EXTRA_BITS = $7FAB10
NEW_SPRITE_NUM = $7FAB9E ;0C bytes custom sprite number

JUMP_TIMER = $163E
RAM_ThrowTimer = $1504

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; sprite data
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

TIME_TO_LOCK = $28

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; init JSL
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

dcb "INIT"
JSR SUB_GET_DIR
TYA
STA $157C,x

LDA $1588,x
ORA #$04
STA $1588,x

STZ $1602,x

TXA
AND #$03
ASL A
ASL A
ASL A
ASL A
PHA
ASL A
ADC #$32
STA RAM_ThrowTimer,x

PLA
ADC #$FE
STA JUMP_TIMER,x

RTL

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; main sprite JSL
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

dcb "MAIN"
HAMMER_BRO_JSL PHB ; \
PHK ; | main sprite function, just calls local subroutine
PLB ; |
JSR DecrementTimers
JSR START_HB_CODE ; |
PLB ; |
RTL ; /

DecrementTimers:
LDA $14C8,x
CMP #$08
BNE DoneDec
LDA $9D
BNE DoneDec
LDA RAM_ThrowTimer,x
BEQ DoneDec
DEC RAM_ThrowTimer,x
DoneDec:
RTS

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; main sprite routine
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

TIME_TO_SHOW = $22 ;time to display the boomerang before it is thrown

X_SPEED dcb $00,$FC,$00,$04 ;rest at bottom, moving up, rest at top, moving down
TIME_IN_POS dcb $48,$10,$48,$10 ;moving up, rest at top, moving down, rest at bottom
TIME_TILL_THROW dcb $F7,$D7

STAR INC RAM_ThrowTimer,x
RETURN RTS
START_HB_CODE JSR SUB_GFX ; draw hammer bro gfx
LDA $14C8,x ; \ if hammer bro status != 8...
CMP #$02 ; } ... not (killed with spin jump [4] or star[2])
BEQ STAR
CMP #$08
BNE RETURN ; / ... return
LDA $9D ; \ if sprites locked...
BNE RETURN ; / ... return

JSR SUB_GET_DIR ; \ always face mario
TYA ; |
STA $157C,x ; /


JSR SUB_OFF_SCREEN_X3 ; only process hammer bro while on screen
INC $1570,x ; increment number of frames hammer bro has been on screen

LDA $1570,x ; \ calculate which frame to show:
LSR A ; |
LSR A ; |
LSR A ; |
LSR A ; |
AND #$01 ; | update every 16 cycles if normal
STA $1602,x ; / write frame to show

LDA RAM_ThrowTimer,x ; \ if time until spit >= $10
CMP #TIME_TO_SHOW ; | just go to normal walking code
BCS JUMP_SPRITE ; /
INC $1602,x
INC $1602,x

LDA RAM_ThrowTimer,x ; \ throw hammer if it's time
BNE NO_RESET ; |
LDY $C2,x ; |
LDA TIME_TILL_THROW,y ; |
STA RAM_ThrowTimer,x ; |
NO_RESET CMP #$01 ; |
BNE JUMP_SPRITE ; |
LDA $C2,x ; |
EOR #$01 ; |
STA $C2,x ; |
JSR SUB_HAMMER_THROW ; /

JUMP_SPRITE LDA JUMP_TIMER,x
CMP #$40 ; | just go to normal walking code
BCS WALK_SPRITE ; /
LDA $1602,x ; \ lock image while jumping
ORA #$01 ; |
STA $1602,x ; /
INC $1540,x ; we didn't move the sprite this frame, so we don't want a decrement
; STZ $B6,x ; stop sprite from moving
LDA JUMP_TIMER,x
CMP #$38
BNE NO_JUMP2
LDA #$00 ; \ y speed (formerly B0)
STA $AA,x ; /
BRA APPLY_SPEED
NO_JUMP2 CMP #$00
BNE APPLY_SPEED
LDA #$FE
STA JUMP_TIMER,x

