegalArgumentException</code>
 * due to an invalid pixel value.
 * <p>
 * This color model is similar to an X11 TrueColor visual.
 * The default RGB ColorModel specified by the 
 * {@link ColorModel#getRGBdefault() getRGBdefault} method is a 
 * <code>DirectColorModel</code> with the following parameters:
 * <pre>
 * Number of bits:        32
 * Red mask:              0x00ff0000
 * Green mask:            0x0000ff00
 * Blue mask:             0x000000ff
 * Alpha mask:            0xff000000
 * Color space:           sRGB
 * isAlphaPremultiplied:  False
 * Transparency:          Transparency.TRANSLUCENT
 * transferType:          DataBuffer.TYPE_INT
 * </pre>
 * <p>
 * Many of the methods in this class are final. This is because the
 * underlying native graphics code makes assumptions about the layout
 * and operation of this class and those assumptions are reflected in
 * the implementations of the methods here that are marked final.  You
 * can subclass this class for other reasons, but you cannot override
 * or modify the behavior of those methods.
 *
 * @see ColorModel
 * @see ColorSpace
 * @see SinglePixelPackedSampleModel
 * @see BufferedImage
 * @see ColorModel#getRGBdefault
 *
 * @version 10 Feb 1997
 */
public class DirectColorModel extends PackedColorModel {
    private int red_mask;
    private int green_mask;
    private int blue_mask;
    private int alpha_mask;
    private int red_offset;
    private int green_offset;
    private int blue_offset;
    private int alpha_offset;
    private int red_scale;
    private int green_scale;
    private int blue_scale;
    private int alpha_scale;
    
    /**
     * Constructs a <code>DirectColorModel</code> from the specified masks 
     * that indicate which bits in an <code>int</code> pixel representation 
     * contain the red, green and blue color samples.  As pixel values do not
     * contain alpha information, all pixels are treated as opaque, which
     * means that alpha = 1.0.  All of the bits
     * in each mask must be contiguous and fit in the specified number
     * of least significant bits of an <code>int</code> pixel representation.
     *  The <code>ColorSpace</code> is the default sRGB space. The
     * transparency value is Transparency.OPAQUE.  The transfer type
     * is the smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT,
     * or DataBuffer.TYPE_INT that can hold a single pixel.
     * @param bits the number of bits in the pixel values; for example, 
     *         the sum of the number of bits in the masks.
     * @param rmask specifies a mask indicating which bits in an 
     *         integer pixel contain the red component
     * @param gmask specifies a mask indicating which bits in an
     *         integer pixel contain the green component
     * @param bmask specifies a mask indicating which bits in an
     *         integer pixel contain the blue component
     * 
     */
    public DirectColorModel(int bits,
			    int rmask, int gmask, int bmask) {
	this(bits, rmask, gmask, bmask, 0);
    }

    /**
     * Constructs a <code>DirectColorModel</code> from the specified masks 
     * that indicate which bits in an <code>int</code> pixel representation
     * contain the red, green and blue color samples and the alpha sample, 
     * if present.  If <code>amask</code> is 0, pixel values do not contain
     * alpha information and all pixels are treated as opaque, which means 
     * that alpha = 1.0.  All of the bits in each mask must
     * be contiguous and fit in the specified number of least significant bits
     * of an <code>int</code> pixel representation.  Alpha, if present, is not
     * premultiplied.  The <code>ColorSpace</code> is the default sRGB space.
     * The transparency value is Transparency.OPAQUE if no alpha is
     * present, or Transparency.TRANSLUCENT otherwise.  The transfer type
     * is the smallest of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT,
     * or DataBuffer.TYPE_INT that can hold a single pixel.
     * @param bits the number of bits in the pixel values; for example, 
     *         the sum of the number of bits in the masks.
     * @param rmask specifies a mask indicating which bits in an
     *         integer pixel contain the red component
     * @param gmask specifies a mask indicating which bits in an
     *         integer pixel contain the green component
     * @param bmask specifies a mask indicating which bits in an
     *         integer pixel contain the blue component
     * @param amask specifies a mask indicating which bits in an
     *         integer pixel contain the alpha component
     */
    public DirectColorModel(int bits, int rmask, int gmask,
                            int bmask, int amask) {
        super (ColorSpace.getInstance(ColorSpace.CS_sRGB),
               bits, rmask, gmask, bmask, amask, false,
               amask == 0 ? Transparency.OPAQUE : Transparency.TRANSLUCENT,
               ColorModel.getDefaultTransferType(bits));
        setFields();
    }

