Object AABB may be much larger than area currently covered by navmesh. In this
case all tiles beyond covered range should be ignored. Attempt to iterate over
them will not result in any new tile updates but can take quite a while. At
maximum this can be pow(INT_MAX - INT_MIN, 2) iterations.
Use arbitrary time limit to check for update call to finish in the test.
Primarily for crossing cell border case. Each Navigator::update call has a cost.
Doing it multiple times per frame increased frame duration on cell loading.
Call Navigator::wait only when cell has changed but do not use
Scene::hasCellChanged because it doesn't always indicates it.
Actors may have different collision shapes. Currently there are axis-aligned
bounding boxes and rotating bounding boxes. With AABB it's required to use
bounding cylinder for navmesh agent to avoid providing paths where actor can't
pass. But for rotating bounding boxes cylinder with diameter equal to the front
face width should be used to not reduce of available paths. For example rats
have rotating bounding box as collision shape because of the difference between
front and side faces width.
* Add agent bounds to navmesh tile db cache key. This is required to distinguish
tiles for agents with different bounds.
* Increase navmesh version because navmesh tile db cache key and data has changed.
* Move navmesh version to the code to avoid misconfiguration by users.
* Fix all places where wrong half extents were used for pathfinding.
If object is too big iteration over all tiles covering it can take too much
time. Limit bounds to a square around a player position to cover only tiles
that will be present in navmesh based on max tiles number option.
Each object is associated with a set of tiles its present in. Culling can
reduce this set but it has to be update when bounds change position. Do this
in TileCachedRecastMeshManager::setBounds updating the set and adding/removing
objects to the corresponding CachedRecastMeshManagers.
Perform all request to db in a single thread to avoid blocking navmesh
generator threads due to slow write operations.
Write to db navmesh for all changes except update as it done for memory cache.
Batch multiple db operations into a single transaction to speed up writing by
not executing fsync after each insert/update query. All reads are performed in
the same transaction so they see uncommited data.
Corresponding recast mesh tiles can be updated but navmesh tiles may never
appear for them. Report back zero navmesh version to allow oscillating recast
objects detection to work. This version is always less than any generated
navmesh tile version so any report for generated navmesh will override it.
If zero navmesh version is reported after recast mesh tile got report about
generated navmesh tile it is a no-op since generated version is always greater
than zero.
Add special loading progress bar.
It should be fast enough to not keep loading screen for noticably long but
will provide better pathfinding for actors inside interior cells.
When there is only one actor (player) on a scene and it moving to other
cell first it will be removed from navigator then added. Remove cause
navmesh removing for its half extents. After it is added navmesh for
same half extents is created and added. While this all happens there are
still jobs for old navmesh are processing. Old navmesh still exists
because it is stored by shared pointer. So jobs take tiles from cache
and place them into old navmesh. After that other jobs take same tiles
from cache (half extents and coordinates are equal) and place them into
other navmesh. dtNavMesh changes tile data on add and remove. Adding tile
to two dtNavMesh corrupts tile in both nameshes.
