From b9c24b87fb231b034225ef78dfadad4295cda754 Mon Sep 17 00:00:00 2001
From: Lukas Krickl <lukas@krickl.dev>
Date: Sat, 4 Oct 2025 20:51:19 +0200
Subject: [PATCH] update: oam now only clears the unused objects each frame

---
 src/mem.s    | 25 ++++++++++++++++++++++++-
 src/update.s |  5 +++--
 2 files changed, 27 insertions(+), 3 deletions(-)

diff --git a/src/mem.s b/src/mem.s
index ae06a61..07c063e 100644
--- a/src/mem.s
+++ b/src/mem.s
@@ -100,7 +100,30 @@ shadow_oam_clear:
   ld hl, shadow_oam
   ld d, 0
   jp memset
-
+	
+	; clears the remaining shadow oam 
+	; entries
+shadow_oam_clear_rest:
+	ld hl, shadow_oam
+	ld d, 0
+	ld a, [current_oam_obj]
+	ld e, a
+	add hl, de ; hl = soam obj offset
+	xor a, a
+
+	sra e
+	sra e ; / 4 for loop coutner
+
+@clear_loop:
+	ld [hl+], a
+	ld [hl+], a
+	ld [hl+], a
+	ld [hl+], a
+	dec e
+	jr nz, @clear_loop REL
+
+	ret
+	
 
 ; dma shadow oam to oam
 ; registers:
diff --git a/src/update.s b/src/update.s
index 010c83a..9ae0149 100644
--- a/src/update.s
+++ b/src/update.s
@@ -5,8 +5,6 @@ update_game:
   ; tick rng every frame
   call rand
 
-  ; clear oam
-  call shadow_oam_clear
 	
 	call video_map_adjust_scroll
 
@@ -16,6 +14,9 @@ update_game:
 	call actor_update_all
 
 	
+  ; clear oam
+  call shadow_oam_clear_rest
+
   ret
 
 new_game:
-- 
2.30.2