New Engine Feature: Tweak op138

.gitignore

@@ -37,6 +37,7 @@
 !/style/*.*
 !/.gitattributes
 !/.gitignore
+!/.gitmessage
 !/EEex.png
 !/package_mod.bat
-!/README.md
+!/README.md

.gitmessage

@@ -0,0 +1,33 @@
+# <type>(<scope>): <imperative summary>
+#
+# Example:
+# fix(opcode): preserve natural roll for op138 crit checks
+#
+# Conventional Commit guidance:
+# - type: feat, fix, refactor, perf, build, docs, test, chore
+# - scope: use one precise EEex area
+# - summary: imperative, specific, <= 72 chars, no trailing period
+#
+# Suggested EEex scopes:
+# action, opcode, sprite, menu, ui, loader, patch, tp2, docs, packaging
+#
+# Why:
+# - State the concrete bug, limitation, or motivation.
+# - Prefer engine behavior over implementation trivia.
+#
+# What:
+# - Summarize the code and behavior changes.
+# - Call out hook sites, scripts, or data files when relevant.
+#
+# Validation:
+# - List the checks you actually ran.
+# - Include build status, luaparse/tests, runtime checks, or engine variants.
+#
+# Risks / Notes:
+# - Record follow-up work, compatibility concerns, or deliberate tradeoffs.
+#
+# Refs:
+# - Optional issue, artifact, dump, or investigation note.
+#
+# BREAKING CHANGE:
+# - Optional footer when behavior or interfaces change incompatibly.

EEex/copy/EEex_Action.lua

@@ -243,6 +243,31 @@ function EEex_Action_Private_SpellObjectOffset(aiBase, curAction, bOnlySprite, r
 	return realActionFunc(aiBase)
 end
 
+local function EEex_Action_Private_AttackOnce(aiBase, curAction)
+
+	if not aiBase:isSprite(true) then
+		return EEex_Action_ReturnType.ACTION_ERROR
+	end
+
+	local target = aiBase:GetTargetShareType1(curAction.m_acteeID, CGameObjectType.SPRITE)
+	if target == nil then
+		return EEex_Action_ReturnType.ACTION_ERROR
+	end
+
+	local sprite = EEex_GameObject_CastUT(aiBase)
+	sprite:UpdateTarget(target)
+
+	-- Use the engine's normal Attack() path so pathing, ranged projectile creation, and
+	-- weapon selection behave exactly like a regular attack. The native op138 bridge stops
+	-- the action after the first matched real roll; doing that purely in Lua was not
+	-- reliable once the sprite had to walk into range first.
+	curAction.m_actionID = 3 -- Attack
+	curAction.m_dest.x = target.m_pos.x
+	curAction.m_dest.y = target.m_pos.y
+
+	return aiBase:virtual_ExecuteAction()
+end
+
 EEex_Action_Private_Switch = {
 
 	-- Bug Fix: Enable ForceSpellRange / ForceSpellRangeRES
@@ -287,6 +312,13 @@ EEex_Action_Private_Switch = {
 		return EEex_Action_ReturnType.ACTION_DONE
 	end,
 
+	-- EEex_AttackOnce
+	[475] = function(aiBase, curAction)
+		-- This is a thin wrapper around Attack(). The "exactly one swing" behavior is
+		-- finalized natively once the first real attack roll is consumed.
+		return EEex_Action_Private_AttackOnce(aiBase, curAction)
+	end,
+
 	-- EEex_SpellObjectOffset / EEex_SpellObjectOffsetRES
 	[476] = function(aiBase, curAction)
 		return EEex_Action_Private_SpellObjectOffset(aiBase, curAction, true, 95, CGameSprite.SpellPoint)

EEex/copy/EEex_Action_Patch.lua

@@ -11,6 +11,7 @@
 	|   473 EEex_MatchObject(S:Chunk*)                                               |
 	|   473 EEex_MatchObjectEx(S:Chunk*,I:Nth*,I:Range*,I:Flags*X-MATOBJ)            |
 	|   474 EEex_SetTarget(S:Name*,O:Target*)                                        |
+	|   475 EEex_AttackOnce(O:Target*)                                               |
 	|   476 EEex_SpellObjectOffset(O:Target*,I:Spell*Spell,P:Offset*)                |
 	|   476 EEex_SpellObjectOffsetRES(S:RES*,O:Target*,P:Offset*)                    |
 	|   477 EEex_SpellObjectOffsetNoDec(O:Target*,I:Spell*Spell,P:Offset*)           |
@@ -72,6 +73,10 @@
 	+----------------------------------------------------------------------------------+
 	--]]
 