    /**
     * Constructs a <code>DirectColorModel</code> from the specified
     * parameters.  Color components are in the specified 
     * <code>ColorSpace</code>, which must be of type ColorSpace.TYPE_RGB.
     * The masks specify which bits in an <code>int</code> pixel 
     * representation contain the red, green and blue color samples and
     * the alpha sample, if present.  If <code>amask</code> is 0, pixel
     * values do not contain alpha information and all pixels are treated 
     * as opaque, which means that alpha = 1.0.  All of the
     * bits in each mask must be contiguous and fit in the specified number
     * of least significant bits of an <code>int</code> pixel 
     * representation.  If there is alpha, the <code>boolean</code>
     * <code>isAlphaPremultiplied</code> specifies how to interpret
     * color and alpha samples in pixel values.  If the <code>boolean</code>
     * is <code>true</code>, color samples are assumed to have been
     * multiplied by the alpha sample.  The transparency value is
     * Transparency.OPAQUE, if no alpha is present, or
     * Transparency.TRANSLUCENT otherwise.  The transfer type
     * is the type of primitive array used to represent pixel values and
     * must be one of DataBuffer.TYPE_BYTE, DataBuffer.TYPE_USHORT, or
     * DataBuffer.TYPE_INT.
     * @param space the specified <code>ColorSpace</code>
     * @param bits the number of bits in the pixel values; for example, 
     *         the sum of the number of bits in the masks.
     * @param rmask specifies a mask indicating which bits in an
     *         integer pixel contain the red component
     * @param gmask specifies a mask indicating which bits in an
     *         integer pixel contain the green component
     * @param bmask specifies a mask indicating which bits in an
     *         integer pixel contain the blue component
     * @param amask specifies a mask indicating which bits in an
     * 	       integer pixel contain the alpha component
     * @param isAlphaPremultiplied <code>true</code> if color samples are
     *        premultiplied by the alpha sample; <code>false</code> otherwise
     * @param transferType the type of array used to represent pixel values
     */
    public DirectColorModel(ColorSpace space, int bits, int rmask,
                            int gmask, int bmask, int amask,
                            boolean isAlphaPremultiplied,
                            int transferType) {
        super (space, bits, rmask, gmask, bmask, amask,
               isAlphaPremultiplied,
               amask == 0 ? Transparency.OPAQUE : Transparency.TRANSLUCENT,
               transferType);  
        setFields();
    }

    /**
     * Returns the mask indicating which bits in an <code>int</code> pixel 
     * representation contain the red color component.
     * @return the mask, which indicates which bits of the <code>int</code> 
     *         pixel representation contain the red color sample. 
     */
    final public int getRedMask() {
	return maskArray[0];
    }

    /**
     * Returns the mask indicating which bits in an <code>int</code> pixel 
     * representation contain the green color component.
     * @return the mask, which indicates which bits of the <code>int</code> 
     *         pixel representation contain the green color sample. 
     */
    final public int getGreenMask() {
	return maskArray[1];
    }

    /**
     * Returns the mask indicating which bits in an <code>int</code> pixel 
     * representation contain the blue color component.
     * @return the mask, which indicates which bits of the <code>int</code> 
     *         pixel representation contain the blue color sample. 
     */
    final public int getBlueMask() {
	return maskArray[2];
    }

    /**
     * Returns the mask indicating which bits in an <code>int</code> pixel 
     * representation contain the alpha component.
     * @return the mask, which indicates which bits of the <code>int</code> 
     *         pixel representation contain the alpha sample. 
     */
    final public int getAlphaMask() {
        if (supportsAlpha) {
            return maskArray[3];
        } else {
            return 0;
        }
    }


    /*
     * Given an int pixel in this ColorModel's ColorSpace, converts
     * it to the default sRGB ColorSpace and returns the R, G, and B
     * components as float values between 0.0 and 1.0.
     */
    private float[] getDefaultRGBComponents(int pixel) {
        int components[] = getComponents(pixel, null, 0);
        float norm[] = getNormalizedComponents(components, 0, null, 0);
        // Note that getNormalizedComponents returns non-premultiplied values
        return colorSpace.toRGB(norm);
    }


    /**
     * Returns the red color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified 
     * as an <code>int</code>.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the red value 
     * is 0.
     * @param pixel the specified pixel
     * @return the red color component for the specified pixel, from 
     *         0 to 255 in the sRGB <code>ColorSpace</code>.
     */
    final public int getRed(int pixel) {
        if (!is_sRGB) {
            float rgb[] = getDefaultRGBComponents(pixel);
            return (int) (rgb[0] * 255.0f);
        }
	int r = ((pixel & maskArray[0]) >>> maskOffsets[0]);
	if (scaleFactors[0] != 1.) {
	    r = (int)(r * scaleFactors[0]);
	}
        if (isAlphaPremultiplied) {
            int a = getAlpha(pixel);
            r = (a == 0) ? 0 : (r * 255/a);
            if (r > 255) {
                r = 255;
            }
        }
	return r;
    }

    /**
     * Returns the green color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified
     * as an <code>int</code>.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the green value
     * is 0.
     * @param pixel the specified pixel
     * @return the green color component for the specified pixel, from 
     *         0 to 255 in the sRGB <code>ColorSpace</code>.
     */
    final public int getGreen(int pixel) {
        if (!is_sRGB) {
            float rgb[] = getDefaultRGBComponents(pixel);
            return (int) (rgb[1] * 255.0f);
        }
	int g = ((pixel & maskArray[1]) >>> maskOffsets[1]);
	if (scaleFactors[1] != 1.) {
	    g = (int) (g * scaleFactors[1]);
	}

        if (isAlphaPremultiplied) {
            int a = getAlpha(pixel);
            g = (a == 0) ? 0 : (g * 255/a);
            if (g > 255) {
                g = 255;
            }
        }
	return g;
    }

