content: /*
   * Copyright (C) 2011 Google Inc.
   * 
   * Licensed 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 com.googlecode.leptonica.android;
  
  /**
   * Image scaling methods.
   * 
   * @author alanv@google.com (Alan Viverette)
   */
  public class Scale {
      static {
          System.loadLibrary("lept");
      }
  
      public enum ScaleType {
          /* Scale in X and Y independently, so that src matches dst exactly. */
          FILL,
  
          /*
           * Compute a scale that will maintain the original src aspect ratio, but
           * will also ensure that src fits entirely inside dst. May shrink or
           * expand src to fit dst.
           */
          FIT,
  
          /*
           * Compute a scale that will maintain the original src aspect ratio, but
           * will also ensure that src fits entirely inside dst. May shrink src to
           * fit dst, but will not expand it.
           */
          FIT_SHRINK,
      }
  
      /**
       * Scales the Pix to a specified width and height using a specified scaling
       * type (fill, stretch, etc.). Returns a scaled image or a clone of the Pix
       * if no scaling is required.
       *
       * @param pixs
       * @param width
       * @param height
       * @param type
       * @return a scaled image or a clone of the Pix if no scaling is required
       */
      public static Pix scaleToSize(Pix pixs, int width, int height, ScaleType type) {
          if (pixs == null)
              throw new IllegalArgumentException("Source pix must be non-null");
  
          int pixWidth = pixs.getWidth();
          int pixHeight = pixs.getHeight();
  
          float scaleX = width / (float) pixWidth;
          float scaleY = height / (float) pixHeight;
  
          switch (type) {
              case FILL:
                  // Retains default scaleX and scaleY values
                  break;
              case FIT:
                  scaleX = Math.min(scaleX, scaleY);
                  scaleY = scaleX;
                  break;
              case FIT_SHRINK:
                  scaleX = Math.min(1.0f, Math.min(scaleX, scaleY));
                  scaleY = scaleX;
                  break;
          }
  
          return scale(pixs, scaleX, scaleY);
      }
  
      /**
       * Scales the Pix to specified scale. If no scaling is required, returns a
       * clone of the source Pix.
       *
       * @param pixs the source Pix
       * @param scale dimension scaling factor
       * @return a Pix scaled according to the supplied factors
       */
      public static Pix scale(Pix pixs, float scale) {
          return scale(pixs, scale, scale);
      }
  
      /**
       * Scales the Pix to specified x and y scale. If no scaling is required,
       * returns a clone of the source Pix.
       *
       * @param pixs the source Pix
       * @param scaleX x-dimension (width) scaling factor
       * @param scaleY y-dimension (height) scaling factor
       * @return a Pix scaled according to the supplied factors
       */
      public static Pix scale(Pix pixs, float scaleX, float scaleY) {
          if (pixs == null)
              throw new IllegalArgumentException("Source pix must be non-null");
          if (scaleX <= 0.0f)
              throw new IllegalArgumentException("X scaling factor must be positive");
          if (scaleY <= 0.0f)
              throw new IllegalArgumentException("Y scaling factor must be positive");
  
          int nativePix = nativeScale(pixs.mNativePix, scaleX, scaleY);
  
          if (nativePix == 0)
              throw new RuntimeException("Failed to natively scale pix");
  
          return new Pix(nativePix);
      }
  
      // ***************
      // * NATIVE CODE *
      // ***************
  
      private static native int nativeScale(int nativePix, float scaleX, float scaleY);
  }
  