Doors: Improved door destruction handling (#1836)

I've made small improvements to door destruction code:
- Carry over door's bodygroups to the destruction prop
- Carry over ents parented to the door to the destruction prop
- Spawn the door's destruction prop as soon as the door is destroyed
instead of waiting a frame (areaportal opening still works)
- Reuse existing vector globals instead of creating new vectors

Author: TW1STaL1CKY

CHANGELOG.md

@@ -4,6 +4,14 @@ All notable changes to TTT2 will be documented here. Inspired by [keep a changel
 
 ## Unreleased
 
+### Changed
+
+- Made improvements to door destruction (by @TW1STaL1CKY)
+  - Bodygroups from destroyed doors are now transferred to their physics prop
+  - Entities parented to destroyed doors are now transferred to their physics prop
+  - Door props are now spawned as soon as the door is destroyed (instead of a frame later)
+  - Reuse existing vector globals instead of creating new vectors
+
 ### Fixed
 
 - Fixed markerVision null entity error (by @mexikoedi)

gamemodes/terrortown/gamemode/shared/sh_door.lua

@@ -362,13 +362,34 @@ if SERVER then
         doorProp:SetCollisionGroup(COLLISION_GROUP_NONE)
         doorProp:SetMoveType(MOVETYPE_VPHYSICS)
         doorProp:SetSolid(SOLID_BBOX)
-        doorProp:SetPos(self:GetPos() + Vector(0, 0, 2))
+        doorProp:SetPos(self:GetPos())
         doorProp:SetAngles(self:GetAngles())
         doorProp:SetModel(self:GetModel())
         doorProp:SetSkin(self:GetSkin())
 
+        local bodygroups = self:GetBodyGroups()
+        for i = 1, #bodygroups do
+            local id = bodygroups[i].id
+            doorProp:SetBodygroup(id, self:GetBodygroup(id))
+        end
+
+        -- if there are entities parented to the door, transfer them over
+        local children = self:GetChildren()
+        for i = 1, #children do
+            local child = children[i]
+            local pos, ang = child:GetLocalPos(), child:GetLocalAngles()
+
+            child:SetParent(doorProp)
+            child:SetLocalPos(pos)
+            child:SetLocalAngles(ang)
+        end
+
         door.HandleDestruction(self)
 
+        -- hide away the real door while it is being opened and destroyed
+        self:SetNoDraw(true)
+        self:SetSolid(SOLID_NONE)
+
         -- disable the door move sound for the destruction
         self:SetKeyValue("soundmoveoverride", "")
 
@@ -379,6 +400,38 @@ if SERVER then
         -- this function is called multiple times for the same door in the same tick
         self.isDestroyed = true
 
+        if IsValid(ply) and ply:IsPlayer() then
+            DamageLog(
+                string.format(
+                    "TTT2Doors: The door with the index %s has been destroyed by %s.",
+                    self:EntIndex(),
+                    ply:Nick()
+                )
+            )
+        else
+            DamageLog(
+                string.format(
+                    "TTT2Doors: The door with the index %s has been destroyed.",
+                    self:EntIndex()
+                )
+            )
+        end
+
+        doorProp:Spawn()
+        doorProp:SetHealth(cvDoorPropHealth:GetInt())
+
+        doorProp.isDoorProp = true
+
+        local physObj = doorProp:GetPhysicsObject()
+
+        if IsValid(physObj) then
+            physObj:ApplyForceCenter(pushForce or vector_origin)
+        end
+
+        ---
+        -- @realm server
+        hook.Run("TTT2DoorDestroyed", doorProp, ply)
+
         -- if the door is grouped as a pair, call the other one as well
         if not surpressPair and IsValid(self.otherPairDoor) then
             self.otherPairDoor:SafeDestroyDoor(ply, pushForce, true)
@@ -392,37 +445,6 @@ if SERVER then
             -- we have to kill the entity here instead of removing it because this way we
             -- have no problems with area portals (invisible rooms after door is destroyed)
             self:Fire("Kill", "", 0)
-
-            if IsValid(ply) and ply:IsPlayer() then
-                DamageLog(
-                    "TTT2Doors: The door with the index "
-                        .. self:EntIndex()
-                        .. " has been destroyed by "
-                        .. ply:Nick()
-                        .. "."
-                )
-            else
-                DamageLog(
-                    "TTT2Doors: The door with the index "
-                        .. self:EntIndex()
-                        .. " has been destroyed."
-                )
-            end
-
-            doorProp:Spawn()
-            doorProp:SetHealth(cvDoorPropHealth:GetInt())
-
-            doorProp.isDoorProp = true
-
-            local physObj = doorProp:GetPhysicsObject()
-
-            if IsValid(physObj) then
-                physObj:ApplyForceCenter(pushForce or Vector(0, 0, 0))
-            end
-
-            ---
-            -- @realm server
-            hook.Run("TTT2DoorDestroyed", doorProp, ply)
         end)
 
         return doorProp