frameskip

inc/conf.h

@@ -1,5 +1,6 @@
 #pragma once
 
+#define TARGET_FPS          60
 #define TILE_SIZE           16
 #define PLAYER_WIDTH        12
 #define PLAYER_HEIGHT       12

src/main.c

@@ -1,27 +1,41 @@
+#include "conf.h"
 #include "input.h"
 #include "level.h"
 #include "player.h"
+#include <gint/cpu.h>
 #include <gint/display.h>
+#include <gint/timer.h>
 
 static struct Player player;
+static int timer;
+static volatile int has_ticked;
 
 static void init(void);
 static void deinit(void);
 static void draw(void);
 static void update(void);
+static int timer_callback(volatile int *);
 
 int
 main(void)
 {
 	extern const struct LevelBin kble_test;
+	int frameskip = 1;
 
 	init();
 	level_load(&kble_test);
 
-	draw();
 	do {
-		update();
+		int i;
 		draw();
+		for (i = 0; i < frameskip; i++) {
+			if (has_ticked > frameskip) frameskip = has_ticked;
+			while (!has_ticked)
+				sleep();
+			while (has_ticked)
+				has_ticked = 0;
+			update();
+		}
 	} while (input_up(K_EXIT));
 
 	deinit();
@@ -31,6 +45,10 @@ main(void)
 static void
 init(void)
 {
+	timer = timer_configure(TIMER_ANY, 1000000 / TARGET_FPS,
+	                        GINT_CALL(timer_callback, &has_ticked));
+	timer_start(timer);
+
 	input_init();
 	level_init();
 	player_init(&player);
@@ -40,6 +58,8 @@ static void
 deinit(void)
 {
 	level_deinit();
+
+	timer_stop(timer);
 }
 
 static void
@@ -57,3 +77,10 @@ draw(void)
 	player_draw(&player);
 	dupdate();
 }
+
+static int
+timer_callback(volatile int *arg)
+{
+	*arg += 1;
+	return 0;
+}