dos33fsprogs/hellmood_memories/sier.orig.s

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2020-05-13 15:12:45 +00:00
; Sierpinski, 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
BH = $EF
Y1 = $F0
Y2 = $F1
NUM1L = $F2
NUM1H = $F3
NUM2L = $F4
NUM2H = $F5
RESULT0 = $F6
RESULT1 = $F7
RESULT2 = $F8
RESULT3 = $F9
TEMP = $FA
TEMPY = $FB
FRAMEL = $FC
FRAMEH = $FD
TEMPX = $FE
SCALED = $FF
; 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 = $F819
sierpinksi:
;===================
; init screen
jsr SETGR ; 3
bit FULLGR ; 3
; lda #>(2048)
lda #0
sta FRAMEH
lda #0
sta FRAMEL
jsr init_multiply_tables
sierpinski_forever:
ldx #47 ; yy ; 2
inc FRAMEL ; 2
bne yloop
inc FRAMEH
yloop:
ldy #39 ; xx ; 2
xloop:
; t=frame-2048 (assuming we are effect #4?)
lda FRAMEL
sta NUM1L
; sec
lda FRAMEH
; sbc #>(2048)
rol NUM1L ; time<<=3, speed up by factor of 8
rol
rol NUM1L
rol
rol NUM1L
rol
sta NUM1H
txa ; yy*=4
asl
asl
sta NUM2L
sta Y1
lda #0
sta NUM2H
jsr multiply_u16x16 ; result = Y*T
tya
asl
asl
sta NUM2L
lda #0
rol NUM2L
rol
sta NUM2H ; NUM2 = X*8
; sign extend X
; xsext=xprime*8; // get X into DL
; if (xsext&0x80*8) xsext|=0xff00*8;
; else xsext&=0x00ff*8;
clc
lda RESULT1
adc NUM2L
sta BH ; bh=((y*t)/256)+X
jsr multiply_u16x16_same_num1 ; result = X*T
; dh=RESULT1
; dh=(temp>>8)&0xff; // dh=(X*T/256)
; color=(yy-dh)&bh; // color=(Y-(X*T/256))&(Y*T/256+X)
sec
txa
lda Y1
sbc RESULT1
and BH
and #$f8 ; thicker sierpinksi
; if zero, color=9. Otherwise, 0
bne color_black ; leave black if not sierpinksi
lda #$99 ; otherwise: a nice orange
bne color_done
color_black:
lda #$00
color_done:
sta COLOR
txa ; A==Y1 ; 1
jsr PLOT ; (X2,Y1) ; 3
dey ; 1
bpl xloop ; 2
dex ; 1
bpl yloop ; 2
bmi sierpinski_forever ; 2
.include "multiply_tables.s"
;.include "multiply_s16x16.s"
.include "multiply_u16x16_mod.s"
; plot is 57 cycles, so 109440 to draw screen
; 169 to cal
; 433k to draw screen (2fps?)