nxu/julia.tal

186 lines
6.7 KiB
Tal
Raw Normal View History

2024-04-19 09:25:51 -04:00
( julia.tal )
( )
( based on mandelbrot.tal by alderwick and d_m )
( )
( uses 4.12 fixed point arithmetic. )
( SCALE LOGICAL SCREENSIZE )
( #0001 21x16 42x32 )
( #0002 42x32 84x64 )
( #0004 84x64 168x128 )
( #0008 168x128 336x256 )
( #0010 336x256 672x512 )
( #0020 672x512 1344x1024 )
%SCALE { #0009 } ( 32 )
%WIDTH { #0015 } ( 21 )
%HEIGHT { #0010 } ( 16 )
%XMIN { #de69 } ( -8601 => -8601/4096 => -2.100 )
%XMAX { #0b33 } ( 2867 => 2867/4096 => 0.700 )
%YMIN { #ecc7 } ( -4915 => -4915/4096 => -1.200 )
%YMAX { #1333 } ( 4915 => 4915/4096 => 1.200 )
|00 @System &vector $2 &wst $1 &rst $1 &eaddr $2 &ecode $1 &pad $1 &r $2 &g $2 &b $2 &debug $1 &halt $1
|20 @Screen &vector $2 &width $2 &height $2 &auto $1 &pad $1 &x $2 &y $2 &addr $2 &pixel $1 &sprite $1
|0100 ( -> )
2024-04-22 22:44:35 -04:00
( set colors )
#00ff .System/r DEO2
#0ff0 .System/g DEO2
#0f0f .System/b DEO2
2024-04-19 09:25:51 -04:00
2024-04-22 22:44:35 -04:00
( set window size )
width #10 SFT2 .Screen/width DEO2
height #10 SFT2 .Screen/height DEO2
2024-04-19 09:25:51 -04:00
2024-04-22 22:44:35 -04:00
( starting c values )
#0630 ;evaluate/cx STA2 #f5e0 ;evaluate/cy STA2
2024-04-19 09:25:51 -04:00
2024-04-22 22:44:35 -04:00
;on-screen .Screen/vector DEO2
BRK
2024-04-19 09:25:51 -04:00
@on-screen ( -> BRK )
2024-04-22 22:44:35 -04:00
#0000 DUP2 .Screen/x DEO2 .Screen/y DEO2
draw-julia
;evaluate/cx LDA2
DUP2 #2000 LTH2 ?&upx
DUP2 #e000 GTH2 ?&upx
#0000 ,&dx LDR2 SUB2 ,&dx STR2
&upx [ LIT2 &dx 0040 ] ADD2 SWP2 STA2
;evaluate/cy LDA2k
DUP2 #2000 LTH2 ?&upy
DUP2 #e000 GTH2 ?&upy
#0000 ,&dy LDR2 SUB2 ,&dy STR2
&upy [ LIT2 &dy 0040 ] ADD2 SWP2 STA2
BRK
2024-04-19 09:25:51 -04:00
( logical width )
@width ( -> w* )
WIDTH SCALE MUL2 JMP2r
( logical height )
@height ( -> h* )
HEIGHT SCALE MUL2 JMP2r
( draw the julia set using 4.12 fixed point numbers )
@draw-julia ( -> )
2024-04-22 22:44:35 -04:00
XMAX XMIN SUB2 width DIV2 ,&dx STR2 ( ; &dx<-{xmax-min}/width )
YMAX YMIN SUB2 height DIV2 ,&dy STR2 ( ; &dy<-{ymax-ymin}/height )
[ LIT2 01 -Screen/auto ] DEO ( ; auto<-1 )
LIT2r 8000 ( [8000] )
YMAX YMIN ( ymax* ymin* [8000] )
&yloop ( ymax* y* [8000] )
XMAX XMIN ( ymax* y* xmax* xmin* [8000] )
&xloop ( ymax* y* xmax* x* [8000] )
ROT2k evaluate ( ymax* y* xmax* x* xmax* count^ [8000] )
draw-px POP2 ( ymax* y* xmax* x* [8000] )
[ LIT2 &dx $2 ] ADD2 ( ymax* y* xmax* x+dx* [8000] )
OVR2 STH2kr ADD2 ( ymax* y* xmax* x+dx* 8000+xmax* [8000] )
OVR2 STH2kr ADD2 ( ymax* y* xmax* x+dx* 8000+xmax* 8000+x+dx* [8000] )
GTH2 ?&xloop ( ymax* y* xmax* x+dx* [8000] )
POP2 POP2 ( ymax* y* [8000] )
#0000 .Screen/x DEO2 ( ymax* y* [8000] ; sc/x<-0 )
.Screen/y ;inc2 adjust ( ymax* y* [8000] ; sc/y<-sy+1 )
[ LIT2 &dy $2 ] ADD2 ( ymax* y+dy* [8000] )
OVR2 STH2kr ADD2 ( ymax* y+dy* 8000+ymax* [8000] )
OVR2 STH2kr ADD2 ( ymax* y+dy* 8000+ymax* 8000+y+dy* [8000] )
GTH2 ?&yloop ( ymax* y+dy* [8000] )
POP2 POP2 POP2r JMP2r ( )
2024-04-19 09:25:51 -04:00
( dithering pattern for 2x2 pixels: )
( )
( |o o| -> |x o| -> |x o| -> |x x| -> |x x| )
( |o o| -> |o o| -> |o x| -> |o x| -> |x x| )
( )
( |[p+3]/4 [px+1]/4| )
( |[p+0]/4 [px+2]/4| )
@draw-px ( px^ -> )
2024-04-22 22:44:35 -04:00
INCk INCk INC ( p+0 p+1 p+3 )
