mirror of
https://github.com/cc65/cc65.git
synced 2024-08-17 03:29:15 +00:00
45 lines
958 B
ArmAsm
45 lines
958 B
ArmAsm
;
|
|
; Ullrich von Bassewitz, 22.06.2002
|
|
;
|
|
; Helper function for getpixel/setpixel. Load X/Y from stack and check if
|
|
; the coordinates are valid. Return carry clear if so.
|
|
;
|
|
|
|
.include "tgi-kernel.inc"
|
|
|
|
.import popax
|
|
.importzp ptr1, ptr2
|
|
|
|
|
|
tgi_getset:
|
|
sta ptr2 ; Y
|
|
stx ptr2+1
|
|
jsr popax
|
|
sta ptr1 ; X
|
|
stx ptr1+1
|
|
|
|
; Are the coordinates are out of range? First check if any ccord is negative.
|
|
|
|
txa
|
|
ora ptr2+1
|
|
asl a
|
|
bcs @L9 ; Bail out if negative
|
|
|
|
; Check if X is larger than the maximum x coord. If so, bail out
|
|
|
|
lda ptr1
|
|
cmp _tgi_xres
|
|
txa
|
|
sbc _tgi_xres+1
|
|
bcs @L9
|
|
|
|
; Check if Y is larger than the maximum y coord.
|
|
|
|
lda ptr2
|
|
cmp _tgi_yres
|
|
lda ptr2+1
|
|
sbc _tgi_yres+1
|
|
@L9: rts
|
|
|
|
|