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cc65/libsrc/c64/soft80_kplot.s

64 lines
1.3 KiB
ArmAsm

;
; Groepaz/Hitmen, 12.10.2015
;
; lowlevel kplot function for the soft80 implementation
;
.export soft80_kplot
.import soft80_internal_cursorxlsb
.include "c64.inc"
.include "soft80.inc"
soft80_kplot:
bcs @getpos
stx CURS_Y
sty CURS_X
sei
lda $01
pha
lda #$34 ; enable RAM under I/O
sta $01
; calc pointer to bitmap
lda soft80_bitmapylo,x
clc
adc soft80_bitmapxlo,y
sta SCREEN_PTR
lda soft80_bitmapyhi,x
adc soft80_bitmapxhi,y
sta SCREEN_PTR+1
tya
and #1
sta soft80_internal_cursorxlsb
; calc pointer to vram
tya
lsr a
clc
adc soft80_vramlo,x
sta CRAM_PTR
lda #0
adc soft80_vramhi,x
sta CRAM_PTR+1
pla
sta $01
cli
@getpos:
ldx CURS_Y
ldy CURS_X
rts
;-------------------------------------------------------------------------------
; force the init constructor to be imported
.import soft80_init
conio_init = soft80_init