    /**
     * Returns the blue color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified
     * as an <code>int</code>.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the blue value
     * is 0.
     * @param pixel the specified pixel
     * @return the blue color component for the specified pixel, from 
     *         0 to 255 in the sRGB <code>ColorSpace</code>.
     */
    final public int getBlue(int pixel) {
        if (!is_sRGB) {
            float rgb[] = getDefaultRGBComponents(pixel);
            return (int) (rgb[2] * 255.0f);
        }
	int b = ((pixel & maskArray[2]) >>> maskOffsets[2]);
	if (scaleFactors[2] != 1.) {
	    b = (int)(b * scaleFactors[2]);
	}

        if (isAlphaPremultiplied) {
            int a = getAlpha(pixel);
            b = (a == 0) ? 0 : (b * 255/a);
            if (b > 255) {
                b = 255;
            }
        }
	return b;
    }

    /**
     * Returns the alpha component for the specified pixel, scaled
     * from 0 to 255.  The pixel value is specified as an <code>int</code>.
     * @param pixel the specified pixel
     * @return the value of the alpha component of <code>pixel</code>
     *         from 0 to 255.    
     */
    final public int getAlpha(int pixel) {
	if (!supportsAlpha) return 255;
	int a = ((pixel & maskArray[3]) >>> maskOffsets[3]);
	if (scaleFactors[3] != 1.) {
	    a = (int)(a * scaleFactors[3]);
	}
	return a;
    }

    /**
     * Returns the color/alpha components of the pixel in the default
     * RGB color model format.  A color conversion is done if necessary.
     * The pixel value is specified as an <code>int</code>.
     * The returned value is in a non pre-multiplied format.  Thus, if
     * the alpha is premultiplied, this method divides it out of the
     * color components.  If the alpha value is 0, for example, the color 
     * values are each 0.
     * @param pixel the specified pixel
     * @return the RGB value of the color/alpha components of the specified
     *         pixel.
     * @see ColorModel#getRGBdefault
     */
    final public int getRGB(int pixel) {
        if (!is_sRGB) {
            float rgb[] = getDefaultRGBComponents(pixel);
            return (getAlpha(pixel) << 24)
                | (((int) (rgb[0] * 255.0f)) << 16)
                | (((int) (rgb[1] * 255.0f)) << 8)
                | (((int) (rgb[2] * 255.0f)) << 0);
        }
	return (getAlpha(pixel) << 24)
	    | (getRed(pixel) << 16)
	    | (getGreen(pixel) << 8)
	    | (getBlue(pixel) << 0);
    }
    
    /**
     * Returns the red color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified
     * by an array of data elements of type <code>transferType</code> passed 
     * in as an object reference.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the red value 
     * is 0.
     * If <code>inData</code> is not a primitive array of type 
     * <code>transferType</code>, a <code>ClassCastException</code> is 
     * thrown.  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>inData</code> is not large enough to hold a
     * pixel value for this <code>ColorModel</code>.  Since
     * <code>DirectColorModel</code> can be subclassed, subclasses inherit
     * the implementation of this method and if they don't override it
     * then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * An <code>UnsupportedOperationException</code> is thrown if this
     * <code>transferType</code> is not supported by this 
     * <code>ColorModel</code>.
     * @param inData the array containing the pixel value
     * @return the value of the red component of the specified pixel.
     * @throws ArrayIndexOutOfBoundsException if <code>inData</code> is not
     *         large enough to hold a pixel value for this color model
     * @throws ClassCastException if <code>inData</code> is not a 
     *         primitive array of type <code>transferType</code>
     * @throws UnsupportedOperationException if this <code>transferType</code>
     *         is not supported by this color model
     */
    public int getRed(Object inData) {
        int pixel=0;
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])inData;
               pixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])inData;
               pixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])inData;
               pixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getRed(pixel);
    }
   

    /**
     * Returns the green color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified
     * by an array of data elements of type <code>transferType</code> passed 
     * in as an object reference.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the green value 
     * is 0.  If <code>inData</code> is not a primitive array of type
     * <code>transferType</code>, a <code>ClassCastException</code> is thrown.
     *  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>inData</code> is not large enough to hold a pixel
     * value for this <code>ColorModel</code>.  Since
     * <code>DirectColorModel</code> can be subclassed, subclasses inherit
     * the implementation of this method and if they don't override it
     * then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * An <code>UnsupportedOperationException</code> is
     * thrown if this <code>transferType</code> is not supported by this 
     * <code>ColorModel</code>.
     * @param inData the array containing the pixel value
     * @return the value of the green component of the specified pixel.
     * @throws ArrayIndexOutOfBoundsException if <code>inData</code> is not
     *         large enough to hold a pixel value for this color model
     * @throws ClassCastException if <code>inData</code> is not a 
     *         primitive array of type <code>transferType</code>
     * @throws UnsupportedOperationException if this <code>transferType</code>
     *         is not supported by this color model
     */
    public int getGreen(Object inData) {
        int pixel=0;
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])inData;
               pixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])inData;
               pixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])inData;
               pixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getGreen(pixel);
    }
   

