Merge pull request #1920 from wiseoldman95/SquashedPathFinder

Implemented A* Pathfinding and updated monster.cpp to use it.

src/Mobs/AggressiveMonster.cpp

@@ -37,10 +37,7 @@ void cAggressiveMonster::InStateChasing(std::chrono::milliseconds a_Dt)
 			}
 		}
 
-		if (!IsMovingToTargetPosition())
+		MoveToPosition(m_Target->GetPosition());
-		{
-			MoveToPosition(m_Target->GetPosition());
-		}
 	}
 }
 

src/Mobs/CMakeLists.txt

@@ -24,6 +24,7 @@ SET (SRCS
 	Mooshroom.cpp
 	PassiveAggressiveMonster.cpp
 	PassiveMonster.cpp
+	Path.cpp
 	Pig.cpp
 	Rabbit.cpp
 	Sheep.cpp
@@ -62,6 +63,7 @@ SET (HDRS
 	Ocelot.h
 	PassiveAggressiveMonster.h
 	PassiveMonster.h
+	Path.h
 	Pig.h
 	Rabbit.h
 	Sheep.h

src/Mobs/Monster.cpp

@@ -13,7 +13,7 @@
 #include "../Chunk.h"
 #include "../FastRandom.h"
 
-
+#include "Path.h"
 
 
 
@@ -74,6 +74,10 @@ cMonster::cMonster(const AString & a_ConfigName, eMonsterType a_MobType, const A
 	, m_EMState(IDLE)
 	, m_EMPersonality(AGGRESSIVE)
 	, m_Target(nullptr)
+	, m_Path(nullptr)
+	, m_PathStatus(ePathFinderStatus::PATH_NOT_FOUND)
+	, m_IsFollowingPath(false)
+	, m_GiveUpCounter(0)
 	, m_bMovingToDestination(false)
 	, m_LastGroundHeight(POSY_TOINT)
 	, m_IdleInterval(0)
@@ -94,8 +98,9 @@ cMonster::cMonster(const AString & a_ConfigName, eMonsterType a_MobType, const A
 	, m_DropChanceLeggings(0.085f)
 	, m_DropChanceBoots(0.085f)
 	, m_CanPickUpLoot(true)
+	, m_TicksSinceLastDamaged(100)
 	, m_BurnsInDaylight(false)
-	, m_RelativeWalkSpeed(1.0)
+	, m_RelativeWalkSpeed(1)
 {
 	if (!a_ConfigName.empty())
 	{
@@ -118,87 +123,52 @@ void cMonster::SpawnOn(cClientHandle & a_Client)
 
 void cMonster::TickPathFinding()
 {
-	const int PosX = POSX_TOINT;
-	const int PosY = POSY_TOINT;
-	const int PosZ = POSZ_TOINT;
 
-	std::vector<Vector3d> m_PotentialCoordinates;
+	if (m_Path == nullptr)
-	m_TraversedCoordinates.push_back(Vector3i(PosX, PosY, PosZ));
+	{
+		Vector3d position = GetPosition();
+		Vector3d Dest = m_FinalDestination;
 
-	static const struct  // Define which directions to try to move to
+		// Can someone explain why are these two NOT THE SAME???
-	{
+		// m_Path = new cPath(GetWorld(), GetPosition(), m_FinalDestination, 30);
-		int x, z;
+		m_Path = new cPath(GetWorld(), Vector3d(floor(position.x), floor(position.y), floor(position.z)), Vector3d(floor(Dest.x), floor(Dest.y), floor(Dest.z)), 20);
-	} gCrossCoords[] =
-	{
-		{ 1, 0},
-		{-1, 0},
-		{ 0, 1},
-		{ 0, -1},
-	} ;
 
-	if ((PosY - 1 < 0) || (PosY + 2 >= cChunkDef::Height) /* PosY + 1 will never be true if PosY + 2 is not */)
+
-	{
+		m_IsFollowingPath = false;
-		// Too low/high, can't really do anything
-		FinishPathFinding();
-		return;
 	}
-
+	m_PathStatus = m_Path->Step();
-	for (size_t i = 0; i < ARRAYCOUNT(gCrossCoords); i++)
+	switch (m_PathStatus)
 	{
-		if (IsCoordinateInTraversedList(Vector3i(gCrossCoords[i].x + PosX, PosY, gCrossCoords[i].z + PosZ)))
+
+		case ePathFinderStatus::PATH_NOT_FOUND:
 		{
-			continue;
+			FinishPathFinding();
+			break;
 		}
 
-		BLOCKTYPE BlockAtY = m_World->GetBlock(gCrossCoords[i].x + PosX, PosY, gCrossCoords[i].z + PosZ);
-		BLOCKTYPE BlockAtYP = m_World->GetBlock(gCrossCoords[i].x + PosX, PosY + 1, gCrossCoords[i].z + PosZ);
-		BLOCKTYPE BlockAtYPP = m_World->GetBlock(gCrossCoords[i].x + PosX, PosY + 2, gCrossCoords[i].z + PosZ);
-		int LowestY = FindFirstNonAirBlockPosition(gCrossCoords[i].x + PosX, gCrossCoords[i].z + PosZ);
-		BLOCKTYPE BlockAtLowestY = (LowestY >= cChunkDef::Height) ? E_BLOCK_AIR : m_World->GetBlock(gCrossCoords[i].x + PosX, LowestY, gCrossCoords[i].z + PosZ);
 
