// ProjectileEntity.cpp
// Implements the cProjectileEntity class representing the common base class for projectiles, as well as individual projectile types
#include "Globals.h"
#include "../Bindings/PluginManager.h"
#include "ProjectileEntity.h"
#include "../BlockInfo.h"
#include "../ClientHandle.h"
#include "../LineBlockTracer.h"
#include "../BoundingBox.h"
#include "../ChunkMap.h"
#include "../Chunk.h"
#include "ArrowEntity.h"
#include "ThrownEggEntity.h"
#include "ThrownEnderPearlEntity.h"
#include "ExpBottleEntity.h"
#include "ThrownSnowballEntity.h"
#include "FireChargeEntity.h"
#include "FireworkEntity.h"
#include "GhastFireballEntity.h"
#include "WitherSkullEntity.h"
#include "SplashPotionEntity.h"
#include "Player.h"
/** Converts an angle in radians into a byte representation used by the network protocol */
#define ANGLE_TO_PROTO(X) static_cast<Byte>(X * 255 / 360)
////////////////////////////////////////////////////////////////////////////////
// cProjectileTracerCallback:
class cProjectileTracerCallback :
public cBlockTracer::cCallbacks
{
public:
cProjectileTracerCallback(cProjectileEntity * a_Projectile) :
m_Projectile(a_Projectile),
m_SlowdownCoeff(0.99) // Default slowdown when not in water
{
}
double GetSlowdownCoeff(void) const { return m_SlowdownCoeff; }
protected:
cProjectileEntity * m_Projectile;
double m_SlowdownCoeff;
// cCallbacks overrides:
virtual bool OnNextBlock(int a_BlockX, int a_BlockY, int a_BlockZ, BLOCKTYPE a_BlockType, NIBBLETYPE a_BlockMeta, eBlockFace a_EntryFace) override
{
/*
// DEBUG:
FLOGD("Hit block {0}:{1} at {2} face {3}, {4} ({5})",
a_BlockType, a_BlockMeta,
Vector3i{a_BlockX, a_BlockY, a_BlockZ}, a_EntryFace,
cBlockInfo::IsSolid(a_BlockType) ? "solid" : "non-solid",
ItemToString(cItem(a_BlockType, 1, a_BlockMeta))
);
*/
if (cBlockInfo::IsSolid(a_BlockType))
{
// The projectile hit a solid block, calculate the exact hit coords:
cBoundingBox bb(a_BlockX, a_BlockX + 1, a_BlockY, a_BlockY + 1, a_BlockZ, a_BlockZ + 1); // Bounding box of the block hit
const Vector3d LineStart = m_Projectile->GetPosition(); // Start point for the imaginary line that goes through the block hit
const Vector3d LineEnd = LineStart + m_Projectile->GetSpeed(); // End point for the imaginary line that goes through the block hit
double LineCoeff = 0; // Used to calculate where along the line an intersection with the bounding box occurs
eBlockFace Face; // Face hit
if (bb.CalcLineIntersection(LineStart, LineEnd, LineCoeff, Face))
{
Vector3d Intersection = LineStart + m_Projectile->GetSpeed() * LineCoeff; // Point where projectile goes into the hit block
if (cPluginManager::Get()->CallHookProjectileHitBlock(*m_Projectile, a_BlockX, a_BlockY, a_BlockZ, Face, Intersection))
{
return false;
}
m_Projectile->OnHitSolidBlock(Intersection, Face);
return true;
}
else
{
LOGD("WEIRD! block tracer reports a hit, but BBox tracer doesn't. Ignoring the hit.");
}
}
// Convey some special effects from special blocks:
switch (a_BlockType)
{
case E_BLOCK_LAVA:
case E_BLOCK_STATIONARY_LAVA:
{
m_Projectile->StartBurning(30);
m_SlowdownCoeff = std::min(m_SlowdownCoeff, 0.9); // Slow down to 0.9* the speed each tick when moving through lava
break;
}
case E_BLOCK_WATER:
case E_BLOCK_STATIONARY_WATER:
{
m_Projectile->StopBurning();