    /**
     * Returns the blue color component for the specified pixel, scaled
     * from 0 to 255 in the default RGB <code>ColorSpace</code>, sRGB.  A 
     * color conversion is done if necessary.  The pixel value is specified
     * by an array of data elements of type <code>transferType</code> passed 
     * in as an object reference.
     * The returned value is a non pre-multiplied value.  Thus, if the
     * alpha is premultiplied, this method divides it out before returning
     * the value.  If the alpha value is 0, for example, the blue value 
     * is 0.  If <code>inData</code> is not a primitive array of type
     * <code>transferType</code>, a <code>ClassCastException</code> is thrown.
     *  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>inData</code> is not large enough to hold a pixel
     * value for this <code>ColorModel</code>.  Since
     * <code>DirectColorModel</code> can be subclassed, subclasses inherit
     * the implementation of this method and if they don't override it
     * then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * An <code>UnsupportedOperationException</code> is
     * thrown if this <code>transferType</code> is not supported by this 
     * <code>ColorModel</code>.
     * @param inData the array containing the pixel value
     * @return the value of the blue component of the specified pixel.
     * @throws ArrayIndexOutOfBoundsException if <code>inData</code> is not
     *         large enough to hold a pixel value for this color model
     * @throws ClassCastException if <code>inData</code> is not a 
     *         primitive array of type <code>transferType</code>
     * @throws UnsupportedOperationException if this <code>transferType</code>
     *         is not supported by this color model
     */
    public int getBlue(Object inData) {
        int pixel=0;
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])inData;
               pixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])inData;
               pixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])inData;
               pixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getBlue(pixel);
    }

    /**
     * Returns the alpha component for the specified pixel, scaled
     * from 0 to 255.  The pixel value is specified by an array of data
     * elements of type <code>transferType</code> passed in as an object
     * reference.
     * If <code>inData</code> is not a primitive array of type 
     * <code>transferType</code>, a <code>ClassCastException</code> is 
     * thrown.  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>inData</code> is not large enough to hold a pixel
     * value for this <code>ColorModel</code>.  Since
     * <code>DirectColorModel</code> can be subclassed, subclasses inherit
     * the implementation of this method and if they don't override it
     * then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * If this <code>transferType</code> is not supported, an
     * <code>UnsupportedOperationException</code> is thrown.
     * @param inData the specified pixel
     * @return the alpha component of the specified pixel, scaled from
     *         0 to 255.
     * @exception <code>ClassCastException</code> if <code>inData</code>
     * 	is not a primitive array of type <code>transferType</code>
     * @exception <code>ArrayIndexOutOfBoundsException</code> if
     *	<code>inData</code> is not large enough to hold a pixel value
     *	for this <code>ColorModel</code>
     * @exception <code>UnsupportedOperationException</code> if this
     *	<code>tranferType</code> is not supported by this
     *	<code>ColorModel</code>
     */
    public int getAlpha(Object inData) {
        int pixel=0;
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])inData;
               pixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])inData;
               pixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])inData;
               pixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getAlpha(pixel);
    }

    /**
     * Returns the color/alpha components for the specified pixel in the
     * default RGB color model format.  A color conversion is done if
     * necessary.  The pixel value is specified by an array of data
     * elements of type <code>transferType</code> passed in as an object
     * reference.  If <code>inData</code> is not a primitive array of type
     * <code>transferType</code>, a <code>ClassCastException</code> is 
     * thrown.  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>inData</code> is not large enough to hold a pixel
     * value for this <code>ColorModel</code>.
     * The returned value is in a non pre-multiplied format.  Thus, if
     * the alpha is premultiplied, this method divides it out of the
     * color components.  If the alpha value is 0, for example, the color 
     * values is 0.  Since <code>DirectColorModel</code> can be
     * subclassed, subclasses inherit the implementation of this method
     * and if they don't override it then
     * they throw an exception if they use an unsupported 
     * <code>transferType</code>.
     *
     * @param inData the specified pixel
     * @return the color and alpha components of the specified pixel.
     * @exception UnsupportedOperationException if this 
     *            <code>transferType</code> is not supported by this
     *            <code>ColorModel</code>
     * @see ColorModel#getRGBdefault
     */
    public int getRGB(Object inData) {
        int pixel=0;
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])inData;
               pixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])inData;
               pixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])inData;
               pixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getRGB(pixel);
    }

