By maintaining a set of changed cells we can avoid repeating work for cells that change multiple times before being rendered. The shroud renderer and radar widget now delay their work until they must render, and thus process each changed cell only once. This avoids significant repetition that was causing major slowdown when many actors were in the world.
A unit with the CreatesShroud or RevealsShroud trait must update all shrouds when it changes position. Calculating the tiles it can currently see is an expensive calculation that previously had to be repeated for every shroud that needed to know these tiles.
Now, we lazily populate a ref parameter to allow it to be reused for an actor if possible. The biggest improvement comes from the fact that allied players can re-use this calculation when updating their shrouds. Since many games includes a neutral player allied to both sides, most games will see a decent speedup.
To resolve the ambiguity introduced when the introduction of isometric maps meant that cell and map coordinates were no longer equivalent, a new type has been introduced so they can each be represented separately.
The bin partitioning in ActorMap worked by dividing the map up into a few chunks of cells, each of which would contain some actors. Unfortunately, the bins were accessed directly in world coordinates which are on a scale 1024x greater than cell coordinates. This lead to all actors being placed into the bottom right bin. When checking for actors in a box, only this bottom right bin would be iterated for actors. Thanks to the fact this bin indeed contained all the actors, some clamps on the input ranges and filtering required per bin anyway, this actually returned correct results. Effectively, it was as if there was no spatial partitioning at all.
Not surprisingly however, this is fairly inefficient. By correcting the spatial partitioning to actually partition we see a 7x speedup in ActorsInBox on the RA shellmap.
Following the same layout as ActorsInBox, this streams the enumerable internally making it cheaper to call if only part of it is required, and also avoids building an intermediate list.
Fixed Mobile.SetPosition
Finally removed old SubCell enum
Folded MobileInfo.CanEnterCell overloads into one
Renamed IPositionable.{IsMovingFrom => IsLeaving}
Changed Crate.IsLeaving to use crate lifetime
Moved the logic from IPositionable.CanEnterCell & integrated sub-cell selection.
Added IPositionable.IsMovingFrom(CPos location, int subCell = -1) - to detect transient actors
Renamed IPositionable.{GetDesiredSubcell => GetAvailableSubcell} - since it checks for available sub-cells
Reduced IPositionable.CanEnterCell to one method that usually uses IPositionable.GetAvailableSubcell
Added actor checking to ActorMap.{HasFreeSubCell, FreeSubCell, AnyUnitsAt} - used by [sub-]cell availability logic
- By ensuring both the add and remove actor lists are sets, we ensure the partitioning bins will contain only distinct actors. We can remove the HashSet and Distinct in ActorsInBox and ActorsInWorld which provides a nice speedup for queries. ActorsInBox sees nearly a 3x speedup in the RA shellmap.
- Only update shroud within the visible screen area, rather than the whole map. This improves performance on larger maps significantly when scrolling around since large portions of the shroud do not need to be updated.
- Provide methods in Shroud to return delegates to check for explored/visibility for tiles within a certain region. This allows it to return more efficient delegates whenever the region is within the map bounds, or shroud/fog is disabled. In the typical case where the region is in bounds and shroud/fog is enabled, the fast check is almost twice as fast as the slow check.
- Use the Shroud delegate functions in shroud rendering, frozen actors, minimap rendering and resource layer areas to provide a speedup since these areas of code can often take advantage of the fact they perform checks within the map boundary.
- Cache current element in CellRegionEnumerator to prevent repeated work if the element is accessed more than once.
- Decrease the size of elements in some arrays in hopes of reducing memory needs and improving cache hits.
- Extract an enum for edges rather than using magic numbers for everything.
- Remove duplicated code between FoggedEdges and ShroudedEdges by hosting the visibility function into a delegate.
- Make minimap methods more readable.
- Tidy formatting.
- Make some fields readonly.
- Remove unused usings.
