colormodel.java

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	 *
	 * <p>This method performs the inverse function of
	 * <code>getDataElements(int rgb, Object pixel)</code>.
	 * I.e. <code>(rgb == cm.getRGB(cm.getDataElements(rgb,
	 * null)))</code>.
	 *
	 * @param inData array of transferType containing a single pixel. The
	 * pixel should be encoded in the natural way of the color model.
	 *
	 * @return a pixel in sRGB color space, encoded in default
	 * 0xAARRGGBB format.
	 *
	 * @see #getDataElements(int, Object)
	 */
	public int getRGB(Object inData) {
		return ((getAlpha(inData) & 0xff) << 24) | ((getRed(inData) & 0xff) << 16) | ((getGreen(inData) & 0xff) << 8) | ((getBlue(inData) & 0xff) << 0);
	}

	/**
	 * Converts an sRGB pixel int value to an array containing a
	 * single pixel of the color space of the color model.
	 * 
	 * <p>This method performs the inverse function of
	 * <code>getRGB(Object inData)</code>.
	 *
	 * Outline of conversion process:
	 *
	 * <ol>
	 *
	 * <li>Convert rgb to normalized [0.0, 1.0] sRGB values.</li>
	 *
	 * <li>Convert to color space components using fromRGB in
	 * ColorSpace.</li>
	 *
	 * <li>If color model has alpha and should be premultiplied,
	 * multiply color space components with alpha value</li>
	 *
	 * <li>Scale the components to the correct number of bits.</li>
	 *
	 * <li>Arrange the components in the output array</li>
	 * 
	 * </ol>
	 *
	 * @param rgb The color to be converted to dataElements.  A pixel
	 * in sRGB color space, encoded in default 0xAARRGGBB format,
	 * assumed not alpha premultiplied.
	 *
	 * @param pixel to avoid needless creation of arrays, an array to
	 * use to return the pixel can be given. If null, a suitable array
	 * will be created.
	 *
	 * @return An array of transferType values representing the color,
	 * in the color model format. The color model defines whether the
	 *  
	 * @see #getRGB(Object)
	 */
	public Object getDataElements(int rgb, Object pixel) {
		// FIXME: implement
		throw new UnsupportedOperationException();
	}

	/**
	 * Fills an array with the unnormalized component samples from a
	 * pixel value. I.e. decompose the pixel, but not perform any
	 * color conversion. 
	 *
	 * This method is typically overriden in subclasses to provide a
	 * more efficient implementation.
	 * 
	 * @param pixel pixel value encoded according to the color model.
	 *
	 * @return arrays of unnormalized component samples of single
	 * pixel.  The scale and multiplication state of the samples are
	 * according to the color model. Each component sample is stored
	 * as a separate element in the array.
	 */
	public int[] getComponents(int pixel, int[] components, int offset) {
		// FIXME: implement
		throw new UnsupportedOperationException();
	}

	/**
	 * Fills an array with the unnormalized component samples from an
	 * array of transferType containing a single pixel. I.e. decompose
	 * the pixel, but not perform any color conversion.
	 *
	 * This method is typically overriden in subclasses to provide a
	 * more efficient implementation.
	 *
	 * @param array of transferType containing a single pixel.  The
	 * pixel should be encoded in the natural way of the color model.
	 * 
	 * @return arrays of unnormalized component samples of single
	 * pixel.  The scale and multiplication state of the samples are
	 * according to the color model. Each component sample is stored
	 * as a separate element in the array.
	 */
	public int[] getComponents(Object pixel, int[] components, int offset) {
		throw new UnsupportedOperationException();
	}

	/**
	 * Convert normalized components to unnormalized components.
	 */
	public int[] getUnnormalizedComponents(float[] normComponents, int normOffset, int[] components, int offset) {
		int numComponents = getNumComponents();
		if (components == null) {
			components = new int[offset + numComponents];
		}

		for (int i = 0; i < numComponents; i++) {
			float in = normComponents[normOffset++];
			int out = (int) (in * ((1 << getComponentSize(i)) - 1));
			components[offset++] = out;
		}
		return components;
	}

	/**
	 * Convert unnormalized components to normalized components.
	 */
	public float[] getNormalizedComponents(int[] components, int offset, float[] normComponents, int normOffset) {
		int numComponents = getNumComponents();
		if (normComponents == null) {
			normComponents = new float[normOffset + numComponents];
		}

		for (int i = 0; i < numComponents; i++) {
			float in = components[offset++];
			float out = in / ((1 << getComponentSize(i)) - 1);
			normComponents[normOffset++] = out;
		}
		return normComponents;
	}