    /**
     * Returns a data element array representation of a pixel in this
     * <code>ColorModel</code>, given an integer pixel representation in the
     * default RGB color model.
     * This array can then be passed to the <code>setDataElements</code>
     * method of a <code>WritableRaster</code> object.  If the pixel variable
     * is <code>null</code>, a new array is allocated.  If <code>pixel</code>
     * is not <code>null</code>, it must be a primitive array of type
     * <code>transferType</code> otherwise, a
     * <code>ClassCastException</code> is thrown.  An 
     * <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>pixel</code> is not large enough to hold a pixel 
     * value for this <code>ColorModel</code>.  The pixel array is returned.
     * Since <code>DirectColorModel</code> can be subclassed, subclasses
     * inherit the implementation of this method and if they don't
     * override it then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     *
     * @param rgb the integer pixel representation in the default RGB
     *            color model
     * @param pixel the specified pixel
     * @return an array representation of the specified pixel in this
     *         <code>ColorModel</code>
     * @exception ClassCastException if <code>pixel</code> 
     *  is not a primitive array of type <code>transferType</code>
     * @exception ArrayIndexOutOfBoundsException if
     *  <code>pixel</code> is not large enough to hold a pixel value
     *  for this <code>ColorModel</code>
     * @exception UnsupportedOperationException if this
     *  <code>transferType</code> is not supported by this 
     *  <code>ColorModel</code> 
     * @see WritableRaster#setDataElements
     * @see SampleModel#setDataElements
     */
    public Object getDataElements(int rgb, Object pixel) {
        //REMIND: maybe more efficient not to use int array for
        //DataBuffer.TYPE_USHORT and DataBuffer.TYPE_INT
        int i;
        int intpixel[] = null;
        if (transferType == DataBuffer.TYPE_INT &&
            pixel != null) {
           intpixel = (int[])pixel;
        } else {
            intpixel = new int[1];
        }

        ColorModel defaultCM = ColorModel.getRGBdefault();
        if (this == defaultCM || equals(defaultCM)) {
            intpixel[0] = rgb;
        } else if (is_sRGB) {
            double normAlpha = 1.;
            int c;
            if (supportsAlpha && isAlphaPremultiplied) {
                normAlpha = ((rgb>>24)&0xff)/255.;
            }

            int[] shifts = {16, 8, 0, 24};

            intpixel[0] = 0;
            for (i=0; i < 3; i++) {
                c = (int)(((rgb>>shifts[i])&0xff)*normAlphascaleFactors[i]);
                intpixel[0] |= (c << maskOffsets[i]) & maskArray[i];
            }
            if (supportsAlpha) {
                c = (int) (((rgb>>shifts[3])&0xff) / scaleFactors[3]);
                intpixel[0] |= (c << maskOffsets[3]) & maskArray[3];
            }
        } else {
            int components[] = defaultCM.getComponents(rgb, null, 0);
            float norm[] = defaultCM.getNormalizedComponents(components, 0,
                                                             null, 0);
            float rgbf[] = colorSpace.fromRGB(norm);
            double normAlpha = 1.;
            int c;
            if (supportsAlpha && isAlphaPremultiplied) {
                normAlpha = ((rgb>>24)&0xff)/255.;
            }

            intpixel[0] = 0;
            for (i=0; i < 3; i++) {
                c = (int) ((rgbf[i] * 255.0)*normAlphascaleFactors[i]);
                intpixel[0] |= (c << maskOffsets[i]) & maskArray[i];
            }
            if (supportsAlpha) {
                c = (int) (((rgb>>24)&0xff) / scaleFactors[3]);
                intpixel[0] |= (c << maskOffsets[3]) & maskArray[3];
            }
        }
        switch (transferType) {
            case DataBuffer.TYPE_BYTE: {
               byte bdata[];
               if (pixel == null) {
                   bdata = new byte[1];
               } else {
                   bdata = (byte[])pixel;
               }
               bdata[0] = (byte)(0xff&intpixel[0]);
               return bdata;
            }
            case DataBuffer.TYPE_USHORT:{
               short sdata[];
               if (pixel == null) {
                   sdata = new short[1];
               } else {
                   sdata = (short[])pixel;
               }
               sdata[0] = (short)(intpixel[0]&0xffff);
               return sdata;
            }
            case DataBuffer.TYPE_INT:
               return intpixel;
        }
        throw new UnsupportedOperationException("This method has not been "+
                 "implemented for transferType " + transferType);

    }

    /**
     * Returns an array of unnormalized color/alpha components given a pixel
     * in this <code>ColorModel</code>.  The pixel value is specified as an 
     * <code>int</code>.  If the <code>components</code> array is 
     * <code>null</code>, a new array is allocated.  The
     * <code>components</code> array is returned.  Color/alpha components are
     * stored in the <code>components</code> array starting at 
     * <code>offset</code>, even if the array is allocated by this method.  
     * An <code>ArrayIndexOutOfBoundsException</code> is thrown if the 
     * <code>components</code> array is not <code>null</code> and is not large
     * enough to hold all the color and alpha components, starting at 
     * <code>offset</code>.
     * @param pixel the specified pixel
     * @param components the array to receive the color and alpha
     * components of the specified pixel
     * @param offset the offset into the <code>components</code> array at
     * which to start storing the color and alpha components
     * @return an array containing the color and alpha components of the
     * specified pixel starting at the specified offset.
     */
    final public int[] getComponents(int pixel, int[] components, int offset) {
        if (components == null) {
            components = new int[offset+numComponents];
        }

