From: Lukas Krickl <lukas@krickl.dev>
Date: Mon, 12 Jan 2026 14:04:01 +0000 (+0100)
Subject: drawing: Added double buffering
X-Git-Url: https://git.krickl.dev/?a=commitdiff_plain;h=bea81d39d62643c48b927ec3cd94e936f51f9736;p=gbrg%2F.git

drawing: Added double buffering
---

diff --git a/src/update.s b/src/update.s
index 96defe7..04da590 100644
--- a/src/update.s
+++ b/src/update.s
@@ -32,8 +32,37 @@ update_render:
 	; TODO: this should be smooth...
 	ld b, RENDER_BUF_H ; loop counter
 	ld de, render_buffer
+	
+	ld a, [scrn_select]
+	cp a, 0
+	jp z, @scrn0
+	
+	; set next select
+	xor a, a
+	ld [scrn_select], a
+	
+	; select screen
+	ld hl, SCRN0+0x240
+
+	; load scroll
+	ld a, 144
+	ld [scroll_y], a
+
+	jr @scrn_selected REL
+@scrn0:
+	; set next screen
+	ld a, 1
+	ld [scrn_select], a
+
+	; select screen
+	ld hl, SCRN0
+	
+	; set scroll
+	xor a, a
+	ld [scroll_y], a
+
+@scrn_selected:
 
-	ld hl, SCRN0	
 	call next_vblank_wait
 
 	; copy buffer into SCRN0
diff --git a/src/wram.s b/src/wram.s
index 085e22b..fb083fe 100644
--- a/src/wram.s
+++ b/src/wram.s
@@ -22,6 +22,9 @@ shadow_robp1: .adv 1
 
 ; shadow version of IE
 shadow_ie: .adv 1
+
+	; either 0/1 for the next redraw
+scrn_select: .adv 1
 	
 	; game state routine ptr
 game_state: .adv 2