From 933aad6e90ab3a21af57cfab7337c4f7a88b7b4c Mon Sep 17 00:00:00 2001
From: Vince Weaver <vincent.weaver@maine.edu>
Date: Thu, 16 Nov 2017 17:17:16 -0500
Subject: [PATCH] tfv: get up/down world wrapping working

---
 tfv/tfv_worldmap.s | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/tfv/tfv_worldmap.s b/tfv/tfv_worldmap.s
index 33d00ba5..c8bd310c 100644
--- a/tfv/tfv_worldmap.s
+++ b/tfv/tfv_worldmap.s
@@ -189,7 +189,6 @@ check_high_x:
 	cmp	#36
 	bmi	check_low_x
 
-
 	; Off screen to right
 	lda	#0
 	sta	TFV_X
@@ -202,15 +201,37 @@ check_low_x:
 	bpl	check_high_y
 
 	dec	MAP_X
-	lda	#25
+	lda	#35
 	sta	TFV_X
 	inc	REFRESH
 
-
-
 check_high_y:
+	lda	TFV_Y			; load Y value
+	cmp	#28
+	bmi	check_low_y		; if less than 28, check low Y
+
+	clc
+	lda	#$4
+	sta	TFV_Y
+	adc	MAP_X
+	sta	MAP_X
+	inc	REFRESH
+	bne	done_map_check
 
 check_low_y:
+	lda	TFV_Y
+	cmp	#4
+	bpl	done_map_check
+
+	lda	#28
+	sta	TFV_Y
+	dec	MAP_X
+	dec	MAP_X
+	dec	MAP_X
+	dec	MAP_X
+	inc	REFRESH
+
+done_map_check:
 
 	;============================
 	; Refresh screen if needed