SCREEN 12
PRINT "afvlakking van een N-polygoon"
PRINT "demping door formule xk=.5*(xk-1 + xk+1)"
PRINT "geef range op voor N (min, max)"
PRINT ""
PRINT "smoothing an N-polyline"
PRINT "thru formula Xk = .5 * (Xk-1 + Xk+1)"
PRINT "give range min-max for N"

PRINT
PRINT "Druk toets = NEXT N/Press a key = NEXT N"
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 11
CLS

RANDOMIZE TIMER
x0% = 320: xmax% = 480: xmin% = 2 * x0% - xmax%
dxmax% = 10
INPUT "Range min. n1 (0 = END):", n1%
IF n1% = 0 THEN END
INPUT "Range max. n2 (0 = END):", n2%
IF n2% = 0 THEN END

FOR n% = n1% TO n2%  ' verfijn met stijgende n
n% = n% + INT(n% / 10)
CLS
PRINT n%; " points  -> key...(SPACE=END)"
REDIM x%(n%), y%(n%), dx%(n%)

FOR k% = 0 TO n%
x%(k%) = xmin% + RND * (xmax% - xmin%)
y%(k%) = 10 + (k% / n%) * 470
NEXT k%

FOR k% = 1 TO n% - 1
LINE (x%(k% - 1), y%(k% - 1))-(x%(k%), y%(k%))
LINE (x%(k%), y%(k%))-(x%(k% + 1), y%(k% + 1))
NEXT k%

t = TIMER: WHILE TIMER - t < .1: WEND

Ciqlus:
FOR k% = 1 TO n% - 1
LINE (x%(k% - 1), y%(k% - 1))-(x%(k%), y%(k%)), 0
LINE (x%(k%), y%(k%))-(x%(k% + 1), y%(k% + 1)), 0
x%(k%) = .5 * x%(k% - 1) + .5 * x%(k% + 1)
LINE (x%(k% - 1), y%(k% - 1))-(x%(k%), y%(k%))
LINE (x%(k%), y%(k%))-(x%(k% + 1), y%(k% + 1))
NEXT k%
a$ = INKEY$
IF a$ = " " THEN END
IF a$ <> "" GOTO volg
GOTO Ciqlus

volg:
NEXT n%
END