m_SlowdownCoeff = std::min(m_SlowdownCoeff, 0.8); // Slow down to 0.8* the speed each tick when moving through water
break;
}
} // switch (a_BlockType)
// Continue tracing
return false;
}
} ;
////////////////////////////////////////////////////////////////////////////////
// cProjectileEntityCollisionCallback:
class cProjectileEntityCollisionCallback
{
public:
cProjectileEntityCollisionCallback(cProjectileEntity * a_Projectile, const Vector3d & a_Pos, const Vector3d & a_NextPos) :
m_Projectile(a_Projectile),
m_Pos(a_Pos),
m_NextPos(a_NextPos),
m_MinCoeff(1),
m_HitEntity(nullptr)
{
}
bool operator () (cEntity & a_Entity)
{
if (
(&a_Entity == m_Projectile) || // Do not check collisions with self
(a_Entity.GetUniqueID() == m_Projectile->GetCreatorUniqueID()) // Do not check whoever shot the projectile
)
{
// Don't check creator only for the first 5 ticks so that projectiles can collide with the creator
if (m_Projectile->GetTicksAlive() <= 5)
{
return false;
}
}
cBoundingBox EntBox(a_Entity.GetPosition(), a_Entity.GetWidth() / 2, a_Entity.GetHeight());
// Instead of colliding the bounding box with another bounding box in motion, we collide an enlarged bounding box with a hairline.
// The results should be good enough for our purposes
double LineCoeff;
eBlockFace Face;
EntBox.Expand(m_Projectile->GetWidth() / 2, m_Projectile->GetHeight() / 2, m_Projectile->GetWidth() / 2);
if (!EntBox.CalcLineIntersection(m_Pos, m_NextPos, LineCoeff, Face))
{
// No intersection whatsoever
return false;
}
if (
!a_Entity.IsMob() &&
!a_Entity.IsMinecart() &&
(
!a_Entity.IsPlayer() ||
static_cast<cPlayer &>(a_Entity).IsGameModeSpectator()
) &&
!a_Entity.IsBoat()
)
{
// Not an entity that interacts with a projectile
return false;
}
if (cPluginManager::Get()->CallHookProjectileHitEntity(*m_Projectile, a_Entity))
{
// A plugin disagreed.
return false;
}
if (LineCoeff < m_MinCoeff)
{
// The entity is closer than anything we've stored so far, replace it as the potential victim
m_MinCoeff = LineCoeff;
m_HitEntity = &a_Entity;
}
// Don't break the enumeration, we want all the entities
return false;
}
/** Returns the nearest entity that was hit, after the enumeration has been completed */
cEntity * GetHitEntity(void) const { return m_HitEntity; }
/** Returns the line coeff where the hit was encountered, after the enumeration has been completed */
double GetMinCoeff(void) const { return m_MinCoeff; }
/** Returns true if the callback has encountered a true hit */
bool HasHit(void) const { return (m_MinCoeff < 1); }
protected:
cProjectileEntity * m_Projectile;
const Vector3d & m_Pos;
const Vector3d & m_NextPos;
double m_MinCoeff; // The coefficient of the nearest hit on the Pos line
// Although it's bad(tm) to store entity ptrs from a callback, we can afford it here, because the entire callback
// is processed inside the tick thread, so the entities won't be removed in between the calls and the final processing
cEntity * m_HitEntity; // The nearest hit entity
} ;
////////////////////////////////////////////////////////////////////////////////
// cProjectileEntity:
cProjectileEntity::cProjectileEntity(eKind a_Kind, cEntity * a_Creator, Vector3d a_Pos, double a_Width, double a_Height):
Super(etProjectile, a_Pos, a_Width, a_Height),
m_ProjectileKind(a_Kind),
m_CreatorData(
