DRI2: Provide an interface for drivers to flush front-buffer rendering

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Kristian Høgsberg <krh@redhat.com>

include/GL/internal/dri_interface.h

@@ -659,7 +659,7 @@ struct __DRIbufferRec {
 };
 
 #define __DRI_DRI2_LOADER "DRI_DRI2Loader"
-#define __DRI_DRI2_LOADER_VERSION 1
+#define __DRI_DRI2_LOADER_VERSION 2
 struct __DRIdri2LoaderExtensionRec {
     __DRIextension base;
 
@@ -667,6 +667,19 @@ struct __DRIdri2LoaderExtensionRec {
 			       int *width, int *height,
 			       unsigned int *attachments, int count,
 			       int *out_count, void *loaderPrivate);
+
+    /**
+     * Flush pending front-buffer rendering
+     *
+     * Any rendering that has been performed to the
+     * \c __DRI_BUFFER_FAKE_FRONT_LEFT will be flushed to the
+     * \c __DRI_BUFFER_FRONT_LEFT.
+     *
+     * \param driDrawable    Drawable whose front-buffer is to be flushed
+     * \param loaderPrivate  Loader's private data that was previously passed
+     *                       into __DRIdri2ExtensionRec::createNewDrawable
+     */
+    void (*flushFrontBuffer)(__DRIdrawable *driDrawable, void *loaderPrivate);
 };
 
 /**

src/glx/x11/dri2_glx.c

@@ -273,6 +273,15 @@ static void dri2WaitGL(__GLXDRIdrawable *pdraw)
     XFixesDestroyRegion(pdraw->psc->dpy, region);
 }
 
+
+static void dri2FlushFrontBuffer(__DRIdrawable *driDrawable,
+				 void *loaderPrivate)
+{
+    (void) driDrawable;
+    dri2WaitGL((__GLXDRIdrawable *) loaderPrivate);
+}
+
+
 static void dri2DestroyScreen(__GLXscreenConfigs *psc)
 {
     /* Free the direct rendering per screen data */
@@ -327,6 +336,7 @@ dri2GetBuffers(__DRIdrawable *driDrawable,
 static const __DRIdri2LoaderExtension dri2LoaderExtension = {
     { __DRI_DRI2_LOADER, __DRI_DRI2_LOADER_VERSION },
     dri2GetBuffers,
+    dri2FlushFrontBuffer
 };
 
 static const __DRIextension *loader_extensions[] = {