dos33fsprogs/demos/lovebyte2024/grow_circle_32/gcircle.s

64 lines
984 B
ArmAsm

; Xdraw test
; use to prototype small xdraw effects
; by Vince `deater` Weaver / DsR
; zero page locations
GBASL = $26
GBASH = $27
HGR_SCALE = $E7
HGR_ROTATION = $F9
; ROM locations
HGR2 = $F3D8
HPOSN = $F411
XDRAW0 = $F65D
XDRAW1 = $F661
HPLOT0 = $F457
xdraw_test:
lda #$1
sta HGR_SCALE
sta HGR_ROTATION
jsr HGR2 ; Hi-res, full screen ; 3
; Y=0, A=0 after this call
; A and Y are 0 here.
; X is left behind by the boot process?
tiny_loop:
ldy #0
ldx #140
lda #96
jsr HPOSN ; set screen position to X= (y,x) Y=(a)
; saves X,Y,A to zero page
; after Y= orig X/7
; A and X are ??
ldx #<our_shape ; load $E2 into A, X, and Y
ldy #>our_shape ; our shape table is in ROM at $E2E2
inc HGR_ROTATION
lda HGR_ROTATION
; and #$7f
bne skip
inc HGR_SCALE
skip:
jsr XDRAW0 ; XDRAW 1 AT X,Y
; Both A and X are 0 at exit
; Z flag set on exit
; Y varies
beq tiny_loop ; bra
our_shape = $E2E0
;our_shape:
;.byte $1a,$2d,$00