Since the SpawnedThings array is still available when polyobjects are spawned it makes no sense to create an expensive linked list in P_SpawnMapThing.
This can be done far better by scanning through the array again and collect all matching items in a second array.
This thing made sense when GZDoom and ZDoom were separate projects to avoid having to change some core files for the added options.
Now, with only 3 ones remaining, one for FraggleScript and two for Extradata the overhead here is just too high. The 3 variables can just be moved to level_info_t without carrying along this much baggage.
Since actors are being spawned before the renderer gets set up this needs to fully initialize the list before spawning the actors, then take it down again for creating the vertex buffer and then recreate it.
Add 'useowncoloradd_{top,mid,bottom}' sidedef properties to the UDMF
spec
Only use side's additive colors if 'useowncoloradd_(top|mid|bottom)' is
set.
Rename UseOwnColors flag to UseOwnSpecialColors
Add UseOwnAdditiveColor flag to side_t::part
Add EnableAdditiveColor to side_t
Add Side.EnableAdditiveColor to ZScript API
Sector.SetAdditiveColor actually called Sector.SetSpecialColor
Add use boolean property, used to determine whether or not to override the sector's additive wall colour with the side's additive colour.
The new specification is more flexible, and allows assigning additive
colors to individual parts of a sector (walls, sprites, flats) and even
individual parts of a side (top, middle, bottom)
Add AdditiveColors arrays to sector_t and side_t::part
Initialize AdditiveColors arrays to 0
Export AdditiveColors to ZScript
Save AdditiveColors in saved game files
Use colors from AdditiveColors arrays when setting the additive color
for the render state
Add code to parse the new UDMF additive color properties
Remove additive color slot from sector color/part enum
Add SetAdditiveColor to sector_t and side_t
Add GetAdditiveColor to side_t
Export new methods and additive color arrays to ZScript
Rename ColorAdd to AddColor
Add AddColor to FRenderState
Tweak SpecialColors array in ZScript to include the additive color
Add uAddColor to the shader compiler
Add uAddColor to the texel
