From: Lukas Krickl <lukas@krickl.dev>
Date: Fri, 1 Aug 2025 15:54:40 +0000 (+0200)
Subject: mapgen: Added check for units spawning in walls and randomized units that are spawned
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=acf31652152a6aeed92881331c908bc36f104008;p=gbrg%2F.git

mapgen: Added check for units spawning in walls and randomized units that are spawned
---

diff --git a/src/defs.s b/src/defs.s
index 1bea292..21c8fc2 100644
--- a/src/defs.s
+++ b/src/defs.s
@@ -21,6 +21,8 @@
 #define NULL 0
 
 #define UNITS_MAX 20
+#define UNITS_SPAWN_MIN 4
+#define UNITS_SPAWN_MASK 7
 
 #define STACK_BEGIN 0xDFFF
 
diff --git a/src/mapgen.s b/src/mapgen.s
index 8c1a99d..b64cc77 100644
--- a/src/mapgen.s
+++ b/src/mapgen.s
@@ -439,6 +439,13 @@ mapgen_place_actors:
 	
 	; b = loop counter
 	ld b, UNITS_MAX - 1
+	push hl
+	call rand
+	and a, UNITS_SPAWN_MASK 
+	add a, UNITS_SPAWN_MIN 
+	ld b, a 
+	; b = units to spawn, at least 4 but might be more
+	pop hl
 @spawn_another:
 		push bc
 		push de
@@ -500,24 +507,37 @@ mapgen_place_actors:
 	;		de: actor table entry
 	; preserves all registers
 mapgent_unit_randomize_or_realod_position:
-	; TODO: check if new position is wall and if so 
-	; try again
 	push_all
+@retry:
 	ld hl, act_pos_y
 	add hl, de ; hl = y pos
 	
 	; select position
 	push hl
 	call rand
-	pop hl
 	and a, MAP_H - 1
-	ld [hl+], a
-	
-	push hl
+	ld b, a
 	call rand
+	and a, MAP_H - 1
+	ld c, a
+	; bc = y/x
+
+	; check if tile is OK to spawn on
+	push bc
+	call map_get_tile
+	and a, CF_COLLISION
+	pop bc
 	pop hl
-	and a, MAP_W - 1
+	; if collision flag is set try again
+	jr nz, @retry REL
+	
+	; write y and x positions
+	ld a, b
+	ld [hl+], a
+	
+	ld a, c
 	ld [hl], a
 
 	pop_all
 	ret
+