org.apache.commons.imaging.formats.png.transparencyfilters.TransparencyFilterIndexedColor Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.
*/
package org.apache.commons.imaging.formats.png.transparencyfilters;
import java.io.IOException;
import org.apache.commons.imaging.ImageReadException;
public class TransparencyFilterIndexedColor extends TransparencyFilter {
public TransparencyFilterIndexedColor(final byte[] bytes) {
super(bytes);
}
@Override
public int filter(final int rgb, final int index) throws ImageReadException, IOException {
final int length = getLength();
if (index >= length) { // TODO see below - is this check correct?
return rgb;
}
if ((index < 0) || (index > length)) { // TODO check for > length cannot be true because of check above
throw new ImageReadException(
"TransparencyFilterIndexedColor index: " + index + ", bytes.length: " + length);
}
final int alpha = getByte(index);
return ((0xff & alpha) << 24) | (0x00ffffff & rgb);
}
}