FloodFill

Flood:
;Inputs:
;     HL points to the buffer (cannot be at saveSScreen)
;     BC=(x,y)
;Needs these RAM addresses:
;     TempWord1
;     TempWord2
;     TempWord3

     ld hl,(TempWord1)
     push bc
     ld de,86ECh
     xor a
     ld bc,768
       ld (de),a
       inc de
       dec c
       jr nz,$-3
       dec b
       jr nz,$-6
     pop bc
     push bc
     call GetPixelLoc
     pop bc
     ret nc
     ld de,(TempWord1)
     add hl,de
     and (hl)
     ret nz
FloodFill:
     ld de,1   ;Direction
;DE is the direction (x,y)
;BC is the current coordinates
FloodFillLoop:
     push bc
     call GetPixelLoc
     jr nc,ChangeDirection
     push hl
     push af
     ld bc,(TempWord1)
     add hl,bc
     and (hl)
     ld (TempWord3),hl
     pop hl
     ld a,h
     pop hl
     jr nz,ChangeDirection

     ld bc,86ECh
     add hl,bc
     ld b,a
     or (hl)
     ld (hl),a
     ld a,b



;     ld bc,86ECh
;     add hl,bc
;     or (hl)
;     ld (hl),a

;     pop hl
;     ld bc,(TempWord1)
;     add hl,bc
;     pop af
;     ld b,a
;     and (hl)
;     ld a,b
;     jr nz,ChangeDirection

     ld hl,(TempWord3)
     pop bc
     ld (TempWord2),bc
     or (hl)
     ld (hl),a
FloodFillLoop0:
     ld a,d
     add a,b
     ld b,a
     ld a,e
     add a,c
     ld c,a
     jp FloodFillLoop
ChangeDirection:
     pop bc
     ld bc,(TempWord2)
     ld a,d
     or a
     jr nz,UpDown
       call CheckLeftRight
       jp z,FloodFillLoop0
       jr NextPath
UpDown:
     call CheckUpDown
     jp z,FloodFillLoop0
NextPath:
     ld hl,86ECh
     xor a
     ld d,a
     ld e,a
     ld c,64
     ld b,12
PathFind:
       cp (hl)
       jr z,$+15
         push bc
         push de
         push hl
         ld a,(hl)
         call PathFound
         pop hl
         jr z,PathSelected
         xor a
         pop de
         pop bc
       inc hl
       inc d
       djnz PathFind
       ld d,0
       inc e
       dec c
       jr nz,PathFind-2
     jp BufferToLCD
PathSelected:
     pop hl
     pop hl
     jp FloodFillLoop0
PathFound:
     ld c,e
     ld b,d
     sla b
     sla b
     sla b
     dec b
     ld a,(hl)
FindXVal:
       inc b
       add a,a
       jr nc,$-2
     ld (TempWord2),a
     ld (TempWord3),bc
;Now BC has the adjusted coordinates
     call CheckLeftRight
     ret z
     call CheckUpDown
     ret z
     call GetPixelLoc
     ld bc,86ECh
     add hl,bc
     cpl
     and (hl)
     ld (hl),a
     ld a,(TempWord2)
     ld bc,(TempWord3)
     or a
     jr nz,FindXVal
     inc a
     ret
CheckLeftRight:
     ld de,$FF00
     push bc
     dec b
     call GetPixelLoc
     jr nc,$+11
       ld bc,(TempWord1)
       add hl,bc
       and (hl)
       jr nz,$+4
       pop bc
       ret z
     pop bc
     ld d,1
     push bc
     inc b
     call GetPixelLoc
     jr nc,$+11
       ld bc,(TempWord1)
       add hl,bc
       and (hl)
       jr nz,$+4
       pop bc
       ret z
     inc b
     pop bc
     ret
CheckUpDown:
     ld de,$00FF
     push bc
     dec c
     call GetPixelLoc
     jr nc,$+11
       ld bc,(TempWord1)
       add hl,bc
       and (hl)
       jr nz,$+4
       pop bc
       ret z
     pop bc
     ld e,1
     push bc
     inc c
     call GetPixelLoc
     jr nc,$+11
       ld bc,(TempWord1)
       add hl,bc
       and (hl)
       jr nz,$+4
       pop bc
       ret z
     inc c
     pop bc
     ret
GetPixelLoc:
;Input:
;     b is X
;     c is y
;Output:
;     HL points to byte
;     A is the mask
;     nc if not computed, c if computed
     ld a,c
     cp 64 \ ret nc
     ld a,b
     cp 96 \ ret nc
     ld l,c
     ld h,0
     ld b,h
     add hl,hl
     add hl,bc
     add hl,hl
     add hl,hl
     ld b,a
     rrca \ rrca \ rrca
     and 0Fh
     ld c,a
     ld a,b
     ld b,0
     add hl,bc
     and 7
     ld b,a
     inc b
     ld a,1
       rrca
       djnz $-1
     scf
     ret