Refine performance measurement

1 files changed, 30 insertions, 4 deletions

diff --git a/src/daw.c b/src/daw.c
index c6553ab..2e4238a 100644
--- a/src/daw.c
+++ b/src/daw.c
@@ -195,6 +195,14 @@ i32 engine_run(Instance* p, StateType initial_state, void* state_arg) {
   /* The target frametime measured in μs */
   const u32 fps_cap = p->fps_target > 0 ? 1000000 / p->fps_target : 0;
 
+  u64 measurement_total[10];
+  u64 measurement_rendering[10];
+  u64 measurement_idle[10];
+
+  memset(measurement_total, 0, sizeof(u64) * 10);
+  memset(measurement_rendering, 0, sizeof(u64) * 10);
+  memset(measurement_idle, 0, sizeof(u64) * 10);
+
   /* Main loop */
   do {
     /* frame_start is μs since engine was initialized */
@@ -202,6 +210,7 @@ i32 engine_run(Instance* p, StateType initial_state, void* state_arg) {
 
     /* dt measured in μs */
     const u64 dt = frame_start - frame_end;
+    measurement_total[ticks%10] = dt;
 
     /* Delta is relative to FPS cap */
     //const f64 delta = (f64)dt / (f64)fps_cap;
@@ -245,14 +254,16 @@ i32 engine_run(Instance* p, StateType initial_state, void* state_arg) {
       const u64 rendertime_begin  = get_time();
       render_begin(p->window);
       render_present(p->window, &default_quad_renderobject);
-      const u64 rendertime_dt = get_time() - rendertime_begin;
+      measurement_rendering[ticks%10] = get_time() - rendertime_begin;
 
       /* Regulate FPS */
       frame_end = get_time();
       const i64 fps_diff = fps_cap - (i64)(frame_end - frame_start);
 
       if (fps_diff > 0) {
+        const u64 idletime_begin  = get_time();
         delay((u64)fps_diff);
+        measurement_idle[ticks%10] = get_time() - idletime_begin;
       }
 
       frame_end = frame_start;
@@ -263,15 +274,30 @@ i32 engine_run(Instance* p, StateType initial_state, void* state_arg) {
       /* only make measurements once a second */
       if (dt_measurement > 1000000) {
 
+        double avg_total = 0;
+        double avg_rendering = 0;
+        double avg_idle = 0;
+
+        for (int i = 0; i < 10; i++) {
+          avg_total += measurement_total[i];
+          avg_rendering += measurement_rendering[i];
+          avg_idle += measurement_idle[i];
+        }
+        avg_total /= 10.0;
+        avg_rendering /= 10.0;
+        avg_idle /= 10.0;
+
         printf("  FPS: %.1f"
                "\tticks: %lu"
-               "\tframetime: %.3fms"
+               "\tdt: %.3fms"
                "\trendertime: %.3fms"
+               "\tidle: %.3fms"
                "\n"
             , ((f64)(ticks - last_fps_ticks)) / ((f64)dt_measurement / 1000000.0)
             , ticks
-            , (double)dt / 1000.0
-            , (double)rendertime_dt / 1000.0
+            , (double)avg_total / 1000.0
+            , (double)avg_rendering / 1000.0
+            , (double)avg_idle / 1000.0
             );
 
         last_fps_measurement = frame_end;