Matthew Flatt c7134a00af racket/gui cocoa: use CGLayer for canvas bitmaps ... The backing bitmap for a canvas is created as a CGLayer, which can make screen refresh much faster. Also, calling the `make-bitmap` method of `canvas%` produces a CGLayer-based bitmap, so drawing those bitmaps to a fast context can be fast. The improvement particularly helps with Retina displays, making DrRacket more responsive and increasing the potential frame rate of Slideshow. original commit: 9cb646bbd23221161ac7e0002b95937e4064e926		2013-11-23 11:38:47 -07:00
pkgs	racket/gui cocoa: use CGLayer for canvas bitmaps	2013-11-23 11:38:47 -07:00