BRA APPLY_SPEED

WALK_SPRITE LDA $151C,x ; \
TAY ; |
LDA $1540,x ; |
BEQ CHANGE_SPEED ; |
LDA X_SPEED,y ; | set x speed
STA $B6,x ; /
BRA APPLY_SPEED

CHANGE_SPEED LDA TIME_IN_POS,y ;A:0001 X:0007 Y:0000 D:0000 DB:01 S:01F5 P:envMXdiZCHC:0654 VC:057 00 FL:24235
STA $1540,x ;A:0020 X:0007 Y:0000 D:0000 DB:01 S:01F5 P:envMXdizCHC:0686 VC:057 00 FL:24235
LDA $151C,x
INC A
AND #$03
STA $151C,x

APPLY_SPEED LDA $1588,x ; push ground status so we can compare later
PHA ;

JSL $01802A ; update position based on speed values

LDA $1588,x ; if on the ground now...
AND #04 ;
BEQ IN_AIR ;
PLA ; ...and not on the ground before
AND #04 ;
BNE CHECK_TOUCH ;
LDA #TIME_TO_LOCK ; \ shake ground
STA $1887 ; /

LDA #$09 ; \ play sound effect
STA $1DFC ; /

LDA $77
AND #$04
BEQ CHECK_TOUCH
LDA #TIME_TO_LOCK ; set timer to freeze mario
STA $18BD

BRA CHECK_TOUCH

IN_AIR PLA

CHECK_TOUCH LDA $1588,x ; \ if hammer bro is touching the side of an object...
AND #$03 ; |
BEQ DONT_CHANGE_DIR ; |
LDA $151C,x
INC A
AND #$03
STA $151C,x

DONT_CHANGE_DIR JSL $018032 ; interact with other sprites
JSL $01A7DC ; check for mario/hammer bro contact

NO_CONTACT RTS ; return





;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; hammer routine
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

X_OFFSET dcb $0C,$F4
X_OFFSET2 dcb $00,$FF

SUB_HAMMER_THROW LDA $15A0,x ; \ no egg if off screen
ORA $186C,x ; |
ORA $15D0,x ; |
BNE NO_CONTACT ; /

JSL $02A9DE ; \ get an index to an unused sprite slot, return if all slots full
BMI RETURN67 ; / after: Y has index of sprite being generated

LDA #$37 ; \ sound effect
STA $1DF9 ; /

LDA #$01 ; \ set sprite status for new sprite
STA $14C8,y ; /

PHX
LDA NEW_SPRITE_NUM,x
INC A
TYX
STA NEW_SPRITE_NUM,x
PLX

PHY
LDA $157C,x
TAY
LDA $E4,x ; \ set x position for new sprite
CLC ; |
ADC X_OFFSET,y ; |
PLY ; |
STA $00E4,y ; |

PHY ; |
LDA $157C,x ; |
TAY ; |
LDA $14E0,x ; |
ADC X_OFFSET2,y ; |
PLY ; |
STA $14E0,y ; /

LDA $D8,x ; \ set y position for new sprite
SEC ; | (y position of generator - 1)
SBC #$0E ; |
STA $00D8,y ; |
LDA $14D4,x ; |
SBC #$00 ; |
STA $14D4,y ; /

PHX ; \ before: X must have index of sprite being generated
TYX ; | routine clears *all* old sprite values...
JSL $07F7D2 ; | ...and loads in new values for the 6 main sprite tables
JSL $0187A7 ; | get table values for custom sprite
LDA #$08 ; |
STA EXTRA_BITS,x ; |
PLX ; /

LDA $157C,x
STA $157C,y

RETURN67 RTS ; return

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; graphics routine
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

