Camera2VideoFragment.java 文件源码

/**
 * Configures the necessary {@link Matrix} transformation to `mTextureView`.
 * This method should not to be called until the camera preview size is determined in
 * openCamera, or until the size of `mTextureView` is fixed.
 *
 * @param viewWidth  The width of `mTextureView`
 * @param viewHeight The height of `mTextureView`
 */
private void configureTransform(int viewWidth, int viewHeight) {
    Activity activity = getActivity();
    if (null == mTextureView || null == mPreviewSize || null == activity) {
        return;
    }
    int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
    Matrix matrix = new Matrix();
    RectF viewRect = new RectF(0, 0, viewWidth, viewHeight);
    RectF bufferRect = new RectF(0, 0, mPreviewSize.getHeight(), mPreviewSize.getWidth());
    float centerX = viewRect.centerX();
    float centerY = viewRect.centerY();
    if (Surface.ROTATION_90 == rotation || Surface.ROTATION_270 == rotation) {
        bufferRect.offset(centerX - bufferRect.centerX(), centerY - bufferRect.centerY());
        matrix.setRectToRect(viewRect, bufferRect, Matrix.ScaleToFit.FILL);
        float scale = Math.max(
                (float) viewHeight / mPreviewSize.getHeight(),
                (float) viewWidth / mPreviewSize.getWidth());
        matrix.postScale(scale, scale, centerX, centerY);
        matrix.postRotate(90 * (rotation - 2), centerX, centerY);
    }
    mTextureView.setTransform(matrix);
}