DECLARE SUB pal ()
DECLARE SUB branch (x, y, length, angle)


' Recursive L-system fractaly stuff
' vertical is 0 degrees ^

pi = ATN(1) * 4
CLS
DIM SHARED br%, ord%, a&
a& = 1
INPUT "# branches (min 1)"; br%
DIM SHARED angle(br%), ratio(br%), di(br%), o%, ps
INPUT "Random stuff"; r$: IF UCASE$(r$) = "Y" THEN INPUT "Seed"; t&: GOTO r

FOR n% = 1 TO br%
PRINT "Angle of branch #" + STR$(n%);
INPUT a
angle(n%) = pi * a / 180
PRINT "Ratio of division for branch #" + STR$(n%) + "(0 at start 1 at other end)";

INPUT ratio(n%)
PRINT "Length diminuation (best less than 1!)";
INPUT di(n%)
NEXT n%
st:
INPUT "# orders"; o%
SCREEN 12
pal
ps = 14 / o%
LINE (320, 420)-(320, 320), 1
branch 320, 420, 100, 0
LOCATE 1, 1: PRINT SPACE$(7)
'BEEP
SLEEP 0
END

r:
RANDOMIZE t&
FOR n% = 1 TO br%
a = RND * 360
IF a > 180 THEN a = 180 - a
angle(n%) = pi * a / 180
ratio(n%) = .3 + RND * .7
di(n%) = .3 + RND * .6
NEXT n%
GOTO st

SUB branch (x, y, length, angle)
ord% = ord% + 1: IF ord% > o% THEN EXIT SUB
FOR n% = 1 TO br%
        xstart = x + length * ratio(n%) * SIN(angle)
        ystart = y - length * ratio(n%) * COS(angle)
        newangle = angle + angle(n%)
        newlength = length * di(n%)
        xend = xstart + newlength * SIN(newangle)
        yend = ystart - newlength * COS(newangle)
        LINE (xstart, ystart)-(xend, yend), ord% * ps: a& = a& + 1
        IF ord% = o% THEN PSET (xend, yend), 15
        branch xstart, ystart, newlength, newangle
ord% = ord% - 1
NEXT n%
END SUB

SUB pal
FOR p% = 1 TO 15
PALETTE p%, p% * 4 * 256 + 37 - (p% * 2) + p% * 65536 * (p% \ 6)
PALETTE 15, 60 + 30 * 256 + 55 * 65536
LINE (p% * 4, 470)-(p% * 4 + 4, 480), p%, BF
NEXT p%

END SUB