' spiral
' made by Svjatoslav Agejenko
' in 2003.12
' H-Page: svjatoslav.eu
' E-Mail: svjatoslavagejenko@gmail.com
 
DECLARE SUB linem (x1!, y1!, x2!, y2!, col!)
DIM SHARED linevx(1 TO 100)
DIM SHARED linevy(1 TO 100)
DIM SHARED z
DIM SHARED zz
SCREEN 12
su = 200
z = 0
FOR a = 1 TO 30 STEP .1
su = (30 - a) * 7
x = SIN(a) * su + 200
y = COS(a) * su + 200
zz = a
linem x + (x / 2) + (a * 3), (y - (x / 3)) + (a * 3), x + 25, y + 25 - (a * 3), z
z = 15
NEXT a

a$ = INPUT$(1)
SYSTEM

SUB linem (x1, y1, x2, y2, col)
x3 = (x2 - x1) / zz
y3 = (y2 - y1) / zz

FOR a = 1 TO zz
IF linevx(a) > 0 THEN LINE (linevx(a), linevy(a))-(x1, y1), col
linevx(a) = x1
linevy(a) = y1
x1 = x1 + x3
y1 = y1 + y3
LINE (linevx(a), linevy(a))-(x1, y1), col
NEXT a
END SUB