directcolormodel.java

JAVA基本类源代码,大家可以学习学习!

     * 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 intpixel[] = null;
        if (transferType == DataBuffer.TYPE_INT &&
            pixel != null) {
            intpixel = (int[])pixel;
            intpixel[0] = 0;
        } else {
            intpixel = new int[1];
        }

        ColorModel defaultCM = ColorModel.getRGBdefault();
        if (this == defaultCM || equals(defaultCM)) {
            intpixel[0] = rgb;
            return intpixel;
        }

        int red, grn, blu, alp;
        red = (rgb>>16) & 0xff;
        grn = (rgb>>8) & 0xff;
        blu = rgb & 0xff;
        if (is_sRGB || is_LinearRGB) {
            int precision;
            float factor;
            if (is_LinearRGB) {
                if (lRGBprecision == 8) {
                    red = fromsRGB8LUT8[red] & 0xff;
                    grn = fromsRGB8LUT8[grn] & 0xff;
                    blu = fromsRGB8LUT8[blu] & 0xff;
                    precision = 8;
                    factor = 1.0f / 255.0f;
                } else {
                    red = fromsRGB8LUT16[red] & 0xffff;
                    grn = fromsRGB8LUT16[grn] & 0xffff;
                    blu = fromsRGB8LUT16[blu] & 0xffff;
                    precision = 16;
                    factor = 1.0f / 65535.0f;
                }
            } else {
                precision = 8;
                factor = 1.0f / 255.0f;
            }
            if (supportsAlpha) {
                alp = (rgb>>24) & 0xff;
                if (isAlphaPremultiplied) {
                    factor *= (alp * (1.0f / 255.0f));
                    precision = -1;  // force component calculations below
                }
                if (nBits[3] != 8) {
                    alp = (int)
                        ((alp * (1.0f / 255.0f) * ((1<<nBits[3]) - 1)) + 0.5f);
                    if (alp > ((1<<nBits[3]) - 1)) {
                        // fix 4412670 - see comment below
                        alp = (1<<nBits[3]) - 1;
                    }
                }
                intpixel[0] = alp << maskOffsets[3];
            }
            if (nBits[0] != precision) {
                red = (int) ((red * factor * ((1<<nBits[0]) - 1)) + 0.5f);
            }
            if (nBits[1] != precision) {
                grn = (int) ((grn * factor * ((1<<nBits[1]) - 1)) + 0.5f);
            }
            if (nBits[2] != precision) {
                blu = (int) ((blu * factor * ((1<<nBits[2]) - 1)) + 0.5f);
            }
        } else {
            // Need to convert the color
            float[] norm = new float[3];
            float factor = 1.0f / 255.0f;
            norm[0] = red * factor;
            norm[1] = grn * factor;
            norm[2] = blu * factor;
            norm = colorSpace.fromRGB(norm);
            if (supportsAlpha) {
                alp = (rgb>>24) & 0xff;
                if (isAlphaPremultiplied) {
                    factor *= alp;
                    for (int i = 0; i < 3; i++) {
                        norm[i] *= factor;
                    }
                }
                if (nBits[3] != 8) {
                    alp = (int)
                        ((alp * (1.0f / 255.0f) * ((1<<nBits[3]) - 1)) + 0.5f);
                    if (alp > ((1<<nBits[3]) - 1)) {
                        // fix 4412670 - see comment below
                        alp = (1<<nBits[3]) - 1;
                    }
                }
                intpixel[0] = alp << maskOffsets[3];
            }
            red = (int) ((norm[0] * ((1<<nBits[0]) - 1)) + 0.5f);
            grn = (int) ((norm[1] * ((1<<nBits[1]) - 1)) + 0.5f);
            blu = (int) ((norm[2] * ((1<<nBits[2]) - 1)) + 0.5f);
        }

        if (maxBits > 23) {
            // fix 4412670 - for components of 24 or more bits
            // some calculations done above with float precision
            // may lose enough precision that the integer result