-		if (
+		case ePathFinderStatus::CALCULATING:
-			(!cBlockInfo::IsSolid(BlockAtY)) &&
-			(!cBlockInfo::IsSolid(BlockAtYP)) &&
-			(!IsBlockLava(BlockAtLowestY)) &&
-			(BlockAtLowestY != E_BLOCK_CACTUS) &&
-			(PosY - LowestY < FALL_DAMAGE_HEIGHT)
-			)
 		{
-			m_PotentialCoordinates.push_back(Vector3d((gCrossCoords[i].x + PosX), PosY, gCrossCoords[i].z + PosZ));
+			m_Destination = GetPosition();
+			break;
 		}
-		else if (
-			(cBlockInfo::IsSolid(BlockAtY)) &&
-			(BlockAtY != E_BLOCK_CACTUS) &&
-			(!cBlockInfo::IsSolid(BlockAtYP)) &&
-			(!cBlockInfo::IsSolid(BlockAtYPP)) &&
-			(BlockAtY != E_BLOCK_FENCE) &&
-			(BlockAtY != E_BLOCK_FENCE_GATE)
-			)
-		{
-			m_PotentialCoordinates.push_back(Vector3d((gCrossCoords[i].x + PosX), PosY + 1, gCrossCoords[i].z + PosZ));
-		}
-	}
 
-	if (!m_PotentialCoordinates.empty())
+
-	{
+		case ePathFinderStatus::PATH_FOUND:
-		Vector3f ShortestCoords = m_PotentialCoordinates.front();
-		for (std::vector<Vector3d>::const_iterator itr = m_PotentialCoordinates.begin(); itr != m_PotentialCoordinates.end(); ++itr)
 		{
-			Vector3f Distance = m_FinalDestination - ShortestCoords;
+			if (ReachedDestination() || !m_IsFollowingPath)
-			Vector3f Distance2 = m_FinalDestination - *itr;
-			if (Distance.SqrLength() > Distance2.SqrLength())
 			{
-				ShortestCoords = *itr;
+				m_Destination = m_Path->GetNextPoint();
+				m_IsFollowingPath = true;
+				m_GiveUpCounter = 40;  // Give up after 40 ticks (2 seconds) if failed to reach m_Dest.
 			}
-		}
+			if (m_Path->IsLastPoint())
+			{
+				FinishPathFinding();
+			}
+			break;
 
-		m_Destination = ShortestCoords;
+		}
-		m_Destination.z += 0.5f;
-		m_Destination.x += 0.5f;
-	}
-	else
-	{
-		FinishPathFinding();
 	}
 }
 
@@ -206,17 +176,28 @@ void cMonster::TickPathFinding()
 
 
 
+/* Currently, the mob will only start moving to a new position after the position it is
+currently going to is reached. */
 void cMonster::MoveToPosition(const Vector3d & a_Position)
 {
-	FinishPathFinding();
-
 	m_FinalDestination = a_Position;
 	m_bMovingToDestination = true;
-	TickPathFinding();
 }
 
 
 
+
+
+void cMonster::StopMovingToPosition()
+{
+	m_bMovingToDestination = false;
+	FinishPathFinding();
+}
+
+
+
+
+
 bool cMonster::IsCoordinateInTraversedList(Vector3i a_Coords)
 {
 	return (std::find(m_TraversedCoordinates.begin(), m_TraversedCoordinates.end(), a_Coords) != m_TraversedCoordinates.end());
@@ -226,6 +207,22 @@ bool cMonster::IsCoordinateInTraversedList(Vector3i a_Coords)
 
 
 
+/* No one should call this except the pathfinder orthe monster tick or StopMovingToPosition.
+Resets the pathfinder, usually starting a brand new path, unless called from StopMovingToPosition. */
+void cMonster::FinishPathFinding(void)
+{
+	if (m_Path != nullptr)
+	{
+		delete m_Path;
+		m_Path = nullptr;
+
+	}
+}
+
+
+
+
+
 bool cMonster::ReachedDestination()
 {
 	if ((m_Destination - GetPosition()).Length() < 0.5f)
@@ -239,6 +236,7 @@ bool cMonster::ReachedDestination()
 
 
 
+
 bool cMonster::ReachedFinalDestination()
 {
 	if ((GetPosition() - m_FinalDestination).Length() <= m_AttackRange)
@@ -268,6 +266,10 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 		return;
 	}
 
+	if (m_TicksSinceLastDamaged < 100)
+	{
+		++m_TicksSinceLastDamaged;
+	}
 	if ((m_Target != nullptr) && m_Target->IsDestroyed())
 	{
 		m_Target = nullptr;
@@ -276,6 +278,8 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	// Burning in daylight
 	HandleDaylightBurning(a_Chunk);
 
+
+
 	if (m_bMovingToDestination)
 	{
 		if (m_bOnGround)
@@ -289,53 +293,51 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 			}
 		}
 
