mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-06-11 05:29:38 +00:00
139 lines
1.5 KiB
ArmAsm
139 lines
1.5 KiB
ArmAsm
; Ovals
|
|
|
|
; zero page
|
|
GBASL = $26
|
|
GBASH = $27
|
|
MASK = $2E
|
|
COLOR = $30
|
|
;CTEMP = $68
|
|
YY = $69
|
|
|
|
HGR_X = $E0
|
|
HGR_XH = $E1
|
|
HGR_Y = $E2
|
|
HGR_COLOR = $E4
|
|
HGR_PAGE = $E6
|
|
|
|
FRAME = $FC
|
|
SUM = $FD
|
|
SAVEX = $FE
|
|
SAVEY = $FF
|
|
|
|
; soft-switches
|
|
FULLGR = $C052
|
|
PAGE1 = $C054
|
|
|
|
; ROM routines
|
|
|
|
HGR2 = $F3D8
|
|
HPOSN = $F411 ; (Y,X),(A) (values stores in HGRX,XH,Y)
|
|
|
|
;================================
|
|
; Clear screen and setup graphics
|
|
;================================
|
|
oval:
|
|
|
|
jsr HGR2 ; set hi-res 140x192, page2, fullscreen
|
|
|
|
draw_oval:
|
|
inc FRAME
|
|
|
|
ldx #191 ; YY
|
|
create_yloop:
|
|
|
|
txa
|
|
ldx #39
|
|
ldy #0
|
|
|
|
jsr HPOSN ; (Y,X),(A) (values stores in HGRX,XH,Y)
|
|
|
|
; restore values
|
|
|
|
ldx HGR_Y
|
|
ldy HGR_X
|
|
|
|
create_xloop:
|
|
|
|
lda FRAME
|
|
sta SUM
|
|
|
|
tya ; XX
|
|
jsr calcsine
|
|
|
|
txa ; YY
|
|
jsr calcsine_div2
|
|
|
|
lsr ; double colors
|
|
and #$7 ; mask
|
|
tax
|
|
lda colorlookup,X
|
|
sta SAVEY
|
|
|
|
tya
|
|
ror
|
|
bcc noshift
|
|
ror SAVEY
|
|
noshift:
|
|
lda SAVEY
|
|
and #$7f
|
|
sta (GBASL),Y
|
|
|
|
ldx SAVEX
|
|
|
|
dey
|
|
bpl create_xloop
|
|
|
|
dex
|
|
bne create_yloop
|
|
|
|
; X and Y both $FF
|
|
|
|
beq draw_oval
|
|
|
|
|
|
|
|
calcsine_div2:
|
|
lsr
|
|
calcsine:
|
|
stx SAVEX
|
|
|
|
and #$3f
|
|
|
|
tax
|
|
rol
|
|
rol
|
|
rol
|
|
bcc sinadd
|
|
|
|
sinsub:
|
|
lda #0
|
|
lda SUM
|
|
; sec
|
|
sbc sinetable-32,X
|
|
jmp sindone
|
|
|
|
sinadd:
|
|
lda SUM
|
|
; clc
|
|
adc sinetable,X
|
|
|
|
sindone:
|
|
sta SUM
|
|
|
|
ldx SAVEX
|
|
rts
|
|
|
|
|
|
colorlookup:
|
|
|
|
.byte $11,$55,$5d,$7f,$5d,$55,$11 ; use 00 from sinetable
|
|
;.byte $00
|
|
|
|
sinetable:
|
|
; this is actually (32*sin(x))
|
|
|
|
.byte $00,$03,$06,$09,$0C,$0F,$11,$14
|
|
.byte $16,$18,$1A,$1C,$1D,$1E,$1F,$1F
|
|
.byte $20,$1F,$1F,$1E,$1D,$1C,$1A,$18
|
|
.byte $16,$14,$11,$0F,$0C,$09,$06,$03
|