(added in version 1.78.00)
The size parameter takes two values. For a line only the first is used (then use ori to specify the orientation). For triangles and rectangles the size specifies the height and width as expected. Note that for pentagons upwards, however, the size determines the width/height of the ellipse on which the vertices will fall, rather than the width/height of the vertices themselves (slightly smaller typically).
nVertices : integer
The number of vertices for your shape (2 gives a line, 3 gives a triangle,... a large number results in a circle/ellipse). It is not (currently) possible to vary the number of vertices dynamically.
fill settings:
Control the color inside the shape. If you set this to None then you will have a transparent shape (the line will remain)
line settings:
Control color and width of the line. The line width is always specified in pixels - it does not honour the units parameter.
See also
API reference for Polygon
API reference for Rect
API reference for ShapeStim
#for arbitrary vertices