Sierpinski carpet: Difference between revisions

==={{header|Quite BASIC}}===

{{trans|BBC BASIC}}

In Quite BASIC, the point on the lower left on the canvas is 0, 0.

<syntaxhighlight lang="basic" >

10 REM Sierpinski carpet

20 CLS

30 LET R = 3

40 LET S = 1

50 FOR P = 1 TO R

60 LET S = R * S

70 NEXT P

80 REM Now S (size) is 3 to the power of R (order)

90 FOR I = 0 TO S - 1

100 FOR J = 0 TO S - 1

110 LET X = J

120 LET Y = I

130 GOSUB 300

140 IF C = 1 THEN PLOT J, I, "white"

150 NEXT J

160 NEXT I

170 END

300 REM Subroutine -- Is (X,Y) in the carpet?

310 REM Returns C = 0 (no) or C = 1 (yes).

320 LET C = 0

330 IF X % 3 = 1 AND Y % 3 = 1 THEN RETURN

340 LET X = FLOOR(X / 3)

350 LET Y = FLOOR(Y / 3)

360 IF X > 0 OR Y > 0 THEN GOTO 330

370 LET C = 1

380 RETURN

</syntaxhighlight>