Add support for "Fleshrender" unique (and general poison stacking mechanics) (#9533)

* Rename `doublePoisonChance` to `additionalPoisonChance`

Renamed for clarity as it is not actually a "doubling" effect

* Add additional poisons and poison stack limits

- parsing and logic for application of more than 1 additional poison per
  hit via "inflict X additional poisons on the same target ..."
- parsing and logic for poison stack limit via "cannot poison enemies
  with at least X poisons on them"
- adds parsing and logic for additional `CannotMultiplie` flag that will
  apply to Viper Strike of the Mamba as of 3.28

* Adjust `PoisonStacks` breakdown

* Add parsing for "Wither on Hit with this weapon against Enemies with at least 12 Poisons on them"

Just setting `Condition:CanWither` flag for now, as actually checking
for number of poisons seems overkill and eliminates too many edge cases

* Add `ModStoreClass:Min()` to `ModStore.lua`

This is the counterpart to `ModStoreClass:Max()` and gives back the
lowest modifier value. This makes sense for things like the poison stack
limit, where neither "BASE" nor "OVERRIDE" would work for multiple mods

* Change `PoisonStackLimit` to use `"MIN"` modType

* Add `"MAX"` & `"MIN"` modType explanation to docs

"MAX" already existed and was used, but was missing from `modSyntax.md`,
so I added the explanation for both now

* Add `PoisonStackLimit` to Viper Strike of the Mamba

* Further improve PoisonStacks breakdown

- Now shows active poison stack limit
- Now shows what uncapped poison stacks would be (to gauge if you're
  close to being under cap)
- Changed wording of "Capped to 1" for `Condition:SinglePoison` hint to
  "Assume non-Poisoned Enemy" because that is what it is actually used
  for

* Appease the spell checking gods `hitrate` -> `hit rate`

---------

Co-authored-by: LocalIdentity <localidentity2@gmail.com>

Author: majochem

docs/modSyntax.md

@@ -13,6 +13,7 @@ Used as a key, so you can reference this mod elsewhere in PoB.  Can really be an
 - "OVERRIDE": used when you want to ignore any calculations done on this mod and just use the value (e.g. "your resistances are 78%" from Loreweave)
 - "FLAG": used for conditions.  Value will be true/false when this type is used.
   - When you need the "FLAG" ModType, consider using the function `flag(name, source, modFlags, keywordFlags, extraTags)` instead. This method shortens the code and clarifies the intent. For example, `flag("ZealotsOath", { type = "Condition", var = "UsingFlask" })` is the same as `mod("ZealotsOath", "FLAG", true, { type = "Condition", var = "UsingFlask" })`
+- "MAX" and "MIN": used for values where only the highest or lowest value should take effect respectively. Examples are `"ImprovedMinionDamageAppliesToPlayer"` for "Increases and Reductions to Minion Damage apply ... at X% of their value" or `"PoisonStackLimit"` for "Cannot Poison Enemies with at least X Poisons on them"
 ### Value
 This represents the raw value of the mod.  When it's used in the skills to map from the skill data, this will be `nil`, as it pulls the number from the gem based on the level.
 ### Source

src/Classes/ModStore.lua

@@ -220,6 +220,17 @@ function ModStoreClass:Max(cfg, ...)
 	return max		
 end
 
+function ModStoreClass:Min(cfg, ...)
+	local min
+	for _, value in ipairs(self:Tabulate("MIN", cfg, ...)) do
+		local val = self:EvalMod(value.mod, cfg)
+		if min == nil or val < min then
+			min = val
+		end	
+	end
+	return min
+end
+
 ---HasMod
 ---  Checks if a mod exists with the given properties.
 ---  Useful for determining if the other aggregate functions will find