TILEMAP dcb $A6,$A9,$E0,$E1,$A6,$A9,$E3,$E4,$A6,$A7,$E0,$E1,$A6,$A7,$E3,$E4
dcb $A6,$A9,$E0,$E1,$A6,$A9,$E3,$E4,$A6,$A7,$E0,$E1,$A6,$A7,$E3,$E4
HORIZ_DISP dcb $FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04
dcb $04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC,$04,$FC
VERT_DISP dcb $F0,$F0,$00,$00,$F0,$F0,$00,$00,$F0,$F0,$00,$00,$F0,$F0,$00,$00
dcb $F0,$F0,$00,$00,$F0,$F0,$00,$00,$F0,$F0,$00,$00,$F0,$F0,$00,$00
PROPERTIES dcb $40,$00 ;xyppccct format

HAMMER_TILE = $A2


SUB_GFX JSR GET_DRAW_INFO ; after: Y = index to sprite tile map ($300)
; $00 = sprite x position relative to screen boarder
; $01 = sprite y position relative to screen boarder
LDA $1602,x ; \
ASL A ; | $03 = index to frame start (frame to show * 2 tile per frame)
ASL A
STA $03 ; /
LDA $157C,x ; \ $02 = sprite direction
STA $02 ; /
BNE NO_ADD
LDA $03
CLC
ADC #$10
STA $03
NO_ADD PHX ; push sprite index

LDX #$03 ; loop counter = (number of tiles per frame) - 1
LOOP_START PHX ; push current tile number
TXA ; \ X = index to horizontal displacement
ORA $03 ; / get index of tile (index to first tile of frame + current tile number)
FACING_LEFT TAX ; \

LDA $00 ; \ tile x position = sprite x location ($00)
CLC ; |
ADC HORIZ_DISP,x ; |
STA $0300,y ; /

LDA $01 ; \ tile y position = sprite y location ($01) + tile displacement
CLC ; |
ADC VERT_DISP,x ; |
STA $0301,y ; /

LDA TILEMAP,x ; \ store tile
STA $0302,y ; /

LDX $02 ; \
LDA PROPERTIES,x ; | get tile properties using sprite direction
LDX $15E9 ; |
ORA $15F6,x ; | get palette info
ORA $64 ; | put in level properties
STA $0303,y ; / store tile properties

PLX ; \ pull, X = current tile of the frame we're drawing
INY ; | increase index to sprite tile map ($300)...
INY ; | ...we wrote 1 16x16 tile...
INY ; | ...sprite OAM is 8x8...
INY ; | ...so increment 4 times
DEX ; | go to next tile of frame and loop
BPL LOOP_START ; /

PLX ; pull, X = sprite index

LDA RAM_ThrowTimer,x
CMP #$02
BCC NO_SHOW_HAMMER
CMP #30
BCS NO_SHOW_HAMMER
LDA $1602,x
CMP #$02
BCS SHOW_HAMMER_TOO

NO_SHOW_HAMMER LDY #$02 ; \ 02, because we didn't write to 460 yet
LDA #$03 ; | A = number of tiles drawn - 1
JSL $01B7B3 ; / don't draw if offscreen
RTS ; return

HAMMER_OFFSET dcb $F4,$0C

SHOW_HAMMER_TOO PHX

LDA $00
LDX $02
CLC
ADC HAMMER_OFFSET,x
STA $0300,y

LDA $01 ; \ tile y position = sprite y location ($01) + tile displacement
CLC ; |
ADC #$E8 ; |
STA $0301,y ; /

LDA #HAMMER_TILE ; \ store tile
STA $0302,y ; /

LDA #$03 ; the hammer palette is set to 09; use second gfx page
CPX #$00
BNE NO_FLIP_HAMMER
ORA #$40
NO_FLIP_HAMMER ORA $64 ; \ put in level properties
STA $0303,y ; / store tile properties

PLX
INY ; | increase index to sprite tile map ($300)...
INY ; | ...we wrote 1 16x16 tile...
INY ; | ...sprite OAM is 8x8...
INY ; | ...so increment 4 times

