Drawing the list of channels on the left side of VSE timeline was taking
surprisingly long time (3.5ms in Sprite Fright Edit v135 on Mac M1 Max).
This PR makes them draw in 0.4ms, i.e. 10x faster, by doing two things:
- Stop "search through the whole timeline" work whenever we need to know
which meta strip (if any) owns some VSE channel. Remember that info in
the "sequence lookup" that already holds data to speedup similar queries
(sequence by name, meta by sequence). I.e. this gains "channel owner by
channel" query hashtable.
- Stop alternating between "regular font glyph cache" and "svg icons glyph
cache" on each channel row, which incurs a draw call / UI batch flush.
Instead, draw all the lock/mute widgets first, then all the channel names.
While at it, simplify code related to sequence lookup:
- Use C++ mutex with lock_guard
- Use BLI Map instead of GHash
- Simplify SEQ_sequence_lookup_tag to just SEQ_sequence_lookup_invalidate
- Remove unused SEQ_get_meta_by_seqbase and SEQ_query_all_meta_strips_recursive
Pull Request: https://projects.blender.org/blender/blender/pulls/127913
754495247b