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 ; /

LDA $15A0,x
ORA $186C,x
BNE Return

#0 @9 q7f v85 y10
r4o3c+4d4d+4
e4f4f+4g4
g+4a4a+4b4
;
#1 @9 q7f v170 y10
e4f4f+4g4
g+4a4a+4b4
;
#2 @9 q7f v255 y10
c4c+4d4d+4
e4f4f+4g4
g+4a4a+4b4
;
#3 @9 q7f v170 y10
>c4c+4d4d+4
e4f4f+4g4
g+4a4a+4b4
;