001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018package org.apache.commons.imaging.formats.png;
019
020import java.util.Arrays;
021
022public enum PngColorType {
023
024    // FIXME can this be merged with ImageInfo.ColorType?
025
026    GREYSCALE(0, true, false, 1, new int[]{1, 2, 4, 8, 16}),
027    TRUE_COLOR(2, false, false, 3, new int[]{8, 16}),
028    INDEXED_COLOR(3, false, false, 1, new int[]{1, 2, 4, 8}),
029    GREYSCALE_WITH_ALPHA(4, true, true, 2, new int[]{8, 16}),
030    TRUE_COLOR_WITH_ALPHA(6, false, true, 4, new int[]{8, 16});
031
032    private final int value;
033    private final boolean greyscale;
034    private final boolean alpha;
035    private final int samplesPerPixel;
036    private final int[] allowedBitDepths;
037
038    PngColorType(final int value, final boolean greyscale, final boolean alpha, final int samplesPerPixel, final int[] allowedBitDepths) {
039        this.value = value;
040        this.greyscale = greyscale;
041        this.alpha = alpha;
042        this.samplesPerPixel = samplesPerPixel;
043        this.allowedBitDepths = allowedBitDepths;
044    }
045
046    int getValue() {
047        return value;
048    }
049
050    boolean isGreyscale() {
051        return greyscale;
052    }
053
054    boolean hasAlpha() {
055        return alpha;
056    }
057
058    int getSamplesPerPixel() {
059        return samplesPerPixel;
060    }
061
062    boolean isBitDepthAllowed(final int bitDepth) {
063        return Arrays.binarySearch(allowedBitDepths, bitDepth) >= 0;
064    }
065
066    public static PngColorType getColorType(final int value) {
067        for (final PngColorType type : values()) {
068            if (type.value == value) {
069                return type;
070            }
071        }
072
073        return null;
074    }
075
076    static PngColorType getColorType(final boolean alpha, final boolean grayscale) {
077        if (grayscale) {
078            if (alpha) {
079                return PngColorType.GREYSCALE_WITH_ALPHA;
080            } else {
081                return PngColorType.GREYSCALE;
082            }
083        } else if (alpha) {
084            return PngColorType.TRUE_COLOR_WITH_ALPHA;
085        } else {
086            return PngColorType.TRUE_COLOR;
087        }
088    }
089}