From 8e5094f3be7c507633ac42fa5b2e831e3eaa58da Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Mon, 27 Oct 2025 15:09:26 +0100
Subject: [PATCH] enemy: added basic walking guard

---
 src/enemy.s | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 105 insertions(+)

diff --git a/src/enemy.s b/src/enemy.s
index 4fc2725..123f625 100644
--- a/src/enemy.s
+++ b/src/enemy.s
@@ -4,6 +4,12 @@
 act_enemy_guard:
 	actdef ACT_T_GUARD, 0, 0, 10, 0
 
+#define ACT_GUARD_WALK_RIGHT 0
+#define ACT_GUARD_SHOOT 1
+#define ACT_GUARD_WALK_LEFT 2
+
+#define ACT_GUARD_MOVE_FRAMES 40
+
 	; updates the guard enemy
 	; inputs:
 	;		de: actor ptr
@@ -29,11 +35,100 @@ act_guard_update:
 	ld a, RF_ENEMY
 	call actor_write_default_collider
 
+	; call states
+	ld hl, act_state
+	add hl, de
+	ld a, [hl]
+	cp a, ACT_GUARD_WALK_RIGHT
+	jp z, act_guard_walk_right
+
+	cp a, ACT_GUARD_SHOOT
+	jp z, act_guard_shoot
+
+	cp a, ACT_GUARD_WALK_LEFT
+	jp z, act_guard_walk_left
+
 	ret
 @despawn:
 	call actor_despawn
 	ret
 	
+	; guard shoot state
+	; inputs:
+	;		de: actor 
+act_guard_shoot:
+	; TODO
+	ld hl, act_state
+	add hl, de
+	ld a, ACT_GUARD_WALK_LEFT
+	ld [hl], a
+	ret
+	
+	; actor walk left state
+	;	inputs:
+	;		de: actor ptr
+	;	uses:
+	;		p0 as timer
+act_guard_walk_left:
+	; walk
+	ld hl, act_pos_x
+	add hl, de
+	ld a, [hl]
+	dec a
+	ld [hl], a
+	
+	; process timer
+	ld hl, act_p0
+	add hl, de
+	ld a, [hl]
+	inc a
+	ld [hl], a
+	cp a, ACT_GUARD_MOVE_FRAMES 
+	jr nz, @not_done REL
+		; clear p0 and transition
+		xor a, a
+		ld [hl], a
+
+		ld hl, act_state
+		add hl, de
+		ld a, ACT_GUARD_WALK_RIGHT
+		ld [hl], a
+@not_done:
+	ret
+	
+	; walk right state
+	; inputs:
+	;		de: actor ptr
+	;	uses:
+	;		p0 as timer
+act_guard_walk_right:
+	; walk
+	ld hl, act_pos_x
+	add hl, de
+	ld a, [hl]
+	inc a
+	ld [hl], a
+	
+	; process timer
+	ld hl, act_p0
+	add hl, de
+	ld a, [hl]
+	inc a
+	ld [hl], a
+	cp a, ACT_GUARD_MOVE_FRAMES ; how many frames do we walk?
+	jr nz, @not_done REL
+		; clear p0 and transition
+		xor a, a
+		ld [hl], a
+	
+		ld hl, act_state
+		add hl, de
+		ld a, ACT_GUARD_SHOOT
+		ld [hl], a
+
+@not_done:
+	ret
+	
 	; draws the guard enemy
 	; inputs:
 	;		de: actor ptr
@@ -90,4 +185,14 @@ act_guard_init:
 	add hl, de
 	ld a, 4
 	ld [hl], a
+	
+	xor a, a
+	ld hl, act_state
+	add hl, de
+	ld [hl], a
+
+	ld hl, act_p0
+	add hl, de
+	ld [hl], a
+
 	ret
-- 
2.30.2