+	-- opcode 138 depends on this native callback as well: the wrapper action can queue
+	-- a normal Attack(), but only the engine knows when movement/pathing has finished and
+	-- the real attack action has actually started for the chosen target.
+
 	EEex_HookAfterCallWithLabels(EEex_Label("CGameSprite::SetCurrAction()-LastCall"), {
 		{"hook_integrity_watchdog_ignore_registers", {EEex_HookIntegrityWatchdogRegister.RAX}}},
 		{[[

EEex/copy/EEex_Fix.lua

@@ -40,6 +40,241 @@ function EEex_Fix_Hook_OnSpellOrSpellPointStartedCastingGlow(sprite)
 	EEex_GetUDAux(sprite)["EEex_Fix_HasSpellOrSpellPointStartedCasting"] = 1
 end
 
+-----------------------------------------------------------------------------------------------------
+-- Fix SPLPROT.2DA stat comparisons not respecting signed stat storage (e.g. negative resistances) --
+-----------------------------------------------------------------------------------------------------
+
+-- The patch-side assembly receives the raw stat id as an unsigned 16-bit value.
+-- A 64 KiB byte map lets the hook answer "is this stat stored as signed?" with
+-- one indexed load and no Lua / table lookup inside the hot compare path.
+-- 0x10000 bytes = one byte for every possible 16-bit stat id value.
+EEex_Fix_Private_SignedSplprotStatBitmap = EEex_Malloc(0x10000)
+-- Default every entry to 0 ("not known to require signed relational compares").
+-- This initial clear is a defensive safe default for freshly allocated native memory,
+-- before the game-state initialization listener has had a chance to populate the bitmap.
+-- Initialization below flips only the confirmed signed stat ids to 1.
+EEex_Memset(EEex_Fix_Private_SignedSplprotStatBitmap, 0, 0x10000)
+
+-- Source of truth for signedness:
+--   * CDerivedStats::GetAtOffset() in the game executable
+--   * CDerivedStatsTemplate in the matching PDB
+--
+-- The generated manifest contains the vanilla stat ids whose engine-native storage is signed.
+--
+-- Variants: BGEE, BG2EE, IWDEE
+
+-- NOTE:
+--   This list is generated from EXE/PDB analysis. It is embedded here so the
+--   runtime hook can stay data-only: the hook just consults the bitmap and does
+--   not need to know anything about engine field names or IDS labels.
+EEex_Fix_Private_SignedSplprotStatIDs = {
+	1, -- m_nMaxHitPoints
+	2, -- m_nArmorClass
+	3, -- m_nACCrushingMod
+	4, -- m_nACMissileMod
+	5, -- m_nACPiercingMod
+	6, -- m_nACSlashingMod
+	7, -- m_nTHAC0
+	8, -- m_nNumberOfAttacks
+	9, -- m_nSaveVSDeath
+	10, -- m_nSaveVSWands
+	11, -- m_nSaveVSPoly
+	12, -- m_nSaveVSBreath
+	13, -- m_nSaveVSSpell
+	14, -- m_nResistFire
+	15, -- m_nResistCold
+	16, -- m_nResistElectricity
+	17, -- m_nResistAcid
+	18, -- m_nResistMagic
+	19, -- m_nResistMagicFire
+	20, -- m_nResistMagicCold
+	21, -- m_nResistSlashing
+	22, -- m_nResistCrushing
+	23, -- m_nResistPiercing
+	24, -- m_nResistMissile
+	25, -- m_nLore
+	26, -- m_nLockPicking
+	27, -- m_nMoveSilently
+	28, -- m_nTraps
