- XLogo animation
This program draws a series of recursive trees, with varying branch angle from 0 to 180 degrees.
To New
# set default screen, pen and turtle values
ResetAll SetScreenSize [400 400] HideTurtle
SetSC Black SetPC Green SetPS 1 PenUp
End
To Tree :Length :Angle
If :Length < 10 [Stop] # ends recursion if length too small
SetPW :Length/9
# reduce pen width as branch length gets smaller
SetPC TreeCol :Length # branch color depends on length
Forward :Length Left :Angle/2
Tree :Length*0.71 :Angle Right :Angle # tree with 0.71 branch length
Tree :Length*0.71 :Angle Left :Angle/2
PenUp Back :Length PenDown # return to starting point
End
To TreeCol :Length
Make "Green Round 2.5*(100-:Length) # green depends on length
Output ( List 255 :Green 0 ) # red set to 255 and blue to 0
End
To Go
New Animation Back 150 PenDown
For [Angle 0 180 4] [ # angle from 0 to 180
Wash Tree 100 :Angle Refresh Wait 20]
End
Also see other recursive tree programs.