write code for a timing

src/game/time.h

@@ -0,0 +1,12 @@
+#pragma once
+
+#include <sys/cdefs.h>
+#include <time.h>
+
+/* gets the current time in milliseconds */
+time_t time_pull(void);
+
+/* Polls the time whether a given timeout has passed, comparing against `curr` as the current time.
+ * if `curr` ≥ `*proj`, `curr` + `delta` is written to `*proj`. `1` is returned.
+ * otherwise, we just return `0`. */
+__nonnull((3)) int time_poll(time_t curr, time_t delta, time_t* restrict proj);