Fix inaccuracy of the DoTTime weapon stat (#6457)

Fixes the DoT effect taking less time than the stat indicates, and updates blueprints to the lower actual time.

Author: lL1l1

changelog/snippets/fix.6457.md

@@ -0,0 +1,3 @@
+- (#6457) Fix weapon projectiles dealing damage over time over a shorter duration than given by the `DoTTime` stat.
+  - `DoTTime` for FAF units is adjusted to the old actual DoT duration, so balance is not changed. 
+  - Unit databases will now show the actual damage over time duration.

lua/sim/DefaultDamage.lua

@@ -14,66 +14,90 @@ local DamageArea = DamageArea
 
 -- cache for performance
 local VectorCache = Vector(0, 0, 0)
-local MathFloor = math.floor
-local CoroutineYield = coroutine.yield
+local MathMod = math.mod
+local MATH_IRound = MATH_IRound
+local WaitTicks = WaitTicks
 
 local EntityBeenDestroyed = _G.moho.entity_methods.BeenDestroyed
 local EntityGetPositionXYZ = _G.moho.entity_methods.GetPositionXYZ
 
---- Performs damage over time on a unit.
+--- Performs damage over time on a target, waiting the interval *before* dealing damage.
 ---@param instigator Unit
----@param unit Unit
----@param pulses any
----@param pulseTime integer
+---@param target Unit | Prop | Projectile
+---@param pulses number
+---@param pulseInterval number
 ---@param damage number
----@param damType DamageType
----@param friendly boolean
-function UnitDoTThread (instigator, unit, pulses, pulseTime, damage, damType, friendly)
-
+---@param damageType DamageType
+function UnitDoTThread(instigator, target, pulses, pulseInterval, damage, damageType)
     -- localize for performance
     local position = VectorCache
-    local DamageArea = DamageArea
-    local CoroutineYield = CoroutineYield
+    local Damage = Damage
+    local EntityGetPositionXYZ = EntityGetPositionXYZ
+    local WaitTicks = WaitTicks
+    local MathMod = MathMod
 
-    -- convert time to ticks
-    pulseTime = 10 * pulseTime + 1
+    -- convert seconds to ticks, have to "wait" 1 extra tick to get to the end of the current tick
+    pulseInterval = 10 * pulseInterval + 1
+    -- accumulator to compensate for error caused by `WaitTicks` only working with integers
+    local accum = 0
 
     for i = 1, pulses do
-        if unit and not EntityBeenDestroyed(unit) then
-            position[1], position[2], position[3] = EntityGetPositionXYZ(unit)
-            Damage(instigator, position, unit, damage, damType )
+        if target and not EntityBeenDestroyed(target) then
+            position[1], position[2], position[3] = EntityGetPositionXYZ(target)
+            Damage(instigator, position, target, damage, damageType)
         else
             break
         end
-        CoroutineYield(pulseTime)
+        accum = accum + pulseInterval
+        if accum > 1 then
+            -- final accumulator value may be #.999 which needs to be rounded
+            if i == pulses then
+                WaitTicks(MATH_IRound(accum))
+            else
+                WaitTicks(accum)
+                accum = MathMod(accum, 1)
+            end
+        end
     end
 end
 
---- Performs damage over time in a given area.
+--- Performs damage over time in a given area, waiting the interval *before* dealing damage.
 ---@param instigator Unit
 ---@param position Vector
 ---@param pulses number
----@param pulseTime number
+---@param pulseInterval number
 ---@param radius number
 ---@param damage number
----@param damType DamageType
----@param friendly boolean
-function AreaDoTThread (instigator, position, pulses, pulseTime, radius, damage, damType, friendly)
-
+---@param damageType DamageType
+---@param damageFriendly boolean
+---@param damageSelf boolean
+function AreaDoTThread(instigator, position, pulses, pulseInterval, radius, damage, damageType, damageFriendly, damageSelf)
     -- localize for performance
     local DamageArea = DamageArea
-    local CoroutineYield = CoroutineYield
+    local WaitTicks = WaitTicks
+    local MathMod = MathMod
 
-    -- compute ticks between pulses
-    pulseTime = 10 * pulseTime + 1
+    -- convert seconds to ticks, have to "wait" 1 extra tick to get to the end of the current tick
+    pulseInterval = 10 * pulseInterval + 1
+    -- accumulator to compensate for error caused by `WaitTicks` only working with integers
+    local accum = 0
 
     for i = 1, pulses do
-        DamageArea(instigator, position, radius, damage, damType, friendly)
-        CoroutineYield(pulseTime)
+        accum = accum + pulseInterval
+        if accum > 1 then
+            -- final accumulator value may be #.999 which needs to be rounded
+            if i == pulses then
+                WaitTicks(MATH_IRound(accum))
+            else
+                WaitTicks(accum)
+                accum = MathMod(accum, 1)
+            end
+        end
+        DamageArea(instigator, position, radius, damage, damageType, damageFriendly, damageSelf)
     end
 end
 
