Fully implemented leashes (#3798)

src/Mobs/Monster.cpp

@@ -11,11 +11,19 @@
 #include "../Entities/Player.h"
 #include "../Entities/ExpOrb.h"
 #include "../MonsterConfig.h"
+#include "BoundingBox.h"
 
 #include "../Chunk.h"
 #include "../FastRandom.h"
 
 #include "PathFinder.h"
+#include "../Entities/LeashKnot.h"
+
+
+
+
+// Ticks to wait to do leash calculations
+#define LEASH_ACTIONS_TICK_STEP 10
 
 
 
@@ -103,6 +111,10 @@ cMonster::cMonster(const AString & a_ConfigName, eMonsterType a_MobType, const A
 	, m_Age(1)
 	, m_AgingTimer(20 * 60 * 20)  // about 20 minutes
 	, m_WasLastTargetAPlayer(false)
+	, m_LeashedTo(nullptr)
+	, m_LeashToPos(nullptr)
+	, m_IsLeashActionJustDone(false)
+	, m_CanBeLeashed(GetMobFamily() == eFamily::mfPassive)
 	, m_Target(nullptr)
 {
 	if (!a_ConfigName.empty())
@@ -124,6 +136,27 @@ cMonster::~cMonster()
 
 
 
+void cMonster::Destroy(bool a_ShouldBroadcast)
+{
+	if (IsLeashed())
+	{
+		cEntity * LeashedTo = GetLeashedTo();
+		Unleash(false, a_ShouldBroadcast);
+
+		// Remove leash knot if there are no more mobs leashed to
+		if (!LeashedTo->HasAnyMobLeashed() && LeashedTo->IsLeashKnot())
+		{
+			LeashedTo->Destroy();
+		}
+	}
+
+	super::Destroy(a_ShouldBroadcast);
+}
+
+
+
+
+
 void cMonster::Destroyed()
 {
 	SetTarget(nullptr);  // Tell them we're no longer targeting them.
@@ -137,6 +170,11 @@ void cMonster::Destroyed()
 void cMonster::SpawnOn(cClientHandle & a_Client)
 {
 	a_Client.SendSpawnMob(*this);
+
+	if (IsLeashed())
+	{
+		a_Client.SendLeashEntity(*this, *this->GetLeashedTo());
+	}
 }
 
 
@@ -201,6 +239,16 @@ void cMonster::MoveToWayPoint(cChunk & a_Chunk)
 		AddSpeedX(Distance.x);
 		AddSpeedZ(Distance.z);
 	}
+
+	// Speed up leashed mobs getting far from player
+	if (IsLeashed() && GetLeashedTo()->IsPlayer())
+	{
+		Distance = GetLeashedTo()->GetPosition() - GetPosition();
+		Distance.Normalize();
+		AddSpeedX(Distance.x);
+		AddSpeedZ(Distance.z);
+	}
+
 }
 
 
@@ -283,7 +331,7 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 	bool a_IsFollowingPath = false;
 	if (m_PathfinderActivated)
 	{
-		if (ReachedFinalDestination())
+		if (ReachedFinalDestination() || (m_LeashToPos != nullptr))
 		{
 			StopMovingToPosition();  // Simply sets m_PathfinderActivated to false.
 		}
@@ -351,6 +399,12 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 		case ATTACKING: break;
 	}  // switch (m_EMState)
 
+	// Leash calculations
+	if ((m_TicksAlive % LEASH_ACTIONS_TICK_STEP) == 0)
+	{
+		CalcLeashActions();
+	}
+
 	BroadcastMovementUpdate();
 
 	if (m_AgingTimer > 0)
@@ -368,6 +422,39 @@ void cMonster::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
 
 
 
