Work around DWM bug on Windows 7 causing horrible performance

This commit is contained in:
Cameron Gutman 2018-08-20 21:17:25 -07:00
parent 5bf88cfe96
commit 9e9fe2a2cf

View file

@ -4,6 +4,10 @@
#include <streaming/streamutils.h>
#include <SDL_syswm.h>
#define WIN32_LEAN_AND_MEAN
#include <Windows.h>
#include <VersionHelpers.h>
#include <dwmapi.h>
#include <Limelight.h>
@ -481,8 +485,22 @@ bool DXVA2Renderer::initializeDevice(SDL_Window* window, bool enableVsync)
// to reduce latency by avoiding double v-syncing.
d3dpp.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;
// On Windows 7, DWM seems to have a nasty bug where using
// FlipEx causes rendering to be locked to 30 FPS. I'm not
// sure if Windows 8 is affected, but I confirmed Windows 8.1
// is not. I'm erring on the side of caution and assuming
// Windows 8 is affected.
if (IsWindows8Point1OrGreater()) {
// Use FlipEx mode if DWM is running to increase efficiency
d3dpp.SwapEffect = D3DSWAPEFFECT_FLIPEX;
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Using FlipEx swapping with DWM");
}
else {
d3dpp.SwapEffect = D3DSWAPEFFECT_DISCARD;
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Using discard swapping with DWM");
}
SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
"Windowed mode with DWM running");