begin_shape('POINTS') does not draw points

[ziyaointl]

Describe the bug
begin_shape('POINTS') does not draw points

To Reproduce

from p5 import *

def draw():
        begin_shape('POINTS')
        vertex(30, 20)
        vertex(85, 20)
        vertex(85, 75)
        vertex(30, 75)
        end_shape()

if __name__ == '__main__':
        run()

Expected behavior
For points appear on the screen.

Screenshots
Expected (from Processing Language):

Actual:

System information:

• p5 release (version number or latest commit): 975f07e
• Python version: 3.8.3
• Operating system: MacOS 10.15.5

[ziyaointl]

Maybe we can use p5.circle instead of the OpenGL primitive points. This way we can easily replicate the behavior here: https://p5js.org/reference/#/p5/point

[arihantparsoya]

Yes, it would also solve #161

[jeremydouglass]

Yes, for the vispy / OpenGL renderer I recommend looking closely at how Processing(Java) (not p5.js) implements point(), and what strokeWeight / strokeCap do to a point. With strokeCap() the behavior is different then just mapping strokeWeight to p5.circle() -- see comments on the Processing reference pages.