draw-quad draw-quad ( p+0 ; draw NW, NE )
.Screen/y ;inc1 adjust ( ; y<-y+1 )
.Screen/x ;sub2 adjust ( ; x<-x-2 )
INCk INC SWP ( p+2 p+0 )
draw-quad draw-quad ( ; draw SW, SE )
.Screen/y ;sub1 !adjust ( ; y<-y-1 )
2024-04-19 09:25:51 -04:00
( draw one quadrant of a 2x2 area )
@draw-quad ( p^ -> )
2024-04-22 22:44:35 -04:00
#02 SFT .Screen/pixel DEO JMP2r ( ; pixel<-p/4 )
2024-04-19 09:25:51 -04:00
( evaluate the julia function at one point )
@evaluate ( x* y* -> count^ )
2024-04-22 22:44:35 -04:00
LIT2r 20 00 ( x* y* [20 00] )
&loop ( x1* y1* [20 n^] )
OVR2 square STH2 ( x1* y1* [20 n^ xx1*] )
DUP2 square STH2 ( x1* y1* [20 n^ xx1* yy1*] )
ADD2kr STH2r ( x1* y1* xx1+yy1* [20 n^ xx1* yy1*] )
#4000 GTH2 ?&end2 ( x1* y1* [20 n^ xx1* yy1*] )
smul2 DUP2 ADD2 ( 2x1y1* [20 n^ xx1* yy1*] )
LIT2 [ &cy $2 ] ADD2 ( y2=2x1y1+cy* [20 n^ xx1* yy1*] )
SUB2r STH2r ( y2* xx1-yy1* [20 n^] )
LIT2 [ &cx $2 ] ADD2 ( y2* x2=xx1-yy1+cx* [20 n^] )
SWP2 INCr GTHkr STHr ?&loop ( x2* y2* [20 n+1^] )
!&end1 ( x2* y2* [20 n+1^] )
&end2 POP2r POP2r ( x* y* [20 count^] )
&end1 POP2 POP2 NIPr STHr JMP2r ( count^ )
2024-04-19 09:25:51 -04:00
( is x a non-negative signed value? )
@non-negative ( x* -> x* x>=0^ )
2024-04-22 22:44:35 -04:00
DUP2 #8000 LTH2 JMP2r
2024-04-19 09:25:51 -04:00
( multiply two signed 4.12 fixed point numbers )
@smul2 ( a* b* -> ab* )
2024-04-22 22:44:35 -04:00
LIT2r 0001 non-negative ?{ negate SWPr } ( a* |b|* [sign*] )
SWP2 non-negative ?{ negate SWPr } ( |b|* |a|* [sign*] )
smul2-pos STHr ?{ negate } POPr JMP2r ( ab* )
2024-04-19 09:25:51 -04:00
( multiply two non-negative fixed point numbers )
( )
( a * b = {a0/16 + a1/4096} * {b0/16 + b1/4096} )
( = a0b0/256 + a1b0/65536 + a0b1/65536 + a1b1/16777216 )
( = x + y + z + 0 ; the last term is too small to represent, i.e. zero )
( )
( x = a0b0 << 4 )
( y = a1b0 >> 4 )
( z = a0b1 >> 4 )
@smul2-pos ( a* b* -> ab* )
2024-04-22 22:44:35 -04:00
aerate ROT2 aerate ( b0* b1* a0* a1* )
STH2 ROT2k STH2 MUL2r ( b0* b1* a0* b1* a0* [a1b0*] )
MUL2 STH2 ADD2r ( b0* b1* a0* [a1b0+a0b1*] )
NIP2 MUL2 #07ff min #40 SFT2 ( a0b0* [y+z*] )
STH2r #04 SFT2 ADD2 ( x* [y+z*] )
#7fff !min ( ab* )
2024-04-19 09:25:51 -04:00
( equivalent to DUP2 smul2 but faster )
@square ( a* -> aa* )
2024-04-22 22:44:35 -04:00
non-negative ?{ negate } ( |a|* )
aerate ( 00 ahi^ 00 alo^ )
OVR2 MUL2 #03 SFT2 SWP2 ( yz* ahi* )
DUP2 MUL2 #07ff min #40 SFT2 ( x* yz* )
ADD2 #7fff !min ( aa* )
2024-04-19 09:25:51 -04:00
( update a device d^ given a function f: x* -> f[x]* )
@adjust ( d^ f* -> )
2024-04-22 22:44:35 -04:00
STH2 DEI2k STH2r JSR2 ROT DEO2 JMP2r
2024-04-19 09:25:51 -04:00
( return the minimum of two non-negative numbers. )
@min ( x* y* )
2024-04-22 22:44:35 -04:00
GTH2k [ JMP SWP2 ] NIP2 JMP2r
2024-04-19 09:25:51 -04:00
( convert each byte of a a short into a short )
@aerate ( x* -> 00 xhi^ 00 xlo^ )
2024-04-22 22:44:35 -04:00
SWP #0000 ROT SWP2 SWP JMP2r
2024-04-19 09:25:51 -04:00
( negate a fixed point number. doesn't work for #8000 )
@negate ( x* -> -x* )
2024-04-22 22:44:35 -04:00
DUP2k EOR2 SWP2 SUB2 JMP2r
2024-04-19 09:25:51 -04:00
( useful arithmetic operations )
@inc2 ( n* -> n+2* ) INC2
@inc1 ( n* -> n+1* ) INC2 JMP2r
@sub1 ( n* -> n-1* ) #0001 SUB2 JMP2r
@sub2 ( n* -> n-2* ) #0002 SUB2 JMP2r