ON ERROR OSCLI "REFRESH ON" : IF ERR=17 CHAIN @lib$+"../examples/tools/touchide" ELSE MODE 3 : PRINT REPORT$ : END
      
      REM Polydots by Richard Russell, http://www.rtrussell.co.uk/
      REM Adapted from a GIF animation by @beesandbombs on Twitter
      
      MIN = 3
      MAX = 13
      DOT = 10
      CYCLE = 17
      SCALE = 5000
      SPEED = 5
      
      VDU 23,22,640;500;8,20,16,128
      ORIGIN 640,500
      OFF
      DIM x(MAX,MAX), y(MAX,MAX), t(MAX), s%(MAX), x%(MAX), y%(MAX)
      
      FOR sides% = MIN TO MAX
        edge = SCALE / (CYCLE - sides%) / sides%
        radius = edge / 2 / SIN(PI / sides%)
        GCOL sides% - MIN
        FOR vertex% = 0 TO sides%
          a = 2 * PI * (vertex% + 0.5) / sides%
          x(sides%, vertex%) = radius * SIN(a)
          y(sides%, vertex%) = -radius * COS(a)
          x% = INT(x(sides%, vertex%) + 0.5)
          y% = INT(y(sides%, vertex%) + 0.5)
          IF vertex% = 0 MOVE x%*2,y%*2 ELSE DRAW x%*2,y%*2
        NEXT
        t(sides%) = edge / 2
        s%(sides%) = sides% - 1
      NEXT
      
      GCOL 3,15
      *REFRESH OFF
      CIRCLE FILL 0, 0, DOT
      REPEAT
        FOR sides% = MIN TO MAX
          edge = SCALE / (CYCLE - sides%) / sides%
          IF t(sides%) >= edge THEN
            t(sides%) -= edge
            s%(sides%) = (s%(sides%) + 1) MOD sides%
          ENDIF
          x1 = x(sides%, s%(sides%))
          y1 = y(sides%, s%(sides%))
          x2 = x(sides%, s%(sides%) + 1)
          y2 = y(sides%, s%(sides%) + 1)
          p = t(sides%) / edge
          CIRCLE FILL x%(sides%)*2, y%(sides%)*2, DOT
          x%(sides%) = INT((1 - p) * x1 + p * x2 + 0.5)
          y%(sides%) = INT((1 - p) * y1 + p * y2 + 0.5)
          CIRCLE FILL x%(sides%)*2, y%(sides%)*2, DOT
          t(sides%) += SPEED
        NEXT
        *REFRESH
        IF INKEY$(-256)="W" WAIT 2
      UNTIL FALSE