SCREEN 12
PRINT "Groeifractal met impact, afgeleid van SloGro"
PRINT "Impact growth fractal, derived from SloGro"
PRINT "********************************************"
PRINT
PRINT "Druk toets om te stoppen/Press Key to stop"
PRINT "******************************************"
PRINT : PRINT : PRINT : COLOR 10
PRINT "     Credits: guido wuyts 1997"
PRINT : PRINT : PRINT : COLOR 3
PRINT "     -> Toets/Key...": COLOR 15
PLAY "o4l24d"
SLEEP: a$ = INKEY$: a$ = "": COLOR 12
CLS

Init:
px = 10: py = 8: nx = INT(640 / px): ny = INT(460 / py)
i0 = INT(nx / 2): j0 = INT(ny / 2): x0 = i0 * px: y0 = j0 * py
DIM toest(nx + 1, ny + 1): toest(i0, j0) = 1: LINE (x0, y0)-(x0 + px - 1, y0 + py - 1), 3, BF
imin = 5: imax = 5: jmin = 5: jmax = 5
RANDOMIZE TIMER
telmax = 500

FOR tel = 1 TO telmax

Inval:
a = RND: b = RND
IF a < .5 THEN
        i = i0 - imin + INT(RND * (imin + imax))
        IF b < .5 THEN
                j = j0 - jmin
                ELSE
                j = j0 + jmax
                END IF
        ELSE
        j = j0 - jmin + INT(RND * (jmin + jmax))
        IF b < .5 THEN
                i = i0 - imin
                ELSE
                i = i0 + imax
                END IF
        END IF
di = RND - .5
dj = RND - .5

LOOPt:
i1 = i + di: j1 = j + dj
x = INT(i) * px: y = INT(j) * py: x1 = INT(i1) * px: y1 = INT(j1) * py
IF i1 < (i0 - imin) OR i1 > (i0 + imax) THEN LINE (x, y)-(x + px - 1, y + py - 1), 0, BF: GOTO Inval
IF j1 < (j0 - jmin) OR j1 > (j0 + jmax) THEN LINE (x, y)-(x + px - 1, y + py - 1), 0, BF: GOTO Inval
IF toest(INT(i1), INT(j1)) = 1 THEN GOSUB Inslag: GOTO Volgend
LINE (x, y)-(x + px - 1, y + py - 1), 0, BF
LINE (x1, y1)-(x1 + px - 1, y1 + py - 1), , BF
i = i1: j = j1
GOTO LOOPt

Volgend:
a$ = INKEY$
IF NOT a$ = "" THEN GOTO Einde
NEXT tel

Einde:
BEEP
END

Inslag:
LINE (x, y)-(x + px - 1, y + py - 1), 3, BF
toest(INT(i), INT(j)) = 1
IF i0 - i > imin - 5 THEN imin = i0 - i + 5
IF i - i0 > imax - 5 THEN imax = i - i0 + 5
IF j0 - j > jmin - 5 THEN jmin = j0 - j + 5
IF j - j0 > jmax - 5 THEN jmax = j - j0 + 5
RETURN