X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fstate_tracker%2Fst_cb_flush.c;h=1329f807bc9a43a81e53992478bf2b9a8df48ddd;hb=f67bc2e87255298ac22e8ccd98f482cc62d0ec26;hp=f8621ab125fbd37df70a1bb10ac28ba3073d0bef;hpb=59edbc70cd1042a884e7d153ba547c2f7f87318d;p=mesa.git

diff --git a/src/mesa/state_tracker/st_cb_flush.c b/src/mesa/state_tracker/st_cb_flush.c
index f8621ab125f..1329f807bc9 100644
--- a/src/mesa/state_tracker/st_cb_flush.c
+++ b/src/mesa/state_tracker/st_cb_flush.c
@@ -47,10 +47,19 @@
 #include "util/u_blit.h"
 
 
+/** Check if we have a front color buffer and if it's been drawn to. */
 static INLINE GLboolean
 is_front_buffer_dirty(struct st_context *st)
 {
-   return st->frontbuffer_status == FRONT_STATUS_DIRTY;
+   if (st->frontbuffer_status == FRONT_STATUS_DIRTY) {
+      return GL_TRUE;
+   }
+   else {
+      GLframebuffer *fb = st->ctx->DrawBuffer;
+      struct st_renderbuffer *strb
+         = st_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
+      return strb && strb->defined;
+   }
 }
 
 
@@ -63,23 +72,26 @@ display_front_buffer(struct st_context *st)
    GLframebuffer *fb = st->ctx->DrawBuffer;
    struct st_renderbuffer *strb
       = st_renderbuffer(fb->Attachment[BUFFER_FRONT_LEFT].Renderbuffer);
-   struct pipe_surface *front_surf = strb->surface;
 
-   /* Hook for copying "fake" frontbuffer if necessary:
-    */
-   st->pipe->screen->flush_frontbuffer( st->pipe->screen, front_surf,
-                                        st->pipe->priv );
-
-   /*
-   st->frontbuffer_status = FRONT_STATUS_UNDEFINED;
-   */
+   if (strb) {
+      struct pipe_surface *front_surf = strb->surface;
+      
+      /* Hook for copying "fake" frontbuffer if necessary:
+       */
+      st->pipe->screen->flush_frontbuffer( st->pipe->screen, front_surf,
+                                           st->pipe->priv );
+
+      /*
+        st->frontbuffer_status = FRONT_STATUS_UNDEFINED;
+      */
+   }
 }
 
 
 void st_flush( struct st_context *st, uint pipeFlushFlags,
                struct pipe_fence_handle **fence )
 {
-   FLUSH_VERTICES(st->ctx, 0);
+   FLUSH_CURRENT(st->ctx, 0);
 
    /* Release any vertex buffers that might potentially be accessed in
     * successive frames:
@@ -117,13 +129,16 @@ static void st_glFlush(GLcontext *ctx)
 {
    struct st_context *st = ctx->st;
 
+   /* Don't call st_finish() here.  It is not the state tracker's
+    * responsibilty to inject sleeps in the hope of avoiding buffer
+    * synchronization issues.  Calling finish() here will just hide
+    * problems that need to be fixed elsewhere.
+    */
+   st_flush(st, PIPE_FLUSH_RENDER_CACHE | PIPE_FLUSH_FRAME, NULL);
+
    if (is_front_buffer_dirty(st)) {
-      st_finish(st);
       display_front_buffer(st);
    }
-   else {
-      st_flush(st, PIPE_FLUSH_RENDER_CACHE, NULL);
-   }
 }
 
 
@@ -146,4 +161,16 @@ void st_init_flush_functions(struct dd_function_table *functions)
 {
    functions->Flush = st_glFlush;
    functions->Finish = st_glFinish;
+
+   /* Windows opengl32.dll calls glFinish prior to every swapbuffers.
+    * This is unnecessary and degrades performance.  Luckily we have some
+    * scope to work around this, as the externally-visible behaviour of
+    * Finish() is identical to Flush() in all cases - no differences in
+    * rendering or ReadPixels are visible if we opt not to wait here.
+    *
+    * Only set this up on windows to avoid suprise elsewhere.
+    */
+#ifdef PIPE_OS_WINDOWS
+   functions->Finish = st_glFlush;
+#endif
 }