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Pathfinding FindGridPath CheckLine Grid Path Override #879

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Pathfinding FindGridPath CheckLine Grid Path Override #879

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e93e024
chore: EntityNPCPlus def
Syntax-Sculptor Jul 9, 2026
738945d
feat: line of sight ASM patch
Syntax-Sculptor Jul 9, 2026
2abe303
fix: removed redundant push causing crash
Syntax-Sculptor Jul 9, 2026
aa7c6a3
refactor: rely on std::optional for safety
Syntax-Sculptor Jul 10, 2026
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4 changes: 4 additions & 0 deletions libzhl/functions/ASM.zhl
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Original file line number Diff line number Diff line change
Expand Up @@ -282,3 +282,7 @@ asm AutoReassignControllers_Reassign "e8????????836d??018b4d";
asm ControllerDisconnected_Unassign "e8????????c645??018d8d";
asm ControllerDisconnected_Reassign "e8????????85ff75??8935";
asm ControllerDisconnected_LoopEnd "8945??3b45??0f82????????85d2";

// Pathfinding

asm NPCAI_Pathfinder_LineOfSightThresholdOverride "516a008d45??8bce";
39 changes: 39 additions & 0 deletions repentogon/LuaInterfaces/Entities/LuaEntity.cpp
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Expand Up @@ -861,6 +861,42 @@ LUA_FUNCTION(Lua_EntitySetVariant) {
return 0;
}

LUA_FUNCTION(Lua_EntityGetLineOfSightCostThreshold) {
Entity* ent = lua::GetLuabridgeUserdata<Entity*>(L, 1, lua::Metatables::ENTITY, "Entity");
EntityPlus* plus = GetEntityPlus(ent);

if (plus && plus->lineOfSightCostThreshold.has_value()) {
lua_pushinteger(L, plus->lineOfSightCostThreshold.value());
}
else {
// TODO: Have fallback match what decomp does internally
lua_pushinteger(L, 900);
}
return 1;
}

LUA_FUNCTION(Lua_EntitySetLineOfSightCostThreshold) {

@ConnorForan ConnorForan Jul 10, 2026

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Had a thought, pretty sure that the Pathfinder class has a reference to its parent Entity:

REPENTOGON/libzhl/functions/NPCAI_Pathfinder.zhl

Line 32 in 2bcd235

Entity * _entity : 0x0;

So in theory, you could still have these as Pathfinder functions, while under the hood they still read/write from EntityPlus

This is hypothetical though, lemme know if it doesn't seem like that would work. Just seems like something that should be in Pathfinder API-wise

@Syntax-Sculptor Syntax-Sculptor Jul 10, 2026

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Good idea.

Entity* ent = lua::GetLuabridgeUserdata<Entity*>(L, 1, lua::Metatables::ENTITY, "Entity");
int threshold = (int)luaL_checkinteger(L, 2);
EntityPlus* plus = GetEntityPlus(ent);

if (plus) {
plus->lineOfSightCostThreshold = threshold;
}

return 0;
}

LUA_FUNCTION(Lua_EntityResetLineOfSightCostThreshold) {
Entity* ent = lua::GetLuabridgeUserdata<Entity*>(L, 1, lua::Metatables::ENTITY, "Entity");
EntityPlus* plus = GetEntityPlus(ent);

if (plus) {
plus->lineOfSightCostThreshold = std::nullopt;
}

return 0;
}

HOOK_METHOD(LuaEngine, RegisterClasses, () -> void) {
super();
Expand Down Expand Up @@ -955,6 +991,9 @@ HOOK_METHOD(LuaEngine, RegisterClasses, () -> void) {
{ "SetWaterClipFlags", Lua_EntitySetWaterClipFlags },
{ "ResetWaterClipFlags", Lua_EntityResetWaterClipFlags },
{ "CanDevolve", Lua_EntityCanDevolve },
{ "GetLineOfSightCostThreshold", Lua_EntityGetLineOfSightCostThreshold },
{ "SetLineOfSightCostThreshold", Lua_EntitySetLineOfSightCostThreshold },
{ "ResetLineOfSightCostThreshold", Lua_EntityResetLineOfSightCostThreshold },
{ NULL, NULL }
};
lua::RegisterFunctions(_state, lua::Metatables::ENTITY, functions);
Expand Down
1 change: 1 addition & 0 deletions repentogon/Patches/ASMPatches.cpp
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Expand Up @@ -210,6 +210,7 @@ void PerformASMPatches() {
ASMPatchHushBug();
ASMPatchFireProjectiles();
ASMPatchFireBossProjectiles();
ASMPatchLineOfSightThreshold();
//ASMPatchApplyFrozenEnemyDeathEffects(); // This was disabled prior to rep+, ignore it!