+		TickPathFinding();
+
 		Vector3d Distance = m_Destination - GetPosition();
 		if (!ReachedDestination() && !ReachedFinalDestination())  // If we haven't reached any sort of destination, move
 		{
-			Distance.y = 0;
+			if (--m_GiveUpCounter == 0)
-			Distance.Normalize();
-
-			if (m_bOnGround)
-			{
-				Distance *= 2.5f;
-			}
-			else if (IsSwimming())
-			{
-				Distance *= 1.3f;
-			}
-			else
-			{
-				// Don't let the mob move too much if he's falling.
-				Distance *= 0.25f;
-			}
-
-			// Apply walk speed:
-			Distance *= m_RelativeWalkSpeed;
-
-			AddSpeedX(Distance.x);
-			AddSpeedZ(Distance.z);
-
-			// It's too buggy!
-			/*
-			if (m_EMState == ESCAPING)
-			{
-				// Runs Faster when escaping :D otherwise they just walk away
-				SetSpeedX (GetSpeedX() * 2.f);
-				SetSpeedZ (GetSpeedZ() * 2.f);
-			}
-			*/
-		}
-		else
-		{
-			if (ReachedFinalDestination())  // If we have reached the ultimate, final destination, stop pathfinding and attack if appropriate
 			{
 				FinishPathFinding();
 			}
 			else
 			{
-				TickPathFinding();  // We have reached the next point in our path, calculate another point
+				Distance.y = 0;
+				Distance.Normalize();
+
+				if (m_bOnGround)
+				{
+					Distance *= 2.5f;
+				}
+				else if (IsSwimming())
+				{
+					Distance *= 1.3f;
+				}
+				else
+				{
+					// Don't let the mob move too much if he's falling.
+					Distance *= 0.25f;
+				}
+
+				// Apply walk speed:
+				Distance *= m_RelativeWalkSpeed;
+
+				/* Reduced default speed.
+				Close to Vanilla, easier for mobs to follow m_Destinations, hence
+				better pathfinding. */
+				Distance *= 0.5;
+
+				AddSpeedX(Distance.x);
+				AddSpeedZ(Distance.z);
+
 			}
 		}
+		else if (ReachedFinalDestination())
+		{
+			StopMovingToPosition();
+		}
 	}
 
 	SetPitchAndYawFromDestination();
@@ -345,13 +347,13 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	{
 		case IDLE:
 		{
-			// If enemy passive we ignore checks for player visibility
+			// If enemy passive we ignore checks for player visibility.
 			InStateIdle(a_Dt);
 			break;
 		}
 		case CHASING:
 		{
-			// If we do not see a player anymore skip chasing action
+			// If we do not see a player anymore skip chasing action.
 			InStateChasing(a_Dt);
 			break;
 		}
@@ -365,7 +367,8 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	}  // switch (m_EMState)
 
 	BroadcastMovementUpdate();
-}
+	}
+
 
 
 
@@ -409,6 +412,7 @@ void cMonster::SetPitchAndYawFromDestination()
 
 
 
+
 void cMonster::HandleFalling()
 {
 	if (m_bOnGround)
@@ -460,7 +464,6 @@ int cMonster::FindFirstNonAirBlockPosition(double a_PosX, double a_PosZ)
 
 
 
-
 bool cMonster::DoTakeDamage(TakeDamageInfo & a_TDI)
 {
 	if (!super::DoTakeDamage(a_TDI))
@@ -476,6 +479,7 @@ bool cMonster::DoTakeDamage(TakeDamageInfo & a_TDI)
 	if (a_TDI.Attacker != nullptr)
 	{
 		m_Target = a_TDI.Attacker;
+		m_TicksSinceLastDamaged = 0;
 	}
 	return true;
 }
@@ -1100,16 +1104,27 @@ void cMonster::HandleDaylightBurning(cChunk & a_Chunk)
 		// Outside the world
 		return;
 	}
-	
-	int RelX = POSX_TOINT - GetChunkX() * cChunkDef::Width;
-	int RelZ = POSZ_TOINT - GetChunkZ() * cChunkDef::Width;
-
 	if (!a_Chunk.IsLightValid())
 	{
 		m_World->QueueLightChunk(GetChunkX(), GetChunkZ());
 		return;
 	}
 
+	if (WouldBurnAt(GetPosition(), a_Chunk))
+	{
+		// Burn for 100 ticks, then decide again
+		StartBurning(100);
+	}
+}
+
+
+
+
+bool cMonster::WouldBurnAt(Vector3d a_Location, cChunk & a_Chunk)
+{
+	int RelX = FloorC(a_Location.x) - a_Chunk.GetPosX() * cChunkDef::Width;
+	int RelY = FloorC(a_Location.y);
+	int RelZ = FloorC(a_Location.z) - a_Chunk.GetPosZ() * cChunkDef::Width;
 	if (
 		(a_Chunk.GetSkyLight(RelX, RelY, RelZ) == 15) &&             // In the daylight
 		(a_Chunk.GetBlock(RelX, RelY, RelZ) != E_BLOCK_SOULSAND) &&  // Not on soulsand
@@ -1118,14 +1133,15 @@ void cMonster::HandleDaylightBurning(cChunk & a_Chunk)
 		GetWorld()->IsWeatherSunnyAt(POSX_TOINT, POSZ_TOINT)         // Not raining
 	)
 	{
-		// Burn for 100 ticks, then decide again
+		return true;
-		StartBurning(100);
 	}
+	return false;
 }
 
 
 
 
+
 cMonster::eFamily cMonster::GetMobFamily(void) const
 {
 	return FamilyFromType(m_MobType);

src/Mobs/Monster.h

@@ -10,11 +10,12 @@
 
 
 
-
-
 class cClientHandle;
 class cWorld;
 
+// Fwd: cPath
+enum class ePathFinderStatus;
+class cPath;
 
 
 
