From b63bbd3148e05efeaaac1a27eef9efc249f58d4d Mon Sep 17 00:00:00 2001
From: KikooDX <kikoodx@paranoici.org>
Date: Tue, 27 Apr 2021 00:52:03 +0200
Subject: [PATCH] Automatic frameskip

---
 include/conf.h |  3 +--
 src/main.c     | 24 ++++++++++++++++--------
 2 files changed, 17 insertions(+), 10 deletions(-)

diff --git a/include/conf.h b/include/conf.h
index f23f5f2..1a6f08d 100644
--- a/include/conf.h
+++ b/include/conf.h
@@ -7,8 +7,7 @@
 #define TILE_WIDTH    16
 #define TILE_HEIGHT   16
 #define TILESET_WIDTH 16
-#define TARGET_FPS    30
-#define TARGET_UPS    60
+#define TARGET_FPS    60
 #define LVL_PER_PACK  4
 #define ACC_GND       0.1
 #define ACC_AIR       0.025
diff --git a/src/main.c b/src/main.c
index 49f4693..fde0b39 100644
--- a/src/main.c
+++ b/src/main.c
@@ -43,13 +43,15 @@ extern char *fatal_error_msg;
 
 extern const font_t font_main;
 
-static int callback(volatile void *arg);
+static int callback(volatile int *arg);
 
 int main(void)
 {
 	int i;
 	int timer;
 	int player_return_code;
+	int frameskip = 0;
+	int toskip = 0;
 	/* int level_pack_beaten; */
 	enum TransitionMode transition_previous_mode;
 	enum GameState game_state = TitleScreen;
@@ -74,7 +76,7 @@ int main(void)
 		PANIC(fatal_error_msg);
 	/* timer setup */
 	timer =
-	    timer_setup(TIMER_ANY, 1000000 / TARGET_UPS, callback, &has_ticked);
+	    timer_setup(TIMER_ANY, 1000000 / TARGET_FPS, callback, &has_ticked);
 	if (timer == -1)
 		PANIC("timer_setup failed");
 	timer_start(timer);
@@ -84,13 +86,19 @@ int main(void)
 
 	/* main game loop */
 	while (!keydown(KEY_EXIT)) {
-		/* do x updates per frame, x being ups/fps */
-		i = TARGET_UPS / TARGET_FPS;
+		/* skip render frames */
+		i = 1 + frameskip;
+		toskip = frameskip;
 		while (i-- > 0) {
+			/* frameskip adjustement */
+			if (has_ticked - 1 > frameskip)
+				frameskip = has_ticked - 1;
+
 			/* speed limiter */
 			while (!has_ticked)
 				sleep();
-			has_ticked = 0;
+			while (has_ticked)
+				has_ticked = 0;
 
 			/* update */
 			input_update(&input);
@@ -204,6 +212,7 @@ int main(void)
 		case Playing:
 			level_draw();
 			particles_draw();
+			trail_draw();
 			player_draw(player);
 			transition_draw(transition);
 			break;
@@ -222,9 +231,8 @@ int main(void)
 	return 1;
 }
 
-static int callback(volatile void *arg)
+static int callback(volatile int *arg)
 {
-	volatile int *has_ticked = arg;
-	*has_ticked = 1;
+	*arg += 1;
 	return 0;
 }