// EntityKnife
Expand Down
35 changes: 35 additions & 0 deletions repentogon/Patches/ASMPatches/ASMEntityNPC.cpp
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Expand Up @@ -2,9 +2,11 @@
#include "../ASMPatches.h"

#include "ASMEntityNPC.h"
#include "../EntityPlus.h"

#include "HookSystem.h"
#include "../XMLData.h"
#include "ASMDefinition.h"

thread_local FireProjectilesStorage projectilesStorage;

Expand Down Expand Up @@ -134,6 +136,39 @@ void ASMPatchApplyFrozenEnemyDeathEffects() {
sASMPatcher.PatchAt(addr, &patch);
}


int __stdcall GetLineOfSightThresholdOverride(Entity* entity, int originalThreshold) {
EntityPlus* plus = GetEntityPlus(entity);

if (plus && plus->lineOfSightCostThreshold.has_value()) {
return plus->lineOfSightCostThreshold.value();
}

return originalThreshold;
}

void ASMPatchLineOfSightThreshold() {
void* addr = sASMDefinitionHolder->GetDefinition(&AsmDefinitions::NPCAI_Pathfinder_LineOfSightThresholdOverride);
printf("[REPENTOGON] Patching NPCAI_Pathfinder::FindGridPath line of sight threshold at %p\n", addr);

ASMPatch::SavedRegisters reg(ASMPatch::SavedRegisters::GP_REGISTERS_STACKLESS & ~ASMPatch::SavedRegisters::Registers::EAX, true);

ASMPatch patch;
patch.PreserveRegisters(reg)
.Push(ASMPatch::Registers::ECX) // Original threshold
.AddBytes("\x8B\x07") // mov eax, [edi] (Get Entity* from Pathfinder)
.Push(ASMPatch::Registers::EAX)
.AddInternalCall(GetLineOfSightThresholdOverride)
// Restore our registers and call our functions as is.
.RestoreRegisters(reg)
.Push(ASMPatch::Registers::EAX)
.Push((int8_t)0)
.LoadEffectiveAddress(ASMPatch::Registers::EBP, -0x48, ASMPatch::Registers::EAX)
.AddRelativeJump((char*)addr + 0x6);

sASMPatcher.PatchAt(addr, &patch);
}

HOOK_METHOD(Entity, IsActiveEnemy, (bool includeDead) -> bool) {
if (this->_type >= ENTITY_GAPER && this->_type < ENTITY_EFFECT) {
const std::string attr = XMLStuff.EntityData->GetAttributeByTypeVarSub(this->_type, this->_variant, this->_subtype, false, "isactiveenemy");
Expand Down
3 changes: 2 additions & 1 deletion repentogon/Patches/ASMPatches/ASMEntityNPC.h
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Expand Up @@ -19,4 +19,5 @@ static std::vector<Entity_Projectile*>& InitProjectileStorage() {
void ASMPatchHushBug();
void ASMPatchFireProjectiles();
void ASMPatchFireBossProjectiles();
void ASMPatchApplyFrozenEnemyDeathEffects();
void ASMPatchApplyFrozenEnemyDeathEffects();
void ASMPatchLineOfSightThreshold();
4 changes: 4 additions & 0 deletions repentogon/Patches/EntityPlus.cpp
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Expand Up @@ -136,6 +136,10 @@ EntityKnifePlus* GetEntityKnifePlus(Entity_Knife* knife) {
return dynamic_cast<EntityKnifePlus*>(GetEntityPlusHolder(knife, true)->data.get());
}

EntityNPCPlus* GetEntityNPCPlus(Entity_NPC* npc) {
return dynamic_cast<EntityNPCPlus*>(GetEntityPlusHolder(npc, true)->data.get());
}


// ----------------------------------------------------------------------------------------------------
// -- Make entities obey EntityPlus.isFlyingOverride
Expand Down
7 changes: 7 additions & 0 deletions repentogon/Patches/EntityPlus.h
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Expand Up @@ -11,6 +11,7 @@ class EntityPlus {
public:
virtual ~EntityPlus() {}

std::optional<int> lineOfSightCostThreshold = std::nullopt;
std::optional<bool> isFlyingOverride = std::nullopt;
std::optional<uint32_t> waterClipInfoFlagsOverride = std::nullopt;
};
Expand Down Expand Up @@ -56,6 +57,11 @@ class EntityKnifePlus : public EntityPlus {
EntityPtr hitboxSource;
};

// Attributes for EntityNPC.
class EntityNPCPlus : public EntityPlus {
public:
};

// Returns a ptr to the base EntityPlus class held by the entity.
// In theory should typically not be nullptr as it, or a child class, is initialized on entity Init.
EntityPlus* GetEntityPlus(Entity* entity);
Expand All @@ -67,5 +73,6 @@ EntityFamiliarPlus* GetEntityFamiliarPlus(Entity_Familiar* familiar);
EntityTearPlus* GetEntityTearPlus(Entity_Tear* tear);
EntityLaserPlus* GetEntityLaserPlus(Entity_Laser* laser);
EntityKnifePlus* GetEntityKnifePlus(Entity_Knife* knife);
EntityNPCPlus* GetEntityNPCPlus(Entity_NPC* npc);

void ASMPatchesForEntityPlus();
7 changes: 7 additions & 0 deletions repentogon/resources/scripts/enums_ex.lua
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Expand Up @@ -3174,6 +3174,13 @@ TrinketSlot = {
BELLY_BUTTON = 1,
}

GridPathThreshold = {
DEFAULT = 900,
IGNORE_DECAY = 950,
IGNORE_FIREPLACES_AND_DECAY = 1000,
IGNORE_EVERYTHING = 1001
}

--deprecated enums

Achievement.REVERSED_THE_HEIROPHANT = 529
Expand Down
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