summaryrefslogtreecommitdiffstats
path: root/src/Entities/ProjectileEntity.cpp
blob: 334973833fa4d24879abe97bab5ff551a2bb46e7 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423

// 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 "../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 "Player.h"





/// Converts an angle in radians into a byte representation used by the network protocol
#define ANGLE_TO_PROTO(X) (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, char a_EntryFace) override
	{
		/*
		// DEBUG:
		LOGD("Hit block %d:%d at {%d, %d, %d} face %d, %s (%s)",
			a_BlockType, a_BlockMeta,
			a_BlockX, a_BlockY, a_BlockZ, a_EntryFace,
			cBlockInfo::IsSolid(a_BlockType) ? "solid" : "non-solid",
			ItemToString(cItem(a_BlockType, 1, a_BlockMeta)).c_str()
		);
		*/
		
		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 cEntityCallback
{
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(NULL)
	{
	}
	
	
	virtual bool Item(cEntity * a_Entity) override
	{
		if (
			(a_Entity == m_Projectile) ||          // Do not check collisions with self
			(a_Entity->GetUniqueID() == m_Projectile->GetCreatorUniqueID())  // Do not check whoever shot the projectile
		)
		{
			// TODO: Don't check creator only for the first 5 ticks
			// so that arrows stuck in ground and dug up can hurt the player
			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() && !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, double a_X, double a_Y, double a_Z, double a_Width, double a_Height) :
	super(etProjectile, a_X, a_Y, a_Z, a_Width, a_Height),
	m_ProjectileKind(a_Kind),
	m_CreatorData(
		((a_Creator != NULL) ? a_Creator->GetUniqueID() : -1),
		((a_Creator != NULL) ? (a_Creator->IsPlayer() ? ((cPlayer *)a_Creator)->GetName() : "") : "")
	),
	m_IsInGround(false)
{
}





cProjectileEntity::cProjectileEntity(eKind a_Kind, cEntity * a_Creator, const Vector3d & a_Pos, const Vector3d & a_Speed, double a_Width, double a_Height) :
	super(etProjectile, a_Pos.x, a_Pos.y, a_Pos.z, a_Width, a_Height),
	m_ProjectileKind(a_Kind),
	m_CreatorData(a_Creator->GetUniqueID(), a_Creator->IsPlayer() ? ((cPlayer *)a_Creator)->GetName() : ""),
	m_IsInGround(false)
{
	SetSpeed(a_Speed);
	SetYawFromSpeed();
	SetPitchFromSpeed();
}





cProjectileEntity * cProjectileEntity::Create(eKind a_Kind, cEntity * a_Creator, double a_X, double a_Y, double a_Z, const cItem & a_Item, const Vector3d * a_Speed)
{
	Vector3d Speed;
	if (a_Speed != NULL)
	{
		Speed = *a_Speed;
	}

	switch (a_Kind)
	{
		case pkArrow:         return new cArrowEntity           (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkEgg:           return new cThrownEggEntity       (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkEnderPearl:    return new cThrownEnderPearlEntity(a_Creator, a_X, a_Y, a_Z, Speed);
		case pkSnowball:      return new cThrownSnowballEntity  (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkGhastFireball: return new cGhastFireballEntity   (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkFireCharge:    return new cFireChargeEntity      (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkExpBottle:     return new cExpBottleEntity       (a_Creator, a_X, a_Y, a_Z, Speed);
		case pkFirework:
		{
			if (a_Item.m_FireworkItem.m_Colours.empty())
			{
				return NULL;
			}

			return new cFireworkEntity(a_Creator, a_X, a_Y, a_Z, a_Item);
		}
	}
	
	LOGWARNING("%s: Unknown projectile kind: %d", __FUNCTION__, a_Kind);
	return NULL;
}





void cProjectileEntity::OnHitSolidBlock(const Vector3d & a_HitPos, eBlockFace a_HitFace)
{
	// Set the position based on what face was hit:
	SetPosition(a_HitPos);
	SetSpeed(0, 0, 0);

	// DEBUG:
	LOGD("Projectile %d: pos {%.02f, %.02f, %.02f}, hit solid block at face %d",
		m_UniqueID,
		a_HitPos.x, a_HitPos.y, a_HitPos.z,
		a_HitFace
	);

	m_IsInGround = 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 "ThrownPotion";
		case pkWitherSkull:   return "WitherSkull";
		case pkFirework:      return "Firework";
		case pkFishingFloat:  return "";  // Unknown, perhaps MC doesn't save this?
	}
	ASSERT(!"Unhandled projectile entity kind!");
	return "";
}





void cProjectileEntity::Tick(float a_Dt, cChunk & a_Chunk)
{
	super::Tick(a_Dt, a_Chunk);
	
	// TODO: see BroadcastMovementUpdate; RelativeMove packet jerkiness affects projectiles too (cause of sympton described in cArrowEntity::Tick())
	if (GetProjectileKind() != pkArrow)
	{
		BroadcastMovementUpdate();
	}
}





void cProjectileEntity::HandlePhysics(float a_Dt, cChunk & a_Chunk)
{
	if (m_IsInGround)
	{
		// Already-grounded projectiles don't move at all
		return;
	}
	
	const Vector3d PerTickSpeed = GetSpeed() / 20;
	const Vector3d Pos = GetPosition();
	const Vector3d NextPos = Pos + PerTickSpeed;

	// 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:
		LOGD("Projectile %d has hit an entity %d (%s) at {%.02f, %.02f, %.02f} (coeff %.03f)",
			m_UniqueID,
			EntityCollisionCallback.GetHitEntity()->GetUniqueID(),
			EntityCollisionCallback.GetHitEntity()->GetClass(),
			HitPos.x, HitPos.y, HitPos.z,
			EntityCollisionCallback.GetMinCoeff()
		);

		OnHitEntity(*(EntityCollisionCallback.GetHitEntity()), HitPos);
	}
	// 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 / 20;
	NewSpeed *= TracerCallback.GetSlowdownCoeff();
	SetSpeed(NewSpeed);
	SetYawFromSpeed();
	SetPitchFromSpeed();

	/*
	LOGD("Projectile %d: pos {%.02f, %.02f, %.02f}, speed {%.02f, %.02f, %.02f}, rot {%.02f, %.02f}",
		m_UniqueID,
		GetPosX(), GetPosY(), GetPosZ(),
		GetSpeedX(), GetSpeedY(), GetSpeedZ(),
		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);
}