dos33fsprogs/hellmood_memories/circles.s
2020-05-05 01:14:22 -04:00

158 lines
2.5 KiB
ArmAsm

; Zooming Circles, based on the code in Hellmood's Memories
; by deater (Vince Weaver) <vince@deater.net>
; Zero Page
BASL = $28
BASH = $29
H2 = $2C
COLOR = $30
X1 = $F0
X2 = $F1
Y1 = $F2
Y2 = $F3
TEMP = $FA
TEMPY = $FB
FRAME = $FC
TEMPX = $FD
; Soft Switches
KEYPRESS= $C000
KEYRESET= $C010
SET_GR = $C050 ; Enable graphics
FULLGR = $C052 ; Full screen, no text
PAGE0 = $C054 ; Page0
PAGE1 = $C055 ; Page1
LORES = $C056 ; Enable LORES graphics
; ROM routines
PLOT = $F800 ; plot, horiz=y, vert=A (A trashed, XY Saved)
SETCOL = $F864
TEXT = $FB36 ;; Set text mode
BASCALC = $FBC1
SETGR = $FB40
HOME = $FC58 ;; Clear the text screen
WAIT = $FCA8 ;; delay 1/2(26+27A+5A^2) us
HLINE = $F819
; 103 bytes
; attempted HLINE, not much help (122 bytes, slow)
; quad plot, also 122
.globalzp squares_table_y
.globalzp color_lookup
.globalzp smc1,smc2,smc3,smc4
.zeropage
zooming_circles:
;===================
; init screen
jsr SETGR ; 3
bit FULLGR ; 3
;====
; 6
circle_forever:
inc FRAME ; 2
ldx #24 ; 2
stx Y2 ; 2
dex ; 1
yloop:
ldy #20 ; 2
sty X2 ; 2
dey ; 1
xloop:
clc ; 1
lda squares_table_y+4,y ; 3
asl ; 1
asl ; 1
adc squares_table_y,x ; 2
lsr ; 1
adc FRAME ; 2
and #$1f ; 2
; and #$18
; 00, 10 = black
; 01 = grey 55 or aa
; 11 = light blue 77
lsr ; 1
lsr ; 1
lsr ; 1
sty TEMPY ; 2
tay ; 1
lda color_lookup,Y ; 3
sta COLOR ; 2
ldy X2 ; Y==X2 ; 2
txa ; A==Y1 ; 1
jsr PLOT ; (X2,Y1) ; 3
lda Y2 ; A==Y2 ; 2
jsr PLOT ; (X2,Y2) ; 3
ldy TEMPY ; Y==X1 ; 2
txa ; A==Y1 ; 1
jsr PLOT ; (X1,Y1) ; 3
lda Y2 ; A==Y2 ; 2
jsr PLOT ; (X1,Y2) ; 3
inc X2 ; 2
dey ; 1
bpl xloop ; 2
inc Y2 ; 2
dex ; 1
bpl yloop ; 2
bmi circle_forever ; 2
; 24 bytes
squares_table_y:
.byte $24,$21,$1e,$1b,$19,$16,$14,$12
.byte $10,$0e,$0c,$0a,$09,$07,$06,$05
.byte $04,$03,$02,$01,$01,$00,$00
color_lookup:
.byte $00 ; also last byte of squares table
.byte $55,$00,$77
;.byte $00,$00,$00,$00,$01,$01,$02,$03
;.byte $04,$05,$06,$07,$09,$0a,$0c,$0e
;.byte $10,$12,$14,$16,$19,$1b,$1e,$21
; 40 bytes
;squares_table_x:
;.byte $71,$6a,$64,$5d,$57,$51,$4b,$45
;.byte $40,$3a,$35,$31,
;.byte $2c,$28,$24,$20
;.byte $1c,$19,$15,$12,$10,$0d,$0b,$09
;.byte $07,$05,$04,$02,$01,$01,$00,$00
;.byte $00,$00,$00,$01,$01,$02,$04,$05
;.byte $07,$09,$0b,$0d,$10,$12,$15,$19
;.byte $1c,$20,$24,$28 ;,$2c,$31,$35,$3a
;;.byte $40,$45,$4b,$51,$57,$5d,$64,$6a