From: Lukas Krickl <lukas@krickl.dev>
Date: Thu, 18 Dec 2025 08:41:10 +0000 (+0100)
Subject: actor: added collision checks for tiles that contain an active actor
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=197aa7bf91d60316fba1696f2e8ca2c135f915af;p=gbrg%2F.git

actor: added collision checks for tiles that contain an active actor
---

diff --git a/src/actor.s b/src/actor.s
index 1f61e2f..0968dfe 100644
--- a/src/actor.s
+++ b/src/actor.s
@@ -394,12 +394,70 @@ act_apply_pos:
 
 	ret
 	
+	; creates a copy of the actors position
+	; in tmp_act_y and _x
+	; inputs:
+	;		de: actor
+	; preverse:
+	;		de
+_act_backup_pos:
+	ld hl, act_pos_y
+	add hl, de
+	ld a, [hl+]
+	ld [tmp_act_y], a
+	ld a, [hl]
+	ld [tmp_act_x], a
+	ret
+	
+	; restores actor position 
+	; from tmp_act_y/x
+	; inputs:
+	;		de: actor
+	; preserves:
+	;		de
+_act_restore_pos:
+	ld hl, act_pos_y
+	add hl, de
+
+	ld a, [tmp_act_y]
+	ld [hl+], a
+	ld a, [tmp_act_x]
+	ld [hl], a
+	ret
+	
+	; tests if the new actor location contains
+	; an actor
+	; rolls back position to tmp_act_y/x if it does
+	; input:
+	;		de: actor
+	; preserves:
+	;		de
+_act_check_act_in_location:
+	push de
+	ld hl, act_pos_y
+	add hl, de
+	ld a, [hl+]
+	ld b, a
+	ld c, [hl]
+	call map_get_tile
+	; hl = tile
+	ld bc, t_act
+	add hl, bc
+
+	ld a, [hl+]
+	or a, [hl]
+	pop de
+	call nz, _act_restore_pos
+	ret
+	
 	
 	; moves the actor forward
 	; performs collision checks
 	; inputs:
 	;		de: actor
 act_move_forward:
+	call _act_backup_pos
+
 	push de
 	ld hl, act_dir_forward
 	call act_can_move
@@ -424,10 +482,10 @@ act_move_forward:
 	
 	call act_apply_vec
 
-	; TODO: check if player collides with actor
+	; check if player collides with actor
 	; at new location
-
 	pop de
+	call _act_check_act_in_location
 	call act_set_tact
 
 	ret
@@ -437,6 +495,8 @@ act_move_forward:
 	; inputs:
 	;		de: actor
 act_move_back:
+	call _act_backup_pos
+
 	push de
 	ld hl, act_dir_back
 	call act_can_move
@@ -468,6 +528,7 @@ act_move_back:
 	call act_apply_vec
 
 	pop de
+	call _act_check_act_in_location
 	call act_set_tact
 	
 	ret
diff --git a/src/wram.s b/src/wram.s
index d79219b..564b36c 100644
--- a/src/wram.s
+++ b/src/wram.s
@@ -130,6 +130,8 @@ tmp_map_near_left_door: .adv 1
 tmp_map_near_right_door: .adv 1
 tmp_map_far_left_door: .adv 1
 tmp_map_far_right_door: .adv 1
+tmp_act_y: .adv 1
+tmp_act_x: .adv 1
 	
 	; actor that is adjacent
 	; to the players current facing