Merge branch 'master' of https://github.com/pret/pokered into rgbgfxrgbgfx

1 files changed, 27 insertions, 24 deletions

diff --git a/home/vcopy.asm b/home/vcopy.asm
index 02caef29..69773cfe 100644
--- a/home/vcopy.asm
+++ b/home/vcopy.asm
@@ -33,23 +33,26 @@ ClearBgMap:: ; 1cf0 (0:1cf0)
 	jr nz,.loop
 	ret
 
-; When the player takes a step, a row or column of 2x2 tile blocks at the edge
-; of the screen toward which they moved is exposed and has to be redrawn.
-; This function does the redrawing.
-RedrawExposedScreenEdge:: ; 1d01 (0:1d01)
-	ld a,[H_SCREENEDGEREDRAW]
+RedrawRowOrColumn:: ; 1d01 (0:1d01)
+; This function redraws a BG row of height 2 or a BG column of width 2.
+; One of its main uses is redrawing the row or column that will be exposed upon
+; scrolling the BG when the player takes a step. Redrawing only the exposed
+; row or column is more efficient than redrawing the entire screen.
+; However, this function is also called repeatedly to redraw the whole screen
+; when necessary. It is also used in trade animation and elevator code.
+	ld a,[hRedrawRowOrColumnMode]
 	and a
 	ret z
 	ld b,a
 	xor a
-	ld [H_SCREENEDGEREDRAW],a
+	ld [hRedrawRowOrColumnMode],a
 	dec b
 	jr nz,.redrawRow
 .redrawColumn
-	ld hl,wScreenEdgeTiles
-	ld a,[H_SCREENEDGEREDRAWADDR]
+	ld hl,wRedrawRowOrColumnSrcTiles
+	ld a,[hRedrawRowOrColumnDest]
 	ld e,a
-	ld a,[H_SCREENEDGEREDRAWADDR + 1]
+	ld a,[hRedrawRowOrColumnDest + 1]
 	ld d,a
 	ld c,SCREEN_HEIGHT
 .loop1
@@ -58,7 +61,7 @@ RedrawExposedScreenEdge:: ; 1d01 (0:1d01)
 	inc de
 	ld a,[hli]
 	ld [de],a
-	ld a,31
+	ld a,BG_MAP_WIDTH - 1
 	add e
 	ld e,a
 	jr nc,.noCarry
@@ -72,23 +75,24 @@ RedrawExposedScreenEdge:: ; 1d01 (0:1d01)
 	dec c
 	jr nz,.loop1
 	xor a
-	ld [H_SCREENEDGEREDRAW],a
+	ld [hRedrawRowOrColumnMode],a
 	ret
 .redrawRow
-	ld hl,wScreenEdgeTiles
-	ld a,[H_SCREENEDGEREDRAWADDR]
+	ld hl,wRedrawRowOrColumnSrcTiles
+	ld a,[hRedrawRowOrColumnDest]
 	ld e,a
-	ld a,[H_SCREENEDGEREDRAWADDR + 1]
+	ld a,[hRedrawRowOrColumnDest + 1]
 	ld d,a
 	push de
-	call .drawHalf ; draw upper half
+	call .DrawHalf ; draw upper half
 	pop de
-	ld a,32 ; width of VRAM background map
+	ld a,BG_MAP_WIDTH ; width of VRAM background map
 	add e
 	ld e,a
-			 ; draw lower half
-.drawHalf
-	ld c,10
+	; fall through and draw lower half
+
+.DrawHalf
+	ld c,SCREEN_WIDTH / 2
 .loop2
 	ld a,[hli]
 	ld [de],a
@@ -113,7 +117,7 @@ RedrawExposedScreenEdge:: ; 1d01 (0:1d01)
 ; background per V-blank. It cycles through which third it draws.
 ; This transfer is turned off when walking around the map, but is turned
 ; on when talking to sprites, battling, using menus, etc. This is because
-; the above function, RedrawExposedScreenEdge, is used when walking to
+; the above function, RedrawRowOrColumn, is used when walking to
 ; improve efficiency.
 AutoBgMapTransfer:: ; 1d57 (0:1d57)
 	ld a,[H_AUTOBGTRANSFERENABLED]
@@ -302,12 +306,11 @@ VBlankCopyDouble::
 
 
 VBlankCopy::
-; Copy [H_VBCOPYSIZE] 2bpp tiles
+; Copy [H_VBCOPYSIZE] 2bpp tiles (or 16 * [H_VBCOPYSIZE] tile map entries)
 ; from H_VBCOPYSRC to H_VBCOPYDEST.
 
-; Source and destination addresses
-; are updated, so transfer can
-; continue in subsequent calls.
+; Source and destination addresses are updated,
+; so transfer can continue in subsequent calls.
 
 	ld a, [H_VBCOPYSIZE]
 	and a