    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}