Fun With Gravity

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;

namespace ParticleSwarm {
	public class Form1 : System.Windows.Forms.Form {
		private System.Windows.Forms.PictureBox pictureBox1;
		private System.Windows.Forms.Timer timer1;
		private System.Windows.Forms.ListView listView1;
		private System.Windows.Forms.ColumnHeader columnHeader2;
		private System.Windows.Forms.ColumnHeader columnHeader3;
		private System.Windows.Forms.ColumnHeader columnHeader4;
		private System.Windows.Forms.ColumnHeader columnHeader5;
		private System.Windows.Forms.ColumnHeader columnHeader6;
		private System.Windows.Forms.ColumnHeader columnHeader7;
		private System.Windows.Forms.CheckBox checkBox1;
		private System.Windows.Forms.CheckBox checkBox2;
		private System.Windows.Forms.CheckBox checkBox3;
		private System.Windows.Forms.TextBox textBox1;
		private System.Windows.Forms.Label label1;
		private System.Windows.Forms.Label label2;
		private System.Windows.Forms.TextBox textBox2;
		private System.Windows.Forms.Label label3;
		private System.Windows.Forms.TextBox textBox3;
		private System.Windows.Forms.Label label4;
		private System.Windows.Forms.TextBox textBox4;
		private System.Windows.Forms.ColumnHeader columnHeader8;
		private System.Windows.Forms.Label label5;
		private System.Windows.Forms.TextBox textBox5;
		private System.Windows.Forms.Button button5;
		private System.Windows.Forms.Button button6;
		private System.Windows.Forms.Button button7;
		private System.Windows.Forms.CheckBox checkBox4;
		private System.Windows.Forms.CheckBox checkBox5;
		private System.Windows.Forms.MainMenu mainMenu1;
		private System.Windows.Forms.MenuItem menuItem1;
		private System.Windows.Forms.MenuItem menuItem2;
		private System.Windows.Forms.MenuItem menuItem3;
		private System.Windows.Forms.MenuItem menuItem4;
		private System.Windows.Forms.CheckBox checkBox6;
		private System.Windows.Forms.Button button1;
		private System.ComponentModel.IContainer components;
		private Brush fadeBrush;

		public Form1() {
			InitializeComponent();
			fadeBrush = new SolidBrush(Color.FromArgb(10, pictureBox1.BackColor.R, pictureBox1.BackColor.G, pictureBox1.BackColor.B));
			SetStyle(ControlStyles.AllPaintingInWmPaint |
					ControlStyles.UserPaint |
					ControlStyles.DoubleBuffer,
					true);
		}

		protected override void Dispose(bool disposing) {
			if (disposing) {
				if (components != null) {
					components.Dispose();
				}
			}
			base.Dispose(disposing);
		}