@@ -61,6 +62,7 @@ public:
 	virtual void OnRightClicked(cPlayer & a_Player) override;
 
 	virtual void MoveToPosition(const Vector3d & a_Position);  // tolua_export
+	virtual void StopMovingToPosition();
 	virtual bool ReachedDestination(void);
 
 	// tolua_begin
@@ -162,6 +164,11 @@ protected:
 
 	/** A pointer to the entity this mobile is aiming to reach */
 	cEntity * m_Target;
+	cPath *  m_Path;  // TODO unique ptr
+	ePathFinderStatus m_PathStatus;
+	bool m_IsFollowingPath;
+	/* If 0, will give up reaching the next m_Dest and will re-compute path. */
+	int m_GiveUpCounter;
 	/** Coordinates of the next position that should be reached */
 	Vector3d m_Destination;
 	/** Coordinates for the ultimate, final destination. */
@@ -201,11 +208,7 @@ protected:
 		This is based on the ultimate, final destination and the current position, as well as the traversed coordinates, and any environmental hazards */
 	void TickPathFinding(void);
 	/** Finishes a pathfinding task, be it due to failure or something else */
-	inline void FinishPathFinding(void)
+	void FinishPathFinding(void);
-	{
-		m_TraversedCoordinates.clear();
-		m_bMovingToDestination = false;
-	}
 	/** Sets the body yaw and head yaw/pitch based on next/ultimate destinations */
 	void SetPitchAndYawFromDestination(void);
 
@@ -239,10 +242,11 @@ protected:
 	float m_DropChanceLeggings;
 	float m_DropChanceBoots;
 	bool m_CanPickUpLoot;
+	int m_TicksSinceLastDamaged;  // How many ticks ago we were last damaged by a player?
 
 	void HandleDaylightBurning(cChunk & a_Chunk);
+	bool WouldBurnAt(Vector3d a_Location, cChunk & a_Chunk);
 	bool m_BurnsInDaylight;
-
 	double m_RelativeWalkSpeed;
 
 	/** Adds a random number of a_Item between a_Min and a_Max to itemdrops a_Drops*/

