31 lines
324 B
ArmAsm
31 lines
324 B
ArmAsm
|
|
//
|
|
// Sets PNTR in a proper range (0-39 or 40-79) depending on the
|
|
//
|
|
|
|
|
|
screen_calculate_PNTR:
|
|
|
|
ldy TBLX
|
|
lda LDTBL, y
|
|
php
|
|
jsr screen_get_clipped_PNTR
|
|
plp
|
|
bmi screen_calculate_PNTR_0_39
|
|
|
|
// FALLTROUGH
|
|
|
|
screen_calculate_PNTR_40_79:
|
|
|
|
tya
|
|
clc
|
|
adc #40
|
|
tay
|
|
|
|
// FALLTROUGH
|
|
|
|
screen_calculate_PNTR_0_39:
|
|
|
|
sty PNTR
|
|
rts
|