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windows: Use wglSwapLayerBuffers if available.

It apparently works better (or can work better?) on multimonitor setups
than SwapBuffers.

This should be available back to Windows 95, but just in case, it falls
back to standard SwapBuffers if not available.

Fixes #13269.

(cherry picked from commit f286558baef3aa9e54a491d744935c8603a90194)
Ryan C. Gordon 3 weeks ago
parent
commit
b8ee44ca6a
2 changed files with 13 additions and 2 deletions
  1. 11 2
      src/video/windows/SDL_windowsopengl.c
  2. 2 0
      src/video/windows/SDL_windowsopengl.h

+ 11 - 2
src/video/windows/SDL_windowsopengl.c

@@ -141,6 +141,9 @@ bool WIN_GL_LoadLibrary(SDL_VideoDevice *_this, const char *path)
         SDL_LoadFunction(handle, "wglMakeCurrent");
         SDL_LoadFunction(handle, "wglMakeCurrent");
     _this->gl_data->wglShareLists = (BOOL (WINAPI *)(HGLRC, HGLRC))
     _this->gl_data->wglShareLists = (BOOL (WINAPI *)(HGLRC, HGLRC))
         SDL_LoadFunction(handle, "wglShareLists");
         SDL_LoadFunction(handle, "wglShareLists");
+    _this->gl_data->wglSwapLayerBuffers = (BOOL (WINAPI *)(HDC, UINT))
+        SDL_LoadFunction(handle, "wglSwapLayerBuffers");
+
     /* *INDENT-ON* */ // clang-format on
     /* *INDENT-ON* */ // clang-format on
 
 
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
@@ -886,8 +889,14 @@ bool WIN_GL_SwapWindow(SDL_VideoDevice *_this, SDL_Window *window)
 {
 {
     HDC hdc = window->internal->hdc;
     HDC hdc = window->internal->hdc;
 
 
-    if (!SwapBuffers(hdc)) {
-        return WIN_SetError("SwapBuffers()");
+    if (_this->gl_data->wglSwapLayerBuffers) {
+        if (!_this->gl_data->wglSwapLayerBuffers(hdc, WGL_SWAP_MAIN_PLANE)) {
+            return WIN_SetError("wglSwapLayerBuffers()");
+        }
+    } else {
+        if (!SwapBuffers(hdc)) {
+            return WIN_SetError("SwapBuffers()");
+        }
     }
     }
     return true;
     return true;
 }
 }

+ 2 - 0
src/video/windows/SDL_windowsopengl.h

@@ -85,6 +85,8 @@ struct SDL_GLDriverData
     BOOL (WINAPI *wglGetPixelFormatAttribivARB)(HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, const int *piAttributes, int *piValues);
     BOOL (WINAPI *wglGetPixelFormatAttribivARB)(HDC hdc, int iPixelFormat, int iLayerPlane, UINT nAttributes, const int *piAttributes, int *piValues);
     BOOL (WINAPI *wglSwapIntervalEXT)(int interval);
     BOOL (WINAPI *wglSwapIntervalEXT)(int interval);
     int (WINAPI *wglGetSwapIntervalEXT)(void);
     int (WINAPI *wglGetSwapIntervalEXT)(void);
+    BOOL (WINAPI *wglSwapLayerBuffers)(HDC hdc, UINT flags);
+
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
 #if defined(SDL_PLATFORM_XBOXONE) || defined(SDL_PLATFORM_XBOXSERIES)
     BOOL (WINAPI *wglSwapBuffers)(HDC hdc);
     BOOL (WINAPI *wglSwapBuffers)(HDC hdc);
     int (WINAPI *wglDescribePixelFormat)(HDC hdc,
     int (WINAPI *wglDescribePixelFormat)(HDC hdc,