        for (int i=0; i < numComponents; i++) {
            components[offset+i] = (pixel & maskArray[i]) >>> maskOffsets[i];
        }

        return components;
    }
    
    /**
     * Returns an array of unnormalized color/alpha components given a pixel
     * in this <code>ColorModel</code>.  The pixel value is specified by an 
     * array of data elements of type <code>transferType</code> passed in as 
     * an object reference.  If <code>pixel</code> is not a primitive array
     * of type <code>transferType</code>, a <code>ClassCastException</code>
     * is thrown.  An <code>ArrayIndexOutOfBoundsException</code> is
     * thrown if <code>pixel</code> is not large enough to hold a
     * pixel value for this <code>ColorModel</code>.  If the 
     * <code>components</code> array is <code>null</code>, a new
     * array is allocated.  The <code>components</code> array is returned.
     * Color/alpha components are stored in the <code>components</code> array 
     * starting at <code>offset</code>, even if the array is allocated by 
     * this method.  An <code>ArrayIndexOutOfBoundsException</code>
     * is thrown if the <code>components</code> array is not 
     * <code>null</code> and is not large enough to hold all the color and 
     * alpha components, starting at <code>offset</code>.
     * Since <code>DirectColorModel</code> can be subclassed, subclasses
     * inherit the implementation of this method and if they don't
     * override it then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * @param pixel the specified pixel
     * @param components the array to receive the color and alpha
     *        components of the specified pixel
     * @param offset the offset into the <code>components</code> array at
     *        which to start storing the color and alpha components
     * @exception ClassCastException if <code>pixel</code> 
     *  is not a primitive array of type <code>transferType</code>
     * @exception ArrayIndexOutOfBoundsException if
     *  <code>pixel</code> is not large enough to hold a pixel value
     *  for this <code>ColorModel</code>, or if <code>components</code>
     *  is not <code>null</code> and is not large enough to hold all the
     *  color and alpha components, starting at <code>offset</code>
     * @exception UnsupportedOperationException if this
     *            <code>transferType</code> is not supported by this
     *            color model 
     */
    final public int[] getComponents(Object pixel, int[] components,
                                     int offset) {
        int intpixel=0;
        switch (transferType) {
     	    case DataBuffer.TYPE_BYTE:
               byte bdata[] = (byte[])pixel;
               intpixel = bdata[0] & 0xff;
            break;
            case DataBuffer.TYPE_USHORT:
               short sdata[] = (short[])pixel;
               intpixel = sdata[0] & 0xffff;
            break;
            case DataBuffer.TYPE_INT:
               int idata[] = (int[])pixel;
               intpixel = idata[0];
            break;
            default:
               throw new UnsupportedOperationException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
        return getComponents(intpixel, components, offset);
    }
    
    /**
     * Creates a <code>WritableRaster</code> with the specified width and
     * height that has a data layout (<code>SampleModel</code>) compatible 
     * with this <code>ColorModel</code>.  
     * @param w the width to apply to the new <code>WritableRaster</code>
     * @param h the height to apply to the new <code>WritableRaster</code>
     * @return a <code>WritableRaster</code> object with the specified
     * width and height.
     * @throws IllegalArgumentException if <code>w</code> or <code>h</code>
     *         is less than or equal to zero  
     * @see WritableRaster
     * @see SampleModel
     */
    final public WritableRaster createCompatibleWritableRaster (int w,
                                                                int h) {
        int[] bandmasks;
        if (supportsAlpha) {
            bandmasks = new int[4];
            bandmasks[3] = alpha_mask;
        }
        else {
            bandmasks = new int[3];
        }
        bandmasks[0] = red_mask;
        bandmasks[1] = green_mask;
        bandmasks[2] = blue_mask;
        
        if (pixel_bits > 16) {
	    return Raster.createPackedRaster(DataBuffer.TYPE_INT,
                                             w,h,bandmasks,null); 
        }
        else if (pixel_bits > 8) {
	    return Raster.createPackedRaster(DataBuffer.TYPE_USHORT,
                                             w,h,bandmasks,null); 
        }
        else {
	    return Raster.createPackedRaster(DataBuffer.TYPE_BYTE,
                                             w,h,bandmasks,null); 
        }
    }

    /**
     * Returns a pixel value represented as an <code>int</code> in this 
     * <code>ColorModel</code>, given an array of unnormalized color/alpha 
     * components.   An <code>ArrayIndexOutOfBoundsException</code> is 
     * thrown if the <code>components</code> array is
     * not large enough to hold all the color and alpha components, starting
     * at <code>offset</code>.
     * @param components an array of unnormalized color and alpha
     * components
     * @param offset the index into <code>components</code> at which to
     * begin retrieving the color and alpha components
     * @return an <code>int</code> pixel value in this
     * <code>ColorModel</code> corresponding to the specified components.  
     * @exception <code>ArrayIndexOutOfBoundsException</code> if
     *  the <code>components</code> array is not large enough to 
     *	hold all of the color and alpha components starting at
     *	<code>offset</code> 
     */
    public int getDataElement(int[] components, int offset) {
        int pixel = 0;
        for (int i=0; i < numComponents; i++) {
            pixel |= ((components[offset+i]<<maskOffsets[i])&maskArray[i]);
        }
        return pixel;
    }
    
