From f1513ae8ad47c603abdba2749ef3e4e046817623 Mon Sep 17 00:00:00 2001
From: Rangi <remy.oukaour+rangi42@gmail.com>
Date: Tue, 19 May 2020 20:00:58 -0400
Subject: [PATCH] Add some comments to UpdateBGMap

---
 home/video.asm | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/home/video.asm b/home/video.asm
index 008f1057c..5578ad293 100644
--- a/home/video.asm
+++ b/home/video.asm
@@ -117,7 +117,7 @@ UpdateBGMap::
 ; Update the BG Map, in thirds, from wTilemap and wAttrmap.
 
 	ldh a, [hBGMapMode]
-	and a
+	and a ; 0
 	ret z
 
 ; BG Map 0
@@ -127,7 +127,7 @@ UpdateBGMap::
 	jr z, .Attr
 
 ; BG Map 1
-	dec a
+	dec a ; useless
 
 	ldh a, [hBGMapAddress]
 	ld l, a
@@ -232,7 +232,7 @@ THIRD_HEIGHT EQU SCREEN_HEIGHT / 3
 	ldh [hBGMapThird], a
 
 ; Rows of tiles in a third
-	ld a, SCREEN_HEIGHT / 3
+	ld a, THIRD_HEIGHT
 
 ; Discrepancy between wTilemap and BGMap
 	ld bc, BG_MAP_WIDTH - (SCREEN_WIDTH - 1)