Add some comments to UpdateBGMap

This commit is contained in:
Rangi 2020-05-19 20:00:58 -04:00
parent 156f2cc3ef
commit f1513ae8ad

View File

@ -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)