pokeyellow/engine/overworld/map_sprites.asm

372 lines
9.1 KiB
NASM

; Loads tile patterns for map's sprites.
; For outside maps, it loads one of several fixed sets of sprites.
; For inside maps, it loads each sprite picture ID used in the map header.
; This is also called after displaying text because loading
; text tile patterns overwrites half of the sprite tile pattern data.
; Note on notation:
; x#SPRITESTATEDATA1_* and x#SPRITESTATEDATA2_* are used to denote wSpriteStateData1 and
; wSpriteStateData2 sprite slot, respectively, within loops. The X is the loop index.
; If there is an inner loop, Y is the inner loop index, i.e. y#SPRITESTATEDATA1_* and
; y#SPRITESTATEDATA2_* denote fields of the sprite slots iterated over in the inner loop.
_InitMapSprites::
call InitOutsideMapSprites
ret c ; return if the map is an outside map (already handled by above call)
; if the map is an inside map (i.e. mapID >= FIRST_INDOOR_MAP)
call LoadSpriteSetFromMapHeader
call LoadMapSpriteTilePatterns
call Func_14150
ret
; Loads sprite set for outside maps (cities and routes) and sets VRAM slots.
; sets carry if the map is a city or route, unsets carry if not
InitOutsideMapSprites:
ld a, [wCurMap]
cp FIRST_INDOOR_MAP ; is the map a city or a route?
ret nc ; if not, return
call GetSplitMapSpriteSetID
; if so, choose the appropriate one
ld b, a ; b = spriteSetID
ld a, [wFontLoaded]
bit 0, a ; reloading upper half of tile patterns after displaying text?
jr nz, .loadSpriteSet ; if so, forcibly reload the sprite set
ld a, [wSpriteSetID]
cp b ; has the sprite set ID changed?
jr z, .skipLoadingSpriteSet ; if not, don't load it again
.loadSpriteSet
ld a, b
ld [wSpriteSetID], a
dec a
ld c, a
ld b, 0
ld a, wSpriteSetID - wSpriteSet
ld hl, SpriteSets
call AddNTimes ; get sprite set offset
ld de, wSpriteSet
ld bc, wSpriteSetID - wSpriteSet
call CopyData ; copy it to wSpriteSet
call LoadMapSpriteTilePatterns
.skipLoadingSpriteSet
call Func_14150
scf
ret
LoadSpriteSetFromMapHeader:
; This loop stores the correct VRAM tile pattern slots according the sprite
; data from the map's header. Since the VRAM tile pattern slots are filled in
; the order of the sprite set, in order to find the VRAM tile pattern slot
; for a sprite slot, the picture ID for the sprite is looked up within the
; sprite set. The index of the picture ID within the sprite set plus two
; (since the Red sprite always has the first VRAM tile pattern slot and the
; Pikachu sprite reserves the second slot) is the VRAM tile pattern slot.
ld hl, wSpriteSet
ld bc, (wSpriteSetID - wSpriteSet)
xor a
call FillMemory
ld a, SPRITE_PIKACHU ; load Pikachu separately
ld [wSpriteSet], a
ld hl, wSprite01StateData1
ld a, 14
.storeVRAMSlotsLoop
push af
ld a, [hl] ; [x#SPRITESTATEDATA1_PICTUREID] (zero if sprite slot is not used)
and a ; is the sprite slot used?
jr z, .continue ; if the sprite slot is not used
ld c, a
call CheckForFourTileSprite ; is this a four tile sprite?
jr nc, .isFourTileSprite
; loop through the space reserved for four tile picture IDs
ld de, wSpriteSet + 9
ld b, 2
call CheckIfPictureIDAlreadyLoaded
jr .continue
.isFourTileSprite
; loop through the space reserved for regular picture IDs
ld de, wSpriteSet
ld b, 9
call CheckIfPictureIDAlreadyLoaded
.continue
ld de, wSprite02StateData1 - wSprite01StateData1
add hl, de
pop af
dec a
jr nz, .storeVRAMSlotsLoop
ret
CheckIfPictureIDAlreadyLoaded:
; Check if the current picture ID has already had its tile patterns loaded.
