dri2: Send out event when auxillary buffers are invalidated

This lets the DRI2 clients rely on the server to notify them when they
need to get new buffers.  Without this, OpenGL clients poll the server
in glViewport() which can be a performance problems and also isn't
completely correct behaviour.

We bump the DRI2 protocol minor to indicate the availability of the
event, which the DRI2 clients can use to avoid polling.  This speeds up
various piglit and oglc test cases as well as real applications.

Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/glx/glxdri2.c b/glx/glxdri2.c
index 4f8e0207e..9df682e71 100644
--- a/glx/glxdri2.c
+++ b/glx/glxdri2.c
@@ -429,6 +429,17 @@ __glXDRIscreenCreateContext(__GLXscreen *baseScreen,
     return &context->base;
 }
 
+static void
+__glXDRIinvalidateBuffers(DrawablePtr pDraw, void *priv)
+{
+#if __DRI2_FLUSH_VERSION >= 3
+    __GLXDRIdrawable *private = priv;
+    __GLXDRIscreen *screen = private->screen;
+
+    (*screen->flush->invalidate)(private->driDrawable);
+#endif
+}
+
 static __GLXdrawable *
 __glXDRIscreenCreateDrawable(ClientPtr client,
 			     __GLXscreen *screen,
@@ -459,7 +470,8 @@ __glXDRIscreenCreateDrawable(ClientPtr client,
     private->base.waitGL	= __glXDRIdrawableWaitGL;
     private->base.waitX		= __glXDRIdrawableWaitX;
 
-    if (DRI2CreateDrawable(client, pDraw, drawId)) {
+    if (DRI2CreateDrawable(client, pDraw, drawId,
+			   __glXDRIinvalidateBuffers, private)) {
 	    free(private);
 	    return NULL;
     }
@@ -573,9 +585,18 @@ static const __DRIdri2LoaderExtension loaderExtension = {
     dri2GetBuffersWithFormat,
 };
 
+#ifdef __DRI_USE_INVALIDATE
+static const __DRIuseInvalidateExtension dri2UseInvalidate = {
+   { __DRI_USE_INVALIDATE, __DRI_USE_INVALIDATE_VERSION }
+};
+#endif
+
 static const __DRIextension *loader_extensions[] = {
     &systemTimeExtension.base,
     &loaderExtension.base,
+#ifdef __DRI_USE_INVALIDATE
+    &dri2UseInvalidate,
+#endif
     NULL
 };