+void cMonster::CalcLeashActions()
+{
+	// This mob just spotted in the world and [m_LeashToPos not null] shows that should be leashed to a leash knot at m_LeashToPos.
+	// This keeps trying until knot is found. Leash knot may be in a different chunk that needn't or can't be loaded yet.
+	if (!IsLeashed() && (m_LeashToPos != nullptr))
+	{
+		auto LeashKnot = cLeashKnot::FindKnotAtPos(*m_World, { FloorC(m_LeashToPos->x), FloorC(m_LeashToPos->y), FloorC(m_LeashToPos->z) });
+		if (LeashKnot != nullptr)
+		{
+			LeashTo(LeashKnot);
+			SetLeashToPos(nullptr);
+		}
+	}
+	else if (IsLeashed())  // Mob is already leashed to an entity: follow it.
+	{
+		// TODO: leashed mobs in vanilla can move around up to 5 blocks distance from leash origin
+		MoveToPosition(m_LeashedTo->GetPosition());
+
+		// If distance to target > 10 break leash
+		Vector3f a_Distance(m_LeashedTo->GetPosition() - GetPosition());
+		double Distance(a_Distance.Length());
+		if (Distance > 10.0)
+		{
+			LOGD("Leash broken (distance)");
+			Unleash(false);
+		}
+	}
+}
+
+
+
+
+
 void cMonster::SetPitchAndYawFromDestination(bool a_IsFollowingPath)
 {
 	Vector3d BodyDistance;
@@ -583,6 +670,26 @@ void cMonster::OnRightClicked(cPlayer & a_Player)
 			a_Player.GetInventory().RemoveOneEquippedItem();
 		}
 	}
+
+	// Using leashes
+	m_IsLeashActionJustDone = false;
+	if (IsLeashed() && (GetLeashedTo() == &a_Player))  // a player can only unleash a mob leashed to him
+	{
+		Unleash(!a_Player.IsGameModeCreative());
+	}
+	else if (IsLeashed())
+	{
+		// Mob is already leashed but client anticipates the server action and draws a leash link, so we need to send current leash to cancel it
+		m_World->BroadcastLeashEntity(*this, *this->GetLeashedTo());
+	}
+	else if (CanBeLeashed() && (EquippedItem.m_ItemType == E_ITEM_LEASH))
+	{
+		if (!a_Player.IsGameModeCreative())
+		{
+			a_Player.GetInventory().RemoveOneEquippedItem();
+		}
+		LeashTo(&a_Player);
+	}
 }
 
 
@@ -1295,3 +1402,67 @@ cMonster::eFamily cMonster::GetMobFamily(void) const
 {
 	return FamilyFromType(m_MobType);
 }
+
+
+
+
+
+void cMonster::LeashTo(cEntity * a_Entity, bool a_ShouldBroadcast)
+{
+	// Do nothing if already leashed
+	if (m_LeashedTo != nullptr)
+	{
+		return;
+	}
+
+	m_LeashedTo = a_Entity;
+
+	a_Entity->AddLeashedMob(this);
+
+	if (a_ShouldBroadcast)
+	{
+		m_World->BroadcastLeashEntity(*this, *a_Entity);
+	}
+
+	m_IsLeashActionJustDone = true;
+}
+
+
+
+
+
+void cMonster::Unleash(bool a_ShouldDropLeashPickup, bool a_ShouldBroadcast)
+{
+	// Do nothing if not leashed
+	if (m_LeashedTo == nullptr)
+	{
+		return;
+	}
+
+	m_LeashedTo->RemoveLeashedMob(this);
+
+	m_LeashedTo = nullptr;
+
+	if (a_ShouldDropLeashPickup)
+	{
+		cItems Pickups;
+		Pickups.Add(cItem(E_ITEM_LEASH, 1, 0));
+		GetWorld()->SpawnItemPickups(Pickups, GetPosX() + 0.5, GetPosY() + 0.5, GetPosZ() + 0.5);
+	}
+
+	if (a_ShouldBroadcast)
+	{
+		m_World->BroadcastUnleashEntity(*this);
+	}
+
+	m_IsLeashActionJustDone = true;
+}
+
+
+
+
+
+void cMonster::Unleash(bool a_ShouldDropLeashPickup)
+{
+	Unleash(a_ShouldDropLeashPickup, true);
+}