src/Data/ModCache.lua

@@ -5086,7 +5086,7 @@ c["325% increased Energy Shield"]={{[1]={flags=0,keywordFlags=0,name="EnergyShie
 c["33% chance to Blind nearby Enemies when gaining Her Blessing"]={{}," to Blind nearby Enemies when gaining Her Blessing "}
 c["33% chance to Blind nearby Enemies when gaining Her Blessing 100% chance to Avoid being Ignited, Chilled or Frozen with Her Blessing"]={{[1]={flags=0,keywordFlags=0,name="AvoidIgnite",type="BASE",value=33}}," to Blind nearby Enemies when gaining Her Blessing 100% chance , Chilled or Frozen with Her Blessing "}
 c["33% chance to gain a Frenzy Charge on Kill"]={nil,"a Frenzy Charge  "}
-c["33% chance to inflict an additional Poison on the same Target when you inflict Poison"]={{[1]={flags=0,keywordFlags=0,name="DoublePoisonChance",type="BASE",value=33}},nil}
+c["33% chance to inflict an additional Poison on the same Target when you inflict Poison"]={{[1]={flags=0,keywordFlags=0,name="AdditionalPoisonChance",type="BASE",value=33}},nil}
 c["33% increased Attack Damage against Bleeding Enemies"]={{[1]={[1]={actor="enemy",type="ActorCondition",var="Bleeding"},flags=1,keywordFlags=0,name="Damage",type="INC",value=33}},nil}
 c["33% increased Attack Speed while Ignited"]={{[1]={[1]={type="Condition",var="Ignited"},flags=1,keywordFlags=0,name="Speed",type="INC",value=33}},nil}
 c["33% increased Cast Speed"]={{[1]={flags=16,keywordFlags=0,name="Speed",type="INC",value=33}},nil}
@@ -5291,7 +5291,7 @@ c["40% chance to Suppress Spell Damage while your Off Hand is empty"]={{[1]={[1]
 c["40% chance to cause Bleeding on Melee Hit"]={{[1]={flags=260,keywordFlags=0,name="BleedChance",type="BASE",value=40}},nil}
 c["40% chance to deal Double Damage while Focused"]={{[1]={[1]={type="Condition",var="Focused"},flags=0,keywordFlags=0,name="DoubleDamageChance",type="BASE",value=40}},nil}
 c["40% chance to gain a Frenzy Charge for each enemy you hit with a Critical Strike"]={nil,"a Frenzy Charge for each enemy you hit with a Critical Strike "}
-c["40% chance to inflict an additional Poison on the same Target when you inflict Poison"]={{[1]={flags=0,keywordFlags=0,name="DoublePoisonChance",type="BASE",value=40}},nil}
+c["40% chance to inflict an additional Poison on the same Target when you inflict Poison"]={{[1]={flags=0,keywordFlags=0,name="AdditionalPoisonChance",type="BASE",value=40}},nil}
 c["40% chance when you Kill a Scorched Enemy to Burn Each surrounding Enemy for 4 seconds, dealing 8% of the Killed Enemy's Life as Fire Damage per second"]={{[1]={flags=0,keywordFlags=0,name="Life",type="BASE",value=40}}," when you Kill a Scorched Enemy to Burn Each surrounding Enemy , dealing 8% of the Killed Enemy's  as Fire Damage per second "}
 c["40% faster start of Energy Shield Recharge"]={{[1]={flags=0,keywordFlags=0,name="EnergyShieldRechargeFaster",type="INC",value=40}},nil}
 c["40% faster start of Energy Shield Recharge while affected by Discipline"]={{[1]={[1]={type="Condition",var="AffectedByDiscipline"},flags=0,keywordFlags=0,name="EnergyShieldRechargeFaster",type="INC",value=40}},nil}

src/Data/SkillStatMap.lua

@@ -150,9 +150,10 @@ return {
 },
 ["cannot_poison_poisoned_enemies"] = {
 	flag("Condition:SinglePoison"),
+	mod("PoisonStackLimit", "MIN", 1),
 },
 ["cannot_inflict_additional_poisons"] = {
-	flag("CannotMultiPoison"),
+	flag("CannotMultiplePoison"),
 },
 ["spell_damage_modifiers_apply_to_skill_dot"] = {
 	skill("dotIsSpell", true),

