The shader is way simpler and run way faster on lower end hardware
(2x faster on intel HD5000) but did not notice any improvement on AMD Vega.
This also adds a few changes to the way the wireframes are drawn:
- the slider is more linearly progressive.
- optimize display shows all wires and progressively decrease "inner" wires
intensity. This is subject to change in the future.
- text/surface/metaballs support is pretty rough. More work needs to be done.
This remove the optimization introduced in f1975a4639.
This also removes the GPU side "sharpness" calculation which means that
animated meshes with wireframe display will update slower.
The CPU sharpness calculation has still room for optimization. Also
it is not excluded that GPU calculation can be added back as a
separate preprocessing pass (saving the computation result [compute or
feedback]).
The goal here was to have more speed for static objects and remove
the dependency of having buffer textures with triangle count. This is
preparation work for multithreading the whole DRW manager.
This method is a bit more optimized than the very first one
because it does not rely on the adjacent faces properties.
That said it's still a bit slower than the per vertex method.
This make the limited wireframe not a performance problem anymore.
However, this does change the number of edges displayed as the threshold
is now computed per vertex instead of per edges.
For this reason we extended (internaly) the range of the slider so that the
users can hide more edge.
This overlay is showing mesh topology. It is usable with transparency
even if the mesh order can mess up with the expected result (some object
more prominent than others).
Edge thickness and alpha values are hardcoded for now but can easily be
added to theme or object settings.