--- Deprecated functionality -- 
+--#region Deprecated functionality 
 
 -- SCALABLE RADIUS AREA DOT
 -- - Allows for a scalable damage radius that begins with DamageStartRadius and ends
@@ -101,4 +125,5 @@ function ScalableRadiusAreaDoT(entity)
         end
     end
     entity:Destroy()
-end
+end
+--#endregion

lua/sim/Projectile.lua

@@ -612,16 +612,11 @@ Projectile = ClassProjectile(ProjectileMethods, DebugProjectileComponent) {
     end,
 
     --- Called by Lua to process the damage logic of a projectile
-    -- @param self The projectile itself
-    -- @param instigator The launcher, and if it doesn't exist, the projectile itself
-    -- @param DamageData The damage data passed by the weapon
-    -- @param targetEntity The entity we hit, is nil if we hit terrain
-    -- @param cachedPosition A cached position that is passed to prevent table allocations, can not be used in fork threads and / or after a yield statement
     ---@param self Projectile
-    ---@param instigator Unit
+    ---@param instigator Unit # The launcher, and if it doesn't exist, the projectile itself
     ---@param DamageData WeaponDamageTable # passed by the weapon
-    ---@param targetEntity Unit | Prop | nil
-    ---@param cachedPosition Vector
+    ---@param targetEntity Unit | Prop | nil # nil if hitting terrain
+    ---@param cachedPosition Vector # A cached position that is passed to prevent table allocations, can not be used in fork threads and / or after a yield statement
     DoDamage = function(self, instigator, DamageData, targetEntity, cachedPosition)
 
         -- this may be a cached vector, we can not send this to threads or use after waiting statements!
@@ -637,66 +632,63 @@ Projectile = ClassProjectile(ProjectileMethods, DebugProjectileComponent) {
                 local damageFriendly =  DamageData.DamageFriendly
                 local damageSelf = DamageData.DamageSelf or false
 
-                -- check for damage-over-time
-                local DoTTime = DamageData.DoTTime
-                if DoTTime <= 0 then
-                    -- no damage over time, do radius-based damage
+                -- do initial damage in a radius
+                DamageArea(
+                    instigator,
+                    cachedPosition,
+                    radius,
+                    damage + (DamageData.InitialDamageAmount or 0),
+                    damageType,
+                    damageFriendly,
+                    damageSelf
+                )
+
+                local damageToShields = DamageData.DamageToShields
+                if damageToShields then
                     DamageArea(
                         instigator,
                         cachedPosition,
                         radius,
-                        damage,
-                        damageType,
+                        damageToShields,
+                        "FAF_AntiShield",
                         damageFriendly,
                         damageSelf
                     )
+                end
 
-                    local damageToShields = DamageData.DamageToShields
-                    if damageToShields then
-                        DamageArea(
-                            instigator,
-                            cachedPosition,
-                            radius,
-                            damageToShields,
-                            "FAF_AntiShield",
-                            damageFriendly,
-                            damageSelf
-                        )
-                    end
-                else
-                    -- check for initial damage
-                    local initialDmg = DamageData.InitialDamageAmount
-                    if initialDmg > 0 then
-                        DamageArea(
+                -- check for and deal damage over time
+                local DoTTime = DamageData.DoTTime
+                if DoTTime > 0 then
+                    -- initial damage pulse was already dealt so subtract 1
+                    local DoTPulses = DamageData.DoTPulses - 1
+                    if DoTPulses >= 1 then
+                        ForkThread(
+                            AreaDoTThread,
                             instigator,
-                            cachedPosition,
+                            self:GetPosition(), -- can't use cachedPosition here: breaks invariant
+                            DoTPulses,
+                            (DoTTime / (DoTPulses)),
                             radius,
-                            initialDmg,
+                            damage,
                             damageType,
-                            damageFriendly,
-                            damageSelf
+                            damageFriendly
                         )
                     end
-
-                    -- apply damage over time
-                    local DoTPulses = DamageData.DoTPulses or 1
-                    ForkThread(
-                        AreaDoTThread,
-                        instigator,
-                        self:GetPosition(), -- can't use cachedPosition here: breaks invariant
-                        DoTPulses,
-                        (DoTTime / (DoTPulses)),
-                        radius,
-                        damage,
-                        damageType,
-                        damageFriendly
-                    )
                 end
 