LDY #$02 ; \ 02, because we didn't write to 460 yet
LDA #$04 ; | A = number of tiles drawn - 1
JSL $01B7B3 ; / don't draw if offscreen
RTS ; return

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; routines below can be shared by all sprites. they are ripped from original
; SMW and poorly documented
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; $B760 - graphics routine helper - shared
; sets off screen flags and sets index to OAM
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;org $03B75C

TABLE1 dcb $0C,$1C
TABLE2 dcb $01,$02

GET_DRAW_INFO STZ $186C,x ; reset sprite offscreen flag, vertical
STZ $15A0,x ; reset sprite offscreen flag, horizontal
LDA $E4,x ; \
CMP $1A ; | set horizontal offscreen if necessary
LDA $14E0,x ; |
SBC $1B ; |
BEQ ON_SCREEN_X ; |
INC $15A0,x ; /

ON_SCREEN_X LDA $14E0,x ; \
XBA ; |
LDA $E4,x ; |
REP #$20 ; |
SEC ; |
SBC $1A ; | mark sprite invalid if far enough off screen
CLC ; |
ADC.W #$0040 ; |
CMP.W #$0180 ; |
SEP #$20 ; |
ROL A ; |
AND #$01 ; |
STA $15C4,x ; /
BNE INVALID ;

LDY #$00 ; \ set up loop:
LDA $1662,x ; |
AND #$20 ; | if not smushed (1662 & 0x20), go through loop twice
BEQ ON_SCREEN_LOOP ; | else, go through loop once
INY ; /
ON_SCREEN_LOOP LDA $D8,x ; \
CLC ; | set vertical offscreen if necessary
ADC TABLE1,y ; |
PHP ; |
CMP $1C ; | (vert screen boundry)
ROL $00 ; |
PLP ; |
LDA $14D4,x ; |
ADC #$00 ; |
LSR $00 ; |
SBC $1D ; |
BEQ ON_SCREEN_Y ; |
LDA $186C,x ; | (vert offscreen)
ORA TABLE2,y ; |
STA $186C,x ; |
ON_SCREEN_Y DEY ; |
BPL ON_SCREEN_LOOP ; /

LDY $15EA,x ; get offset to sprite OAM
LDA $E4,x ; \
SEC ; |
SBC $1A ; | $00 = sprite x position relative to screen boarder
STA $00 ; /
LDA $D8,x ; \
SEC ; |
SBC $1C ; | $01 = sprite y position relative to screen boarder
STA $01 ; /
RTS ; return

INVALID PLA ; \ return from *main gfx routine* subroutine...
PLA ; | ...(not just this subroutine)
RTS ; /

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; $B817 - horizontal mario/sprite check - shared
; Y = 1 if mario left of sprite??
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;org $03B817 ; Y = 1 if contact

SUB_GET_DIR LDY #$00 ;A:25D0 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:1020 VC:097 00 FL:31642
LDA $94 ;A:25D0 X:0006 Y:0000 D:0000 DB:03 S:01ED P:envMXdiZCHC:1036 VC:097 00 FL:31642
SEC ;A:25F0 X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizCHC:1060 VC:097 00 FL:31642
SBC $E4,x ;A:25F0 X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizCHC:1074 VC:097 00 FL:31642
STA $0F ;A:25F4 X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizcHC:1104 VC:097 00 FL:31642
LDA $95 ;A:25F4 X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizcHC:1128 VC:097 00 FL:31642
SBC $14E0,x ;A:2500 X:0006 Y:0000 D:0000 DB:03 S:01ED P:envMXdiZcHC:1152 VC:097 00 FL:31642
BPL LABEL16 ;A:25FF X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizcHC:1184 VC:097 00 FL:31642
INY ;A:25FF X:0006 Y:0000 D:0000 DB:03 S:01ED P:eNvMXdizcHC:1200 VC:097 00 FL:31642
LABEL16 RTS ;A:25FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:1214 VC:097 00 FL:31642


