    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 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   private final int units;
    028   private final double horizontalUnitsPerPixel;
    029   private final double verticalUnitsPerPixel;
    030
    031   private PhysicalScale(final int units, final double horizontalUnitsPerPixel,
    032                         final double verticalUnitsPerPixel) {
    033      this.units = units;
    034      this.horizontalUnitsPerPixel = horizontalUnitsPerPixel;
    035      this.verticalUnitsPerPixel = verticalUnitsPerPixel;
    036   }
    037
    038   public static PhysicalScale createFromMeters(final double x, final double y) {
    039      return new PhysicalScale(METER_UNITS, x, y);
    040   }
    041
    042   public static PhysicalScale createFromRadians(final double x, final double y) {
    043      return new PhysicalScale(RADIAN_UNITS, x, y);
    044   }
    045
    046   public boolean isInMeters() {
    047      return METER_UNITS == units;
    048   }
    049
    050   public boolean isInRadians() {
    051      return RADIAN_UNITS == units;
    052   }
    053
    054   public double getHorizontalUnitsPerPixel() {
    055      return horizontalUnitsPerPixel;
    056   }
    057
    058   public double getVerticalUnitsPerPixel() {
    059      return verticalUnitsPerPixel;
    060   }
    061}