+	29, -- m_nPickPocket
+	30, -- m_nFatigue
+	31, -- m_nIntoxication
+	32, -- m_nLuck
+	33, -- m_nTracking
+	35, -- m_nSex
+	36, -- m_nSTR
+	37, -- m_nSTRExtra
+	38, -- m_nINT
+	39, -- m_nWIS
+	40, -- m_nDEX
+	41, -- m_nCON
+	42, -- m_nCHR
+	48, -- m_nReputation
+	49, -- m_nHatedRace
+	50, -- m_nDamageBonus
+	51, -- m_nSpellFailureMage
+	52, -- m_nSpellFailurePriest
+	53, -- m_nSpellDurationModMage
+	54, -- m_nSpellDurationModPriest
+	55, -- m_nTurnUndeadLevel
+	56, -- m_nBackstabDamageMultiplier
+	57, -- m_nLayOnHandsAmount
+	58, -- m_bHeld
+	59, -- m_bPolymorphed
+	60, -- m_nTranslucent
+	61, -- m_bIdentifyMode
+	62, -- m_bEntangle
+	63, -- m_bSanctuary
+	64, -- m_bMinorGlobe
+	65, -- m_bShieldGlobe
+	66, -- m_bGrease
+	67, -- m_bWeb
+	70, -- m_bCasterHold
+	71, -- m_nEncumberance
+	72, -- m_nMissileTHAC0Bonus
+	73, -- m_nMagicDamageResistance
+	74, -- m_nResistPoison
+	75, -- m_bDoNotJump
+	76, -- m_bAuraCleansing
+	77, -- m_nMentalSpeed
+	78, -- m_nPhysicalSpeed
+	79, -- m_nCastingLevelBonusMage
+	80, -- m_nCastingLevelBonusCleric
+	81, -- m_bSeeInvisible
+	82, -- m_bIgnoreDialogPause
+	83, -- m_nMinHitPoints
+	84, -- m_THAC0BonusRight
+	85, -- m_THAC0BonusLeft
+	86, -- m_DamageBonusRight
+	87, -- m_DamageBonusLeft
+	88, -- m_nStoneSkins
+	89, -- m_nProficiencyBastardSword
+	90, -- m_nProficiencyLongSword
+	91, -- m_nProficiencyShortSword
+	92, -- m_nProficiencyAxe
+	93, -- m_nProficiencyTwoHandedSword
+	94, -- m_nProficiencyKatana
+	95, -- m_nProficiencyScimitarWakisashiNinjaTo
+	96, -- m_nProficiencyDagger
+	97, -- m_nProficiencyWarhammer
+	98, -- m_nProficiencySpear
+	99, -- m_nProficiencyHalberd
+	100, -- m_nProficiencyFlailMorningStar
+	101, -- m_nProficiencyMace
+	102, -- m_nProficiencyQuarterStaff
+	103, -- m_nProficiencyCrossbow
+	104, -- m_nProficiencyLongBow
+	105, -- m_nProficiencyShortBow
+	106, -- m_nProficiencyDart
+	107, -- m_nProficiencySling
+	108, -- m_nProficiencyBlackjack
+	109, -- m_nProficiencyGun
+	110, -- m_nProficiencyMartialArts
+	111, -- m_nProficiency2Handed
+	112, -- m_nProficiencySwordAndShield
+	113, -- m_nProficiencySingleWeapon
+	114, -- m_nProficiency2Weapon
+	115, -- m_nProficiencyClub
+	116, -- m_nExtraProficiency2
+	117, -- m_nExtraProficiency3
+	118, -- m_nExtraProficiency4
+	119, -- m_nExtraProficiency5
+	120, -- m_nExtraProficiency6
+	121, -- m_nExtraProficiency7
+	122, -- m_nExtraProficiency8
+	123, -- m_nExtraProficiency9
+	124, -- m_nExtraProficiency10
+	125, -- m_nExtraProficiency11
+	126, -- m_nExtraProficiency12
+	127, -- m_nExtraProficiency13
+	128, -- m_nExtraProficiency14
+	129, -- m_nExtraProficiency15
+	130, -- m_nExtraProficiency16
+	131, -- m_nExtraProficiency17
+	132, -- m_nExtraProficiency18
+	133, -- m_nExtraProficiency19
+	134, -- m_nExtraProficiency20
+	135, -- m_nHideInShadows
+	136, -- m_nDetectIllusion
+	137, -- m_nSetTraps
+	138, -- m_nPuppetMasterId
+	139, -- m_nPuppetMasterType
+	140, -- m_nPuppetType
+	141, -- m_nPuppetId
+	142, -- m_bCheckForBerserk
