The entire setup was quite broken with each item using its own activation result and the ones of the subsequent items in the list as the return value.
This rendered the STANDSTILL check in the main function totally unpredictable because the value it depended on could come from any item in the list.
Changed it so that the main dispatcher function is part of sector_t and does the stepping through the list iteratively instead of letting each item recursively call its successor and let this function decide for each item alone whether it should be removed.
The broken setup also had the effect that any MusicChanger would trigger all following SecActEnter specials right on msp start.
This can be done with a lot less overhead by using one of the object's properties to store the activation flag, so that all the nearly redundant trigger methods can be folded into one.
This was done to ensure it can be properly overridden in scripts without causing problems when called during engine shutdown for the type and symbol objects the VM needs to work and to have the scripted version always run first.
Since the scripted OnDestroy method never calls the native version - the native one is run after the scripted one - this can be simply skipped over during shutdown.
There are a few which require explicit native construction or destruction that need to be exported to the VM, e.g. FCheckPosition.
The VM cannot handle this directly, it needs two special functions to be attached to handle such elements.
- created script exports for all relevant functions with all integral types.
- created script side definitions for the underlying data types.
- added a void pointer type so that the prototype for the pointer array can use a generic type every pointer can be assigned to.
- made ModifyDamage calls iterative instead of recursive. With going through the VM they'd be too costly otherwise.
- small optimization: Detect empty VM functions right when entering the VM and shortcut them. This is to reduce the overhead of virtual placeholders, which in a few cases (e.g. CanCollideWith and ModifyDamage) can be called quite frequently.
- made some changes to PowerMorph to better deal with recursive calls from UndoPlayerMorph. The flag hackery was only needed because the 'alternative' pointers were cleared far too late.
This function calculated everything correctly but ultimately set the vertical velocity wrong. Most importantly this meant that the actual velocity vector and actor pitch - if CMF_SAVEPITCH was used - did not match.
Since this bug has been present since the pitch parameter was added, this deprecates A_CustomMissile and replaces it with a properly implemented A_SpawnProjectile function and handling the compatibility case with a new flag and a scripted wrapper function.
All internal uses of A_CustomMissile have been replaced as well.
