The marker can also be a tuple (numsides,
style, angle), which will create a custom,
regular symbol.
numsides:
the number of sides
style:
the style of the regular symbol:
0
a regular polygon
1
a star-like symbol
2
an asterisk
3
a circle (numsides and angle is
ignored)
angle:
the angle of rotation of the symbol
For backward compatibility, the form (verts, 0) is also accepted,
but it is equivalent to just verts for giving a raw set of vertices
that define the shape.
None is the default which means ‘nothing’, however this table is
referred to from other docs for the valid inputs from marker inputs and in
those cases None still means ‘default’.