src/Mobs/Path.cpp

@@ -0,0 +1,379 @@
+#include "Globals.h"
+#ifndef COMPILING_PATHFIND_DEBUGGER
+	/* MCServer headers */
+	#include "../World.h"
+	#include "../Chunk.h"
+#endif
+
+#include <cmath>
+#include "Path.h"
+
+#define DISTANCE_MANHATTAN 0  // 1: More speed, a bit less accuracy 0: Max accuracy, less speed.
+#define HEURISTICS_ONLY 0  // 1: Much more speed, much less accurate.
+#define CALCULATIONS_PER_STEP 5  // Higher means more CPU load but faster path calculations.
+// The only version which guarantees the shortest path is 0, 0.
+
+enum class eCellStatus {OPENLIST,  CLOSEDLIST,  NOLIST};
+struct cPathCell
+{
+	Vector3d m_Location;   // Location of the cell in the world.
+	int m_F, m_G, m_H;  // F, G, H as defined in regular A*.
+	eCellStatus m_Status;  // Which list is the cell in? Either non, open, or closed.
+	cPathCell * m_Parent;  // Cell's parent, as defined in regular A*.
+	bool m_IsSolid;	   // Is the cell an air or a solid? Partial solids are currently considered solids.
+};
+
+
+
+
+
+bool compareHeuristics::operator()(cPathCell * & a_Cell1, cPathCell * & a_Cell2)
+{
+	return a_Cell1->m_F > a_Cell2->m_F;
+}
+
+
+
+
+
+/* cPath implementation */
+cPath::cPath(
+	cWorld * a_World,
+	const Vector3d & a_StartingPoint, const Vector3d & a_EndingPoint, int a_MaxSteps,
+	double a_BoundingBoxWidth, double a_BoundingBoxHeight,
+	int a_MaxUp, int a_MaxDown
+)
+{
+	// TODO: if src not walkable OR dest not walkable, then abort.
+	// Borrow a new "isWalkable" from ProcessIfWalkable, make ProcessIfWalkable also call isWalkable
+
+	m_World = a_World;
+	// m_World = cRoot::Get()->GetDefaultWorld();
+
+	m_Source = a_StartingPoint.Floor();
+	m_Destination = a_EndingPoint.Floor();
+
+	if (GetCell(m_Source)->m_IsSolid || GetCell(m_Destination)->m_IsSolid)
+	{
+		m_Status = ePathFinderStatus::PATH_NOT_FOUND;
+		return;
+	}
+
+	m_Status = ePathFinderStatus::CALCULATING;
+
+	m_StepsLeft = a_MaxSteps;
+	m_PointCount = 0;
+
+	ProcessCell(GetCell(a_StartingPoint), nullptr, 0);
+}
+
+
+
+
+
+cPath::~cPath()
+{
+	if (m_Status == ePathFinderStatus::CALCULATING)
+	{
+		FinishCalculation();
+	}
+}
+
+
+
+
+
+ePathFinderStatus cPath::Step()
+{
+	if (m_Status != ePathFinderStatus::CALCULATING)
+	{
+		return m_Status;
+	}
+
+	if (m_StepsLeft == 0)
+	{
+		FinishCalculation(ePathFinderStatus::PATH_NOT_FOUND);
+	}
+	else
+	{
+		--m_StepsLeft;
+		int i;
+		for (i = 0; i < CALCULATIONS_PER_STEP; ++i)
+		{
+			if (Step_Internal())  // Step_Internal returns true when no more calculation is needed.
+			{
+				break;  // if we're here, m_Status must have changed either to PATH_FOUND or PATH_NOT_FOUND.
+			}
+		}
+	}
+	return m_Status;
+}
+
+
+
+
+
+#ifndef COMPILING_PATHFIND_DEBUGGER
+bool cPath::IsSolid(const Vector3d & a_Location)
+{
+	int ChunkX, ChunkZ;
+	m_Item_CurrentBlock = a_Location;
+	cChunkDef::BlockToChunk(a_Location.x, a_Location.z, ChunkX, ChunkZ);
+	return !m_World->DoWithChunk(ChunkX, ChunkZ, * this);
+}
+#endif
+
+
+
+
+
+bool cPath::Step_Internal()
+{
+	cPathCell * CurrentCell = OpenListPop();
+
+	// Path not reachable, open list exauhsted.
+	if (CurrentCell == nullptr)
+	{
+		FinishCalculation(ePathFinderStatus::PATH_NOT_FOUND);
+		ASSERT(m_Status == ePathFinderStatus::PATH_NOT_FOUND);
+		return true;
+	}
+
+	// Path found.
+	if (CurrentCell->m_Location == m_Destination)
+	{
+		do
+		{
+			AddPoint(CurrentCell->m_Location + Vector3d(0.5, 0, 0.5));  // Populate the cPath with points.
+			CurrentCell = CurrentCell->m_Parent;
+		} while (CurrentCell != nullptr);
+
+		m_CurrentPoint = -1;
+		FinishCalculation(ePathFinderStatus::PATH_FOUND);
+		return true;
+	}
+
+	// Calculation not finished yet, process a currentCell by inspecting all neighbors.
+
+	// Check North, South, East, West on all 3 different heights.
+	int i;
+	for (i = -1; i <= 1; ++i)
+	{
+		ProcessIfWalkable(CurrentCell->m_Location + Vector3d(1, i, 0),  CurrentCell, 10);
+		ProcessIfWalkable(CurrentCell->m_Location + Vector3d(-1, i, 0), CurrentCell, 10);
+		ProcessIfWalkable(CurrentCell->m_Location + Vector3d(0, i, 1),  CurrentCell, 10);
+		ProcessIfWalkable(CurrentCell->m_Location + Vector3d(0, i, -1), CurrentCell, 10);
+	}
+
+	// Check diagonals on mob's height only.
+	int x, z;
+	for (x = -1; x <= 1; x += 2)
+	{
+		for (z = -1; z <= 1; z += 2)
+		{
+			// This condition prevents diagonal corner cutting.
+			if (!GetCell(CurrentCell->m_Location + Vector3d(x, 0, 0))->m_IsSolid && !GetCell(CurrentCell->m_Location + Vector3d(0, 0, z))->m_IsSolid)
+			{
+				// This prevents falling of "sharp turns" e.g. a 1x1x20 rectangle in the air which breaks in a right angle suddenly.
+				if (GetCell(CurrentCell->m_Location + Vector3d(x, -1, 0))->m_IsSolid && GetCell(CurrentCell->m_Location + Vector3d(0, -1, z))->m_IsSolid)
+				{
+					ProcessIfWalkable(CurrentCell->m_Location + Vector3d(x, 0, z), CurrentCell, 14);  // 14 is a good enough approximation of sqrt(10 + 10).
+				}
+			}