             -- damage a single entity
             elseif targetEntity then
                 local damageType = DamageData.DamageType
 
+                -- do initial damage
+                Damage(
+                    instigator,
+                    cachedPosition,
+                    targetEntity,
+                    damage + (DamageData.InitialDamageAmount or 0),
+                    damageType
+                )
+
                 local damageToShields = DamageData.DamageToShields
                 if damageToShields then
                     Damage(
@@ -708,43 +700,22 @@ Projectile = ClassProjectile(ProjectileMethods, DebugProjectileComponent) {
                     )
                 end
 
-                -- check for damage-over-time
+                -- check for and apply damage over time
                 local DoTTime = DamageData.DoTTime
-                if DoTTime <= 0 then
-
-                    -- no damage over time, do single target damage
-                    Damage(
-                        instigator,
-                        cachedPosition,
-                        targetEntity,
-                        damage,
-                        damageType
-                    )
-                else
-                    -- check for initial damage
-                    local initialDmg = DamageData.InitialDamageAmount or 0
-                    if initialDmg > 0 then
-                        Damage(
+                if DoTTime > 0 then
+                    -- initial damage pulse was already dealt so subtract 1
+                    local DoTPulses = DamageData.DoTPulses - 1
+                    if DoTPulses >= 1 then
+                        ForkThread(
+                            UnitDoTThread,
                             instigator,
-                            cachedPosition,
                             targetEntity,
-                            initialDmg,
+                            DoTPulses,
+                            (DoTTime / (DoTPulses)),
+                            damage,
                             damageType
                         )
                     end
-
-                    -- apply damage over time
-                    local DoTPulses = DamageData.DoTPulses or 1
-                    ForkThread(
-                        UnitDoTThread,
-                        instigator,
-                        targetEntity,
-                        DoTPulses,
-                        (DoTTime / (DoTPulses)),
-                        damage,
-                        damageType,
-                        DamageData.DamageFriendly
-                    )
                 end
             end
         end

units/DAA0206/DAA0206_unit.bp

@@ -170,7 +170,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Kamikaze",
             DoTPulses = 20,
-            DoTTime = 10,
+            DoTTime = 9.5,
             EffectiveRadius = 0,
             FireTargetLayerCapsTable = {
                 Air = "Land|Seabed|Water",

units/DEA0202/DEA0202_unit.bp

@@ -346,7 +346,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Napalm Carpet Bomb",
             DoTPulses = 10,
-            DoTTime = 6,
+            DoTTime = 5.4,
             FireTargetLayerCapsTable = {
                 Air = "Land|Seabed|Water",
                 Land = "Land|Seabed|Water",

units/UAB2302/UAB2302_unit.bp

@@ -149,7 +149,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Sonance Artillery",
             DoTPulses = 2,
-            DoTTime = 2,
+            DoTTime = 1,
             EnergyDrainPerSecond = 4250,
             EnergyRequired = 17000,
             FireTargetLayerCapsTable = {

units/UAB2303/UAB2303_unit.bp

@@ -132,7 +132,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Miasma Artillery",
             DoTPulses = 5,
-            DoTTime = 1,
+            DoTTime = 0.8,
             EnergyDrainPerSecond = 145,
             EnergyRequired = 1450,
             FireTargetLayerCapsTable = {

units/UAL0304/UAL0304_unit.bp

@@ -148,7 +148,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Sonance Artillery",
             DoTPulses = 15,
-            DoTTime = 5,
+            DoTTime = 4.2,
             FireTargetLayerCapsTable = {
                 Land = "Land|Water|Seabed",
                 Water = "Land|Water|Seabed",

units/UEA0103/UEA0103_unit.bp

@@ -192,7 +192,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Napalm Carpet Bomb",
             DoTPulses = 10,
-            DoTTime = 4.2,
+            DoTTime = 3.6,
             FireTargetLayerCapsTable = {
                 Air = "Land|Water|Seabed",
                 Land = "Land|Water|Seabed",

units/URA0204/URA0204_unit.bp

@@ -205,7 +205,7 @@ UnitBlueprint{
             DamageType = "Normal",
             DisplayName = "Nanite Torpedo",
             DoTPulses = 5,
-            DoTTime = 1,
+            DoTTime = 0.8,
             FireTargetLayerCapsTable = {
                 Air = "Seabed|Sub|Water",
                 Land = "Seabed|Sub|Water",