Two different issues were causing a path search to not explore cells in order of the cheapest estimated route first. This meant the search could sometimes miss a cheaper route and return a suboptimal path.
- PriorityQueue had a bug which would cause it to not check some elements when restoring the heap property of its internal data structure. Failing to do this would invalidate the heap property, meaning it would not longer return the items in correct priority order. Additional tests ensure this is covered.
- When a path search encountered the same cell again with a lower cost, it would not update the priority queue with the new cost. This meant the cell was not explored early enough as it was in the queue with its original, higher cost. Exploring other paths might close off surrounding cells, preventing the cell with the lower cost from progressing. Instead we now add a duplicate with the lower cost to ensure it gets explored at the right time. We remove the duplicate with the higher cost in CanExpand by checking for already Closed cells.
Requires<T> means that trait of type T will be initialized first, and asserts that at least one exists. The new NotBefore<T> means that trait of type T will be initialized first, but allows no traits.
This allows traits to control initialization order for optional dependencies. They want to be initialized second so they can rely on the dependencies having been initialized. But if the dependencies are optional then to not throw if none are present.
We apply this to Locomotor which was previously using AddFrameEndTask to work around trait order initialization. This improves the user experience as the initialization is applied whilst the loading screen is still visible, rather than the game starting and creating jank by performing initialization on the first tick.
- Stream lines in as memory rather than needing to realise a string for each line, via a new method in StreamExts.
- Use span to avoid string allocations during parsing until we want to realise the node itself, in MiniYaml.FromLines.
- Change several callsites to use the streaming extension method rather than string method where possible.
The Makefile behaviour is recreated using the new and significantly
cleaner .NET Core csproj format.
fixheader.exe is promoted to OpenRA.PostProcess.exe and now runs
on all platforms.
- Add support for escaping '#' inside values
- Add support for escaping leading and trailing whitespace
And when discardCommentsAndWhitespace is set to false:
- Add proper support for comments
- Persist empty lines
Whitespace and comment support requires an explicit opt-in because
they produce MiniYamlNodes with null keys. Supporting these through
the entire game engine would require changing all yaml enumerations
to explicitly check and account for these keys with no benefit.
Comments and whitespace are now treated as real nodes during parsing,
which means that the yaml parser will throw errors if they have
incorrect indentation, even if these nodes will be discarded.
Attempts to use features from a new version will generate compile errors (on Roslyn and possibly other compilers), preventing accidental adoption of new language features.
