android开发步步为营之112:关于Camera镜像上下左右颠倒问题的解决办法

          我们在做自定义相机开发的过程中，一般会使用SurfaceView或者GlSurfaceView做预览，预览或拍照的时候经常会碰到镜像的左右颠倒或者上下颠倒？这个该怎么处理，这里给出解决方案。

          一、拍照照片镜像左右颠倒，使用Matrix来设置

           Matrix m = new Matrix();
           m.postScale(-1, 1); // 镜像水平翻转
           bmpPreview = Bitmap.createBitmap(bmpPreview, 0, 0, bmpPreview.getWidth(), bmpPreview.getHeight(), m, true);

          二、镜像上下颠倒，需要设置相机预览的显示方向

 public static void setCameraDisplayOrientation(Activity activity,
                                                   int cameraId, android.hardware.Camera camera) {
        try {
            android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
            android.hardware.Camera.getCameraInfo(cameraId, info);
            int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
            int degrees = 0;
            switch (rotation) {
                case Surface.ROTATION_0:
                    degrees = 0;
                    break;
                case Surface.ROTATION_90:
                    degrees = 90;
                    break;
                case Surface.ROTATION_180:
                    degrees = 180;
                    break;
                case Surface.ROTATION_270:
                    degrees = 270;
                    break;
            }

            int result;
            if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                result = (info.orientation + degrees) % 360;
                result = (360 - result) % 360;  // compensate the mirror
            } else {  // back-facing
                result = (info.orientation - degrees + 360) % 360;
            }
            camera.setDisplayOrientation(result);
        } catch (Exception e) {
            CommonUtil.printStackTrace(e);
        }

    }

        拍完照后还得旋转图片

      Matrix matrix = new Matrix();
      matrix.postRotate(CamParaUtil.getCameraDisplayOrientation(StickerMakeActivity.this, mCameraId, mCamera));
      matrix.postScale(scale, isCameraFront() ? -scale : scale);
      Bitmap cropRotateScaled = Bitmap.createBitmap(origin, (int) resultRect.left, (int) resultRect.top, (int) resultRect.width(), (int) resultRect.height(), matrix, true);

public static int getCameraDisplayOrientation(Activity activity,
                                                  int cameraId, android.hardware.Camera camera) {
        int result = 90;
        try {
            android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
            android.hardware.Camera.getCameraInfo(cameraId, info);
            int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
            int degrees = 0;
            switch (rotation) {
                case Surface.ROTATION_0:
                    degrees = 0;
                    break;
                case Surface.ROTATION_90:
                    degrees = 90;
                    break;
                case Surface.ROTATION_180:
                    degrees = 180;
                    break;
                case Surface.ROTATION_270:
                    degrees = 270;
                    break;
            }

            if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                result = (info.orientation + degrees) % 360;
                result = (360 - result) % 360;  // compensate the mirror
            } else {  // back-facing
                result = (info.orientation - degrees + 360) % 360;
            }
        } catch (Exception e) {
            CommonUtil.printStackTrace(e);
        }
        return result;

    }