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authorIan Romanick <ian.d.romanick@intel.com>2009-01-30 14:43:03 -0800
committerIan Romanick <ian.d.romanick@intel.com>2009-01-30 14:45:01 -0800
commit58b9cd411fd81e257364efb3f2738bd1ac556e34 (patch)
tree341742bf36fa5372d9f67caa1d918af4adc5443c /progs
parent7c48719a5f22648302bbd0026681770d8cc43914 (diff)
glxgears: Log a message if synched to vblank
Tries to use either GLX_MESA_swap_control or GLX_SGI_video_sync to detect whether the display is synchronized to the vertical blank. If it detects this, a message will be printed. HOPEFULLY this will prevent some of the bug reports such as "glxgears only gets 59.7fps. What's wrong with my driver?"
Diffstat (limited to 'progs')
-rw-r--r--progs/xdemos/glxgears.c74
1 files changed, 74 insertions, 0 deletions
diff --git a/progs/xdemos/glxgears.c b/progs/xdemos/glxgears.c
index 8db717f1aa3..dfe071b9c2e 100644
--- a/progs/xdemos/glxgears.c
+++ b/progs/xdemos/glxgears.c
@@ -39,6 +39,9 @@
#include <GL/gl.h>
#include <GL/glx.h>
+static int is_glx_extension_supported(Display *dpy, const char *query);
+
+static void query_vsync(Display *dpy);
#define BENCHMARK
@@ -561,12 +564,82 @@ make_window( Display *dpy, const char *name,
/**
+ * Determine whether or not a GLX extension is supported.
+ */
+int
+is_glx_extension_supported(Display *dpy, const char *query)
+{
+ const int scrnum = DefaultScreen(dpy);
+ const char *glx_extensions = NULL;
+ const size_t len = strlen(query);
+ const char *ptr;
+
+ if (glx_extensions == NULL) {
+ glx_extensions = glXQueryExtensionsString(dpy, scrnum);
+ }
+
+ ptr = strstr(glx_extensions, query);
+ return ((ptr != NULL) && ((ptr[len] == ' ') || (ptr[len] == '\0')));
+}
+
+
+/**
+ * Attempt to determine whether or not the display is synched to vblank.
+ */
+void
+query_vsync(Display *dpy)
+{
+ int interval = 0;
+
+
+#ifdef GLX_MESA_swap_control
+ if ((interval <= 0)
+ && is_glx_extension_supported(dpy, "GLX_MESA_swap_control")) {
+ PFNGLXGETSWAPINTERVALMESAPROC pglXGetSwapIntervalMESA =
+ (PFNGLXGETSWAPINTERVALMESAPROC)
+ glXGetProcAddressARB((const GLubyte *) "glXGetSwapIntervalMESA");
+
+ interval = (*pglXGetSwapIntervalMESA)();
+ }
+#endif
+
+
+#ifdef GLX_SGI_video_sync
+ if ((interval <= 0)
+ && is_glx_extension_supported(dpy, "GLX_SGI_video_sync")) {
+ PFNGLXGETVIDEOSYNCSGIPROC pglXGetVideoSyncSGI =
+ (PFNGLXGETVIDEOSYNCSGIPROC)
+ glXGetProcAddressARB((const GLubyte *) "glXGetVideoSyncSGI");
+ unsigned count;
+
+ if ((*pglXGetVideoSyncSGI)(& count) == 0) {
+ interval = (int) count;
+ }
+ }
+#endif
+
+
+ if (interval > 0) {
+ printf("Running synchronized to the vertical refresh. The framerate should be\n");
+ if (interval == 1) {
+ printf("approximately the same as the montior refresh rate.\n");
+ } else if (interval > 1) {
+ printf("approximately 1/%d the montior refresh rate.\n",
+ interval);
+ }
+ }
+}
+
+/**
* Handle one X event.
* \return NOP, EXIT or DRAW
*/
static int
handle_event(Display *dpy, Window win, XEvent *event)
{
+ (void) dpy;
+ (void) win;
+
switch (event->type) {
case Expose:
return DRAW;
@@ -686,6 +759,7 @@ main(int argc, char *argv[])
make_window(dpy, "glxgears", x, y, winWidth, winHeight, &win, &ctx);
XMapWindow(dpy, win);
glXMakeCurrent(dpy, win, ctx);
+ query_vsync(dpy);
if (printInfo) {
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));