    /**
     * Returns a data element array representation of a pixel in this
     * <code>ColorModel</code>, given an array of unnormalized color/alpha 
     * components.
     * This array can then be passed to the <code>setDataElements</code> 
     * method of a <code>WritableRaster</code> object.
     * An <code>ArrayIndexOutOfBoundsException</code> is thrown if the 
     * <code>components</code> array
     * is not large enough to hold all the color and alpha components,
     * starting at offset.  If the <code>obj</code> variable is 
     * <code>null</code>, a new array is allocated.  If <code>obj</code> is 
     * not <code>null</code>, it must be a primitive array
     * of type <code>transferType</code> otherwise, a 
     * <code>ClassCastException</code> is thrown.
     * An <code>ArrayIndexOutOfBoundsException</code> is thrown if 
     * <code>obj</code> is not large enough to hold a pixel value for this 
     * <code>ColorModel</code>.
     * Since <code>DirectColorModel</code> can be subclassed, subclasses
     * inherit the implementation of this method and if they don't
     * override it then they throw an exception if they use an unsupported
     * <code>transferType</code>.
     * @param components an array of unnormalized color and alpha
     * components
     * @param offset the index into <code>components</code> at which to
     * begin retrieving color and alpha components
     * @param obj the <code>Object</code> representing an array of color
     * and alpha components
     * @return an <code>Object</code> representing an array of color and
     * alpha components.
     * @exception <code>ClassCastException</code> if <code>obj</code>
     *  is not a primitive array of type <code>transferType</code>
     * @exception <code>ArrayIndexOutOfBoundsException</code> if
     *  <code>obj</code> is not large enough to hold a pixel value
     *  for this <code>ColorModel</code> or the <code>components</code>
     *	array is not large enough to hold all of the color and alpha
     *	components starting at <code>offset</code> 
     * @exception UnsupportedOperationException if this
     *            <code>transferType</code> is not supported by this
     *            color model
     * @see WritableRaster#setDataElements
     * @see SampleModel#setDataElements
     */
    public Object getDataElements(int[] components, int offset, Object obj) {
        int pixel = 0;
        for (int i=0; i < numComponents; i++) {
            pixel |= ((components[offset+i]<<maskOffsets[i])&maskArray[i]);
        }
        switch (transferType) {
            case DataBuffer.TYPE_BYTE:
               if (obj instanceof byte[]) {
                   byte bdata[] = (byte[])obj;
                   bdata[0] = (byte)(pixel&0xff);
                   return bdata;
               } else {
                   byte bdata[] = {(byte)(pixel&0xff)};
                   return bdata;
               }
            case DataBuffer.TYPE_USHORT:
               if (obj instanceof short[]) {
                   short sdata[] = (short[])obj;
                   sdata[0] = (short)(pixel&0xffff);
                   return sdata;
               } else {
                   short sdata[] = {(short)(pixel&0xffff)};
                   return sdata;
               }
            case DataBuffer.TYPE_INT:
               if (obj instanceof int[]) {
                   int idata[] = (int[])obj;
                   idata[0] = pixel;
                   return idata;
               } else {
                   int idata[] = {pixel};
                   return idata;
               }
            default:
               throw new ClassCastException("This method has not been "+
                   "implemented for transferType " + transferType);
        }
    }

    /**
     * Forces the raster data to match the state specified in the
     * <code>isAlphaPremultiplied</code> variable, assuming the data is
     * currently correctly described by this <code>ColorModel</code>.  It
     * may multiply or divide the color raster data by alpha, or do
     * nothing if the data is in the correct state.  If the data needs to
     * be coerced, this method will also return an instance of this
     * <code>ColorModel</code> with the <code>isAlphaPremultiplied</code> 
     * flag set appropriately.  This method will throw a
     * <code>UnsupportedOperationException</code> if this transferType is
     * not supported by this <code>ColorModel</code>.  Since
     * <code>ColorModel</code> can be subclassed, subclasses inherit the
     * implementation of this method and if they don't override it then
     * they throw an exception if they use an unsupported transferType.
     *
     * @param raster the <code>WritableRaster</code> data
     * @param isAlphaPremultiplied <code>true</code> if the alpha is
     * premultiplied; <code>false</code> otherwise
     * @return a <code>ColorModel</code> object that represents the
     * coerced data.
     * @exception UnsupportedOperationException if this 
     *            <code>transferType</code> is not supported by this
     *            color model
     */
    final public ColorModel coerceData (WritableRaster raster,
                                        boolean isAlphaPremultiplied)
    {
        if (!supportsAlpha ||
            this.isAlphaPremultiplied() == isAlphaPremultiplied) {
            return this;
        }
        
