@Override
    public void onSurfaceChanged(SurfaceHolder surfaceHolder, int format, int width, int height) {
      super.onSurfaceChanged(surfaceHolder, format, width, height);

      if (mRenderScript != null) {
        mRenderScript.setSurface(surfaceHolder, width, height);
      }

      if (mWallpaperRS == null) {
        mWallpaperRS = new PhaseBeamRS();
        mWallpaperRS.init(mDensityDPI, mRenderScript, getResources(), width, height);
        mWallpaperRS.start();
      }

      mWallpaperRS.resize(width, height);
    }