directcolormodel.java

JAVA基本类源代码,大家可以学习学习!

               } 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;
        float alphaScale = 1.0f / ((float) ((1 << nBits[aIdx]) - 1));

        int rminX = raster.getMinX();
        int rY = raster.getMinY();
        int rX;
        int pixel[] = null;
        int zpixel[] = 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 +
                                                      0.5f);
                                }
                                raster.setPixel(rX, rY, pixel);
                            } else {
                                if (zpixel == null) {
                                    zpixel = new int[numComponents];
                                    java.util.Arrays.fill(zpixel, 0);
                                }
                                raster.setPixel(rX, rY, zpixel);
                            }
                        }
                    }
                }
                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 +
                                                      0.5f);
                                }
                                raster.setPixel(rX, rY, pixel);
                            } else {
                                if (zpixel == null) {
                                    zpixel = new int[numComponents];
                                    java.util.Arrays.fill(zpixel, 0);
                                }
                                raster.setPixel(rX, rY, zpixel);
                            }
                        }
                    }
                } 
                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 +
                                                      0.5f);
                                }
                                raster.setPixel(rX, rY, pixel);
                            } else {
                                if (zpixel == null) {
                                    zpixel = new int[numComponents];
                                    java.util.Arrays.fill(zpixel, 0);
                                }
                                raster.setPixel(rX, rY, zpixel);
                            }
                        }
                    }
                }
                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 != 0.0f) {
                                float invAlpha = 1.0f / normAlpha;
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int) (pixel[c] * invAlpha +
                                                      0.5f);
                                }
                                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) {
                                float invAlpha = 1.0f / normAlpha;
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int) (pixel[c] * invAlpha +
                                                      0.5f);
                                }
                                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) {
                                float invAlpha = 1.0f / normAlpha;
                                for (int c=0; c < aIdx; c++) {
                                    pixel[c] = (int) (pixel[c] * invAlpha +
                                                      0.5f);
                                }
                                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));
    }
}