rotate Bitmap for degree and mirror - Android android.graphics

Android examples for android.graphics:Bitmap Operation

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  4. Bitmap Operation

Description

rotate Bitmap for degree and mirror

Demo Code

/*/*from  ww  w.jav  a2 s .c  o  m*/
 * Copyright (C) 2009 The Android Open Source Project
 *
 * 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.
 */
 
import android.graphics.Bitmap;
import android.graphics.Matrix;

public class Main {

  public static Bitmap rotate(Bitmap b, int degrees) {
    return rotateAndMirror(b, degrees, false);
  }

  public static Bitmap rotateAndMirror(Bitmap b, int degrees, boolean mirror) {
    if ((degrees != 0 || mirror) && b != null) {
      Matrix m = new Matrix();
      // Mirror first.
      // horizontal flip + rotation = -rotation + horizontal flip
      if (mirror) {
        m.postScale(-1, 1);
        degrees = (degrees + 360) % 360;
        if (degrees == 0 || degrees == 180) {
          m.postTranslate(b.getWidth(), 0);
        } else if (degrees == 90 || degrees == 270) {
          m.postTranslate(b.getHeight(), 0);
        } else {
          throw new IllegalArgumentException("Invalid degrees=" + degrees);
        }
      }
      if (degrees != 0) {
        // clockwise
        m.postRotate(degrees, (float) b.getWidth() / 2, (float) b.getHeight() / 2);
      }

      try {
        Bitmap b2 = Bitmap.createBitmap(b, 0, 0, b.getWidth(), b.getHeight(), m, true);
        if (b != b2) {
          b.recycle();
          b = b2;
        }
      } catch (OutOfMemoryError ex) {
        // We have no memory to rotate. Return the original bitmap.
      }
    }
    return b;
  }

}

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