src/engine/performance.c

   1 #ifndef _POSIX_C_SOURCE
   2 #define _POSIX_C_SOURCE 199309L
   3 #endif
   4
   5 #include "performance.h"
   6
   7 #include <stdbool.h>
   8 #include <stdio.h> // TODO remove
   9 #include <time.h>
  10
  11 #include "logger.h"
  12
  13 typedef struct timespec Timepoint;
  14
  15 static Timepoint lastDisplayTime;
  16 static int frames = 0;
  17 static bool meteringEnabled = false;
  18
  19
  20
  21 void initPerformanceMetering() {
  22         if (clock_gettime(CLOCK_MONOTONIC, &lastDisplayTime) != 0) {
  23                 logWarning("Clock read failed, performance metering unavailable");
  24         }
  25         else {
  26                 meteringEnabled = true;
  27         }
  28 }
  29
  30 void frameRendered() {
  31         if (meteringEnabled) {
  32                 ++frames;
  33                 Timepoint now;
  34
  35                 if (clock_gettime(CLOCK_MONOTONIC, &now) != 0) {
  36                         logWarning("Clock read failed, stopping performance metering");
  37                         meteringEnabled = false;
  38                         return;
  39                 }
  40
  41                 time_t fullSeconds = now.tv_sec - lastDisplayTime.tv_sec;
  42                 if (now.tv_nsec < lastDisplayTime.tv_nsec) --fullSeconds;
  43
  44                 if (fullSeconds > 0) {
  45                         float seconds = (now.tv_nsec - lastDisplayTime.tv_nsec) / 1000000000.0f;
  46                         seconds += (float) (now.tv_sec - lastDisplayTime.tv_sec);
  47                         // This goes to STDOUT because it's, uh, temporary
  48                         printf("frametime avg %.1f ms; fps avg %.f\n", (seconds / frames) * 1000.0f, (frames / seconds));
  49                         lastDisplayTime = now;
  50                         frames = 0;
  51                 }
  52         }
  53 }