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 */
017package org.apache.commons.imaging.formats.png;
018
019/**
020 * Used to specify physical scale when reading or storing image information.
021 */
022public final class PhysicalScale {
023    private static final int METER_UNITS = 1;
024    private static final int RADIAN_UNITS = 2;
025    public static final PhysicalScale UNDEFINED = createFromMeters(-1.0, -1.0);
026
027    public static PhysicalScale createFromMeters(final double x, final double y) {
028        return new PhysicalScale(METER_UNITS, x, y);
029    }
030
031    public static PhysicalScale createFromRadians(final double x, final double y) {
032        return new PhysicalScale(RADIAN_UNITS, x, y);
033    }
034
035    private final int units;
036
037    private final double horizontalUnitsPerPixel;
038
039    private final double verticalUnitsPerPixel;
040
041    private PhysicalScale(final int units, final double horizontalUnitsPerPixel, final double verticalUnitsPerPixel) {
042        this.units = units;
043        this.horizontalUnitsPerPixel = horizontalUnitsPerPixel;
044        this.verticalUnitsPerPixel = verticalUnitsPerPixel;
045    }
046
047    public double getHorizontalUnitsPerPixel() {
048        return horizontalUnitsPerPixel;
049    }
050
051    public double getVerticalUnitsPerPixel() {
052        return verticalUnitsPerPixel;
053    }
054
055    public boolean isInMeters() {
056        return METER_UNITS == units;
057    }
058
059    public boolean isInRadians() {
060        return RADIAN_UNITS == units;
061    }
062}