In engine renderer profiling

[Kangz]

The goal is to have the infrastructure necessary to do a renderer profiler like the one shown in this video https://www.youtube.com/watch?v=DMO4X9leTG8 The first and most useful step will be to have a hierarchical nesting of renderer blocks like Forward pass -> BSP -> leaf N.

Performance on the GPU can be measured using OpenGL timestamp queries for a small performance cost. A RAII way to do this with some magic seems best (to avoid devs forgetting to pop the block), of course cvar-controlled. When the OpenGL context is created, we will need to create a lot of timestamp queries as several frames can be queued in the GPU.

Also we might at that time try to limit the number of frames queued to reduce latency (using gl fences).

For a start the frame profiling can be dumped in a file, waiting for facilities to draw debug UI.

• Mentor: Kangz (gimhael, Fuma?)
• Knowledge: Renderer, OpenGL, C++ hacks to make the API fluid
• Difficulty: 5 (without visualization) 8 (with visualization)

Mentored projects on the Unv wiki

[ghost]

While I see the point for this, this is a complex task that I think is above what unvanquished can afford.

Still, some input about implementing that kind of things:

• there is the dear imgui library for the rendering of the UI
• it would be useful to have faster but cruder rendering of things like navedit enable ... , cg_drawbbox and several others
• AI behavior system could really use a way to show in "semi real time" the decisions and moves bots do. I understand they're not under engine's responsibility, but it would be nice to have some debug interface still

Imo, this is, as #355 a feature request. I'm even tempted to call this a duplicate.