/*
* #%L
* ACS AEM Commons Bundle
* %%
* Copyright (C) 2013 - 2014 Adobe
* %%
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
* #L%
*/
package com.adobe.acs.commons.images.transformers.impl.composites;
import java.awt.Composite;
import java.awt.CompositeContext;
import java.awt.RenderingHints;
import java.awt.image.ColorModel;
import java.awt.image.DirectColorModel;
import java.awt.image.RasterFormatException;
import com.adobe.acs.commons.images.transformers.impl.composites.contexts.MultiplyCompositeContext;
/**
* Applies a multiply blend to the models.
*
* Follows the rules defined here:
* http://helpx.adobe.com/after-effects/using/blending
* -modes-layer-styles.html#Multiply
*
* Based on
* http://www.java2s.com/Code/Java/2D-Graphics-GUI/BlendCompositeDemo.htm
*/
public class MultiplyBlendComposite implements Composite {
private static final DirectColorModel COLOR_MODEL = (DirectColorModel) ColorModel.getRGBdefault();
private final float alpha;
public MultiplyBlendComposite(float alpha) {
this.alpha = alpha;
}
@Override
public CompositeContext createContext(ColorModel srcColorModel, ColorModel dstColorModel, RenderingHints hints) {
if (!isValidColorModel(srcColorModel) || !isValidColorModel(dstColorModel)) {
throw new RasterFormatException("Invalid color model provided.");
}
return new MultiplyCompositeContext(alpha);
}
private static boolean isValidColorModel(ColorModel cm) {
if (!(cm instanceof DirectColorModel)) {
return false;
}
DirectColorModel dcm = (DirectColorModel) cm;
return (dcm.getAlphaMask() == COLOR_MODEL.getAlphaMask() && dcm.getRedMask() == COLOR_MODEL.getRedMask()
&& dcm.getGreenMask() == COLOR_MODEL.getGreenMask() && dcm.getBlueMask() == COLOR_MODEL.getBlueMask());
}
}