src/Modules/CalcOffence.lua

@@ -4412,12 +4412,35 @@ function calcs.offence(env, actor, activeSkill)
 			globalOutput.PoisonDuration = durationBase * durationMod / rateMod * debuffDurationMult
 			-- The chance any given hit applies poison
 			local poisonChance = output.PoisonChanceOnHit / 100 * (1 - output.CritChance / 100) + output.PoisonChanceOnCrit / 100 * output.CritChance / 100
-			local doublePoisonChance = 1 + (skillModList:Flag(nil, "CannotMultiPoison") and 0 or m_min(skillModList:Sum("BASE", cfg, "DoublePoisonChance")/ 100, 1))
-			-- The average number of poisons that will be active on the enemy at once
-			local PoisonStacks = output.HitChance / 100 * poisonChance * doublePoisonChance * skillData.dpsMultiplier * (skillData.stackMultiplier or 1) * quantityMultiplier
+			
+			-- Handling of "inflict x additional poisons"
+			local additionalPoisonStacks = 1
+			if not skillModList:Flag(nil, "CannotMultiplePoison") then
+				additionalPoisonStacks = 1 + m_min(skillModList:Sum("BASE", cfg, "AdditionalPoisonChance")/ 100, 1) + (skillModList:Sum("BASE", cfg, "AdditionalPoisonStacks"))
+			end
+
+			-- Calculate average number of poisons that will be active on the enemy at once
+			local poisonStackLimit = skillModList:Min(cfg, "PoisonStackLimit")
+			local PoisonStacks = output.HitChance / 100 * poisonChance * additionalPoisonStacks * skillData.dpsMultiplier * (skillData.stackMultiplier or 1) * quantityMultiplier
+			local uncappedPoisonStacks
 			if (globalOutput.HitSpeed or globalOutput.Speed) > 0 then
 				--assume skills with no cast, attack, or cooldown time are single cast
 				PoisonStacks = PoisonStacks * globalOutput.PoisonDuration * (globalOutput.HitSpeed or globalOutput.Speed) 
+				
+				-- If stack limit exists, avg. poison stack is more complicated
+				if poisonStackLimit and poisonStackLimit > 0 and PoisonStacks > poisonStackLimit then
+					-- Calc number of avg. poisons applied per hit (without hit rate multipliers)
+					local singleHitPoisonChance = output.HitChance / 100 * poisonChance
+					local singleHitPoisonStacks = singleHitPoisonChance * additionalPoisonStacks
+
+					-- Calc how many hits will poison before limit is reached and theoretical max poison stacks, which is different from `poisonStackLimit` due to "additional" poison mechanics 
+					local numPoisoningHits = m_ceil(poisonStackLimit / singleHitPoisonStacks)
+					local maxPoisonStacks = numPoisoningHits * singleHitPoisonStacks
+
+					-- Only use `maxPoisonStacks` if original value exceeds it
+					uncappedPoisonStacks = m_max(PoisonStacks, maxPoisonStacks)
+					PoisonStacks = m_min(PoisonStacks, maxPoisonStacks)
+				end
 			end
 			if PoisonStacks < 1 and (env.configInput.multiplierPoisonOnEnemy or 0) <= 1 then
 				skillModList:NewMod("Condition:SinglePoison", "FLAG", true, "poison")
@@ -4428,15 +4451,22 @@ function calcs.offence(env, actor, activeSkill)
 					base = { "%.2fs ^8(poison duration)", globalOutput.PoisonDuration },
 					{ "%.2f ^8(poison chance)", poisonChance },
 					{ "%.2f ^8(hit chance)", output.HitChance / 100 },
-					{ "%.2f ^8(double poison chance)", doublePoisonChance },
+					{ "%.2f ^8(avg. # of poisons inflicted)", additionalPoisonStacks },
 					{ "%.2f ^8(hits per second)", globalOutput.HitSpeed or globalOutput.Speed },
 					{ "%g ^8(dps multiplier for this skill)", skillData.dpsMultiplier or 1 },
 					{ "%g ^8(stack multiplier for this skill)", skillData.stackMultiplier or 1 },
 					{ "%g ^8(quantity multiplier for this skill)", quantityMultiplier },
 					total = s_format("= %.2f", PoisonStacks),
 				})
 				if skillModList:Flag(nil, "Condition:SinglePoison") then
-					t_insert(globalBreakdown.PoisonStacks, "Capped to 1")
+					t_insert(globalBreakdown.PoisonStacks, "Assuming 'non-Poisoned' Enemy")
+				end
+				if poisonStackLimit and PoisonStacks >= poisonStackLimit then
+					t_insert(globalBreakdown.PoisonStacks, "^8(affected by poison stack limit of: " .. poisonStackLimit .. ")")
+					if uncappedPoisonStacks then
+						t_insert(globalBreakdown.PoisonStacks, "^8(uncapped poison stacks: " .. s_format("%.2f", uncappedPoisonStacks) .. ")")
+					end
+
 				end
 			end
 			for sub_pass = 1, 2 do

