/*
    * 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;
  
  /**
   * Used to specify physical scale when reading or storing image information.
   */
  public final class PhysicalScale {
      private static final int METER_UNITS = 1;
      private static final int RADIAN_UNITS = 2;
      public static final PhysicalScale UNDEFINED = createFromMeters(-1.0, -1.0);
  
      public static PhysicalScale createFromMeters(final double x, final double y) {
          return new PhysicalScale(METER_UNITS, x, y);
      }
  
      public static PhysicalScale createFromRadians(final double x, final double y) {
          return new PhysicalScale(RADIAN_UNITS, x, y);
      }
  
      private final int units;
  
      private final double horizontalUnitsPerPixel;
  
      private final double verticalUnitsPerPixel;
  
      private PhysicalScale(final int units, final double horizontalUnitsPerPixel, final double verticalUnitsPerPixel) {
          this.units = units;
          this.horizontalUnitsPerPixel = horizontalUnitsPerPixel;
          this.verticalUnitsPerPixel = verticalUnitsPerPixel;
      }
  
      public double getHorizontalUnitsPerPixel() {
          return horizontalUnitsPerPixel;
      }
  
      public double getVerticalUnitsPerPixel() {
          return verticalUnitsPerPixel;
      }
  
      public boolean isInMeters() {
          return METER_UNITS == units;
      }
  
      public boolean isInRadians() {
          return RADIAN_UNITS == units;
      }
  }