outline shapes with GLSL

[i-make-robots]

Is your feature request related to a problem? Please describe. The current programmable shader uses https://alexanderameye.github.io/notes/rendering-outlines/#vertex-extrusion method 2, "Normal vector". In the process it uses the stencil buffer to erase everything inside the shape, creating the halo effect.

It would be better to use the jump fill a

Describe the solution you'd like https://www.reddit.com/r/opengl/comments/11mb9lm/screenspace_outline_using_stencilbuffer/

Describe alternatives you've considered leave it as is.

Additional context Priority: low. Difficulty: high.

[i-make-robots]

Current selected view shown here. note gaps between offset fragments.

[i-make-robots]

See also https://open.gl/depthstencils and https://alexanderameye.github.io/notes/rendering-outlines/ and https://github.com/kiwipxl/GLSL-shaders/blob/master/outline.glsl

[i-make-robots]

[i-make-robots]

completed in #168