- tiled grid
The circles appear to scintillate. This illusion was created by Italian vision scientists Baingio Pinna and Lothar Spillman in 2002. This code is adapted from Tiles.
To New
# set default screen, pen and turtle values
ResetAll SetScreenSize [400 400] HideTurtle
SetSC Black SetPC Green SetPS 1 PenUp
End
To GridSq :Order :Side
# draw tile at each column x row position
LocalMake "Offset (1+:Order)/2
For (List "Col 1 :Order) [
For (List "Row 1 :Order) [
SetXY :Side*(:Col-:Offset) :Side*(:Row-:Offset)
Tile :Col :Row :Side] ]
End
To Tile :Col :Row :Side
# draw tile from centre
SetPC White SetPW 2
Burst 18 :Side/2.1
SetPC Gray Circle :Side/8 FillZone
SetPC Purple SetPW 4 Circle :Side/8
End
To Burst :Spokes :Radius
# star burst drawn from centre (tp)
Repeat :Spokes [
PenDown Forward :Radius
PenUp Back :Radius
Right 360/:Spokes Wait 2]
End
To Go :Order
New GridSq :Order 380 /:Order
End