diff options
Diffstat (limited to 'home/vcopy.asm')
| -rw-r--r-- | home/vcopy.asm | 79 |
1 files changed, 42 insertions, 37 deletions
diff --git a/home/vcopy.asm b/home/vcopy.asm index 4ce297d2..da85e3e7 100644 --- a/home/vcopy.asm +++ b/home/vcopy.asm @@ -33,32 +33,35 @@ 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:: ; 1ada (0:1ada) - ld a,[H_SCREENEDGEREDRAW] +; 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. +RedrawRowOrColumn:: ; 1ada (0:1ada) + 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,18 ; screen height + ld c,SCREEN_HEIGHT .loop1 ld a,[hli] ld [de],a 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:: ; 1ada (0:1ada) 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:: ; 1ada (0:1ada) ; 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:: ; 1b30 (0:1b30) ld a,[H_AUTOBGTRANSFERENABLED] @@ -126,7 +130,7 @@ AutoBgMapTransfer:: ; 1b30 (0:1b30) dec a jr z,.transferMiddleThird .transferBottomThird - hlCoord 0, 12 + coord hl, 0, 12 ld sp,hl ld a,[H_AUTOBGTRANSFERDEST + 1] ld h,a @@ -137,7 +141,7 @@ AutoBgMapTransfer:: ; 1b30 (0:1b30) xor a ; TRANSFERTOP jr .doTransfer .transferTopThird - hlCoord 0, 0 + coord hl, 0, 0 ld sp,hl ld a,[H_AUTOBGTRANSFERDEST + 1] ld h,a @@ -146,7 +150,7 @@ AutoBgMapTransfer:: ; 1b30 (0:1b30) ld a,TRANSFERMIDDLE jr .doTransfer .transferMiddleThird - hlCoord 0, 6 + coord hl, 0, 6 ld sp,hl ld a,[H_AUTOBGTRANSFERDEST + 1] ld h,a @@ -283,12 +287,11 @@ VBlankCopyDouble:: ; 1bd1 (0:1bd1) VBlankCopy:: ; 1c21 (0:1c21) -; 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 @@ -354,21 +357,23 @@ UpdateMovingBgTiles:: ; 1c75 (0:1c75) cp $90 ; check if not in vblank period??? (maybe if vblank is too long) ret c - ld a, [$ffd8] + ld a, [hMovingBGTilesCounter1] inc a - ld [$ffd8], a - cp $14 + ld [hMovingBGTilesCounter1], a + cp 20 ret c - cp $15 + cp 21 jr z, .flower +; water + ld hl, vTileset + $14 * $10 ld c, $10 - ld a, [wd085] + ld a, [wMovingBGTilesCounter2] inc a and 7 - ld [wd085], a + ld [wMovingBGTilesCounter2], a and 4 jr nz, .left @@ -391,14 +396,14 @@ UpdateMovingBgTiles:: ; 1c75 (0:1c75) ret nc ; if in a cave, no flower animations xor a - ld [$ffd8], a + ld [hMovingBGTilesCounter1], a ret .flower xor a - ld [$ffd8], a + ld [hMovingBGTilesCounter1], a - ld a, [wd085] + ld a, [wMovingBGTilesCounter2] and 3 cp 2 ld hl, FlowerTile1 |