((a_Creator != nullptr) ? a_Creator->GetUniqueID() : cEntity::INVALID_ID),
((a_Creator != nullptr) ? (a_Creator->IsPlayer() ? static_cast<cPlayer *>(a_Creator)->GetName() : "") : ""),
((a_Creator != nullptr) ? a_Creator->GetEquippedWeapon().m_Enchantments : cEnchantments())
),
m_IsInGround(false)
{
SetGravity(-12.0f);
SetAirDrag(0.01f);
}
cProjectileEntity::cProjectileEntity(eKind a_Kind, cEntity * a_Creator, Vector3d a_Pos, Vector3d a_Speed, double a_Width, double a_Height):
cProjectileEntity(a_Kind, a_Creator, a_Pos, a_Width, a_Height)
{
SetSpeed(a_Speed);
SetYawFromSpeed();
SetPitchFromSpeed();
}
std::unique_ptr<cProjectileEntity> cProjectileEntity::Create(
eKind a_Kind,
cEntity * a_Creator,
Vector3d a_Pos,
const cItem * a_Item,
const Vector3d * a_Speed
)
{
Vector3d Speed;
if (a_Speed != nullptr)
{
Speed = *a_Speed;
}
switch (a_Kind)
{
case pkArrow: return cpp14::make_unique<cArrowEntity> (a_Creator, a_Pos, Speed);
case pkEgg: return cpp14::make_unique<cThrownEggEntity> (a_Creator, a_Pos, Speed);
case pkEnderPearl: return cpp14::make_unique<cThrownEnderPearlEntity>(a_Creator, a_Pos, Speed);
case pkSnowball: return cpp14::make_unique<cThrownSnowballEntity> (a_Creator, a_Pos, Speed);
case pkGhastFireball: return cpp14::make_unique<cGhastFireballEntity> (a_Creator, a_Pos, Speed);
case pkFireCharge: return cpp14::make_unique<cFireChargeEntity> (a_Creator, a_Pos, Speed);
case pkExpBottle: return cpp14::make_unique<cExpBottleEntity> (a_Creator, a_Pos, Speed);
case pkSplashPotion: return cpp14::make_unique<cSplashPotionEntity> (a_Creator, a_Pos, Speed, *a_Item);
case pkWitherSkull: return cpp14::make_unique<cWitherSkullEntity> (a_Creator, a_Pos, Speed);
case pkFirework:
{
ASSERT(a_Item != nullptr);
if (a_Item->m_FireworkItem.m_Colours.empty())
{
return nullptr;
}
return cpp14::make_unique<cFireworkEntity>(a_Creator, a_Pos, *a_Item);
}
case pkFishingFloat: break;
}
LOGWARNING("%s: Unknown projectile kind: %d", __FUNCTION__, a_Kind);
return nullptr;
}
void cProjectileEntity::OnHitSolidBlock(Vector3d a_HitPos, eBlockFace a_HitFace)
{
// Set the position based on what face was hit:
SetPosition(a_HitPos);
SetSpeed(0, 0, 0);
// DEBUG:
FLOGD("Projectile {0}: pos {1:.02f}, hit solid block at face {2}",
m_UniqueID, a_HitPos, a_HitFace
);
m_IsInGround = true;
}
void cProjectileEntity::OnHitEntity(cEntity & a_EntityHit, Vector3d a_HitPos)
{
UNUSED(a_HitPos);
// If we were created by a player and we hit a pawn, notify attacking player's wolves
if (a_EntityHit.IsPawn() && (GetCreatorName() != ""))
{
auto EntityHit = static_cast<cPawn *>(&a_EntityHit);
m_World->DoWithEntityByID(GetCreatorUniqueID(), [=](cEntity & a_Hitter)
{
static_cast<cPlayer&>(a_Hitter).NotifyNearbyWolves(EntityHit, true);
return true;
}
);
}
}
AString cProjectileEntity::GetMCAClassName(void) const
{
switch (m_ProjectileKind)
{
case pkArrow: return "Arrow";
case pkSnowball: return "Snowball";
case pkEgg: return "Egg";
case pkGhastFireball: return "Fireball";
case pkFireCharge: return "SmallFireball";
case pkEnderPearl: return "ThrownEnderpearl";
case pkExpBottle: return "ThrownExpBottle";
case pkSplashPotion: return "SplashPotion";
case pkWitherSkull: return "WitherSkull";
case pkFirework: return "Firework";
case pkFishingFloat: return ""; // Unknown, perhaps MC doesn't save this?
