http://bugs.winehq.org/show_bug.cgi?id=60207 --- Comment #5 from Zeb Figura <z.figura12@gmail.com> ---
Per Microsoft's flip-model presentation documentation, the scroll rectangle is "the area of the previous frame that the operating system needs to copy to the current frame before it renders the current frame". That copy is the runtime's responsibility, and Wine never performs it.
The documentation also states that you're not supposed to touch any pixel outside of that area, though. And retrieving the old data is not trivial. Once we present a swapchain with DISCARD it's gone; we have no idea if the next one is going to use dirty rects or not. If we store a copy we've given up the point of using DISCARD in the first place and pessimized performance for every application. -- Do not reply to this email, post in Bugzilla using the above URL to reply. You are receiving this mail because: You are watching all bug changes.