From: Lukas Krickl <lukas@krickl.dev>
Date: Tue, 29 Jul 2025 15:51:19 +0000 (+0200)
Subject: mapgen: added fix for left doors
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=2871810577cd327c7d0f06d42cf220a10daaf45f;p=gbrg%2F.git

mapgen: added fix for left doors

This fix prevents doors from being generated
next to walls
---

diff --git a/src/mapgen.s b/src/mapgen.s
index 948502e..bfe045d 100644
--- a/src/mapgen.s
+++ b/src/mapgen.s
@@ -281,6 +281,7 @@ mapgen_draw_room_pattern_row:
   push de  
 @x_loop:
     ld a, [bc]
+		call mapgen_fix_door_adjacent_to_collider
 
     ; read from tile and flag tables and write to map
 
@@ -307,3 +308,66 @@ mapgen_draw_room_pattern_row:
 
   pop de
   ret
+
+	; fixed door tile if it is adjacent to
+	; a collider tile
+	; inputs:
+	; 	hl: map_ptr
+	;		 a: pattern entry
+	; returns:
+	;		a: unchanged if not next to collider or not a door pattern
+	;   a: changed to wall tile if it is a door and is next to a collider
+	; preserves:
+	;		hl, bc, de
+mapgen_fix_door_adjacent_to_collider:
+	cp a, RPDU
+	jp z, @up_door 
+
+	cp a, RPDB
+	jp z, @down_door 
+
+	cp a, RPDL
+	jp z, @left_door 
+
+	cp a, RPDR
+	jp z, @right_door 
+
+	ret
+@up_door:
+
+	; move up one row
+	; and see if the tile is a collider
+
+	ret
+
+@down_door:
+	ret
+@left_door:
+	push hl
+	push de
+
+	; move left one tile
+	; and check for colliders
+	ld de, (-c_size) & 0xFFFF
+	add hl, de
+	; hl = tile to the left
+
+	inc hl ; go to flags
+	ld d, a ; store a for later
+	ld a, [hl]
+	and a, CF_COLLISION
+	ld a, d ; restore a's value
+
+	; if not collider do not fix
+	jr z, @no_left_fix REL
+		; otherwise load left wall into a
+		ld a, RPLW
+
+@no_left_fix:
+		
+	pop de
+	pop hl
+
+	ret
+@right_door:
+	ret