        int w = raster.getWidth();
        int h = raster.getHeight();
        int aIdx = numColorComponents;
        float normAlpha;
        int alphaScale = (1 << nBits[aIdx]) - 1;

        int rminX = raster.getMinX();
        int rY = raster.getMinY();
        int rX;
        int pixel[] = null;

        if (isAlphaPremultiplied) {
            // Must mean that we are currently not premultiplied so
            // multiply by alpha
            switch (transferType) {
                case DataBuffer.TYPE_BYTE: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0.f) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int)(pixel[c]*normAlpha);
                                }
                                raster.setPixel(rX, rY, pixel);
                            }
                        }
                    }
                }
                break;
                case DataBuffer.TYPE_USHORT: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0.f) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int)(pixel[c]*normAlpha);
                                }
                                raster.setPixel(rX, rY, pixel);
                            }
                        }
                    }
                } 
                break; 
                case DataBuffer.TYPE_INT: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0.f) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int)(pixel[c]*normAlpha);
                                }
                                raster.setPixel(rX, rY, pixel);
                            }
                        }
                    }
                }
                break; 
                default:
                    throw new UnsupportedOperationException("This method has not been "+
                         "implemented for transferType " + transferType);
            }
        }
        else {
            // We are premultiplied and want to divide it out
            switch (transferType) {
                case DataBuffer.TYPE_BYTE: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] /= normAlpha;
                                }
                            }
                            raster.setPixel(rX, rY, pixel);
                        }
                    }
                }
                break;
                case DataBuffer.TYPE_USHORT: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] /= normAlpha;
                                }
                            }
                            raster.setPixel(rX, rY, pixel);
                        }
                    }
                }
                break;
                case DataBuffer.TYPE_INT: {
                    for (int y = 0; y < h; y++, rY++) {
                        rX = rminX;
                        for (int x = 0; x < w; x++, rX++) {
                            pixel = raster.getPixel(rX, rY, pixel);
                            normAlpha = pixel[aIdx]/alphaScale;
                            if (normAlpha != 0) {
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] /= normAlpha;
                                }
                            }
                            raster.setPixel(rX, rY, pixel);
                        }
                    }
                }
                break;
                default:
                    throw new UnsupportedOperationException("This method has not been "+
                         "implemented for transferType " + transferType);
            }
        }

        // Return a new color model
        return new DirectColorModel(colorSpace, pixel_bits, maskArray[0],
                                    maskArray[1], maskArray[2], maskArray[3],
                                    isAlphaPremultiplied,
                                    transferType);
                                    
    }

    /**
      * Returns <code>true</code> if <code>raster</code> is compatible
      * with this <code>ColorModel</code> and <code>false</code> if it is
      * not.
      * @param raster the {@link Raster} object to test for compatibility
      * @return <code>true</code> if <code>raster</code> is compatible
      * with this <code>ColorModel</code> <code>false</code> otherwise.
      */
    public boolean isCompatibleRaster(Raster raster) {
        SampleModel sm = raster.getSampleModel();
        SinglePixelPackedSampleModel spsm;
        if (sm instanceof SinglePixelPackedSampleModel) {
            spsm = (SinglePixelPackedSampleModel) sm;
        }
        else {
            return false;
        }
        if (spsm.getNumBands() != getNumComponents()) {
            return false;
        }

	int[] bitMasks = spsm.getBitMasks();
	for (int i=0; i<numComponents; i++) {
	    if (bitMasks[i] != maskArray[i]) {
		return false;
	    }
	}
	    
        return (raster.getTransferType() == transferType);
    }
    
    private void setFields() {
        // Set the private fields
        // REMIND: Get rid of these from the native code
        red_mask     = maskArray[0];
        red_offset   = maskOffsets[0];
        green_mask   = maskArray[1];
        green_offset = maskOffsets[1];
        blue_mask    = maskArray[2];
        blue_offset  = maskOffsets[2];
        if (nBits[0] < 8) {
            red_scale = (1 << nBits[0]) - 1;
        }
        if (nBits[1] < 8) {
            green_scale = (1 << nBits[1]) - 1;
        }
        if (nBits[2] < 8) {
            blue_scale = (1 << nBits[2]) - 1;
        }
        if (supportsAlpha) {
            alpha_mask   = maskArray[3];
            alpha_offset = maskOffsets[3];
            if (nBits[3] < 8) {
                alpha_scale = (1 << nBits[3]) - 1;
            }
        }
    }

    /**
     * Returns a <code>String</code> that represents this
     * <code>DirectColorModel</code>.
     * @return a <code>String</code> representing this 
     * <code>DirectColorModel</code>.
     */
    public String toString() {
        return new String("DirectColorModel: rmask="
                          +Integer.toHexString(red_mask)+" gmask="
                          +Integer.toHexString(green_mask)+" bmask="
                          +Integer.toHexString(blue_mask)+" amask="
                          +Integer.toHexString(alpha_mask));
    }
}