public PrimitiveParticleSystem(PrimitiveParticleSystemInfo psi)
{
for (int i = 0; i < MAX_PARTICLES; i++)
{
particles[i] = new ParticlePrimitive();
}
info = psi;
vecLocation.X=vecPrevLocation.X=0.0f;
vecLocation.Y=vecPrevLocation.Y=0.0f;
fTx=fTy=0;
fScale = 1.0f;
fEmissionResidue=0.0f;
nParticlesAlive=0;
fAge=-2.0f;
}
public ParticlePrimitive(ParticlePrimitive o)
{
this.vecLocation = o.vecLocation;
this.vecVelocity = o.vecVelocity;
this.fGravity = o.fGravity;
this.fRadialAccel = o.fRadialAccel;
this.fTangentialAccel = o.fTangentialAccel;
this.fSpin = o.fSpin;
this.fSpinDelta = o.fSpinDelta;
this.fSize = o.fSize;
this.fSizeDelta = o.fSizeDelta;
this.colColour = o.colColour; // + alpha
this.colColourStart = o.colColourStart;
this.colColourEnd = o.colColourEnd;
this.fAge = o.fAge;
this.fTerminalAge = o.fTerminalAge;
}
public void Update(float fDeltaTime)
{
int i;
float ang;
ParticlePrimitive par = null;
Vector2 vecAccel, vecAccel2;
if(fAge >= 0)
{
fAge += fDeltaTime;
if(fAge >= info.fLifetime)
fAge = -2.0f;
}
// update all alive particles
if (bUpdateBoundingBox)
rectBoundingBox.Clear();
for(i=0; i<nParticlesAlive; i++)
{
par=particles[i];
par.fAge += fDeltaTime;
//need to kill this particle
if(par.fAge >= par.fTerminalAge)
{
nParticlesAlive--;
particles[i] = new ParticlePrimitive (particles[nParticlesAlive]);
i--;
continue;
}
vecAccel = par.vecLocation-vecLocation;
vecAccel.Normalise ();
vecAccel2 = vecAccel;
vecAccel *= par.fRadialAccel;
// vecAccel2.Rotate(M_PI_2);
// the following is faster
ang = vecAccel2.X;
vecAccel2.X = -vecAccel2.Y;
vecAccel2.X = ang;
vecAccel2 *= par.fTangentialAccel;
par.vecVelocity += (vecAccel+vecAccel2)*fDeltaTime;
par.vecVelocity.Y += par.fGravity*fDeltaTime;
par.vecLocation += par.vecVelocity*fDeltaTime;
par.fSpin += par.fSpinDelta*fDeltaTime;
par.fSize += par.fSizeDelta*fDeltaTime;
float factor = par.fAge / par.fTerminalAge;
par.colColour = Rgba32.Lerp(par.colColourStart, par.colColourEnd, factor);
//par.colColour = new Rgba32(par.colColour.ToVector4() + (par.colColourEnd.ToVector4() * fDeltaTime));
}
if (bUpdateBoundingBox)
rectBoundingBox.Encapsulate(par.vecLocation.X, par.vecLocation.Y);
// generate new particles
if(fAge != -2.0f)
{
float fParticlesNeeded = ((float)info.nEmission)*fDeltaTime + fEmissionResidue;
int nParticlesCreated = (int) fParticlesNeeded;
fEmissionResidue=fParticlesNeeded-((float)nParticlesCreated);
for(i=0; i<nParticlesCreated; i++)
{
if(nParticlesAlive>=MAX_PARTICLES) break;
par = particles[nParticlesAlive];
par.fAge = 0.0f;
par.fTerminalAge = RandomGenerator.Default.GetRandomSingle(info.fParticleLifeMin, info.fParticleLifeMax);
par.vecLocation = vecPrevLocation + (vecLocation - vecPrevLocation) * RandomGenerator.Default.GetRandomSingle(0.0f, 1.0f);
par.vecLocation.X += RandomGenerator.Default.GetRandomSingle(-2.0f, 2.0f);
par.vecLocation.Y += RandomGenerator.Default.GetRandomSingle(-2.0f, 2.0f);
ang = info.fDirection - ((float)Math.PI / 2.0f) + RandomGenerator.Default.GetRandomSingle(0.0f, info.fSpread) - info.fSpread / 2.0f;
if(info.bRelative)
ang += ( (float) Math.Atan2( (vecPrevLocation-vecLocation).Y, (vecPrevLocation-vecLocation).X ) )+( (float)Math.PI / 2.0f );
par.vecVelocity.X = (float) Math.Cos(ang);
par.vecVelocity.Y = (float) Math.Sin(ang);
par.vecVelocity *= info.fSpeed;
par.fGravity = info.fGravity;
par.fRadialAccel = info.fRadialAccel;
par.fTangentialAccel = info.fTangentialAccel;
par.fSize = RandomGenerator.Default.GetRandomSingle(info.fSizeStart, info.fSizeStart + (info.fSizeEnd - info.fSizeStart) * info.fSizeVar);
par.fSizeDelta = (info.fSizeEnd-par.fSize) / par.fTerminalAge;
par.fSpin = RandomGenerator.Default.GetRandomSingle(info.fSpinStart, info.fSpinStart + (info.fSpinEnd - info.fSpinStart) * info.fSpinVar);
par.fSpinDelta = (info.fSpinEnd-par.fSpin) / par.fTerminalAge;
//Vector4 start = info.colColourStart.ToVector4();
//Vector4 finish = info.colColourEnd.ToVector4();
//Vector4 colColourV = new Vector4(
// Euclid.RandomHelper.Random_Float(start.W, finish.W + (finish.W - start.W) * info.fColourEndVar),
// Euclid.RandomHelper.Random_Float(start.X, start.X + (finish.X - start.X) * info.fColourStartVar),
// Euclid.RandomHelper.Random_Float(start.Y, finish.Y + (finish.Y - start.Y) * info.fColourStartVar),
// Euclid.RandomHelper.Random_Float(start.Z, finish.Z + (finish.Z - start.Z) * info.fColourStartVar)
// );
//par.colColourStart = new Rgba32(colColourV);
//Vector4 colColourDeltaV = new Vector4();
//colColourDeltaV.W = (finish.W - start.W) / par.fTerminalAge;
//colColourDeltaV.X = (finish.X - start.X) / par.fTerminalAge;
//colColourDeltaV.Y = (finish.Y - start.Y) / par.fTerminalAge;
//colColourDeltaV.Z = (finish.Z - start.Z) / par.fTerminalAge;
//par.colColourEnd = new Rgba32(colColourDeltaV);
par.colColourStart = RandomGenerator.Default.GetRandomColourNearby(info.colColourStart, info.fColourStartVar);
par.colColourEnd = RandomGenerator.Default.GetRandomColourNearby(info.colColourEnd, info.fColourEndVar);
if (bUpdateBoundingBox)
rectBoundingBox.Encapsulate(par.vecLocation.X, par.vecLocation.Y);
nParticlesAlive++;
}
}
vecPrevLocation=vecLocation;
}