;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; $B85D - off screen processing code - shared
; sprites enter at different points
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;org $03B83B

TABLE3 dcb $40,$B0
TABLE6 dcb $01,$FF
TABLE4 dcb $30,$C0,$A0,$80,$A0,$40,$60,$B0
TABLE5 dcb $01,$FF,$01,$FF,$01,$00,$01,$FF

SUB_OFF_SCREEN_X0 LDA #$06 ; \ entry point of routine determines value of $03
BRA STORE_03 ; |
SUB_OFF_SCREEN_X1 LDA #$04 ; |
BRA STORE_03 ; |
SUB_OFF_SCREEN_X2 LDA #$02 ; |
STORE_03 STA $03 ; |
BRA START_SUB ; |
SUB_OFF_SCREEN_X3 STZ $03 ; /

START_SUB JSR SUB_IS_OFF_SCREEN ; \ if sprite is not off screen, return
BEQ RETURN_2 ; /
LDA $5B ; \ goto VERTICAL_LEVEL if vertical level
AND #$01 ; |
BNE VERTICAL_LEVEL ; /
LDA $D8,x ; \
CLC ; |
ADC #$50 ; | if the sprite has gone off the bottom of the level...
LDA $14D4,x ; | (if adding 0x50 to the sprite y position would make the high byte >= 2)
ADC #$00 ; |
CMP #$02 ; |
BPL ERASE_SPRITE ; / ...erase the sprite
LDA $167A,x ; \ if "process offscreen" flag is set, return
AND #$04 ; |
BNE RETURN_2 ; /
LDA $13 ; \
AND #$01 ; |
ORA $03 ; |
STA $01 ; |
TAY ; /
LDA $1A ;x boundry ;A:0101 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0256 VC:090 00 FL:16953
CLC ;A:0100 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZcHC:0280 VC:090 00 FL:16953
ADC TABLE4,y ;A:0100 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZcHC:0294 VC:090 00 FL:16953
ROL $00 ;A:01C0 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0326 VC:090 00 FL:16953
CMP $E4,x ;x pos ;A:01C0 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0364 VC:090 00 FL:16953
PHP ;A:01C0 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:0394 VC:090 00 FL:16953
LDA $1B ;x boundry hi ;A:01C0 X:0006 Y:0001 D:0000 DB:03 S:01EC P:eNvMXdizCHC:0416 VC:090 00 FL:16953
LSR $00 ;A:0100 X:0006 Y:0001 D:0000 DB:03 S:01EC P:envMXdiZCHC:0440 VC:090 00 FL:16953
ADC TABLE5,y ;A:0100 X:0006 Y:0001 D:0000 DB:03 S:01EC P:envMXdizcHC:0478 VC:090 00 FL:16953
PLP ;A:01FF X:0006 Y:0001 D:0000 DB:03 S:01EC P:eNvMXdizcHC:0510 VC:090 00 FL:16953
SBC $14E0,x ;x pos high ;A:01FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:0538 VC:090 00 FL:16953
STA $00 ;A:01FE X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:0570 VC:090 00 FL:16953
LSR $01 ;A:01FE X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:0594 VC:090 00 FL:16953
BCC LABEL20 ;A:01FE X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZCHC:0632 VC:090 00 FL:16953
EOR #$80 ;A:01FE X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZCHC:0648 VC:090 00 FL:16953
STA $00 ;A:017E X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizCHC:0664 VC:090 00 FL:16953
LABEL20 LDA $00 ;A:017E X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizCHC:0688 VC:090 00 FL:16953
BPL RETURN_2 ;A:017E X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizCHC:0712 VC:090 00 FL:16953
ERASE_SPRITE LDA $14C8,x ; \ if sprite status < 8, permanently erase sprite
CMP #$08 ; |
BCC KILL_SPRITE ; /
LDY $161A,x ;A:FF08 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZCHC:0140 VC:071 00 FL:21152
CPY #$FF ;A:FF08 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizCHC:0172 VC:071 00 FL:21152
BEQ KILL_SPRITE ;A:FF08 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0188 VC:071 00 FL:21152
LDA #$00 ; \ mark sprite to come back A:FF08 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0204 VC:071 00 FL:21152
STA $1938,y ; / A:FF00 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdiZcHC:0220 VC:071 00 FL:21152
KILL_SPRITE STZ $14C8,x ; erase sprite
RETURN_2 RTS ; return

