/// <summary>
/// Create particles evenly spaced on ground of the boundary.
/// </summary>
public static FluidParticles Create(int nParticles, float cellSpace, RectangleF domain, float particleMass)
{
FluidParticles particles = new FluidParticles(nParticles);
// Init. Particle positions
float x0 = domain.X + cellSpace;
float x = x0;
float y = domain.Y;
for (int i = 0; i < nParticles; i++)
{
if (x == x0)
{
y += cellSpace;
}
Vector2 pos = new Vector2(x, y);
particles.Add(new FluidParticle
{
Position = pos,
PositionOld = pos,
Mass = particleMass,
});
x = x + cellSpace < domain.Width ? x + cellSpace : x0;
}
return(particles);
}
/// <summary>
/// Emits particles.
/// </summary>
/// <param name="dTime">The delta time.</param>
/// <returns></returns>
public FluidParticles Emit(double dTime)
{
FluidParticles particles = new FluidParticles();
if (this.Enabled)
{
// Calc particle count based on frequency
m_time += dTime;
int nParts = (int)(this.Frequency * m_time);
if (nParts > 0)
{
// Create Particles
for (int i = 0; i < nParts; i++)
{
// Calc velocity based on the distribution along the normalized direction
float dist = (float)m_randGen.NextDouble() * this.Distribution - this.Distribution * 0.5f;
Vector2 normal = this.Direction.PerpendicularRight;
Vector2.Mult(ref normal, dist, out normal);
Vector2 vel = this.Direction + normal;
vel.Normalize();
float velLen = (float)m_randGen.NextDouble() * (this.VelocityMax - this.VelocityMin) + this.VelocityMin;
Vector2.Mult(ref vel, velLen, out vel);
// Calc Oldpos (for right velocity) using simple euler
// oldPos = this.Position - vel * m_time;
Vector2 oldPos = this.Position - vel * (float)m_time;
particles.Add(new FluidParticle
{
Position = this.Position,
PositionOld = oldPos,
Velocity = vel,
Mass = this.ParticleMass
});
}
// Reset time
m_time = 0.0;
}
}
return(particles);
}