+		}
+	}
+
+
+	return false;
+}
+
+
+
+
+
+void cPath::FinishCalculation()
+{
+	for (auto && pair : m_Map)
+	{
+		delete pair.second;
+	}
+
+	m_Map.clear();
+	m_OpenList.empty();
+}
+
+
+
+
+
+void cPath::FinishCalculation(ePathFinderStatus a_NewStatus)
+{
+	m_Status = a_NewStatus;
+	FinishCalculation();
+}
+
+
+
+
+
+void cPath::OpenListAdd(cPathCell * a_Cell)
+{
+	a_Cell->m_Status = eCellStatus::OPENLIST;
+	m_OpenList.push(a_Cell);
+	#ifdef COMPILING_PATHFIND_DEBUGGER
+	si::setBlock(a_Cell->m_Location.x, a_Cell->m_Location.y, a_Cell->m_Location.z, debug_open, SetMini(a_Cell));
+	#endif
+}
+
+
+
+
+
+cPathCell * cPath::OpenListPop()  // Popping from the open list also means adding to the closed list.
+{
+	if (m_OpenList.size() == 0)
+	{
+		return nullptr;  // We've exhausted the search space and nothing was found, this will trigger a PATH_NOT_FOUND status.
+	}
+
+	cPathCell * Ret = m_OpenList.top();
+	m_OpenList.pop();
+	Ret->m_Status = eCellStatus::CLOSEDLIST;
+	#ifdef COMPILING_PATHFIND_DEBUGGER
+si::setBlock((Ret)->m_Location.x, (Ret)->m_Location.y, (Ret)->m_Location.z, debug_closed, SetMini(Ret));
+	#endif
+	return Ret;
+}
+
+
+
+
+
+void cPath::ProcessIfWalkable(const Vector3d & a_Location, cPathCell * a_Parent, int a_Cost)
+{
+	cPathCell * cell =  GetCell(a_Location);
+	if (!cell->m_IsSolid && GetCell(a_Location + Vector3d(0, -1, 0))->m_IsSolid && !GetCell(a_Location + Vector3d(0, 1, 0))->m_IsSolid)
+	{
+		ProcessCell(cell, a_Parent, a_Cost);
+	}
+}
+
+
+
+
+
+void cPath::ProcessCell(cPathCell * a_Cell, cPathCell * a_Caller, int a_GDelta)
+{
+	// Case 1: Cell is in the closed list, ignore it.
+	if (a_Cell->m_Status == eCellStatus::CLOSEDLIST)
+	{
+		return;
+	}
+	if (a_Cell->m_Status == eCellStatus::NOLIST)  // Case 2: The cell is not in any list.
+	{
+		// Cell is walkable, add it to the open list.
+		// Note that non-walkable cells are filtered out in Step_internal();
+		// Special case: Start cell goes here, gDelta is 0, caller is NULL.
+		a_Cell->m_Parent = a_Caller;
+		if (a_Caller != nullptr)
+		{
+			a_Cell->m_G = a_Caller->m_G + a_GDelta;
+		}
+		else
+		{
+			a_Cell->m_G = 0;
+		}
+
+		// Calculate H. This is A*'s Heuristics value.
+		#if DISTANCE_MANHATTAN == 1
+			// Manhattan distance. DeltaX + DeltaY + DeltaZ.
+			a_Cell->m_H = 10 * (abs(a_Cell->m_Location.x-m_Destination.x) + abs(a_Cell->m_Location.y-m_Destination.y) + abs(a_Cell->m_Location.z-m_Destination.z));
+		#else
+			// Euclidian distance. sqrt(DeltaX^2 + DeltaY^2 + DeltaZ^2), more precise.
+			a_Cell->m_H = std::sqrt((a_Cell->m_Location.x - m_Destination.x) * (a_Cell->m_Location.x - m_Destination.x) * 100 + (a_Cell->m_Location.y - m_Destination.y) * (a_Cell->m_Location.y - m_Destination.y) * 100 + (a_Cell->m_Location.z - m_Destination.z) * (a_Cell->m_Location.z - m_Destination.z) * 100);
+		#endif
+
+		#if HEURISTICS_ONLY == 1
+			a_Cell->m_F = a_Cell->m_H;  // Greedy search. https://en.wikipedia.org/wiki/Greedy_search
+		#else
+			a_Cell->m_F = a_Cell->m_H + a_Cell->m_G;  // Regular A*.
+		#endif
+
+		OpenListAdd(a_Cell);
+		return;
+	}
+
+	// Case 3: Cell is in the open list, check if G and H need an update.
+	int NewG = a_Caller->m_G + a_GDelta;
+	if (NewG < a_Cell->m_G)
+	{
+		a_Cell->m_G = NewG;
+		a_Cell->m_H = a_Cell->m_F + a_Cell->m_G;
+		a_Cell->m_Parent = a_Caller;
+	}
+
+}
+
+
+
+
+
+cPathCell * cPath::GetCell(const Vector3d & a_Location)
+{
+	// Create the cell in the hash table if it's not already there.
+	cPathCell * Cell;
+	if (m_Map.count(a_Location) == 0)  // Case 1: Cell is not on any list. We've never checked this cell before.
+	{
+		Cell = new cPathCell();
+		Cell->m_Location = a_Location;
+		m_Map[a_Location] = Cell;
+		Cell->m_IsSolid = IsSolid(a_Location);
+		Cell->m_Status = eCellStatus::NOLIST;
+		#ifdef COMPILING_PATHFIND_DEBUGGER
+			#ifdef COMPILING_PATHFIND_DEBUGGER_MARK_UNCHECKED
+				si::setBlock(a_Location.x, a_Location.y, a_Location.z, debug_unchecked, Cell->m_IsSolid ? NORMAL : MINI);
+			#endif
+		#endif
+		return Cell;
+	}
+	else
+	{
+		return m_Map[a_Location];
+	}
+}
+
+
+
+
+
+// Add the next point in the final path.
+void cPath::AddPoint(Vector3d a_Vector)
+{
+	m_PathPoints.push_back(a_Vector);
+	++m_PointCount;
+}
+
+
+
+
+
+#ifndef COMPILING_PATHFIND_DEBUGGER
+bool cPath::Item(cChunk * a_Chunk)  // returns FALSE if there's a solid or if we failed.
+{
+	int RelX = m_Item_CurrentBlock.x - a_Chunk->GetPosX() * cChunkDef::Width;
+	int RelZ = m_Item_CurrentBlock.z - a_Chunk->GetPosZ() * cChunkDef::Width;
+
+	if (!a_Chunk->IsValid())
+	{
+		return false;
+	}
+	BLOCKTYPE BlockType;
+	NIBBLETYPE BlockMeta;
+	a_Chunk->GetBlockTypeMeta(RelX, m_Item_CurrentBlock.y, RelZ, BlockType, BlockMeta);
+	return (!cBlockInfo::IsSolid(BlockType));
+
+	// TODO Maybe I should queue several blocks and call item() at once for all of them for better performance?
+	// I think Worktycho said each item() call needs 2 locks.
+
+}
+#endif

