Renames previous METRICS to COUNTERS. These are still reset to zero
every frame.
Adds new METRICS which are preserved, maintained externally to speeds,
and only sampled by speeds code once per frame.
Also adds new metrics:
- `studio.cached_submodels` -- number of submodels in cache
- `geom.used` -- memory used by long allocations
- `geom.{vertices,indices}` -- counts of vertices/indices for long
allocations
- `geom.dyn_{vertices,indices}` -- counts of vertices/indices for
single-frame dynamic allocations
Make sure that things get created and destroyed at the right times.
Allow longer-than-map block allocations.
Fix brush model leaks -- previously they weren't destroyed on map
change/game exit properly. Also free geometry ranges accordingly.
Add a note about map loading process, and various models lifetimes.
The intent is to manage long-vs-single-frame allocations better.
Previously long allocations were map-long bump allocations, and couldn't be freed
mid-map, as there was neither a reference to the allocated range, nor a
way to actully free it.
Add a two-mode block allocator (similar to previous debuffer alloc) that
allows making long and once allocations. But now long allocations are
backed by "pool" allocator and return references to the range.
This commit doesn't do the deallocation yet, so map chaning doesn't yet
work.