add gametime

src/game/game.c

@@ -1,18 +1,17 @@
 #include "game.h"
 
-#include "../error.h"
+#include "gametime.h"
 
 void game_init(game_data* dat) {
-    (void)dat;
-    //error(STATUS_ERROR, "function not defined");
+    *dat = (game_data){
+        gametime_new(),
+    };
 }
 
 void game_update(game_data* dat) {
-    (void)dat;
-    //error(STATUS_ERROR, "function not defined");
+    gametime_update(&dat->time);
 }
 
 void game_free(game_data* dat) {
     (void)dat;
-    error(STATUS_ERROR, "function not defined");
 }

src/game/game.h

@@ -1,9 +1,10 @@
 #pragma once
 
 #include <stdint.h>
+#include "gametime.h"
 
 typedef struct {
-    uint8_t tmp;
+    gametime time;
 } game_data;
 
 void game_init(game_data*);   // initializes everything needed to start the game; outputs to game_data

src/game/gametime.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <time.h>
+
+typedef struct {
+    struct timespec ts; // stores the time at the current update
+    float timescale;    // multiplier for the time calculation, default value is 1.0
+    float deltatime;    // the time that it took between updates
+} gametime;
+
+// initializes the gametime struct
+static inline gametime gametime_new(void) {
+    return (gametime){
+        {0},
+        1.0F,
+        0.0F,
+    };
+}
+
+// updates the internal variables
+static inline void gametime_update(gametime* gt) {
+    struct timespec ts;
+    timespec_get(&ts, TIME_UTC);
+    gt->deltatime = ((double)(ts.tv_nsec - gt->ts.tv_nsec) * 1e-9) * gt->timescale;
+    gt->ts = ts;
+}
+
+// gets how many times the
+static inline float gametime_get_ups(gametime* gt) {
+    return 1.0F / gt->deltatime;
+}