//Cohesion produces a steering force that moves a vehicle toward the center of mass of its neighbors
//A sheep running after its flock is demonstrating cohesive behavior. Use this force to keep a group of vehicles together.
public static Vector2 Cohesion(ref Vehicle[] allCars, Vehicle me, Vector2 currentPosition, Vector2 velocity, int max_speed, int cohesionRadius)
{
int j = 0;
Vector2 averagePosition = Vector2.Zero;
Vector2 distance = Vector2.Zero;
for (int i = 0; i < allCars.Length; i++)
{
distance = Vector2.Subtract(currentPosition, allCars[i].CurrentPosition);
if (VectorHelpers.Length(distance) < cohesionRadius && allCars[i] != me)
{
j++;
averagePosition = Vector2.Add(averagePosition, allCars[i].CurrentPosition);
}
}
if (j == 0)
{
return(Vector2.Zero);
}
else
{
averagePosition = averagePosition / j;
return(Seek(ref averagePosition, ref currentPosition, ref velocity, max_speed));
}
}
//Separation creates a force that steers a vehicle away from those in its neighborhood region.
//When applied to a number of vehicles, they will spread out, trying to maximize their distance from every other vehicle
public static Vector2 Separation(ref Vehicle[] allCars, Vehicle me, ref Vector2 currentPosition, ref Vector2 velocity, int max_speed)
{
int j = 0;
Vector2 separationForce = new Vector2(0);
Vector2 averageDirection = new Vector2(0);
Vector2 distance = new Vector2(0);
for (int i = 0; i < allCars.Length; i++)
{
distance = Vector2.Subtract(currentPosition, allCars[i].CurrentPosition);
if (VectorHelpers.Length(distance) < 100 && allCars[i] != me)
{
j++;
separationForce += Vector2.Subtract(currentPosition, allCars[i].CurrentPosition);
separationForce = Vector2.Normalize(separationForce);
separationForce = Vector2.Multiply(separationForce, 1 / .7f);
averageDirection = Vector2.Add(averageDirection, separationForce);
}
}
if (j == 0)
{
return(Vector2.Zero);
}
else
{
//averageDirection = averageDirection / j;
return(averageDirection);
}
}
//Alignment attempts to keep a vehicle's heading aligned with its neighbors
//The force is calculated by first iterating through all the neighbors and averaging their heading vectors.
//This value is the desired heading, so we just subtract the vehicle's heading to get the steering force.
public static Vector2 Alignment(ref Vehicle[] allCars, Vehicle me, ref Vector2 currentPosition, ref Vector2 velocity, int max_speed)
{
int j = 0;
Vector2 averageDirection = new Vector2(0);
Vector2 distance = new Vector2(0);
for (int i = 0; i < allCars.Length; i++)
{
distance = Vector2.Subtract(currentPosition, allCars[i].CurrentPosition);
if (VectorHelpers.Length(distance) < 100 && allCars[i] != me)
{
j++;
averageDirection = Vector2.Add(averageDirection, allCars[i].Velocity);
}
}
if (j == 0)
{
return(Vector2.Zero);
}
else
{
averageDirection = averageDirection / j;
return(Vector2.Subtract(averageDirection, velocity));
}
}
//Flee is the opposite of seek. Instead of producing a steering force to steer the agent toward a target position, flee creates a force that steers the agent away.
public static Vector2 Flee(ref Vector2 targetPosition, ref Vector2 currentPosition, ref Vector2 Velocity, int max_speed, int FOV, int vehicleNo)
{
if (VectorHelpers.Length(Vector2.Subtract(targetPosition, currentPosition)) > FOV)
{
return(Vector2.Zero);
}
Vector2 desired_V = Vector2.Normalize(Vector2.Subtract(currentPosition, targetPosition)) * max_speed;
return(Vector2.Subtract(desired_V, Velocity));
}