src/Mobs/Path.h

@@ -0,0 +1,161 @@
+#pragma once
+
+/* Wanna use the pathfinder? Put this in your header file:
+
+// Fwd: cPath
+enum class ePathFinderStatus;
+class cPath;
+
+Put this in your .cpp:
+#include "...Path.h"
+*/
+
+#ifdef COMPILING_PATHFIND_DEBUGGER
+	/* Note: the COMPILING_PATHFIND_DEBUGGER flag is used by Native/WiseOldMan95 to debug
+	this class outside of MCServer. This preprocessor flag is never set when compiling MCServer. */
+	#include "PathFinderIrrlicht_Head.h"
+#endif
+
+#include <unordered_map>
+
+/* MCServer forward declarations */
+#ifndef COMPILING_PATHFIND_DEBUGGER
+
+// fwd: cChunkMap.h
+typedef cItemCallback<cChunk> cChunkCallback;
+#endif
+
+/* Various little structs and classes */
+enum class ePathFinderStatus {CALCULATING,  PATH_FOUND,  PATH_NOT_FOUND};
+struct cPathCell;  // Defined inside Path.cpp
+class compareHeuristics
+{
+public:
+	bool operator()(cPathCell * & a_V1,  cPathCell * &  a_V2);
+};
+
+class cPath
+#ifndef COMPILING_PATHFIND_DEBUGGER
+: public cChunkCallback
+#endif
+{
+public:
+	/** Creates a pathfinder instance. A Mob will probably need a single pathfinder instance for its entire life.
+
+	Note that if you have a man-sized mob (1x1x2, zombies, etc), you are advised to call this function without parameters
+	because the declaration might change in later version of the pathFinder, and a parameter-less call always assumes a man-sized mob.
+
+	If your mob is not man-sized, you are advised to use cPath(width, height), this would be compatible with future versions,
+	but please be aware that as of now those parameters will be ignored and your mob will be assumed to be man sized.
+
+	@param a_BoundingBoxWidth the character's boundingbox width in blocks. Currently the parameter is ignored and 1 is assumed.
+	@param a_BoundingBoxHeight the character's boundingbox width in blocks. Currently the parameter is ignored and 2 is assumed.
+	@param a_MaxUp the character's max jump height in blocks. Currently the parameter is ignored and 1 is assumed.
+	@param a_MaxDown How far is the character willing to fall? Currently the parameter is ignored and 1 is assumed. */
+	/** Attempts to find a path starting from source to destination.
+	After calling this, you are expected to call Step() once per tick or once per several ticks until it returns true. You should then call getPath() to obtain the path.
+	Calling this before a path is found resets the current path and starts another search.
+	@param a_StartingPoint The function expects this position to be the lowest block the mob is in, a rule of thumb: "The block where the Zombie's knees are at".
+	@param a_EndingPoint "The block where the Zombie's knees want to be".
+	@param a_MaxSteps The maximum steps before giving up. */
+	cPath(
+		cWorld * a_World,
+		const Vector3d & a_StartingPoint, const Vector3d & a_EndingPoint, int a_MaxSteps,
+		double a_BoundingBoxWidth = 1, double a_BoundingBoxHeight = 2,
+		int a_MaxUp = 1, int a_MaxDown = 1
+	);
+
+	/** Destroys the path and frees its memory. */
+	~cPath();
+
+	/** Performs part of the path calculation and returns true if the path computation has finished. */
+	ePathFinderStatus Step();
+
+	/* Point retrieval functions, inlined for performance. */
+	/** Returns the next point in the path. */
+	inline Vector3d GetNextPoint()
+	{
+		ASSERT(m_Status == ePathFinderStatus::PATH_FOUND);
+		return m_PathPoints[m_PointCount - 1 - (++m_CurrentPoint)];
+	}
+	/** Checks whether this is the last point or not. Never call getnextPoint when this is true. */
+	inline bool IsLastPoint()
+	{
+		ASSERT(m_Status == ePathFinderStatus::PATH_FOUND);
+		ASSERT(m_CurrentPoint != -1);  // You must call getFirstPoint at least once before calling this.
+		return (m_CurrentPoint == m_PointCount - 1);
+	}
+	/** Get the point at a_index. Remark: Internally, the indexes are reversed. */
+	inline Vector3d GetPoint(int a_index)
+	{
+		ASSERT(m_Status == ePathFinderStatus::PATH_FOUND);
+		ASSERT(a_index < m_PointCount);
+		return m_PathPoints[m_PointCount - 1 - a_index];
+	}
+	/** Returns the total number of points this path has. */
+	inline int GetPointCount()
+	{
+		ASSERT(m_Status == ePathFinderStatus::PATH_FOUND);
+		return m_PointCount;
+	}
+
+	struct VectorHasher
+	{
+		std::size_t operator()(const Vector3d & a_Vector) const
+		{
+			// Guaranteed to have no hash collisions for any 128x128x128 area. Suitable for pathfinding.
+			int32_t t = 0;
+			t += (int8_t)a_Vector.x;
+			t = t << 8;
+			t += (int8_t)a_Vector.y;
+			t = t << 8;
+			t += (int8_t)a_Vector.z;
+			t = t << 8;
+			return (size_t)t;
+		}
+	};
+private:
+
+	/* General */
+	bool IsSolid(const Vector3d & a_Location);  // Query our hosting world and ask it if there's a solid at a_location.
+	bool Step_Internal();  // The public version just calls this version * CALCULATIONS_PER_CALL times.
+	void FinishCalculation();  // Clears the memory used for calculating the path.
+	void FinishCalculation(ePathFinderStatus a_NewStatus);  // Clears the memory used for calculating the path and changes the status.
+
+	/* Openlist and closedlist management */
+	void OpenListAdd(cPathCell * a_Cell);
+	cPathCell * OpenListPop();
+	void ProcessIfWalkable(const Vector3d &a_Location, cPathCell * a_Parent, int a_Cost);
+
+	/* Map management */
+	void ProcessCell(cPathCell * a_Cell,  cPathCell * a_Caller,  int a_GDelta);
+	cPathCell * GetCell(const Vector3d & a_location);
+
+	/* Pathfinding fields */
+	std::priority_queue<cPathCell *,  std::vector<cPathCell *>,  compareHeuristics> m_OpenList;
+	std::unordered_map<Vector3d,  cPathCell *, VectorHasher> m_Map;
+	Vector3d m_Destination;
+	Vector3d m_Source;
+	int m_StepsLeft;
+
+	/* Control fields */
+	ePathFinderStatus m_Status;
+
+	/* Final path fields */
+	int m_PointCount;
+	int m_CurrentPoint;
+	std::vector<Vector3d> m_PathPoints;
+	void AddPoint(Vector3d a_Vector);
+
+	/* Interfacing with MCServer's world */
+	cWorld * m_World;
+	#ifndef COMPILING_PATHFIND_DEBUGGER
+	Vector3d m_Item_CurrentBlock;  // Read by Item();, it's the only way to "pass it" parameters
+protected:
+	virtual bool Item(cChunk * a_Chunk) override;
+
+	/* Interfacing with Irrlicht, has nothing to do with MCServer*/
+	#else
+	#include "../path_irrlicht.cpp"
+	#endif
+};