}
UNREACHABLE("Unsupported projectile kind");
}
void cProjectileEntity::Tick(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
{
Super::Tick(a_Dt, a_Chunk);
if (!IsTicking())
{
// The base class tick destroyed us
return;
}
BroadcastMovementUpdate();
}
void cProjectileEntity::HandlePhysics(std::chrono::milliseconds a_Dt, cChunk & a_Chunk)
{
if (m_IsInGround)
{
// Already-grounded projectiles don't move at all
return;
}
auto DtSec = std::chrono::duration_cast<std::chrono::duration<double>>(a_Dt);
const Vector3d DeltaSpeed = GetSpeed() * DtSec.count();
const Vector3d Pos = GetPosition();
const Vector3d NextPos = Pos + DeltaSpeed;
// Test for entity collisions:
cProjectileEntityCollisionCallback EntityCollisionCallback(this, Pos, NextPos);
a_Chunk.ForEachEntity(EntityCollisionCallback);
if (EntityCollisionCallback.HasHit())
{
// An entity was hit:
Vector3d HitPos = Pos + (NextPos - Pos) * EntityCollisionCallback.GetMinCoeff();
// DEBUG:
FLOGD("Projectile {0} has hit an entity {1} ({2}) at {3:.02f} (coeff {4:.03f})",
m_UniqueID,
EntityCollisionCallback.GetHitEntity()->GetUniqueID(),
EntityCollisionCallback.GetHitEntity()->GetClass(),
HitPos,
EntityCollisionCallback.GetMinCoeff()
);
OnHitEntity(*(EntityCollisionCallback.GetHitEntity()), HitPos);
if (!IsTicking())
{
return; // We were destroyed by an override of OnHitEntity
}
}
// TODO: Test the entities in the neighboring chunks, too
// Trace the tick's worth of movement as a line:
cProjectileTracerCallback TracerCallback(this);
if (!cLineBlockTracer::Trace(*m_World, TracerCallback, Pos, NextPos))
{
// Something has been hit, abort all other processing
return;
}
// The tracer also checks the blocks for slowdown blocks - water and lava - and stores it for later in its SlowdownCoeff
// Update the position:
SetPosition(NextPos);
// Add slowdown and gravity effect to the speed:
Vector3d NewSpeed(GetSpeed());
NewSpeed.y += m_Gravity * DtSec.count();
NewSpeed -= NewSpeed * (m_AirDrag * 20.0f) * DtSec.count();
SetSpeed(NewSpeed);
SetYawFromSpeed();
SetPitchFromSpeed();
/*
FLOGD("Projectile {0}: pos {1:.02f}, speed {2:.02f}, rot {{{3:.02f}, {4:.02f}}}",
m_UniqueID, GetPos(), GetSpeed(), GetYaw(), GetPitch()
);
*/
}
void cProjectileEntity::SpawnOn(cClientHandle & a_Client)
{
// Default spawning - use the projectile kind to spawn an object:
a_Client.SendSpawnObject(*this, m_ProjectileKind, 12, ANGLE_TO_PROTO(GetYaw()), ANGLE_TO_PROTO(GetPitch()));
a_Client.SendEntityMetadata(*this);
}
void cProjectileEntity::CollectedBy(cPlayer & a_Dest)
{
// Overriden in arrow
UNUSED(a_Dest);
}
