using Microsoft.DirectX;using Microsoft.DirectX.Direct3D;using System;using System.ComponentModel;using System.Drawing;using System.Windows.Forms;using System.Diagnostics;using System.Net;namespace DirectX{    public class Newton    {        // Newton v1.1        // Author: Mykel Ne'Oa Ikon        // Description: This class is a functional n-body system        //it requires a DirectX Based project that is setup to the point that a blank scene        // is being drawn. You can then invoke the class and use the functions        //        // Add_NBody - adds a n-body to the system        // Delete_NBody - deletes a n-body from the system        // Toggle - by passing true(On) or false (Off) you can cause the particle to be affected by other particles gravity or not, other particles will still be affected by the off particle        Int32 Max = 500; // This is the maximum number of particles we can have through newton               Int32 N = 0; // This is the particle counter, when we add a particle this increments, and decrements when we delete it        n_body[] newton = new n_body[1000]; // Our array for our particle structure        float GC = 6.673e-11f; // Our gravitational constant, .00000000006.673        float MC = 1e+22f; // We multiply this by our radius, double squared.                float GD = 1000000000000; // our galactic distance, makes the force seem like we're at large                // This method allows us to add a particle        public void Add_NBody(Mesh mesh, Vector3 position, Vector3 acceleration, Color diffuse, float radius)        {            if (N < Max)            {                                newton[N].nradius = radius; // Pass the radius                newton[N].nmass = (radius * radius) * MC; // Turn the radius into mass                newton[N].ncutoff = (radius * radius) + radius;// * (newton.nradius + newton.nradius); // Set the gravity cutoff distance                newton[N].nmesh = mesh; // Set the mesh                newton[N].nposition = position; // Set the mesh position                newton[N].nacceleration += acceleration; // Define the acceleration                newton[N].nmaterial.Diffuse = diffuse; // Set the diffuse color                newton[N].ngravity = true; // Turn the particle on                N += 1; // Increase our particle counter            }        }        public void Add_NBody(Mesh mesh, Vector3 position, Vector3 acceleration, Color diffuse, float radius, Boolean status)        {            if (N < Max)            {                newton[N].nradius = radius; // Pass the radius                newton[N].nmass = (radius * radius) * MC; // Turn the radius into mass                newton[N].ncutoff = (radius * radius) + radius;// * (newton.nradius + newton.nradius); // Set the gravity cutoff distance                newton[N].nmesh = mesh; // Set the mesh                newton[N].nposition = position; // Set the mesh position                newton[N].nacceleration += acceleration; // Define the acceleration                newton[N].nmaterial.Diffuse = diffuse; // Set the diffuse color                newton[N].ngravity = status; // Turn the particle on                N += 1; // Increase our particle counter            }        }        // This method allows us to delete a particle        public void Delete_NBody(Int32 ndex)        {            if (N > 0) // Providing we have items to work with            {                for (Int32 x = ndex; x <= N; x++) // loop through each one at the position we want to delete                {                    newton[x] = newton[x + 1]; // And copy the one ahead of it                }                N -= 1; // Decrement our counter            }        }        // This method allows us to turn off/on a particle by passing off(False) or on(True) to it        public void Toggle(Int32 ndex, Boolean status)        {            newton[ndex].ngravity = status;        }        // This method calculates the gravitation on each particle, then updates the position        public void Update()        {            #region process gravity            if (N > 0) // If we have particles to process            {                for (Int32 i = 0; i < N; i++) // Loop through our particles and update the positions                {                    newton.nposition += newton.nacceleration;                }                for (Int32 i = 0; i < N; i++) // Go though our particles                {                    // When we're ready, on this line we will move the position + acceleration bit in the loop above                    for (Int32 ii = 0; ii < N; ii++) // Go through our particles                    {                        if (i != ii) // If the focus(i) and target(ii) particles aren't the same                        {                            if (newton.ngravity != false) // If our particle can calculate gravity                            {                                float d = v3dist(newton.nposition, newton[ii].nposition); // Get the distance between them                                if (v3collision(i,ii, d) == false) // If we're greater than the cutoff distance                                {                                        float g = v3grav(newton[ii].nmass, newton.nposition, newton[ii].nposition); // Get the gravitational force                                        Vector3 vd = v3direction(newton.nposition, newton[ii].nposition, d); // get a vector representing a normalized direction to our target                                        newton.nacceleration += new Vector3(vd.X * g, vd.Y * g, vd.Z * g); // calculate our acceleration                                }                             }                        }                                            }                }            }            #endregion        }        // This method renders our particles        public void Render(Device device)        {            for (Int32 i = 0; i < N; i++) // Go through each particle            {                if (newton.nmass != 0) // Check to make sure it isn't blank                {                    device.Transform.World = Matrix.Translation(newton.nposition); // Position our particle                    device.Material = newton.nmaterial; // Apply its material                    newton.nmesh.DrawSubset(0); // Draw it                }            }        }        // This method calculates the gravity        public float v3grav(float mass, Vector3 object1, Vector3 object2)        {            // this function will calculate true gravity between 2 objects            float dist = (float)v3dist(object1, object2); // Get the distance between the 2 points            float gf = (GC * mass); // Get the gravitational force            return gf / (dist * GD); // Return the gravitational force after dividing it by r2 and scaling it        }        // This method calculates a scalar vector toward our target        public Vector3 v3direction(Vector3 object1, Vector3 object2, float d)        {            float x = (object1.X - object2.X); // Get our x distance            float y = (object1.Y - object2.Y); // Get our y distance            float z = (object1.Z - object2.Z); // Get our z distance            return new Vector3(-(x / d), -(y / d), -(z / d)); // Return our vector        }        // Get the distance between 2 points        public float v3dist(Vector3 object1, Vector3 object2)        {            Double x = (object1.X - object2.X) * (object1.X - object2.X); // Get X            Double y = (object1.Y - object2.Y) * (object1.Y - object2.Y); // Get Y            Double z = (object1.Z - object2.Z) * (object1.Z - object2.Z); // Get Z            float dist = (float)(x + y + z); // Get distance            return dist; // Return distance        }        // Returns true if we have a collision with the two particles in question using sphere bound detection        public Boolean v3collision(Int32 object1, Int32 object2, float dist)        {                        float collisiondistance = newton[object1].ncutoff + newton[object2].ncutoff; // The collision distance is the sum of both particles cutoffs, while not exact it works            if (dist <= collisiondistance) // If we're closer than our colision distance, we're colliding            {                return true; // return true            }            else            {                return false; // return false            }        }        public struct n_body        {            public Mesh nmesh;            public float ncutoff;            public Vector3 nposition;            public Vector3 nacceleration;            public Material nmaterial;            public float nradius;            public float nmass;            public bool ngravity;        }    }}