src/performance.c

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