void CParticleJetEffectPainter::CreateLinearParticles (CSpaceObject *pObj, int iCount, const CVector &vInitialPos, const CVector &vInitialVel)
// CreateLinearParticles
//
// Creates new particles on a straight line
{
int i;
// Compute some basic stuff
const Metric rJitterFactor = LIGHT_SPEED / 100000.0;
Metric rCurRotation = AngleToRadians(180 + m_iXformRotation + m_iCurDirection);
// Compute the spread angle, in radians
Metric rSpread = AngleToRadians(Max(0, m_SpreadAngle.Roll()));
Metric rHalfSpread = 0.5 * rSpread;
// Calculate where last tick's particles would be based on the last rotation.
Metric rAveSpeed = m_EmitSpeed.GetAveValue() * LIGHT_SPEED / 100.0;
CVector vCurStart = (m_vLastEmitPos + (m_rXformTime * ::PolarToVectorRadians(rCurRotation, rAveSpeed * g_SecondsPerUpdate))) - vInitialPos;
// Create particles
for (i = 0; i < iCount; i++)
{
Metric rSlide = mathRandom(0, 9999) / 10000.0;
// We place the particle along the line betwen the current
// and last emit positions
CVector vPos = vInitialPos + rSlide * vCurStart;
// Generate a random velocity backwards
Metric rRotation = rCurRotation + (rHalfSpread * mathRandom(-1000, 1000) / 1000.0);
Metric rSpeed = m_EmitSpeed.Roll() * LIGHT_SPEED / 100.0;
CVector vVel = m_rXformTime * (vInitialVel + ::PolarToVectorRadians(rRotation, rSpeed + rJitterFactor * mathRandom(-500, 500)));
// Lifetime
int iLifeLeft = m_ParticleLifetime.Roll();
// Add the particle
m_Particles.AddParticle(vPos, vVel, iLifeLeft, AngleToDegrees(rRotation));
}
// Remember the last position
m_iLastDirection = m_iCurDirection;
m_vLastEmitPos = vInitialPos;
}
void CParticleJetEffectPainter::CreateInterpolatedParticles (CSpaceObject *pObj, int iCount, const CVector &vInitialPos, const CVector &vInitialVel)
// CreateInterpolatedParticles
//
// Creates particles interpolated between to directions.
{
int i;
// Compute some basic stuff
const Metric rJitterFactor = LIGHT_SPEED / 100000.0;
Metric rLastRotation = AngleToRadians(180 + m_iXformRotation + m_iLastDirection);
Metric rCurRotation = AngleToRadians(180 + m_iXformRotation + m_iCurDirection);
// Compute the spread angle, in radians
Metric rSpread = AngleToRadians(Max(0, m_SpreadAngle.Roll()));
Metric rHalfSpread = 0.5 * rSpread;
// Calculate where last tick's particles would be based on the last rotation.
Metric rAveSpeed = m_EmitSpeed.GetAveValue() * LIGHT_SPEED / 100.0;
CVector vLastStart = (m_vLastEmitPos + (m_rXformTime * ::PolarToVectorRadians(rLastRotation, rAveSpeed * g_SecondsPerUpdate))) - vInitialPos;
// Calculate where last tick's particles would be IF we have used the current
// rotation. This allows us to interpolate a turn.
CVector vCurStart = (m_vLastEmitPos + (m_rXformTime * ::PolarToVectorRadians(rCurRotation, rAveSpeed * g_SecondsPerUpdate))) - vInitialPos;
// Create particles
for (i = 0; i < iCount; i++)
{
Metric rSlide = mathRandom(0, 9999) / 10000.0;
// Compute two points along the two slide vectors (last and current)
CVector vSlide1 = rSlide * vLastStart;
CVector vSlide2 = rSlide * vCurStart;
CVector vAdj = (rSlide * vSlide1) + ((1.0 - rSlide) * vSlide2);
// We place the particle along the line betwen the current
// and last emit positions
CVector vPos = vInitialPos + vAdj;
// We blend the rotation as well
if (Absolute(rCurRotation - rLastRotation) > g_Pi)
{
if (rLastRotation < rCurRotation)
rLastRotation += g_Pi * 2.0;
else
rCurRotation += g_Pi * 2.0;
}
Metric rSlideRotation = (rSlide * rLastRotation) + ((1.0 - rSlide) * rCurRotation);
// Generate a random velocity backwards
Metric rRotation = rSlideRotation + (rHalfSpread * mathRandom(-1000, 1000) / 1000.0);
Metric rSpeed = m_EmitSpeed.Roll() * LIGHT_SPEED / 100.0;
CVector vVel = m_rXformTime * (vInitialVel + ::PolarToVectorRadians(rRotation, rSpeed + rJitterFactor * mathRandom(-500, 500)));
// Lifetime
int iLifeLeft = m_ParticleLifetime.Roll();
// Add the particle
m_Particles.AddParticle(vPos, vVel, iLifeLeft, AngleToDegrees(rRotation));
}
// Remember the last position
m_iLastDirection = m_iCurDirection;
m_vLastEmitPos = vInitialPos;
}
void CParticleJetEffectPainter::CreateFixedParticles (CSpaceObject *pObj, int iCount, const CVector &vInitialPos, const CVector &vInitialVel)
// CreateFixedParticles
//
// Creates particles along the objects path (e.g., missile exhaust).
{
int i;
// Calculate a vector to our previous position
//
// NOTE: In this mode m_vLastEmitPos is the last position of the object.
CVector vCurPos = (pObj ? pObj->GetPos() : CVector());
CVector vToOldPos;
if (m_bTrackingObject)
{
Metric rAveSpeed = m_rXformTime * m_EmitSpeed.GetAveValue() * LIGHT_SPEED / 100.0;
vToOldPos = m_vLastEmitPos - (vCurPos + vInitialPos) + ::PolarToVector(180 + m_iLastDirection, rAveSpeed * g_SecondsPerUpdate);
}
else
{
Metric rSpeed = (pObj ? pObj->GetVel().Length() : 0.0);
vToOldPos = ::PolarToVector(180 + m_iLastDirection, rSpeed * g_SecondsPerUpdate);
}
// Compute two orthogonal coordinates
CVector vAxis = ::PolarToVector(m_iCurDirection + 180, 1.0);
CVector vTangent = ::PolarToVector(m_iCurDirection + 90, 1.0);
// Create particles
for (i = 0; i < iCount; i++)
{
Metric rSlide = mathRandom(0, 9999) / 10000.0;
// Compute a position randomly along the line between the current and
// last emit positions.
CVector vPos = vInitialPos + rSlide * vToOldPos;
// Generate a random velocity along the tangent
Metric rTangentSlide = mathRandom(-9999, 9999) / 10000.0;
Metric rAxisJitter = mathRandom(-50, 50) / 100.0;
CVector vVel = (vTangent * rTangentSlide * m_rXformTime * m_TangentSpeed.Roll() * LIGHT_SPEED / 100.0)
+ (vAxis * (m_EmitSpeed.Roll() + rAxisJitter) * LIGHT_SPEED / 100.0);
// Lifetime
int iLifeLeft = m_ParticleLifetime.Roll();
// Add the particle
m_Particles.AddParticle(vPos, vVel, iLifeLeft, m_iCurDirection);
}
// Remember the last position
m_iLastDirection = m_iCurDirection;
m_vLastEmitPos = vCurPos + vInitialPos;
}
