update gametime to be less heavy and more flexible

src/game/gametime.h

@@ -1,39 +1,24 @@
 #pragma once
-
 #include <time.h>
 
-#include "../util/attributes.h"
-
-typedef struct {
-	struct timespec ts; // stores the time at the current update
-	double sec;         // stores the current time in seconds
-	float scale;        // multiplier for the time calculation, default value is 1.0
-	float delta;        // the time that it took between updates
-} gametime;
-
-// initializes the gametime struct
-atrb_const static inline gametime gametime_new(void) {
+struct gametime {
 	struct timespec ts;
-	timespec_get(&ts, TIME_UTC);
+	float delta;
+};
 
-	return (gametime){
-		ts,
-		0.0,
-		1.0F,
-		0.0F,
-	};
+#if _POSIX_C_SOURCE >= 199309L
+static inline void gametime_get(struct timespec* ts) {
+	clock_gettime(CLOCK_MONOTONIC, ts);
 }
-
-// updates the internal variables
-static inline void gametime_update(gametime* gt) {
-	struct timespec ts;
-	timespec_get(&ts, TIME_UTC);
-	gt->sec = (double)ts.tv_nsec * 1e-9 + ts.tv_sec;                        // calculate the current time in seconds
-	gt->delta = ((double)(ts.tv_nsec - gt->ts.tv_nsec) * 1e-9) * gt->scale; // calculate how much time has passed between this and last frame
-	gt->ts = ts;                                                            // update the game's timespec
-}
-
-// gets how many times the game updates per second
-atrb_const static inline float gametime_get_ups(gametime const* gt) {
-	return 1.0F / gt->delta;
+#elif defined _WIN32
+# include <windows.h>
+static inline void gametime_get(struct timespec* ts) {
+	LARGE_INTEGER cnt, frq;
+	QueryPerformanceCounter(&cnt);
+	QueryPerformanceFrequency(&frq);
+	ts->tv_sec = (time_t)(cnt.QuadPart / frq.QuadPart);
+	ts->tv_nsec = (time_t)((cnt.QuadPart % frq.QuadPart) * 1000000000 / frq.QuadPart);
 }
+#else
+# error platform not supported
+#endif