Blender Git Commit Log

BLF: Optimize text rendering and caching

The current code allocates and transfers a lot of memory to the GPU,
but only a small portion of this memory is actually used.
In addition, the code calls many costly gl operations during the
caching process.

This commit significantly reduce the amount of memory by allocating
and transferring a flat array without pads to the GPU.
It also calls as little as possible the gl operations during the cache.

This code also simulate a billinear filter `GL_LINEAR` using a 1D texture.

**Average drawing time:**
|before:|0.00003184 sec
|now:|0.00001943 sec
|fac:|1.6385156675048407

**5 worst times:**
|before:|[0.001075, 0.001433, 0.002143, 0.002915, 0.003242]
|now:|[0.00094, 0.000993, 0.001502, 0.002284, 0.002328]

Differential Revision: https://developer.blender.org/D6886