Add support for EXT_timer_query.

1 files changed, 75 insertions, 3 deletions

diff --git a/glass.c b/glass.c
index 14e1719..a670535 100644
--- a/glass.c
+++ b/glass.c
@@ -103,8 +103,15 @@ GLUmat4 ring_obj_to_world[NUM_RINGS];
 
 static time_t start_tv_sec = 0;
 static float start_time, cur_time, last_fps_time = 0;
-int no_multi_draw_arrays = 0, benchmark = 0;
 static int frames = 0, last_fps_frames = 0;
+
+/* Timer queries */
+static GLboolean timers = GL_FALSE;
+static float clear_time = 0, shadow_generate_time = 0;
+static float rings_draw_time = 0, ground_draw_time = 0;
+static GLuint timer_query;
+
+int no_multi_draw_arrays = 0, benchmark = 0;
 static SDL_Surface *sdl_surf = NULL;
 static GLboolean done = GL_FALSE;
 
@@ -250,12 +257,60 @@ draw_shadow_map(void)
 }
 
 static void
+start_timer_query(void)
+{
+	if (!timers)
+		return;
+
+	if (!timer_query)
+		glGenQueries(1, &timer_query);
+
+	glBeginQuery(GL_TIME_ELAPSED_EXT, timer_query);
+}
+
+static void
+end_timer_query(float *time)
+{
+	GLint passed;
+
+	if (!timers)
+		return;
+
+	glEndQuery(GL_TIME_ELAPSED_EXT);
+	glGetQueryObjectiv(timer_query, GL_QUERY_RESULT, &passed);
+
+	*time += passed / 1000000000.0;
+}
+
+static void
+report_timers(void)
+{
+	if (!timers)
+		return;
+
+	printf("  clear time: %.2f secs\n"
+	       "  shadow time: %.2f secs\n"
+	       "  rings time: %.2f secs\n"
+	       "  ground time: %.2f secs\n",
+	       clear_time,
+	       shadow_generate_time,
+	       rings_draw_time,
+	       ground_draw_time);
+	clear_time = 0;
+	shadow_generate_time = 0;
+	rings_draw_time = 0;
+	ground_draw_time = 0;
+}
+
+static void
 draw(void)
 {
 	int instance;
 
+	start_timer_query();
 	glClearColor(0.0, 0.0, 0.8, 0.0);
 	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	end_timer_query(&clear_time);
 
 	glEnable(GL_CULL_FACE);
 	glEnable(GL_DEPTH_TEST);
@@ -264,15 +319,22 @@ draw(void)
 	for (instance = 0; instance < NUM_RINGS; instance++)
 		calc_new_ring_transforms(instance);
 
+	start_timer_query();
 	generate_rings_shadowmap();
+	end_timer_query(&shadow_generate_time);
 
 	glViewport(0, 0, win_width, win_height);
 
 	if (display_shadow_map) {
 		draw_shadow_map();
 	} else {
+		start_timer_query();
 		draw_rings();
+		end_timer_query(&rings_draw_time);
+
+		start_timer_query();
 		draw_ground();
+		end_timer_query(&ground_draw_time);
 	}
 
 	SDL_GL_SwapBuffers();
@@ -288,6 +350,7 @@ draw(void)
 		       frames,
 		       total_time,
 		       frames / total_time) ;
+		report_timers();
 		done = GL_TRUE;
 	}
 }
@@ -521,6 +584,7 @@ idle(void)
 			       (cur_time - last_fps_time));
 			last_fps_time = cur_time;
 			last_fps_frames = frames;
+			report_timers();
 		}
 	}
 }
@@ -548,7 +612,8 @@ key(SDLKey sym)
 
 static void usage(char *program)
 {
-	fprintf(stderr, "usage: %s [-nomultidraw] [-benchmark]\n", program);
+	fprintf(stderr, "usage: %s [-nomultidraw] [-benchmark] [-timers]\n",
+		program);
 	exit(1);
 }
 
@@ -613,6 +678,7 @@ int main(int argc, char **argv)
 	int i;
 
 	start_time = get_time_in_secs();
+	last_fps_time = start_time;
 
 	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) < 0)
 		errx(1, "sdl init fail");
@@ -623,7 +689,9 @@ int main(int argc, char **argv)
 	for (i = 1; i < argc; i++) {
 		if (strcmp(argv[i], "-nomultidraw") == 0)
 			no_multi_draw_arrays = 1;
-		if (strcmp(argv[i], "-benchmark") == 0)
+		else if (strcmp(argv[i], "-timers") == 0)
+			timers = 1;
+		else if (strcmp(argv[i], "-benchmark") == 0)
 			benchmark = 1;
 		else
 			usage(argv[0]);
@@ -631,6 +699,10 @@ int main(int argc, char **argv)
 
 	init();
 
+	if (timers && !GLEW_EXT_timer_query) {
+		errx(1, "Requires EXT_timer_query\n");
+	}
+
 	while (!done) {
 		SDL_Event event;