예제 #1
0
bool P_Thing_Projectile (int tid, AActor *source, int type, const char *type_name, DAngle angle,
	double speed, double vspeed, int dest, AActor *forcedest, int gravity, int newtid,
	bool leadTarget)
{
	int rtn = 0;
	PClassActor *kind;
	AActor *spot, *mobj, *targ = forcedest;
	FActorIterator iterator (tid);
	int defflags3;

	if (type_name == NULL)
	{
		kind = P_GetSpawnableType(type);
	}
	else
	{
		kind = PClass::FindActor(type_name);
	}
	if (kind == NULL)
	{
		return false;
	}

	// Handle decorate replacements.
	kind = kind->GetReplacement();

	defflags3 = GetDefaultByType(kind)->flags3;
	if ((defflags3 & MF3_ISMONSTER) && 
		((dmflags & DF_NO_MONSTERS) || (level.flags2 & LEVEL2_NOMONSTERS)))
		return false;

	if (tid == 0)
	{
		spot = source;
	}
	else
	{
		spot = iterator.Next();
	}
	while (spot != NULL)
	{
		FActorIterator tit (dest);

		if (dest == 0 || (targ = tit.Next()))
		{
			do
			{
				double z = spot->Z();
				if (defflags3 & MF3_FLOORHUGGER)
				{
					z = ONFLOORZ;
				}
				else if (defflags3 & MF3_CEILINGHUGGER)
				{
					z = ONCEILINGZ;
				}
				else if (z != ONFLOORZ)
				{
					z -= spot->Floorclip;
				}
				mobj = Spawn (kind, spot->PosAtZ(z), ALLOW_REPLACE);

				if (mobj)
				{
					mobj->tid = newtid;
					mobj->AddToHash ();
					P_PlaySpawnSound(mobj, spot);
					if (gravity)
					{
						mobj->flags &= ~MF_NOGRAVITY;
						if (!(mobj->flags3 & MF3_ISMONSTER) && gravity == 1)
						{
							mobj->Gravity = 1./8;
						}
					}
					else
					{
						mobj->flags |= MF_NOGRAVITY;
					}
					mobj->target = spot;

					if (targ != NULL)
					{
						DVector3 aim = mobj->Vec3To(targ);
						aim.Z += targ->Height / 2;

						if (leadTarget && speed > 0 && !targ->Vel.isZero())
						{
							// Aiming at the target's position some time in the future
							// is basically just an application of the law of sines:
							//     a/sin(A) = b/sin(B)
							// Thanks to all those on the notgod phorum for helping me
							// with the math. I don't think I would have thought of using
							// trig alone had I been left to solve it by myself.

							DVector3 tvel = targ->Vel;
							if (!(targ->flags & MF_NOGRAVITY) && targ->waterlevel < 3)
							{ // If the target is subject to gravity and not underwater,
							  // assume that it isn't moving vertically. Thanks to gravity,
							  // even if we did consider the vertical component of the target's
							  // velocity, we would still miss more often than not.
								tvel.Z = 0.0;
								if (targ->Vel.X == 0 && targ->Vel.Y == 0)
								{
									goto nolead;
								}
							}
							double dist = aim.Length();
							double targspeed = tvel.Length();
							double ydotx = -aim | tvel;
							double a = g_acos (clamp (ydotx / targspeed / dist, -1.0, 1.0));
							double multiplier = double(pr_leadtarget.Random2())*0.1/255+1.1;
							double sinb = -clamp (targspeed*multiplier * g_sin(a) / speed, -1.0, 1.0);

