KOTORBASE: Add SwitchPlayerCharacter nwscript method

[Nostritius]

This PR implements the SwitchPlayerCharacter nwscript method. It allows the switch in the kotor2 prologue from the main character to T3M4. I hope, i did everything right, concerning object creation and destruction.

[DrMcCoy]

Apparently not, since it invokes UB :P

sanitizer log here: https://gist.github.com/DrMcCoy/94d189fb6136cf2f5e5316dde6fdaaa3

[seedhartha]

Object registration is handled automatically when the object is created and destroyed. See

xoreos/src/engines/kotorbase/object.cpp

Line 54 in 9000339

ObjectMan.registerObject(this);

[seedhartha]

Module::removeObject is called implicitly in Area::removeObject. See

xoreos/src/engines/kotorbase/area.cpp

Line 872 in 9000339

_module->removeObject(*object);

[seedhartha]

Player character will not always be the party leader. Maybe we should modify Module::_pc instead?

[Nostritius]

The double free should now be fixed. About the use of _pc, I'm unsure. Can _pc be considered the player generated character or the currently controlled character and therefore being equal to the party leader?

[seedhartha]

Currently, Player Character and Party Leader are two separate roles, which may or may not be represented by a single object. PC is instantiated once per module (Module::loadPC()), while the party leader a.k.a. currently controlled character, is a changing reference to either the PC or one of the party members. SwitchPlayerCharacter should probably recreate the PC object (Module::_pc), regardless of his status in the party, while persisting Module::_pcInfo and Module::_chargenInfo of the original PC.

[DrMcCoy]

Yeah, I guess we have three separate concepts here, in the KotOR games.

1. The originally created player character
2. The current player character, which can be different when the game switches to another POV (during the tutorial, for example)
3. The party leader

Maybe we should call 1. something else, and keep that around permanently too. Especially because we need to remember the inventory and other things that might modify this entitiy during gameplay.

Module::_pc would then be pointer or copy of this entity (again, maing sure to keep everything in sync).

[DrMcCoy]

The crash is gone, btw. But skipping the prologue doesn't work now:

WARNING: Failed running dialog script "a_end_001"
    Because: Failed running engine function "SwitchPlayerCharacter" (11)
    Because: 4294967295 is not an available npc id

Also, maybe we should investigate how the original keeps track of the original PC first?

[DrMcCoy]

Just to make sure, this is still currently blocked by us not really knowing how this should be implemented, right?

Might be worth waiting to see what seedhartha will do in his reone project there :P

[Nostritius]

Yes, I'm still not sure how to best realize this.