retro-rpg/engine/engine.c

96 lines
2.4 KiB
C

/*
* Copyright (c) Camden Dixie O'Brien
* SPDX-License-Identifier: AGPL-3.0-only
*/
#include "engine_hooks.h"
#include <assert.h>
#include <stdatomic.h>
#include <stdbool.h>
#include <stdlib.h>
#define FRAMERATE 60
#define INTERVAL (1000 / FRAMERATE)
#define VT100_CURSORTOPLEFT "\33[H"
#define VT100_CLEAR "\33[2J"
typedef struct {
double freq;
uint64_t start, evt, update, render;
} perf_t;
int main(int argc, char *argv[])
{
int err = SDL_Init(SDL_INIT_VIDEO);
assert(0 == err);
SDL_Window *window = SDL_CreateWindow(
game_conf.win.title, SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED, game_conf.win.w, game_conf.win.h, 0);
assert(NULL != window);
SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, 0);
assert(NULL != renderer);
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();
while (1) {
const uint64_t t = SDL_GetTicks64();
const uint64_t dt = t - prevt;
if (dt >= INTERVAL) {
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)
goto quit;
perf.update = SDL_GetPerformanceCounter();
// Render frame
SDL_RenderClear(renderer);
game_render(gamemem, renderer, t);
SDL_RenderPresent(renderer);
perf.render = SDL_GetPerformanceCounter();
// Print performance if frame counter divisible by 8
if ((frame & 7) == 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);
}
// Increment frame counter and update time
++frame;
prevt = t;
}
SDL_Delay(INTERVAL / 8);
}
quit:
game_teardown(gamemem);
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
}