From d053049fd52bba3a89527c81e0a4a52f19552e1e Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Wed, 26 Sep 2007 11:01:07 -0700
Subject: [PATCH] winex11: Load and use GLX_MESA_copy_sub_buffer for swapping
 buffers on a GLXPixmap.

---
 dlls/winex11.drv/opengl.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/dlls/winex11.drv/opengl.c b/dlls/winex11.drv/opengl.c
index 74ab94016c1..8224f68de2e 100644
--- a/dlls/winex11.drv/opengl.c
+++ b/dlls/winex11.drv/opengl.c
@@ -256,6 +256,9 @@ static BOOL  (*pglXDrawableAttribATI)(Display *dpy, GLXDrawable draw, const int
 static void* (*pglXAllocateMemoryNV)(GLsizei size, GLfloat readfreq, GLfloat writefreq, GLfloat priority);
 static void  (*pglXFreeMemoryNV)(GLvoid *pointer);
 
+/* MESA GLX Extensions */
+static void (*pglXCopySubBufferMESA)(Display *dpy, GLXDrawable drawable, int x, int y, int width, int height);
+
 /* Standard OpenGL */
 MAKE_FUNCPTR(glBindTexture)
 MAKE_FUNCPTR(glBitmap)
@@ -508,6 +511,10 @@ LOAD_FUNCPTR(glXFreeMemoryNV)
         pglXDrawableAttribATI = (void*)pglXGetProcAddressARB((const GLubyte *) "glXDrawableAttribATI");
     }
 
+    if(glxRequireExtension("GLX_MESA_copy_sub_buffer")) {
+        pglXCopySubBufferMESA = (void*)pglXGetProcAddressARB((const GLubyte *) "glXCopySubBufferMESA");
+    }
+
     X11DRV_WineGL_LoadExtensions();
 
     wine_tsx11_unlock();
@@ -3268,7 +3275,23 @@ BOOL X11DRV_SwapBuffers(X11DRV_PDEVICE *physDev)
 
   wine_tsx11_lock();
   sync_context(ctx);
-  pglXSwapBuffers(gdi_display, drawable);
+  if(physDev->pixmap) {
+      if(pglXCopySubBufferMESA) {
+          int w = physDev->dc_rect.right - physDev->dc_rect.left;
+          int h = physDev->dc_rect.bottom - physDev->dc_rect.top;
+
+          /* (glX)SwapBuffers has an implicit glFlush effect, however
+           * GLX_MESA_copy_sub_buffer doesn't. Make sure GL is flushed before
+           * copying */
+          pglFlush();
+          if(w > 0 && h > 0)
+              pglXCopySubBufferMESA(gdi_display, drawable, 0, 0, w, h);
+      }
+      else
+          pglXSwapBuffers(gdi_display, drawable);
+  }
+  else
+      pglXSwapBuffers(gdi_display, drawable);
   update_drawable(physDev);
   wine_tsx11_unlock();
 
-- 
2.11.4.GIT