From 2368fa7b7f7fe2da5a2b29dbb0887023769a7d89 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Juhani=20Krekel=C3=A4?= <juhani@krekelä.fi>
Date: Sat, 14 Jan 2023 22:14:07 +0200
Subject: [PATCH] Tune snake speed and fix a bug with turning code

---
 mato8.asm | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/mato8.asm b/mato8.asm
index 3587355..50f2a0e 100644
--- a/mato8.asm
+++ b/mato8.asm
@@ -4,7 +4,7 @@
 ; Under Creative Commons Zero 1.0
 ; Assemble with c8asm (https://github.com/wernsey/chip8)
 
-define frames_wait 4
+define frames_wait 5
 
 define up_key 2
 define down_key 8
@@ -46,6 +46,8 @@ mainloop:
 	ld v0, frames_wait
 	ld dt, v0
 
+	ld v1, head_direction_reg
+
 	ld v0, up_key
 	sknp v0
 	call turn_up
@@ -116,22 +118,22 @@ spawn_fruit:
 
 turn_up:
 	; Don't allow 180° turns (which would kill the snake instantly)
-	se head_direction_reg, direction_down
+	se v1, direction_down
 	ld head_direction_reg, direction_up
 	ret
 
 turn_down:
-	se head_direction_reg, direction_up
+	se v1, direction_up
 	ld head_direction_reg, direction_down
 	ret
 
 turn_left:
-	se head_direction_reg, direction_right
+	se v1, direction_right
 	ld head_direction_reg, direction_left
 	ret
 
 turn_right:
-	se head_direction_reg, direction_left
+	se v1, direction_left
 	ld head_direction_reg, direction_right
 	ret