From 6a915cf02964f16e7a531c75f6033028f9c4537f Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Fri, 8 Aug 2025 17:21:10 +0200
Subject: [PATCH] objanim: Added placeholder animation for when a door opens.

This serves as a proof of concept for obj animations.
Soon there should be proper opening sprites for doors in all directions.
---
 src/defs.s    |  2 ++
 src/objanim.s | 71 +++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/src/defs.s b/src/defs.s
index b12ada4..a2a6990 100644
--- a/src/defs.s
+++ b/src/defs.s
@@ -328,6 +328,8 @@
 .de obja_pos_y, 1
 .de obja_pos_x, 1
 .de obja_dat, 1
+	; time in frames
+.de obja_timer, 1
 .de obja_size, 0
 
 ; special text commands
diff --git a/src/objanim.s b/src/objanim.s
index 7775a55..ae697f3 100644
--- a/src/objanim.s
+++ b/src/objanim.s
@@ -15,20 +15,87 @@ objanim_init:
 	; inputs:
 	;		a: tile flags
 	;		b: tile index
+	;	 de: actor
 objanim_door_open:
+	push de
+	push bc
 	ld de, st_objanim_door_open
 	ld hl, objanim
 	ld bc, st_size
 	call memcpy
+	pop bc
+
+	pop de
+	ld hl, act_pos_y
+	add hl, de ; hl = act y pos
+
+
+	xor a, a
+	ld de, objanim+obja_flags	
+	ld [de], a
+	inc de ; de = y pos
+	
+	ld a, [hl+]
+	ld [de], a
+	inc de ; de = x pos
+
+	ld a, [hl]
+	ld [de], a
+	inc de ; de = dat
+	
+	; dat = tile index
+	ld a, b
+	ld [de], a
+	inc de ; de = timer
+	
+	; set timer
+	ld a, 0x40
+	ld [de], a
+
 	ret
 
 	; state function for door opening animation
 	; inputs:
 	;		de: objanim
 objanim_door_open_fn:
-	BREAK
+	call load_unit_obj
+	ld de, objanim+st_size
+	call load_scroll
+
+	; hl = oam ptr
+	; de = anim flags 
+
+	inc de ; skip flags
+	ld a, [de] ; a = y position
+	inc de ; de = x postion
+	mul16 a
+	add a, OBJ_OFF_Y
+	sub a, b
+	ld [hl+], a
+
+	ld a, [de] ; a = x position
+	mul16 a
+	add a, OBJ_OFF_X
+	sub a, c
+	ld [hl+], a
+	
+	ld a, 0x80 
+	ld [hl+], a
+
+	xor a, a
+	ld [hl+], a  ; no flags
+
+	ld de, objanim+obja_timer
+	ld a, [de]
+	dec a
+	ld [de], a ; timer--
+	jr z, @timer_done REL
+
 	ldnull bc
 	ret
+@timer_done:	
+	ld bc, st_null
+	ret
 
 st_objanim_door_open:
-	st_def 0x08, objanim_door_open_fn, st_null 
+	st_def 0x00, objanim_door_open_fn, st_objanim_door_open 
-- 
2.30.2