yellow map_sprites.asm

; 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:
; $C1X* and $C2X* are used to denote wSpriteStateData1-wSpriteStateData1 + $ff and wSpriteStateData2 + $00-wSpriteStateData2 + $ff sprite slot
; fields, respectively, within loops. The X is the loop index.
; If there is an inner loop, Y is the inner loop index, i.e. $C1Y* and $C2Y*
; denote fields of the sprite slots interated over in the inner loop.
_InitMapSprites: ; 1401b (5:401b)
    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 >= $25)
    call Func_14061
    call Func_140b7
    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: ; 14029 (5:4029)
    ld a,[wCurMap]
    cp a,REDS_HOUSE_1F ; is the map a city or a route (map ID less than $25)?
    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 Func_140b7
    call Func_14150
    scf
    ret

Func_14061: ; 14061 (5:4061)
; 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 one
; (since the Red sprite always has the first VRAM tile pattern slot) is the
; VRAM tile pattern slot.
    ld hl, wSpriteSet
    ld bc, (wSpriteSetID - wSpriteSet)
    xor a
    call FillMemory
    ld a, SPRITE_RED
    ld [wSpriteSet], a
    ld hl,wSpriteStateData1 + $10
    ld a,$0e
.storeVRAMSlotsLoop
    push af
    ld a, [hl] ; $C1X0 (picture ID) (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 Func_140ac
    jr nc, .asm_1408a
    ld de, wSpriteSet + 9
    ld b, 2
    call Func_1409b
    jr .continue
.asm_1408a
    ld de, wSpriteSet
    ld b, 9
    call Func_1409b
.continue
    ld de, $10
    add hl, de
    pop af
    dec a
    jr nz, .storeVRAMSlotsLoop
    ret

Func_1409b: ; 1409b (5:409b)
    ld a, [de]
    and a
    jr z, .asm_140a7
    cp c
    ret z
    dec b
    jr z, .asm_140aa
    inc de
    jr Func_1409b
.asm_140a7
    ld a, c
    ld [de], a
    ret
.asm_140aa
    scf
    ret

Func_140ac: ; 140ac (5:40ac)
    cp SPRITE_BALL
    ret z
    cp SPRITE_LYING_OLD_MAN_UNUSED_2 ; probably PIKACHU_SPRITE
    jr nc, .asm_140b5
    and a
    ret
.asm_140b5
    scf
    ret

Func_140b7: ; 140b7 (5:40b7)
    ld a, $0
.loop
    ld [hVRAMSlot], a
    cp 9
    jr nc, .asm_140c7
    call LoadStillTilePattern
    call LoadWalkingTilePattern
    jr .continue
.asm_140c7
    call LoadStillTilePattern
.continue
    ld a, [hVRAMSlot]
    inc a
    cp 11
    jr nz, .loop
    ret

Func_140d2: ; 140d2 (5:40d2)
    xor a
.loop
    ld [hVRAMSlot], a
    cp 9
    jr nc, .asm_140dc
    call LoadWalkingTilePattern
.asm_140dc
    ld a, [hVRAMSlot]
    inc a
    cp 11
    jr nz, .loop
    ret

LoadStillTilePattern: ; 140e4 (5:40e4)
    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: ; 140f5 (5:40f5)
    call ReadSpriteSheetData
    ret nc
    ld hl, $c0
    add hl, de
    ld d, h
    ld e, l
    call GetSpriteVRAMAddress
    set 3, h ; add $800 to hl
    call CopyVideoDataAlternate
    ret

GetSpriteVRAMAddress: ; 14018 (5:4108)
    push bc
    ld 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: ; 14118 (5:4118)
; Equivalent to multiplying $C0 (number of bytes in 12 tiles) times the VRAM
; slot and adding the result to $8000 (the VRAM base address).
    dw vChars0 + $c0
    dw vChars0 + $180
    dw vChars0 + $240
    dw vChars0 + $300
    dw vChars0 + $3c0
    dw vChars0 + $480
    dw vChars0 + $540
    dw vChars0 + $600
    dw vChars0 + $6c0
    dw vChars0 + $780
    dw vChars0 + $7c0

ReadSpriteSheetData: ; 1412e (5:412e)
    ld 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: ; 14150 (5:4150)
    ld a, $1
    ld [wSpriteStateData2 + $e], a
    ld a, $2
    ld [wSpriteStateData2 + $fe], a
    ld a, $e
    ld hl, wSpriteStateData1 + $10
.loop
    ld [hVRAMSlot], a
    ld a, [hl]
    and a
    jr z, .asm_1416f
    call Func_14179
    push hl
    ld de, $10e
    add hl, de
    ld [hl], a
    pop hl
.asm_1416f
    ld de, $10
    add hl, de
    ld a, [hVRAMSlot]
    dec a
    jr nz, .loop
    ret

Func_14179: ; 14179 (5:4179)
    push de
    push bc
    ld c, a
    ld b, 11
    ld de, wSpriteSet
    ld a, [de]
    cp c
    jr z, .asm_1418d
    inc de
    dec b
    jr nz, .asm_14181
    ld a, $1
    jr .done
.asm_1418d
    ld a, $d
    sub b
.done
    pop bc
    pop de
    ret

GetSplitMapSpriteSetID: ; 14193 (5:4193)
    ld e, a
    ld d, 0
    ld hl,MapSpriteSets
    add hl, de
    ld a,[hl] ; a = spriteSetID
    cp a,$f0 ; does the map have 2 sprite sets?
    ret c
; GetSplitMapSpriteSetID
; Chooses the correct sprite set ID depending on the player's position within
; the map for maps with two sprite sets.
    cp a,$f8
    jr z,.route20
    ld hl,SplitMapSpriteSets
    and a,$0f
    dec a
    add a
    add a
    add l
    ld l,a
    jr nc,.noCarry
    inc h
.noCarry
    ld a,[hli] ; determines whether the map is split East/West or North/South
    cp a,$01
    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 $01 for West side and $0A 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
    ld a,[hl]
    cp a,$2b
    ld a,$01
    ret c
    ld a,[hl]
    cp a,$3e
    ld a,$0a
    ret nc
    ld a,[hl]
    cp a,$37
    ld b,$08
    jr nc,.next
    ld b,$0d
.next
    ld a,[wYCoord]
    cp b
    ld a,$0a
    ret c
    ld a,$01
    ret

INCLUDE "data/sprite_sets.asm"