/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2002-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*/
package org.geotools.resources.image;
import java.awt.color.ColorSpace;
import java.awt.image.ComponentColorModel;
import java.awt.image.ComponentSampleModel;
import java.awt.image.DataBuffer;
import java.awt.image.SampleModel;
import javax.media.jai.ComponentSampleModelJAI;
import javax.media.jai.FloatDoubleColorModel;
import javax.media.jai.iterator.RectIter;
/**
* A {@link ComponentColorModel} modified for interoperability with Java Advanced Imaging.
* JAI 1.1 was designed for use with J2SE 1.3 and is not aware of new features in J2SE 1.4.
* This leads to the following problems:
*
* <ul>
* <li>{@link ComponentColorModel} supports {@code float} and {@code double}
* datatypes since J2SE 1.4 only. The workaround for J2SE 1.3 is to use the
* {@link FloatDoubleColorModel} provided with JAI 1.1.</li>
* <li>{@link FloatDoubleColorModel} ignores the new API in {@link ColorSpace}, especially
* the {@code getMinValue} and {@code getMaxValue} methods. Consequently,
* rendering of any image using our custom {@code ScaledColorSpace} is wrong.</li>
* <li>{@link ComponentColorModel} uses {@link java.awt.image.DataBufferFloat} and {@link
* java.awt.image.DataBufferDouble}, which are unknown to JAI 1.1. Consequently, trying
* to use {@link RectIter} with one of those will throw {@link ClassCastException}.</li>
* </ul>
*
* The work around is to use J2SE's {@link ComponentColorModel} (which work with our custom
* {@link ColorSpace}) and override its {@code createCompatibleSampleModel} in order to
* returns {@link ComponentSampleModelJAI} instead of {@link ComponentSampleModel} when
* {@code float} or {@code double} datatype is requested.
*
* @todo Remove this patch when JAI will recognize J2SE 1.4 classes.
*
* @since 2.0
*
*
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*/
public class ComponentColorModelJAI extends ComponentColorModel {
/**
* Whatever usage of this class should be enabled or not.
*/
public static final boolean ENABLED = false;
/**
* Construct a new color model.
*/
public ComponentColorModelJAI(final ColorSpace colorSpace,
final int[] bits,
final boolean hasAlpha,
final boolean isAlphaPremultiplied,
final int transparency,
final int transferType)
{
super(colorSpace, bits, hasAlpha, isAlphaPremultiplied, transparency, transferType);
}
/**
* Construct a new color model.
*/
public ComponentColorModelJAI(final ColorSpace colorSpace,
final boolean hasAlpha,
final boolean isAlphaPremultiplied,
final int transparency,
final int transferType)
{
super(colorSpace, hasAlpha, isAlphaPremultiplied, transparency, transferType);
}
/**
* Returns a compatible sample model. This implementation is nearly identical
* to default J2SE's implementation, except that it construct a JAI color model
* instead of a J2SE one.
*/
public SampleModel createCompatibleSampleModel(final int w, final int h) {
switch (transferType) {
default: {
return super.createCompatibleSampleModel(w, h);
}
case DataBuffer.TYPE_FLOAT: // fall through
case DataBuffer.TYPE_DOUBLE: {
final int numComponents = getNumComponents();
final int[] bandOffsets = new int[numComponents];
for (int i=0; i<numComponents; i++) {
bandOffsets[i] = i;
}
return new ComponentSampleModelJAI(transferType, w, h, numComponents,
w*numComponents, bandOffsets);
}
}
}
/**
* Returns the {@code String} representation of the contents of
* this {@code ColorModel}object.
*
* @return a {@code String} representing the contents of this
* {@code ColorModel} object.
*/
public String toString() {
return new String("ComponentColorModelJAI: #pixelBits = "+pixel_bits
+ " numComponents = "+ super.getNumComponents()
+ " color space = "+ super.getColorSpace()
+ " transparency = "+ super.getTransparency()
+ " has alpha = "+ super.hasAlpha()
+ " isAlphaPre = "+ super.isAlphaPremultiplied());
}
}