							// Use the cross product of two of the triangle's sides to get a
							// rotation vector.
							DVector3 rv(tvel ^ aim);
							// The vector must be normalized.
							rv.MakeUnit();
							// Now combine the rotation vector with angle b to get a rotation matrix.
							DMatrix3x3 rm(rv, g_cos(g_asin(sinb)), sinb);
							// And multiply the original aim vector with the matrix to get a
							// new aim vector that leads the target.
							DVector3 aimvec = rm * aim;
							// And make the projectile follow that vector at the desired speed.
							mobj->Vel = aimvec * (speed / dist);
							mobj->AngleFromVel();
						}
						else
						{
nolead:
							mobj->Angles.Yaw = mobj->AngleTo(targ);
							mobj->Vel = aim.Resized (speed);
						}
						if (mobj->flags2 & MF2_SEEKERMISSILE)
						{
							mobj->tracer = targ;
						}
					}
					else
					{
						mobj->Angles.Yaw = angle;
						mobj->VelFromAngle(speed);
						mobj->Vel.Z = vspeed;
					}
					// Set the missile's speed to reflect the speed it was spawned at.
					if (mobj->flags & MF_MISSILE)
					{
						mobj->Speed = mobj->VelToSpeed();
					}
					// Hugger missiles don't have any vertical velocity
					if (mobj->flags3 & (MF3_FLOORHUGGER|MF3_CEILINGHUGGER))
					{
						mobj->Vel.Z = 0;
					}
					if (mobj->flags & MF_SPECIAL)
					{
						mobj->flags |= MF_DROPPED;
					}
					if (mobj->flags & MF_MISSILE)
					{
						if (P_CheckMissileSpawn (mobj, spot->radius))
						{
							rtn = true;
						}
					}
					else if (!P_TestMobjLocation (mobj))
					{
						// If this is a monster, subtract it from the total monster
						// count, because it already added to it during spawning.
						mobj->ClearCounters();
						mobj->Destroy ();
					}
					else
					{
						// It spawned fine.
						rtn = 1;
					}
				}
			} while (dest != 0 && (targ = tit.Next()));
		}
		spot = iterator.Next();
	}

	return rtn != 0;
}
예제 #2
0
// [MC] Was part of P_Thing_Projectile, now its own function for use in ZScript.
// Aims mobj at targ based on speed and targ's velocity.
static void VelIntercept(AActor *targ, AActor *mobj, double speed, bool aimpitch = false, bool oldvel = false, bool leadtarget = true)
{
	if (targ == nullptr || mobj == nullptr)	return;

	DVector3 aim = mobj->Vec3To(targ);
	aim.Z += targ->Height / 2;

	if (leadtarget && speed > 0 && !targ->Vel.isZero())
	{
		// Aiming at the target's position some time in the future
		// is basically just an application of the law of sines:
		//     a/sin(A) = b/sin(B)
		// Thanks to all those on the notgod phorum for helping me
		// with the math. I don't think I would have thought of using
		// trig alone had I been left to solve it by myself.

		DVector3 tvel = targ->Vel;
		if (!(targ->flags & MF_NOGRAVITY) && targ->waterlevel < 3)
		{ // If the target is subject to gravity and not underwater,
		  // assume that it isn't moving vertically. Thanks to gravity,
		  // even if we did consider the vertical component of the target's
		  // velocity, we would still miss more often than not.
			tvel.Z = 0.0;

			if (targ->Vel.X == 0 && targ->Vel.Y == 0)
			{
				InterceptDefaultAim(mobj, targ, aim, speed);
				return;
			}
		}
		double dist = aim.Length();
		double targspeed = tvel.Length();
		double ydotx = -aim | tvel;
		double a = g_acos(clamp(ydotx / targspeed / dist, -1.0, 1.0));
		double multiplier = double(pr_leadtarget.Random2())*0.1 / 255 + 1.1;
		double sinb = -clamp(targspeed*multiplier * g_sin(a) / speed, -1.0, 1.0);
		DVector3 prevel = mobj->Vel;
		// Use the cross product of two of the triangle's sides to get a
		// rotation vector.
		DVector3 rv(tvel ^ aim);
		// The vector must be normalized.
		rv.MakeUnit();
		// Now combine the rotation vector with angle b to get a rotation matrix.
		DMatrix3x3 rm(rv, g_cos(g_asin(sinb)), sinb);
		// And multiply the original aim vector with the matrix to get a
		// new aim vector that leads the target.
		DVector3 aimvec = rm * aim;
		// And make the projectile follow that vector at the desired speed.
		mobj->Vel = aimvec * (speed / dist);
		mobj->AngleFromVel();
		if (oldvel)
		{
			mobj->Vel = prevel;
		}
		if (aimpitch) // [MC] Ripped right out of A_FaceMovementDirection
		{
			const DVector2 velocity = mobj->Vel.XY();
			mobj->Angles.Pitch = -VecToAngle(velocity.Length(), mobj->Vel.Z);
		}
	}
	else
	{
		InterceptDefaultAim(mobj, targ, aim, speed);
	}
}