Adjustable line thickness / point size

[i-make-robots]

OpenGL3 does not provide an easy way to change line thickness.

Here are three shaders that combine in one program to produce thick line effect. study them!
https://github.com/tksuoran/erhe/blob/main/src/editor/res/shaders/compute_before_line.comp
https://github.com/tksuoran/erhe/blob/main/src/editor/res/shaders/line_after_compute.vert
https://github.com/tksuoran/erhe/blob/main/src/editor/res/shaders/line_after_compute.frag