+ // Ratio of backbuffer size in pixels to layer size in points.
+ CGSize ssize = backbuffer_size;
+ CGSize bsize = [self bounds].size;
+ GLfloat s = ((ssize.width > ssize.height ? ssize.width : ssize.height) /
+ (bsize.width > bsize.height ? bsize.width : bsize.height));
+
+ self.layer.contentsScale = s;
+ self.layer.affineTransform = t;