Java tutorial
//package com.java2s; /* * 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 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((float) b.getWidth(), 0); } else if (degrees == 90 || degrees == 270) { m.postTranslate((float) 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; } }