- shapes
This program draws lens shapes of different angles. It requires a bit of trigonometry to find the distance :Dist of each arch from the centre of the lens.
To New
# set default screen, pen and turtle values
ResetAll SetScreenSize [400 400] HideTurtle
SetSC Black SetPC Green SetPS 1 PenUp
End
To Lens :Angle :Size
# lens shape drawn from centre (tp)
Make "Dist (:Size/2)/Tan :Angle/2
Repeat 2 [
Back :Dist Arch :Angle (:Size/2) / Sin :Angle/2
Forward :Dist Left 180]
End
To Arch :Angle :Radius
# symmetrical arc drawn relative to turtle heading
Arc :Radius Heading-:Angle/2
Heading+:Angle/2
End
To Go
New
For [Ang 150 10 -20] [ # 230 10 -20
Home Left 45
SetPC Green Lens :Ang 448 # 256
SetPC (List :Ang :Ang :Ang) Fill
Back 1.15 *:Ang Right 45
SetPC White Label :Ang Wait 30]
SetPos [-190 182] Label [Lens Shapes]
End
Type in Lens :Angle :Size for individual lens shapes.
Also see: Lune Trees