Update AbilityPawnFlyer to 1.5

[SokyranTheDragon]

The PawnFlyer received some substantial changes in 1.5, specifically - PawnJumper (previously DLC only feature) was (basically) merged with PawnFlyer, no longer locking any of its features behind DLC, along with a multitude of other changes/improvements. Because of this, some of the changes in this PR will break existing mods and require them to update their implementations. Because the 1.5 update is not yet officially release, I felt that it's the perfect moment to introduce changes such as these. All the changes I've introduced, as well as extra details and explanations are below.

 

Traverse to access effecters was removed:

• It's no longer needed as vanilla now uses DrawPosHeld instead of DrawPos for its SubEffecter classes
  • If a mod is still using DrawPos for its SubEffecter classes then they should be updated, as they will cause issues with vanilla/other modded flyers as well
• The patch was not really working properly for the most part
  • This is due to vanilla code for the effecters still running (it was running before the one included here), and some SubEffecter classes only allowing for spawning motes every X ticks - only allowing them to spawn in the wrong position
• Traverse is a very slow approach (slightly slower than a pure reflection approach), and should have been replaced by a different one

 

Position calculations were removed:

• Vanilla now calculates position in DrawPos - it can be changed in several ways:
  • Make a custom Verse.PawnFlyerWorker subclass in C# (XML path: Defs\ThingDef\pawnFlyer\workerClass, C# location: Verse.PawnFlyerProperties.workerClass)
  • Override DrawPos property in C#
• The way vanilla handles those calculations is better for performance, only recalculating the position once a tick if the pawn is being drawn (instead of each tick, even if not drawn)

 

Property for accessing destCell field:

• The field is private in the game at the moment.
• While not used by the type itself, other types inheriting from it may find it useful
• Uses Harmony's FieldRef, so it should be fairly fast (especially when compared to operating on FieldInfo or using Harmony's Traverse)
  • The FieldRef is stored as a static field in AbilityPawnFlyer itself, but could be moved outside if needed
• It's a ref getter, so it's possible to both read and modify the field
  • Alternatively this could be implemented as a getter/setter without the use of references if desired
• There's several other private fields - they could also be exposed like that, however I've decided that destination position may be the most useful one

 

Pawn respawn changes:

• Setting of position before spawning no longer required, vanilla code uses target position instead
• Removed LandingEffects/playing of soundLanding sound, as vanilla will do it now
• A non-null check for pawn added
  • The vanilla flyer now supports flying Thing, which doesn't necessarily have to be a pawn

 

Forced direction removed:

• From my testing it was not needed, possibly due to 1.5 changes.
  • If it's really needed for something, then I can restore.

 

Save/reload bug fixed:

• In 1.4 (and earlier) saving and reloading caused each flying pawn to fly towards the (0,0) cell
• This was caused by not using the vanilla's target cell field, instead adding a new field (which was then never exposed, causing the bug)
• It should no longer be relevant as the code now uses the vanilla's target cell field, which vanilla properly exposes

[SokyranTheDragon]

Not implemented, but something to consider - vanilla flyer iterates over all Ability comps and calls ICompAbilityEffectOnJumpCompleted.OnJumpCompleted (if interface is implemented). However, since VFE abilities don't use comps it would need to be used in some other capacity. Perhaps do the same, but with Ability.abilityModExtensions or AbilityDef.modExtensions?