	/**
	 * Converts the unnormalized component samples from an array to a
	 * pixel value. I.e. composes the pixel from component samples, but
	 * does not perform any color conversion or scaling of the samples.
	 * 
	 * This method performs the inverse function of
	 * <code>getComponents(int pixel, int[] components,
	 *			       int offset)</code>. I.e.
	 *
	 * <code>(pixel == cm.getDataElement(cm.getComponents(pixel, null,
	 * 0), 0))</code>.
	 *
	 * This method is typically overriden in subclasses to provide a
	 * more efficient implementation.
	 *
	 * @param arrays of unnormalized component samples of single
	 * pixel.  The scale and multiplication state of the samples are
	 * according to the color model. Each component sample is stored
	 * as a separate element in the array.
	 *
	 * @return pixel value encoded according to the color model.
	 */
	public int getDataElement(int[] components, int offset) {
		throw new UnsupportedOperationException();
	}

	public Object getDataElements(int[] components, int offset, Object obj) {
		throw new UnsupportedOperationException();
	}

	public boolean equals(Object obj) {
		if (!(obj instanceof ColorModel))
			return false;

		ColorModel o = (ColorModel) obj;
		return (pixel_bits == o.pixel_bits)
			&& (transferType == o.transferType)
			&& (transparency == o.transparency)
			&& (hasAlpha == o.hasAlpha)
			&& (isAlphaPremultiplied == isAlphaPremultiplied)
			&& (bits.equals(o.bits))
			&& (cspace.equals(o.cspace));
	}

	public final ColorSpace getColorSpace() {
		return cspace;
	}

	// Typically overridden
	public ColorModel coerceData(WritableRaster raster, boolean isAlphaPremultiplied) {
		if (this.isAlphaPremultiplied == isAlphaPremultiplied)
			return this;

		int w = raster.getWidth();
		int h = raster.getHeight();
		int x = raster.getMinX();
		int y = raster.getMinY();
		int size = w * h;
		int numColors = getNumColorComponents();
		int numComponents = getNumComponents();
		int alphaScale = (1 << getComponentSize(numColors)) - 1;
		double[] pixels = raster.getPixels(x, y, w, h, (double[]) null);

		for (int i = 0; i < size; i++) {
			double alpha = pixels[i * numComponents + numColors] * alphaScale;
			for (int c = 0; c < numColors; c++) {
				int offset = i * numComponents + c;
				if (isAlphaPremultiplied)
					pixels[offset] = pixels[offset] / alpha;
				else
					pixels[offset] = pixels[offset] * alpha;
			}
		}

		raster.setPixels(0, 0, w, h, pixels);

		// FIXME: what can we return?
		return null;
	}

	// Typically overridden
	public boolean isCompatibleRaster(Raster raster) {
		SampleModel sampleModel = raster.getSampleModel();
		return isCompatibleSampleModel(sampleModel);
	}

	// Typically overridden
	public WritableRaster createCompatibleWritableRaster(int w, int h) {
		return new WritableRaster(createCompatibleSampleModel(w, h), new Point(0, 0));
	}

	// Typically overridden
	public SampleModel createCompatibleSampleModel(int w, int h) {
		throw new UnsupportedOperationException();
	}

	// Typically overridden
	public boolean isCompatibleSampleModel(SampleModel sm) {
		return sm.getTransferType() == transferType;
	}

	public void finalize() {
	}

	/**
	 * Subclasses must override this method if it is possible for the
	 * color model to have an alpha channel.
	 *
	 * @return null, as per JDK 1.3 doc. Subclasses will only return
	 * null if no alpha raster exists.
	 */
	public WritableRaster getAlphaRaster(WritableRaster raster) {
		return null;

		/* It is a mystery to me why we couldn't use the following code...
		   
		   
		   if (!hasAlpha()) return null;
		   
		   SampleModel sm = raster.getSampleModel();
		   int[] alphaBand = { sm.getNumBands() - 1 };
		   SampleModel alphaModel = sm.createSubsetSampleModel(alphaBand);
		   DataBuffer buffer = raster.getDataBuffer();
		   Point origin = new Point(0, 0);
		   return Raster.createWritableRaster(alphaModel, buffer, origin);
		   
		
		   ...here, and avoided overriding the method in subclasses,
		   but the Sun docs state that this method always will return
		   null, and that overriding is required. Oh, well.
		*/
	}

	String stringParam() {
		return "pixel_bits="
			+ pixel_bits
			+ ", cspace="
			+ cspace
			+ ", transferType="
			+ transferType
			+ ", transparency="
			+ transparency
			+ ", hasAlpha="
			+ hasAlpha
			+ ", isAlphaPremultiplied="
			+ isAlphaPremultiplied;
	}

	public String toString() {
		return getClass().getName() + "[" + stringParam() + "]";
	}
}