src/Modules/CalcSections.lua

@@ -916,7 +916,16 @@ return {
 		{ label = "Main Hand", flag = "weapon1Attack", modName = "PoisonChance", modType = "BASE", cfg = "weapon1" },
 		{ label = "Off Hand", flag = "weapon2Attack", modName = "PoisonChance", modType = "BASE", cfg = "weapon2" },
 	}, },
-	{ label = "Poison Stacks", { format = "{2:output:PoisonStacks}", { breakdown = "PoisonStacks" } }},
+	{ label = "Poison Stacks", { format = "{2:output:PoisonStacks}", 
+		{ breakdown = "PoisonStacks" },
+		{ label = "% chance to inflict 1 additional poison", notFlag = "attack", modName = { "AdditionalPoisonChance" }, modType = "BASE", cfg = "skill" },
+		{ label = "% chance to inflict 1 additional poison (Main Hand)", flag = "weapon1Attack", modName = { "AdditionalPoisonChance" }, modType = "BASE", cfg = "weapon1" },
+		{ label = "% chance to inflict 1 additional poison (Off Hand)", flag = "weapon2Attack", modName = { "AdditionalPoisonChance" }, modType = "BASE", cfg = "weapon2" },
+		{ label = "inflict # additional poisons", notFlag = "attack", modName = { "AdditionalPoisonStacks" }, modType = "BASE", cfg = "skill" },
+		{ label = "inflict # additional poisons (Main Hand)", flag = "weapon1Attack", modName = { "AdditionalPoisonStacks" }, modType = "BASE", cfg = "weapon1" },
+		{ label = "inflict # additional poisons (Off Hand)", flag = "weapon2Attack", modName = { "AdditionalPoisonStacks" }, modType = "BASE", cfg = "weapon2" },
+		{ label = "Poison Stack Limits", modName = { "PoisonStackLimit", "CannotMultiplePoison" }, cfg = "skill" },
+	}, },
 	{ label = "Total Increased", { format = "{0:mod:1}%", { modName = { "Damage", "ChaosDamage" }, modType = "INC", cfg = "poison" }, }, },
 	{ label = "Total More", { format = "{0:mod:1}%", { modName = { "Damage", "ChaosDamage" }, modType = "MORE", cfg = "poison" }, }, },
 	{ label = "Eff. DoT Multi", notFlag = "attack", haveOutput = "PoisonDotMulti", { format = "x {2:output:PoisonDotMulti}", { breakdown = "PoisonDotMulti" }, { modName = { "DotMultiplier", "ChaosDotMultiplier" }, cfg = "poison" }, }, },

src/Modules/ModParser.lua

@@ -3725,7 +3725,11 @@ local specialModList = {
 		mod("Damage", "INC", num, nil, 0, KeywordFlag.Poison, { type = "Condition", var = "SinglePoison" }, { type = "SkillName", skillNameList = { "Sunder", "Ground Slam" }, includeTransfigured = true })
 	} end,
 	["poisons on you expire (%d+)%% slower"] = function(num) return { mod("SelfPoisonDebuffExpirationRate", "BASE", -num) } end,
-	["(%d+)%% chance to inflict an additional poison on the same target when you inflict poison"] = function(num) return { mod("DoublePoisonChance", "BASE", num) } end,
+	["(%d+)%% chance to inflict an additional poison on the same target when you inflict poison"] = function(num) return { mod("AdditionalPoisonChance", "BASE", num) } end,
+	["inflict (%d+) additional poisons? on the same target when you inflict poisons? with this weapon"] = function(num) return { mod("AdditionalPoisonStacks", "BASE", num, { type = "Condition", var = "{Hand}Attack" } ) } end,
+	["cannot poison enemies with at least (%d+) poisons? on them"] = function(num) return { mod("PoisonStackLimit", "MIN", num ) } end,
+	["cannot inflict multiple poisons in the same hit"] = { flag("CannotMultiplePoison") },
+	["wither on hit with this weapon against enemies with at least (%d+) poisons on them"] = { flag("Condition:CanWither") },
 	-- Suppression
 	["y?o?u?r? ?chance to suppress spell damage is lucky"] = { flag("SpellSuppressionChanceIsLucky") },
 	["y?o?u?r? ?chance to suppress spell damage is unlucky"] = { flag("SpellSuppressionChanceIsUnlucky") },