ADDING SMOOTHNESS VIA TESSELLATION SHADERS

[perminder-17]

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[perminder-17]

All the work for this branch is completed successfully. Here's the result of it's working.

The main thing was to implement something like Laplacian/Gaussian smoothing to remove the artifacts. But as we moved to the algorithm we noticed that these algorithm can't be implemented via tessellation shaders. I'm not sure there's a shader construct that gives the information you'd need to do Laplace Smoothing.

So, for now, we can do use both Laplacian smoothing(at CPU) and bezier smoothing(via tessellation). Since, after this algorithm, we will have more no. of triangles, so if we apply Laplacian smoothing (maybe 1 iteration) we can have a better result that we were having without bezier smoothing.

Here's the result of my work. (you can see smooth curves instead of sharp right angles)

here's the maximum result we can achieve with similar or maybe a better algorithm (catmull-clark)

[BEFORE]

[AFTER]

So, the result looks excatly same. If anyone want's to test it please request the version of opengl to 4.0 (can only be tested in linux/windows not in mac because we currently lack core profile)

  defaultFormat.setVersion(4,0);
  defaultFormat.setProfile(QSurfaceFormat::CompatibilityProfile);
  defaultFormat.setOptions(QSurfaceFormat::DeprecatedFunctions);

[perminder-17]

Removed the debugging pieces which was previously added for testing purpose.

[github-actions]

Here are the build results
Avogadro2.AppImage
Win64.exe
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