Wait for remaining time in interval rather than busy looping

This commit is contained in:
Camden Dixie O'Brien 2025-01-02 16:15:18 +00:00
parent 178d6a23d3
commit cda484c9ab

View File

@ -37,54 +37,52 @@ int main(int argc, char *argv[])
void *gamemem = calloc(1, game_conf.memsize);
game_init(argc, argv, gamemem, renderer);
perf_t perf = { .freq = SDL_GetPerformanceFrequency() / 1000000.0 };
uint64_t frame = 0, prevt = SDL_GetTicks64();
const uint64_t perfhz = SDL_GetPerformanceFrequency();
const uint64_t intervalperf = (INTERVAL * perfhz) / 1000;
perf_t perf = { .freq = perfhz / 1000000.0 };
uint64_t frame = 0;
while (1) {
const uint64_t t = SDL_GetTicks64();
const uint64_t dt = t - prevt;
if (dt >= INTERVAL) {
perf.start = SDL_GetPerformanceCounter();
perf.start = SDL_GetPerformanceCounter();
// Handle all events currently in queue
SDL_Event evt;
while (SDL_PollEvent(&evt)) {
if (game_evthandle(gamemem, &evt) != GAMESTATUS_OK)
goto quit;
}
perf.evt = SDL_GetPerformanceCounter();
// Update game state
if (game_update(gamemem, INTERVAL) != GAMESTATUS_OK)
// Handle all events currently in queue
SDL_Event evt;
while (SDL_PollEvent(&evt)) {
if (game_evthandle(gamemem, &evt) != GAMESTATUS_OK)
goto quit;
perf.update = SDL_GetPerformanceCounter();
}
perf.evt = SDL_GetPerformanceCounter();
// Render frame
SDL_RenderClear(renderer);
game_render(gamemem, renderer, t);
SDL_RenderPresent(renderer);
perf.render = SDL_GetPerformanceCounter();
// Update game state
if (game_update(gamemem, INTERVAL) != GAMESTATUS_OK)
goto quit;
perf.update = SDL_GetPerformanceCounter();
// Print performance analysis every 16 frames
if ((frame & 15) == 0) {
const double evt = (perf.evt - perf.start) / perf.freq;
const double update = (perf.update - perf.evt) / perf.freq;
const double render
= (perf.render - perf.update) / perf.freq;
const double total = (perf.render - perf.start) / perf.freq;
const double total_pc = (100 * total / (1000 * INTERVAL));
printf(
VT100_CLEAR VT100_CURSORTOPLEFT
"evt\t%10.3f μs\nupdate\t%10.3f μs\nrender\t"
"%10.3f μs\ntotal\t%10.3f μs (%05.2f%%)\n",
evt, update, render, total, total_pc);
}
// Render frame
SDL_RenderClear(renderer);
game_render(gamemem, renderer, SDL_GetTicks64());
SDL_RenderPresent(renderer);
perf.render = SDL_GetPerformanceCounter();
// Increment frame counter and update time
++frame;
prevt = t;
// Print performance analysis every 16 frames
if ((frame & 15) == 0) {
const double evt = (perf.evt - perf.start) / perf.freq;
const double update = (perf.update - perf.evt) / perf.freq;
const double render
= (perf.render - perf.update) / perf.freq;
const double total = (perf.render - perf.start) / perf.freq;
const double total_pc = (100 * total / (1000 * INTERVAL));
printf(
VT100_CLEAR VT100_CURSORTOPLEFT
"evt\t%10.3f μs\nupdate\t%10.3f μs\nrender\t"
"%10.3f μs\ntotal\t%10.3f μs (%05.2f%%)\n",
evt, update, render, total, total_pc);
}
SDL_Delay(INTERVAL / 8);
// Increment frame counter and wait until next interval
++frame;
const uint64_t elapsed = SDL_GetPerformanceCounter() - perf.start;
assert(elapsed < intervalperf);
SDL_Delay((1000 * (intervalperf - elapsed)) / perfhz);
}
quit: