Improve performance of projectiles (FAForever#3718)

Improves the performance of all projectiles and specifically the projectiles of the Zthuee. Changes across the hierarchy that includes the upvalue strategy, better memory management and a reduction of engine calls.

Part of a Youtube series where we look at code and improve the performance by rewriting it.

engine/Sim/Projectile.lua

@@ -18,6 +18,7 @@ end
 
 ---
 --  Projectile:CreateChildProjectile(blueprint)
+-- Internally calls import to find the projectile
 function Projectile:CreateChildProjectile(blueprint)
 end
 

lua/proptree.lua

@@ -84,11 +84,10 @@ Tree = Class(Prop) {
             local canBurn = (not self.Burning) and (not self.NoBurn)
 
             if type == 'Disintegrate' or type == "Reclaimed" then 
-                LOG("Desintegrated!")
                 -- we just got obliterated
                 EntityDestroy(self)
 
-            elseif type == 'Force' then
+            elseif type == 'Force' or type == "KnockTree" then
                 if canFall then 
                     -- change internal state
                     self.NoBurn = true

lua/sim/DefaultProjectiles.lua

@@ -4,6 +4,7 @@
 -- Summary  : Script for default projectiles
 -- Copyright © 2005 Gas Powered Games, Inc.  All rights reserved.
 -----------------------------------------------------------------
+
 local Projectile = import('/lua/sim/Projectile.lua').Projectile
 local DummyProjectile = import('/lua/sim/Projectile.lua').DummyProjectile
 local UnitsInSphere = import('/lua/utilities.lua').GetTrueEnemyUnitsInSphere
@@ -13,6 +14,20 @@ local OCProjectiles = {}
 -- shared between sim and ui
 local OverchargeShared = import('/lua/shared/overcharge.lua')
 
+-- upvalue globals for performance
+local Random = Random
+local CreateTrail = CreateTrail
+local CreateEmitterOnEntity = CreateEmitterOnEntity
+local CreateBeamEmitterOnEntity = CreateBeamEmitterOnEntity
+
+local TableGetn = table.getn
+
+local MathFloor = math.floor 
+
+-- upvalue moho functions for performance
+local IEffectScaleEmitter = _G.moho.IEffect.ScaleEmitter
+local IEffectOffsetEmitter = _G.moho.IEffect.OffsetEmitter
+
 -----------------------------------------------------------------
 -- Null Shell
 -----------------------------------------------------------------
@@ -21,15 +36,27 @@ NullShell = Class(Projectile) {}
 -----------------------------------------------------------------
 -- PROJECTILE WITH ATTACHED EFFECT EMITTERS
 -----------------------------------------------------------------
+
 EmitterProjectile = Class(Projectile) {
     FxTrails = {'/effects/emitters/missile_munition_trail_01_emit.bp',},
     FxTrailScale = 1,
     FxTrailOffset = 0,
 
     OnCreate = function(self)
         Projectile.OnCreate(self)
+
+        local effect
         for i in self.FxTrails do
-            CreateEmitterOnEntity(self, self.Army, self.FxTrails[i]):ScaleEmitter(self.FxTrailScale):OffsetEmitter(0, 0, self.FxTrailOffset)
+            effect = CreateEmitterOnEntity(self, self.Army, self.FxTrails[i])
+
+            -- only do these engine calls when they matter
+            if self.FxTrailScale ~= 1 then 
+                IEffectScaleEmitter(effect, self.FxTrailScale)
+            end
+
+            if self.FxTrailOffset ~= 1 then 
+                IEffectOffsetEmitter(effect, 0, 0, self.FxTrailOffset)
+            end
         end
     end,
 }
@@ -44,6 +71,7 @@ SingleBeamProjectile = Class(EmitterProjectile) {
 
     OnCreate = function(self)
         EmitterProjectile.OnCreate(self)
+
         if self.BeamName then
             CreateBeamEmitterOnEntity(self, -1, self.Army, self.BeamName)
         end
@@ -57,6 +85,7 @@ MultiBeamProjectile = Class(EmitterProjectile) {
 
     OnCreate = function(self)
         EmitterProjectile.OnCreate(self)
+
         local beam = nil
         for k, v in self.Beams do
             CreateBeamEmitterOnEntity(self, -1, self.Army, v)
@@ -187,12 +216,21 @@ SinglePolyTrailProjectile = Class(EmitterProjectile) {
 
     OnCreate = function(self)
         EmitterProjectile.OnCreate(self)
+
         if self.PolyTrail ~= '' then
-            CreateTrail(self, -1, self.Army, self.PolyTrail):OffsetEmitter(0, 0, self.PolyTrailOffset)
+            local effect = CreateTrail(self, -1, self.Army, self.PolyTrail)
+
+            -- only do these engine calls when they matter
+            if self.PolyTrailOffset ~= 0 then 
+                IEffectOffsetEmitter(effect, 0, 0, self.PolyTrailOffset)
+            end
         end
     end,
 }
 
+-- upvalue for performance
+
+
 MultiPolyTrailProjectile = Class(EmitterProjectile) {
 
     PolyTrails = {'/effects/emitters/test_missile_trail_emit.bp'},
@@ -202,18 +240,31 @@ MultiPolyTrailProjectile = Class(EmitterProjectile) {
 
     OnCreate = function(self)
         EmitterProjectile.OnCreate(self)
+
         if self.PolyTrails then
-            local NumPolyTrails = table.getn(self.PolyTrails)
+            local effect
+            local army = self.Army 
+            local NumPolyTrails = TableGetn(self.PolyTrails)
 
             if self.RandomPolyTrails ~= 0 then
-                local index = nil
+                local index
                 for i = 1, self.RandomPolyTrails do
-                    index = math.floor(Random(1, NumPolyTrails))
-                    CreateTrail(self, -1, self.Army, self.PolyTrails[index]):OffsetEmitter(0, 0, self.PolyTrailOffset[index])
+                    index = Random(1, NumPolyTrails)
+                    effect = CreateTrail(self, -1, army, self.PolyTrails[index])
+
+                    -- only do these engine calls when they matter
+                    if self.PolyTrailOffset[index] ~= 0 then 
+                        IEffectOffsetEmitter(effect, 0, 0, self.PolyTrailOffset[index])
+                    end
                 end
             else
                 for i = 1, NumPolyTrails do
-                    CreateTrail(self, -1, self.Army, self.PolyTrails[i]):OffsetEmitter(0, 0, self.PolyTrailOffset[i])
+                    effect = CreateTrail(self, -1, army, self.PolyTrails[i])
+
+                    -- only do these engine calls when they matter
+                    if self.PolyTrailOffset[i] ~= 0 then 
+                        IEffectOffsetEmitter(effect, 0, 0, self.PolyTrailOffset[i])
+                    end
                 end
             end
         end
@@ -234,6 +285,7 @@ SingleCompositeEmitterProjectile = Class(SinglePolyTrailProjectile) {
 
     OnCreate = function(self)
         SinglePolyTrailProjectile.OnCreate(self)
+
         if self.BeamName ~= '' then
             CreateBeamEmitterOnEntity(self, -1, self.Army, self.BeamName)
         end
@@ -251,6 +303,7 @@ MultiCompositeEmitterProjectile = Class(MultiPolyTrailProjectile) {
 
     OnCreate = function(self)
         MultiPolyTrailProjectile.OnCreate(self)
+
         local beam = nil
         for k, v in self.Beams do
             CreateBeamEmitterOnEntity(self, -1, self.Army, v)
@@ -272,23 +325,61 @@ OnWaterEntryEmitterProjectile = Class(Projectile) {
 
     OnCreate = function(self, inWater)
         Projectile.OnCreate(self, inWater)
+
         if inWater then
+
+            local effect 
+            local army = self.Army 
+
             for i in self.FxTrails do
-                CreateEmitterOnEntity(self, self.Army, self.FxTrails[i]):ScaleEmitter(self.FxTrailScale):OffsetEmitter(0, 0, self.FxTrailOffset)
+                effect = CreateEmitterOnEntity(self, army, self.FxTrails[i])
+
+                -- only do these engine calls when they matter
+                if self.FxTrailScale ~= 1 then 
+                    IEffectScaleEmitter(effect, self.FxTrailScale)
+                end
+
+                if self.FxTrailOffset ~= 1 then 
+                    IEffectOffsetEmitter(effect, 0, 0, self.FxTrailOffset)
+                end
             end
+
             if self.PolyTrail ~= '' then
-                CreateTrail(self, -1, self.Army, self.PolyTrail):OffsetEmitter(0, 0, self.PolyTrailOffset)
+                effect = CreateTrail(self, -1, army, self.PolyTrail)
+
+                -- only do these engine calls when they matter
+                if self.PolyTrailOffset ~= 0 then 
+                    IEffectOffsetEmitter(effect, 0, 0, self.PolyTrailOffset)
+                end
             end
         end
     end,
 
     EnterWaterThread = function(self)
         WaitTicks(self.TrailDelay)
+
+        local effect 
+        local army = self.Army 
+
         for i in self.FxTrails do
-            CreateEmitterOnEntity(self, self.Army, self.FxTrails[i]):ScaleEmitter(self.FxTrailScale):OffsetEmitter(0, 0, self.FxTrailOffset)
+            effect = CreateEmitterOnEntity(self, army, self.FxTrails[i])
+
+            -- only do these engine calls when they matter
+            if self.FxTrailScale ~= 1 then 
+                IEffectScaleEmitter(effect, self.FxTrailScale)
+            end
+
+            if self.FxTrailOffset ~= 1 then 
+                IEffectOffsetEmitter(effect, 0, 0, self.FxTrailOffset)
+            end
         end
         if self.PolyTrail ~= '' then
-            CreateTrail(self, -1, self.Army, self.PolyTrail):OffsetEmitter(0, 0, self.PolyTrailOffset)
+            local effect = CreateTrail(self, -1, army, self.PolyTrail)
+
+            -- only do these engine calls when they matter
+            if self.PolyTrailOffset ~= 0 then 
+                IEffectOffsetEmitter(effect, 0, 0, self.PolyTrailOffset)
+            end
         end
     end,
 
@@ -387,6 +478,7 @@ BaseGenericDebris = Class(DummyProjectile){
 -----------------------------------------------------------
 -- PROJECTILE THAT ADJUSTS DAMAGE AND ENERGY COST ON IMPACT
 -----------------------------------------------------------
+
 OverchargeProjectile = Class() {
     OnImpact = function(self, targetType, targetEntity)
         -- Stop us doing blueprint damage in the other OnImpact call if we ditch this one without resetting self.DamageData

lua/sim/Profiler.lua

@@ -19,6 +19,8 @@ local thread = false
 --- Data that we send over to the UI
 local data = CreateEmptyProfilerTable()
 
+local traces = { }
+
 --- Toggles the profiler on / off
 function ToggleProfiler(army, forceEnable)
 
@@ -103,6 +105,16 @@ function ToggleProfiler(army, forceEnable)
                     scope = "other"
                 end
 
+                if name == "lambda" then 
+                    local trace = repr(debug.traceback())
+                    if not traces[trace] or traces[trace] == 500 then
+                        traces[trace] = traces[trace] or 0  
+                        LOG(tostring(traces[trace]) .. ": " .. trace)
+                    end
+
+                    traces[trace] = traces[trace] + 1
+                end
+
                 -- keep track 
                 local count = data[source][scope][name]
                 if not count then