; This done by looping through the previous sprite slots and seeing if any of
; their picture ID's match that of the current sprite slot.
.loop
ld a, [de]
and a ; is sprite set slot not taken up yet?
jr z, .spriteSlotNotTaken ; if so, load it as it signifies we've reached
; the end of data for the last sprite set
cp c ; is the tile pattern already loaded?
ret z ; don't redundantly load
dec b ; have we reached the end of the sprite set?
jr z, .spriteNotAlreadyLoaded ; if so, we're done here
inc de
jr .loop
.spriteSlotNotTaken
ld a, c
ld [de], a
ret
.spriteNotAlreadyLoaded
scf
ret
CheckForFourTileSprite:
; Checks for a sprite added in yellow
; Returns no carry if the sprite is Pikachu, as its sprite is handled separately
; Else, returns carry if the sprite uses 4 tiles
cp SPRITE_PIKACHU ; is this the Pikachu Sprite?
ret z ; return if yes
cp FIRST_STILL_SPRITE ; is this a four tile sprite?
jr nc, .notYellowSprite ; set carry if yes
; regular sprite
and a
ret
.notYellowSprite
scf
ret
LoadMapSpriteTilePatterns:
ld a, 0
.loop
ldh [hVRAMSlot], a
cp 9
jr nc, .fourTileSprite
call LoadStillTilePattern
call LoadWalkingTilePattern
jr .continue
.fourTileSprite
call LoadStillTilePattern
.continue
ldh a, [hVRAMSlot]
inc a
cp 11
jr nz, .loop
ret
ReloadWalkingTilePatterns:
xor a
.loop
ldh [hVRAMSlot], a
cp 9
jr nc, .fourTileSprite
call LoadWalkingTilePattern
.fourTileSprite
ldh a, [hVRAMSlot]
inc a
cp 11
jr nz, .loop
ret
LoadStillTilePattern:
ld a, [wFontLoaded]
bit 0, a ; reloading upper half of tile patterns after displaying text?
ret nz ; if so, skip loading data into the lower half
call ReadSpriteSheetData
ret nc
call GetSpriteVRAMAddress
call CopyVideoDataAlternate ; new yellow function
ret
LoadWalkingTilePattern:
call ReadSpriteSheetData
ret nc
ld hl, $c0
add hl, de
ld d, h
ld e, l
call GetSpriteVRAMAddress
set 3, h ; add $80 tiles to hl
call CopyVideoDataAlternate
ret
GetSpriteVRAMAddress:
push bc
ldh a, [hVRAMSlot]
ld c, a
ld b, 0
ld hl, SpriteVRAMAddresses
add hl, bc
add hl, bc
ld a, [hli]
ld h, [hl]
ld l, a
pop bc
ret
SpriteVRAMAddresses:
dw vChars0 + (1 * 12) tiles
dw vChars0 + (2 * 12) tiles
dw vChars0 + (3 * 12) tiles
dw vChars0 + (4 * 12) tiles
dw vChars0 + (5 * 12) tiles
dw vChars0 + (6 * 12) tiles
dw vChars0 + (7 * 12) tiles
dw vChars0 + (8 * 12) tiles
dw vChars0 + (9 * 12) tiles
dw vChars0 + (10 * 12) tiles ; 4-tile sprites
dw vChars0 + (10 * 12 + 4) tiles ; 4-tile sprites
ReadSpriteSheetData:
ldh a, [hVRAMSlot]
ld e, a
ld d, 0
ld hl, wSpriteSet
add hl, de
ld a, [hl]
and a
ret z
dec a
ld l, a
ld h, 0
add hl, hl
add hl, hl
ld de, SpriteSheetPointerTable
add hl, de
ld e, [hl]
inc hl
ld d, [hl]
inc hl
ld c, [hl]
swap c ; get the number of tiles, not the raw byte length
; this is because of the use of CopyVideoDataAlternate
inc hl
ld b, [hl]
inc hl
scf
ret
Func_14150:
ld a, $1
ld [wSpritePlayerStateData2ImageBaseOffset], a ; vram slot for player
ld a, $2
ld [wSpritePikachuStateData2ImageBaseOffset], a ; vram slot for Pikachu
ld a, $e
ld hl, wSprite01StateData1
.loop
ldh [hVRAMSlot], a ; store current sprite set slot as a counter
ld a, [hl] ; [x#SPRITESTATEDATA1_PICTUREID]
and a ; is the sprite unused?