VERTICAL_LEVEL LDA $167A,x ; \ if "process offscreen" flag is set, return
AND #$04 ; |
BNE RETURN_2 ; /
LDA $13 ; \ only handle every other frame??
LSR A ; |
BCS RETURN_2 ; /
AND #$01 ;A:0227 X:0006 Y:00EC D:0000 DB:03 S:01ED P:envMXdizcHC:0228 VC:112 00 FL:1142
STA $01 ;A:0201 X:0006 Y:00EC D:0000 DB:03 S:01ED P:envMXdizcHC:0244 VC:112 00 FL:1142
TAY ;A:0201 X:0006 Y:00EC D:0000 DB:03 S:01ED P:envMXdizcHC:0268 VC:112 00 FL:1142
LDA $1C ;A:0201 X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0282 VC:112 00 FL:1142
CLC ;A:02BD X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0306 VC:112 00 FL:1142
ADC TABLE3,y ;A:02BD X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0320 VC:112 00 FL:1142
ROL $00 ;A:026D X:0006 Y:0001 D:0000 DB:03 S:01ED P:enVMXdizCHC:0352 VC:112 00 FL:1142
CMP $D8,x ;A:026D X:0006 Y:0001 D:0000 DB:03 S:01ED P:enVMXdizCHC:0390 VC:112 00 FL:1142
PHP ;A:026D X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNVMXdizcHC:0420 VC:112 00 FL:1142
LDA.W $001D ;A:026D X:0006 Y:0001 D:0000 DB:03 S:01EC P:eNVMXdizcHC:0442 VC:112 00 FL:1142
LSR $00 ;A:0200 X:0006 Y:0001 D:0000 DB:03 S:01EC P:enVMXdiZcHC:0474 VC:112 00 FL:1142
ADC TABLE6,y ;A:0200 X:0006 Y:0001 D:0000 DB:03 S:01EC P:enVMXdizCHC:0512 VC:112 00 FL:1142
PLP ;A:0200 X:0006 Y:0001 D:0000 DB:03 S:01EC P:envMXdiZCHC:0544 VC:112 00 FL:1142
SBC $14D4,x ;A:0200 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNVMXdizcHC:0572 VC:112 00 FL:1142
STA $00 ;A:02FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0604 VC:112 00 FL:1142
LDY $01 ;A:02FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizcHC:0628 VC:112 00 FL:1142
BEQ LABEL22 ;A:02FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0652 VC:112 00 FL:1142
EOR #$80 ;A:02FF X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0668 VC:112 00 FL:1142
STA $00 ;A:027F X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0684 VC:112 00 FL:1142
LABEL22 LDA $00 ;A:027F X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0708 VC:112 00 FL:1142
BPL RETURN_2 ;A:027F X:0006 Y:0001 D:0000 DB:03 S:01ED P:envMXdizcHC:0732 VC:112 00 FL:1142
BMI ERASE_SPRITE ;A:0280 X:0006 Y:0001 D:0000 DB:03 S:01ED P:eNvMXdizCHC:0170 VC:064 00 FL:1195

SUB_IS_OFF_SCREEN LDA $15A0,x ; \ if sprite is on screen, accumulator = 0
ORA $186C,x ; |
RTS ; / return