Multiple layers of Lazy<T>ness are replaced with
an explicit two-part loading scheme.
Sequences are parsed immediately, without the need
for the sprite assets, and tell the SpriteCache
which frames they need. Use-cases that want the
actual sprites can then tell the SpriteCache to
load the frames and the sequences to resolve the
sprites.
An event is added to Map to indicate when the cell projection is changed. This is important as this can mean Map.Contains(CPos) could now return different results for the cell. The HierarchicalPathFinder is made aware of these changes so it can rebuild any out-of-date information. This fixes prevent a crash if a cell that was previously outside the map changes height and becomes inside the map. The local path search will explore the cell as it is inside the map - but if the HPF was unaware if had been updated, it will still consider the cell to be outside the map and unreachable, resulting in a crash.
Replaces the existing bi-directional search between points used by the pathfinder with a guided hierarchical search. The old search was a standard A* search with a heuristic of advancing in straight line towards the target. This heuristic performs well if a mostly direct path to the target exists, it performs poorly it the path has to navigate around blockages in the terrain. The hierarchical path finder maintains a simplified, abstract graph. When a path search is performed it uses this abstract graph to inform the heuristic. Instead of moving blindly towards the target, it will instead steer around major obstacles, almost as if it had been provided a map which ensures it can move in roughly the right direction. This allows it to explore less of the area overall, improving performance.
When a path needs to steer around terrain on the map, the hierarchical path finder is able to greatly improve on the previous performance. When a path is able to proceed in a straight line, no performance benefit will be seen. If the path needs to steer around actors on the map instead of terrain (e.g. trees, buildings, units) then the same poor pathfinding performance as before will be observed.
We observe that most cells within a map lie within a region where no matter their height, their projection would still remain in map bounds. We can utilise this to perform a fast check for such cells and skipping the expensive checks on their actual height. We only need to check the actual height of a cell if this could cause the projection to go out of bounds.
* TSVeinsRenderer now shows border cells on the radar
* BuildableTerrainLayer now uses the radar colors defined on the individual tiles
* CliffBackImpassabilityLayer no longer overrides the underlying terrain color.
Our SpriteFrameType names refer to the byte channel order rather than
the bit order, meaning that SpriteFrameType.BGRA corresponds to the
standard Color.ToArgb() etc byte order when the (little-endian) integer
is read as 4 individual bytes.
The previous code did not account for the fact that non-indexed Png
uses big-endian storage for its RGBA colours, and that SheetBuilder
had the color channels incorrectly swapped to match and cancel this out.
New SpriteFrameType enums are introduced to distinguish between BGRA
(little-endian) and RGBA (big-endian) formats, and also for 24bit data
without alpha. The channel swizzling / alpha creation is now handled
when copying into the texture atlas, removing the need for non-png
ISpriteLoader implementations to allocate an additional temporary array
and reorder the channels during load.