jr z, .spriteUnused
call Func_14179
push hl
ld de, wSpritePlayerStateData2ImageBaseOffset - wSpriteStateData1
add hl, de ; [x#SPRITESTATEDATA2_IMAGEBASEOFFSET]
ld [hl], a ; write offset
pop hl
.spriteUnused
ld de, wSprite02StateData1 - wSprite01StateData1
add hl, de
ldh a, [hVRAMSlot]
dec a
jr nz, .loop
ret
Func_14179:
push de
push bc
ld c, a ; c = picture ID
ld b, 11
ld de, wSpriteSet
.findSpriteImageBaseOffsetLoop
ld a, [de] ; a = sprite set picture ID
cp c ; have we found a match?
jr z, .foundSpritePictureID ; if so, get the sprite image base offset and return
inc de
dec b ; have we looped through all entries in wSpriteSet?
jr nz, .findSpriteImageBaseOffsetLoop ; continue looping if not
ld a, $1 ; assume slot one if this ever happens
jr .done
.foundSpritePictureID
ld a, 13
sub b ; get sprite image base offset
.done
pop bc
pop de
ret
GetSplitMapSpriteSetID:
ld e, a
ld d, 0
ld hl, MapSpriteSets
add hl, de
ld a, [hl] ; a = spriteSetID
cp FIRST_SPLIT_SET - 1 ; does the map have 2 sprite sets?
ret c
; Chooses the correct sprite set ID depending on the player's position within
; the map for maps with two sprite sets.
cp SPLITSET_ROUTE_20
jr z, .route20
ld hl, SplitMapSpriteSets
and $0f
dec a
add a
add a
add l
ld l, a
jr nc, .noCarry
inc h
.noCarry
ld a, [hli] ; whether the map is split EAST_WEST or NORTH_SOUTH
cp EAST_WEST
ld a, [hli] ; position of dividing line
ld b, a
jr z, .eastWestDivide
.northSouthDivide
ld a, [wYCoord]
jr .compareCoord
.eastWestDivide
ld a, [wXCoord]
.compareCoord
cp b
jr c, .loadSpriteSetID
; if in the east side or south side
inc hl
.loadSpriteSetID
ld a, [hl]
ret
; Uses sprite set SPRITESET_PALLET_VIRIDIAN for west side and SPRITESET_FUCHSIA for east side.
; Route 20 is a special case because the two map sections have a more complex
; shape instead of the map simply being split horizontally or vertically.
.route20
ld hl, wXCoord
; Use SPRITESET_PALLET_VIRIDIAN if X < 43
ld a, [hl]
cp 43
ld a, SPRITESET_PALLET_VIRIDIAN
ret c
; Use SPRITESET_FUCHSIA if X >= 62.
ld a, [hl]
cp 62
ld a, SPRITESET_FUCHSIA
ret nc
; If 55 <= X < 62, split Y at 8; else 43 <= X < 55, so split Y at 13
ld a, [hl]
cp 55
ld b, 8
jr nc, .next
ld b, 13
.next
; Use SPRITESET_FUCHSIA if Y < split; else use SPRITESET_PALLET_VIRIDIAN
ld a, [wYCoord]
cp b
ld a, SPRITESET_FUCHSIA
ret c
ld a, SPRITESET_PALLET_VIRIDIAN
ret
INCLUDE "data/maps/sprite_sets.asm"
INCLUDE "data/sprites/sprites.asm"