PROGRAM CIRCULAR_SIERPINSKI   !Basic Version © W.van Duyn 21st MAY 2004
SET MODE "color"
SET WINDOW 0,1199,0,903
SET BACKGROUND COLOR "white"
PRINT "input order, try 3 : scale try 320 "
INPUT m,f
CLEAR
SET COLOR 16
BOX AREA 0,1199,0,903
SET BACKGROUND COLOR "black"
SET COLOR "white"
PRINT"Circular Sierpinski Gasket"
RANDOMIZE
LET x=1
LET y=1
FOR i= 1 TO 1000000
LET c = INT(RND*m+1)
LET xx=x/((x^2 + y^2)*2) + cos(2*pi*c/m)-cos(2*pi*(c+1)/m)
LET yy=y/((x^2 + y^2)*2) + sin(2*pi*c/m)-sin(2*pi*(c+1)/m)
LET x=xx/(xx^2 + yy^2)
LET y=yy/(xx^2 + yy^2)
CALL colorTable(c,m)
IF i >100 THEN PLOT 600+f*x,450+f*y
NEXT i
END

SUB colorTable(c,m)
SET COLOR MIX (c+100) 1,1-c/m,c/m
SET COLOR MIX (2*c+100) c/m,1,1-c/m
SET COLOR MIX (3*c+100) 1-c/m,c/m,1
IF MOD(c,3)=0 THEN SET COLOR c+100
IF MOD(c,3)=1 THEN SET COLOR 2*c+100
IF MOD(c,3)=2 THEN SET COLOR 3*c+100
END SUB