/// <summary>
/// Add an object to the list
/// </summary>
/// <param name="co"></param>
public static void AddObject(IQuadtreeObject co)
{
if (co != null)
{
AllObjects.Add(co);
}
}
/// <summary>
/// Draws an object on screen
/// </summary>
/// <param name="obj"></param>
/// <param name="size"></param>
void Draw(IQuadtreeObject obj, int size)
{
Ellipse circle = new Ellipse();
circle.Fill = obj.visuals.colour;
circle.Height = obj.visuals.size;
circle.Width = obj.visuals.size;
if (obj.screenPosition.x + obj.visuals.size < centre.x && obj.screenPosition.y + obj.visuals.size < centre.y)
{
Canvas.SetTop(circle, obj.screenPosition.y + (size / 2) + 200);
Canvas.SetLeft(circle, obj.screenPosition.x + (size / 2) + 150);
Simulation.Children.Add(circle);
}
}
///// Methods /////
public void AddBody(IQuadtreeObject body)
{
if (_childA != null)
{
var child = GetQuadrant(body.Position);
child.AddBody(body);
}
else
{
_bodies.Add(body);
if (_bodies.Count > _maxBodiesPerNode && _curLevel < _maxLevel)
{
Split();
}
}
}
/// <summary>
/// Calculate the force between this object and another object then return the values
/// </summary>
/// <param name="co"></param>
/// <returns></returns>
public double[] Attraction(IQuadtreeObject co)
{
if (co == null)
{
return(null);
}
double[] forces = new double[2];
double distance = Vector2.DistanceSqr(position, co.position);
if (DebugTools.PrintForces)
{
Console.WriteLine("Celestial Object Attraction() - Distance: " + Math.Sqrt(distance));
Console.WriteLine(Name + " Position: " + position.ToString());
Console.WriteLine(co.Name + " Position: " + co.position.ToString());
}
// If the objects are on top of each other, a DivideByZero error would occur so return
if (distance == 0)
{
Console.WriteLine("Objects {0} {1} are on top of each other!", Name, co.Name);
return(null);
}
// Using the formula F = GMm/d^2
double force = (Constants.Gravitational * Mass * co.Mass) / distance;
double differenceX = Vector2.DifferenceX(position, co.position);
double differenceY = Vector2.DifferenceY(position, co.position);
// Calculate the angle between the objects
double theta = Math.Atan2(differenceY, differenceX);
// Split the force in the x and y components
double forceX = force * Math.Cos(theta);
double forceY = force * Math.Sin(theta);
forces[0] = forceX;
forces[1] = forceY;
return(forces);
}
// Update the velocites of the objects
static Vector2[] OnCollision(IQuadtreeObject obj1, IQuadtreeObject obj2)
{
Vector2[] velocities = new Vector2[2];
double combinedMasses = obj1.Mass + obj2.Mass;
double differenceObj1Obj2Mass = obj1.Mass - obj2.Mass;
double differenceObj2Obj1Mass = obj2.Mass - obj1.Mass;
double obj1Horizontal = obj1.velocity.x * ((differenceObj1Obj2Mass) / (combinedMasses)) + ((2 * obj2.Mass * obj2.velocity.x) / (combinedMasses));
double obj1Vertical = obj1.velocity.y * ((differenceObj1Obj2Mass) / (combinedMasses)) + ((2 * obj2.Mass * obj2.velocity.y) / (combinedMasses));
double obj2Horizontal = obj2.velocity.x * ((differenceObj2Obj1Mass) / (combinedMasses)) + ((2 * obj1.Mass * obj1.velocity.x) / (combinedMasses));
double obj2Vertical = obj2.velocity.y * ((differenceObj2Obj1Mass) / (combinedMasses)) + ((2 * obj1.Mass * obj1.velocity.y) / (combinedMasses));
velocities[0] = new Vector2(obj1Horizontal, obj1Vertical);
velocities[1] = new Vector2(obj2Horizontal, obj2Vertical);
return(velocities);
}
/// <summary>
/// Find the first object with the name "name" and then return it
/// </summary>
/// <param name="name"></param>
/// <returns>The object with the name</returns>
public static IQuadtreeObject FindObjectWithName(string name)
{
IQuadtreeObject co = AllObjects.First(s => s.Name == name);
return(co);
}
