public static Vector3[] GetAs(MyPlanet p1, MyPlanet p2, float step_time, float G = 1f)
{
Vector3 a1 = p1.GetA(p2, step_time, G);
Vector3 a2 = p2.GetA(p1, step_time, G);
Vector3[] all = new Vector3[2] {
a1, a2
};
return(all);
}
public bool AddPlanet(MyPlanet p)
{
Vector3 position = p.GetPosition();
if (__NextID > 0)
{
foreach (MyPlanet old in Environment.Values)
{
if (Vector3.Equals(old.GetPosition(), position))
{
return(false);
}
}
}
Environment.Add(__NextID, p);
__NextID += 1;
return(true);
}
public Dictionary <int, Vector3>[] StepMove(float step_time = 0.1f, float G = 1f)
{
Dictionary <int, Vector3> id_to_accelerations = new Dictionary <int, Vector3>();
foreach (int akey in Environment.Keys)
{
MyPlanet aplanet = Environment[akey];
for (int bkey = akey + 1; bkey < __NextID; bkey++)
{
MyPlanet bplanet = Environment[bkey];
Vector3[] accelerations = MyPlanet.GetAs(aplanet, bplanet, step_time, G);
if (id_to_accelerations.ContainsKey(akey))
{
id_to_accelerations[akey] += accelerations[0];
}
else
{
id_to_accelerations.Add(akey, accelerations[0]);
}
if (id_to_accelerations.ContainsKey(bkey))
{
id_to_accelerations[akey] += accelerations[1];
}
else
{
id_to_accelerations.Add(bkey, accelerations[1]);
}
}
}
Dictionary <int, Vector3> id_to_position = new Dictionary <int, Vector3>();
Dictionary <int, Vector3> id_to_speed = new Dictionary <int, Vector3>();
foreach (int akey in Environment.Keys)
{
MyPlanet aplanet = Environment[akey];
Vector3 p = aplanet.Step(id_to_accelerations[akey], step_time);
id_to_position.Add(akey, p);
id_to_speed.Add(akey, aplanet.GetSpeed());
}
return(new Dictionary <int, Vector3>[] { id_to_position, id_to_speed, id_to_accelerations });
}
public bool AddPlanet(Vector3 x, Vector3 v, float mass = 0, float size = 0.5f)
{
var position = x;
var speed = v;
if (__NextID > 0)
{
foreach (MyPlanet old in Environment.Values)
{
if (Vector3.Equals(old.GetPosition(), position))
{
return(false);
}
}
}
MyPlanet planet = new MyPlanet(position, speed, mass, size);
Environment.Add(__NextID, planet);
__NextID += 1;
return(true);
}
public bool AddPlanet(float x = 0, float y = 0, float z = 0, float vx = 0, float vy = 0, float vz = 0, float mass = 0, float size = 0.5f)
{
var position = new Vector3(x, y, z);
var speed = new Vector3(vx, vy, vz);
if (__NextID > 0)
{
foreach (MyPlanet old in Environment.Values)
{
if (Vector3.Equals(old.GetPosition(), position))
{
return(false);
}
}
}
MyPlanet planet = new MyPlanet(position, speed, mass, size);
Environment.Add(__NextID, planet);
__NextID += 1;
return(true);
}
public Vector3 GetA(MyPlanet another, float step_time = 1f, float G = 1f)
{
Vector3 distance = Position - another.GetPosition();
var direction = -Vector3.Normalize(distance);
float distanceLength = Vector3.DistanceSquared(Position, another.GetPosition());
Vector3 a;
if (distanceLength > Size + another.Size)
{
a = (G * another.GetMass() * direction) / distanceLength;
}
else
{
//这是完全弹性碰撞公式
var m1 = Mass;
var m2 = another.Mass;
var v1 = Speed;
var v2 = another.Speed;
var new_v1 = ((m1 - m2) * v1 + 2 * m2 * v2) / ((m1 + m2));
a = (new_v1 - v1) / step_time;
}
return(a);
}
