From ce0e8daf319c841632941a47b6a0c1825921ee41 Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Fri, 1 Aug 2025 17:13:18 +0200
Subject: [PATCH] mapgen: actor type and positions are now randomly selected

This is done by selecting a random actor form the map's actor table.
Currently psotions can be anywhere including walls. This will need to be fixed later :^)
---
 src/actortables.s |   2 +-
 src/mapgen.s      | 114 ++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 115 insertions(+), 1 deletion(-)

diff --git a/src/actortables.s b/src/actortables.s
index 8dad2a9..ee73654 100644
--- a/src/actortables.s
+++ b/src/actortables.s
@@ -9,7 +9,7 @@
 ;   as needed and setting act_loot_table_dat.
 
 map_c_actor_table:
-.db 10 ; size
+.db 7 ; size
 dw unit_demo_2
 dw unit_demo_warrior
 dw unit_demo_warrior
diff --git a/src/mapgen.s b/src/mapgen.s
index dfb7560..8c1a99d 100644
--- a/src/mapgen.s
+++ b/src/mapgen.s
@@ -396,14 +396,128 @@ mapgen_fix_door_adjacent_to_collider:
 	; places actors from a valid actor table
 	; in the current map's header. This will overwrite the 
 	; header loaded by map_load. Preserves player entry.
+	; the length of the actor table must be maskable
 	; inputs:
 	;		a loaded map
 	;		[map_header] ptr
 mapgen_place_actors:
+	; clear everything past player
+	ld hl, p0_units + act_size 
+	ld bc, (UNITS_MAX - 1) * act_size
+	ld d, 0
+	call memset
+
 	; load map ptr
 	ld a, [map_header]
 	ld l, a
 	ld a, [map_header+1]
 	ld h, a
 
+	; now load the actor table template into hl
+	ld de, map_actor_table_ptr 
+	add hl, de
+	; hl = actor table ptr
+
+	; load actor table ptr
+	ld a, [hl+]
+	ld b, a
+	ld a, [hl+]
+	; hl = map header actor table ptr
+	ld h, a 
+	ld l, b
+	
+	ld a, [hl+]
+	ld c, a
+	cp a, 0
+	ret z ; if length is 0 we bail
+	; c = actor table length
+	; hl = actor entries
+
+	; load actor table starting after plater
+	ld de, p0_units + act_size
+	; de = actor table
+	
+	; b = loop counter
+	ld b, UNITS_MAX - 1
+@spawn_another:
+		push bc
+		push de
+		push hl
+		call rand
+		pop hl
+		pop de
+		pop bc
+	
+		; mask the rand result
+		and a, c
+
+		; now we know which actor to pick
+		add a, a ; * 2 because the table is a ptr table
+
+		push hl
+		push bc
+		push de
+
+		ld d, 0
+		ld e, a
+		add hl, de
+		; hl = actor picked ptr
+		ld a, [hl+]
+		ld e, a
+		ld a, [hl+]
+		ld d, a
+		; de = actor picked = src
+
+
+		pop hl ; hl = actor table dst
+		push hl ; re-push for pop de later
+		ld bc, act_size 
+		call memcpy
+
+		pop de
+		pop bc	
+		pop hl
+
+		; move to next actor table entry
+		push hl
+		call mapgent_unit_randomize_or_realod_position
+		ld hl, act_size
+		add hl, de
+		push hl
+		pop de ; de = next entry
+		pop hl
+
+		dec b
+	jp nz, @spawn_another 
+
+	; TODO: reload flags and positions
+	
+	ret
+	
+	; randomizes (or reloads from sram)
+	; an actors position
+	; inputs:
+	;		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
+	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
+	call rand
+	pop hl
+	and a, MAP_W - 1
+	ld [hl], a
+
+	pop_all
 	ret
-- 
2.30.2