/// <summary>
/// Copies the information from a particle to a new one.
/// </summary>
public static Particle Copy(Particle Input)
{
Particle ReturnParticle = new Particle(Input.Acceleration.Capacity, Input.Properties.Capacity);
for (int i = 0; i < Input.Acceleration.Capacity; i++)
{
ReturnParticle.Acceleration[i] = Input.Acceleration[i];
ReturnParticle.Velocity[i] = Input.Velocity[i];
ReturnParticle.Position[i] = Input.Position[i];
}
for (int i = 0; i < Input.Properties.Capacity; i++)
{
ReturnParticle.Properties[i] = Input.Properties[i];
}
return ReturnParticle;
}
/// <summary>
/// Updates a single particle.
/// </summary>
public static Particle UpdateParticle(Particle Input, List<Particle> ParticleList, double Precision, double SofteningValue, double GravityConstant, double MaxVelocity)
{
//Create a copy of the input particle that we can return without modifying the origional
Particle ReturnParticle = Particle.Copy(Input);
//First thing, we need to calculate acceleration:
foreach (Particle Comparison in ParticleList)
{
//This will add each change in acceleration to the acceleration for each particle
ReturnParticle.Acceleration = AddLists(ReturnParticle.Acceleration, CalculateGravitationalAcceleration(ReturnParticle, Comparison, Precision, SofteningValue, GravityConstant));
}
//Here we multiply by 0.0001 to account of the max timer speed
ReturnParticle.Acceleration = MultiplyListByScalar(ReturnParticle.Acceleration, 0.0001);
//Now we need to calculate velocity
ReturnParticle.Velocity = AddLists(ReturnParticle.Velocity, ReturnParticle.Acceleration);
//Check to see if anything goes over the max velocity
double VelMag = VectorMagnitude(ReturnParticle.Velocity);
if (VelMag > MaxVelocity)
{
for (int i = 0; i < ReturnParticle.Velocity.Capacity; i++)
{
//The new velocity is equal to the old direction multiplied by the new magnitude
ReturnParticle.Velocity[i] = (ReturnParticle.Velocity[i] / VelMag) * MaxVelocity;
}
}
//Now we calculate position and we're done (Note the multiplication by 0.0001 to account for the max timer speed - NOT NEEDED)
ReturnParticle.Position = AddLists(ReturnParticle.Position, ReturnParticle.Velocity);
return ReturnParticle;
}
/// <summary>
/// Creates a set of particles with random initialized positions within a given grid size.
/// </summary>
public static List<Particle> Get_RandomParticleSet(int NumberParticles, double GridSize, int NumberDimensions, int NumberProperties)
{
//Create a new list of particles with a default capacity equal to the amount we want
List<Particle> ReturnList = new List<Particle>(NumberParticles);
//For each "slot" in the list:
for (int i = 0; i < ReturnList.Capacity; i++)
{
Particle x = new Particle(NumberDimensions, NumberProperties); //Create a new particle
x.Position = Get_RandomPosition(GridSize, NumberDimensions); //Set it to a random position
ReturnList.Add(x); //Add it to the list
}
//Return the finished list of particles
return ReturnList;
}
/// <summary>
/// Calculates the CHANGE in acceleration from one particle acting on another.
/// </summary>
public static List<double> CalculateGravitationalAcceleration(Particle Input, Particle Comparison, double Precision, double SofteningValue, double GravityConstant)
{
//First we create a new list of acceleration components with the same capacity of the input
List<double> Acceleration = new List<double>(Input.Acceleration.Capacity);
//Now we calculate the actual distance between the particles (we will need this later)
double ActualDistance = CalculateActualDistance(Input.Position, Comparison.Position);
//Check to see if the actual distance is under the precision value
if (Math.Abs(ActualDistance) <= Precision)
{
//If it is, then we can just return a list with zero change
for (int i = 0; i < Acceleration.Capacity; i++)
{
Acceleration.Add(0);
}
return Acceleration;
}
//Calculate the denominator of the equation
double Denominator = Math.Pow(((ActualDistance * ActualDistance) + (SofteningValue * SofteningValue)), (3 / 2));
//For each dimension of movement/location:
for (int i = 0; i < Acceleration.Capacity; i++)
{
//Calculate the component distance of this dimension
double ComponentDistance = Comparison.Position[i] - Input.Position[i];
//Calculate the change in acceleration
Acceleration.Add(GravityConstant * ((Comparison.Properties[0] * ComponentDistance) / Denominator));
}
return Acceleration;
}
public static List<double> CalculateElectrostaticAcceleration(Particle Input, Particle Comparison, double SofteningValue, double ElectrostaticConstant)
{
//First we create a new list of acceleration components with the same capacity of the input
List<double> Acceleration = new List<double>(Input.Acceleration.Capacity);
//Now we calculate the actual distance between the particles (we will need this later)
double ActualDistance = CalculateActualDistance(Input.Position, Comparison.Position);
//Since we are dealing with electrostatics, we only want to worry about distances equal to zero
if (Math.Abs(ActualDistance) == 0)
{
//If it is, then we can just return a list with zero change
for (int i = 0; i < Acceleration.Capacity; i++)
{
Acceleration.Add(0);
}
return Acceleration;
}
//Calculate the denominator of the equation
double Denominator = Math.Pow(((ActualDistance * ActualDistance) + (SofteningValue * SofteningValue)), (3 / 2));
//For each dimension of movement/location:
for (int i = 0; i < Acceleration.Capacity; i++)
{
//Calculate the component distance of this dimension
double ComponentDistance = Comparison.Position[i] - Input.Position[i];
//Calculate the change in acceleration
Acceleration.Add((ElectrostaticConstant * ((Comparison.Properties[1] * Input.Properties[1] * ComponentDistance) / Denominator)) / Input.Properties[0]);
}
return Acceleration;
}