+	143, -- m_bBerserkStage1
+	144, -- m_bBerserkStage2
+	145, -- m_nDamageLuck
+	147, -- m_nVisualRange
+	148, -- m_bExplore
+	149, -- m_bThrullCharm
+	150, -- m_bSummonDisable
+	151, -- m_nHitBonus
+	153, -- m_bForceSurge
+	154, -- m_nSurgeMod
+	155, -- m_bImprovedHaste
+	166, -- m_nMeleeTHAC0Bonus
+	167, -- m_nMeleeDamageBonus
+	168, -- m_nMissileDamageBonus
+	169, -- m_bDisableCircle
+	170, -- m_nFistTHAC0Bonus
+	171, -- m_nFistDamageBonus
+	174, -- m_bPreventSpellProtectionEffects
+	175, -- m_bImmunityToBackStab
+	176, -- m_nLockPickingMTPBonus
+	177, -- m_nMoveSilentlyMTPBonus
+	178, -- m_nTrapsMTPBonus
+	179, -- m_nPickPocketMTPBonus
+	180, -- m_nHideInShadowsMTPBonus
+	181, -- m_nDetectIllusionMTPBonus
+	182, -- m_nSetTrapsMTPBonus
+	183, -- m_bPreventAISlowDown
+	184, -- m_nExistanceDelayOverride
+	185, -- m_bAnimationOnlyHaste
+	186, -- m_bNoPermanentDeath
+	187, -- m_bImmuneToTurnUndead
+	188, -- m_bSummonDisableAction
+	189, -- m_nChaosShield
+	190, -- m_bNPCBump
+	191, -- m_bUseAnyItem
+	192, -- m_nAssassinate
+	193, -- m_bSexChanged
+	194, -- m_nSpellFailureInnate
+	195, -- m_bImmuneToTracking
+	196, -- m_bDeadMagic
+	197, -- m_bImmuneToTimeStop
+	198, -- m_bImmuneToSequester
+	199, -- m_nStoneSkinsGolem
+	200, -- m_nLevelDrain
+	201, -- m_bDoNotDraw
+	202, -- m_bIgnoreDrainDeath
+}
+
+-- Special cases intentionally excluded from EEex_Fix_Private_SignedSplprotStatIDs:
+--   Stat id 146: GetAtOffset() does not resolve this case to a single CDerivedStatsTemplate field load.
+--   m_nSpellDurationModBard: signed CDerivedStatsTemplate field, but no vanilla GetAtOffset() case returns it.
+--   m_nClassTypeOverrideMixed: signed CDerivedStatsTemplate field, but no vanilla GetAtOffset() case returns it.
+--   m_nClassTypeOverrideLower: signed CDerivedStatsTemplate field, but no vanilla GetAtOffset() case returns it.
+
+local function EEex_Fix_Private_InitializeSignedSplprotStatBitmap()
+	-- Rebuild from the manifest each time the game state initializes so the
+	-- bitmap always reflects the authoritative signed-id list for this build.
+	-- This clear is still required even though the buffer was zeroed at allocation time:
+	-- reinitialization only writes 1-bits for signed ids, so stale entries must be cleared first.
+	EEex_Memset(EEex_Fix_Private_SignedSplprotStatBitmap, 0, 0x10000)
+
+	for _, statID in ipairs(EEex_Fix_Private_SignedSplprotStatIDs) do
+		-- Presence means "treat relational SPLPROT compares for this stat as signed".
+		EEex_Write8(EEex_Fix_Private_SignedSplprotStatBitmap + statID, 1)
+	end
+end
+
+EEex_GameState_AddInitializedListener(function()
+	-- The patch code reads this bitmap from native memory, so populate it only
+	-- once EEex runtime state is fully available for the current game session.
+	EEex_Fix_Private_InitializeSignedSplprotStatBitmap()
+end)
+
 --------------------------------------------
 -- Fix Baldur.lua values not escaping '\' --
 --------------------------------------------