Roderick Colenbrander : wined3d: Prevent unneeded context switches.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: 817b520c3d5ed88abb959dbbbd85aa53eecb661d
URL:    http://source.winehq.org/git/wine.git/?a=commit;h=817b520c3d5ed88abb959dbbbd85aa53eecb661d

Author: Roderick Colenbrander <thunderbird2k at gmx.net>
Date:   Fri Nov  9 16:38:50 2007 +0100

wined3d: Prevent unneeded context switches.

---

 dlls/wined3d/context.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/dlls/wined3d/context.c b/dlls/wined3d/context.c
index 8311ab5..32d75b6 100644
--- a/dlls/wined3d/context.c
+++ b/dlls/wined3d/context.c
@@ -860,10 +860,17 @@ void ActivateContext(IWineD3DDeviceImpl *This, IWineD3DSurface *target, ContextU
     /* Activate the opengl context */
     if(context != This->activeContext) {
         BOOL ret;
-        TRACE("Switching gl ctx to %p, hdc=%p ctx=%p\n", context, context->hdc, context->glCtx);
-        ret = pwglMakeCurrent(context->hdc, context->glCtx);
-        if(ret == FALSE) {
-            ERR("Failed to activate the new context\n");
+
+        /* Prevent an unneeded context switch as those are expensive */
+        if(context->glCtx && (context->glCtx == pwglGetCurrentContext())) {
+            TRACE("Already using gl context %p\n", context->glCtx);
+        }
+        else {
+            TRACE("Switching gl ctx to %p, hdc=%p ctx=%p\n", context, context->hdc, context->glCtx);
+            ret = pwglMakeCurrent(context->hdc, context->glCtx);
+            if(ret == FALSE) {
+                ERR("Failed to activate the new context\n");
+            }
         }
         This->activeContext = context;
     }