src/Mobs/Pig.cpp

@@ -90,7 +90,6 @@ void cPig::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 		if (m_Attachee->IsPlayer() && (m_Attachee->GetEquippedWeapon().m_ItemType == E_ITEM_CARROT_ON_STICK))
 		{
 			MoveToPosition((m_Attachee->GetPosition()) + (m_Attachee->GetLookVector()*10));
-			m_bMovingToDestination = true;
 		}
 	}
 }

src/Mobs/Sheep.cpp

@@ -98,7 +98,7 @@ void cSheep::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 
 	if (m_TimeToStopEating > 0)
 	{
-		m_bMovingToDestination = false;  // The sheep should not move when he's eating
+		StopMovingToPosition();
 		m_TimeToStopEating--;
 
 		if (m_TimeToStopEating == 0)

src/Mobs/Skeleton.cpp

@@ -50,17 +50,18 @@ void cSkeleton::GetDrops(cItems & a_Drops, cEntity * a_Killer)
 
 void cSkeleton::MoveToPosition(const Vector3d & a_Position)
 {
-	// If the destination is sufficiently skylight challenged AND the skeleton isn't on fire then block the movement
+	// Todo use WouldBurnAt(), not sure how to obtain a chunk though...
+	super::MoveToPosition(a_Position);  // Look at the player and update m_Destination to hit them if they're close
+
+	// If the destination is sufficiently skylight challenged AND the skeleton isn't on fire AND we weren't attacked recently then block the movement
 	if (
 		!IsOnFire() &&
-		(m_World->GetBlockSkyLight((int)floor(a_Position.x), (int)floor(a_Position.y), (int)floor(a_Position.z)) - m_World->GetSkyDarkness() > 8)
+		(m_World->GetBlockSkyLight((int)floor(a_Position.x), (int)floor(a_Position.y), (int)floor(a_Position.z)) - m_World->GetSkyDarkness() > 8) &&
+			m_TicksSinceLastDamaged == 100
 		)
 	{
-		m_bMovingToDestination = false;
+		StopMovingToPosition();
-		return;
 	}
-
-	super::MoveToPosition(a_Position);
 }
 
 

src/Mobs/Wolf.cpp

@@ -203,7 +203,7 @@ void cWolf::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	}
 	else if (IsSitting())
 	{
-		m_bMovingToDestination = false;
+		StopMovingToPosition();
 	}
 }
 

src/Mobs/Zombie.cpp

@@ -44,17 +44,18 @@ void cZombie::GetDrops(cItems & a_Drops, cEntity * a_Killer)
 
 void cZombie::MoveToPosition(const Vector3d & a_Position)
 {
-	// If the destination is sufficiently skylight challenged AND the skeleton isn't on fire then block the movement
+	// Todo use WouldBurnAt(), not sure how to obtain a chunk though...
+	super::MoveToPosition(a_Position);  // Look at the player and update m_Destination to hit them if they're close
+
+	// If the destination is sufficiently skylight challenged AND the skeleton isn't on fire AND we weren't attacked recently then block the movement
 	if (
 		!IsOnFire() &&
-		(m_World->GetBlockSkyLight((int)floor(a_Position.x), (int)floor(a_Position.y), (int)floor(a_Position.z)) - m_World->GetSkyDarkness() > 8)
+		(m_World->GetBlockSkyLight((int)floor(a_Position.x), (int)floor(a_Position.y), (int)floor(a_Position.z)) - m_World->GetSkyDarkness() > 8) &&
+			m_TicksSinceLastDamaged == 100
 		)
 	{
-		m_bMovingToDestination = false;
+		StopMovingToPosition();
-		return;
 	}
-
-	super::MoveToPosition(a_Position);
 }
 
 

src/Vector3.h

@@ -354,6 +354,7 @@ protected:
 
 
 
+
 template <> inline Vector3<int> Vector3<int>::Floor(void) const
 {
 	return *this;