		#region Windows Form Designer generated code
		private void InitializeComponent() {
			this.components = new System.ComponentModel.Container();
			this.pictureBox1 = new System.Windows.Forms.PictureBox();
			this.timer1 = new System.Windows.Forms.Timer(this.components);
			this.listView1 = new System.Windows.Forms.ListView();
			this.columnHeader8 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader5 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader6 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader7 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader2 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader3 = new System.Windows.Forms.ColumnHeader();
			this.columnHeader4 = new System.Windows.Forms.ColumnHeader();
			this.checkBox1 = new System.Windows.Forms.CheckBox();
			this.checkBox2 = new System.Windows.Forms.CheckBox();
			this.checkBox3 = new System.Windows.Forms.CheckBox();
			this.textBox1 = new System.Windows.Forms.TextBox();
			this.label1 = new System.Windows.Forms.Label();
			this.label2 = new System.Windows.Forms.Label();
			this.textBox2 = new System.Windows.Forms.TextBox();
			this.label3 = new System.Windows.Forms.Label();
			this.textBox3 = new System.Windows.Forms.TextBox();
			this.label4 = new System.Windows.Forms.Label();
			this.textBox4 = new System.Windows.Forms.TextBox();
			this.label5 = new System.Windows.Forms.Label();
			this.textBox5 = new System.Windows.Forms.TextBox();
			this.button5 = new System.Windows.Forms.Button();
			this.button6 = new System.Windows.Forms.Button();
			this.button7 = new System.Windows.Forms.Button();
			this.checkBox4 = new System.Windows.Forms.CheckBox();
			this.checkBox5 = new System.Windows.Forms.CheckBox();
			this.mainMenu1 = new System.Windows.Forms.MainMenu(this.components);
			this.menuItem1 = new System.Windows.Forms.MenuItem();
			this.menuItem2 = new System.Windows.Forms.MenuItem();
			this.menuItem3 = new System.Windows.Forms.MenuItem();
			this.menuItem4 = new System.Windows.Forms.MenuItem();
			this.checkBox6 = new System.Windows.Forms.CheckBox();
			this.button1 = new System.Windows.Forms.Button();
			((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
			this.SuspendLayout();
			// 
			// pictureBox1
			// 
			this.pictureBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
						| System.Windows.Forms.AnchorStyles.Left)
						| System.Windows.Forms.AnchorStyles.Right)));
			this.pictureBox1.BackColor = System.Drawing.Color.White;
			this.pictureBox1.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle;
			this.pictureBox1.Location = new System.Drawing.Point(84, 0);
			this.pictureBox1.Name = "pictureBox1";
			this.pictureBox1.Size = new System.Drawing.Size(540, 380);
			this.pictureBox1.TabIndex = 0;
			this.pictureBox1.TabStop = false;
			this.pictureBox1.BackColorChanged += new System.EventHandler(this.pictureBox1_BackColorChanged);
			this.pictureBox1.Resize += new System.EventHandler(this.pictureBox1_Resize);
			this.pictureBox1.MouseUp += new System.Windows.Forms.MouseEventHandler(this.pictureBox1_MouseUp);
			// 
			// timer1
			// 
			this.timer1.Interval = 10;
			this.timer1.Tick += new System.EventHandler(this.timer1_Tick);
			// 
			// listView1
			// 
			this.listView1.Anchor = ((System.Windows.Forms.AnchorStyles)(((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)
						| System.Windows.Forms.AnchorStyles.Right)));
			this.listView1.Columns.AddRange(new System.Windows.Forms.ColumnHeader[] {
            this.columnHeader8,
            this.columnHeader5,
            this.columnHeader6,
            this.columnHeader7,
            this.columnHeader2,
            this.columnHeader3,
            this.columnHeader4});
			this.listView1.FullRowSelect = true;
			this.listView1.HeaderStyle = System.Windows.Forms.ColumnHeaderStyle.Nonclickable;
			this.listView1.HideSelection = false;
			this.listView1.Location = new System.Drawing.Point(0, 384);
			this.listView1.Name = "listView1";
			this.listView1.Size = new System.Drawing.Size(620, 80);
			this.listView1.Sorting = System.Windows.Forms.SortOrder.Descending;
			this.listView1.TabIndex = 4;
			this.listView1.UseCompatibleStateImageBehavior = false;
			this.listView1.View = System.Windows.Forms.View.Details;
			this.listView1.KeyUp += new System.Windows.Forms.KeyEventHandler(this.listView1_KeyUp);
			// 
			// columnHeader8
			// 
			this.columnHeader8.Text = "Mass";
			// 
			// columnHeader5
			// 
			this.columnHeader5.Text = "X";
			// 
			// columnHeader6
			// 
			this.columnHeader6.Text = "Y";
			// 
			// columnHeader7
			// 
			this.columnHeader7.Text = "Z";
			// 
			// columnHeader2
			// 
			this.columnHeader2.Text = "V.X";
			this.columnHeader2.Width = 89;
			// 
			// columnHeader3
			// 
			this.columnHeader3.Text = "V.Y";
			this.columnHeader3.Width = 97;
			// 
			// columnHeader4
			// 
			this.columnHeader4.Text = "V.Z";
			this.columnHeader4.Width = 102;
			// 
			// checkBox1
			// 
			this.checkBox1.Location = new System.Drawing.Point(4, 4);
			this.checkBox1.Name = "checkBox1";
			this.checkBox1.Size = new System.Drawing.Size(72, 16);
			this.checkBox1.TabIndex = 6;
			this.checkBox1.Text = "Trace";
			this.checkBox1.CheckedChanged += new System.EventHandler(this.checkBox1_CheckedChanged);
			// 
			// checkBox2
			// 
			this.checkBox2.Location = new System.Drawing.Point(4, 44);
			this.checkBox2.Name = "checkBox2";
			this.checkBox2.Size = new System.Drawing.Size(72, 16);
			this.checkBox2.TabIndex = 7;
			this.checkBox2.Text = "Show Vel";
			this.checkBox2.CheckedChanged += new System.EventHandler(this.checkBox2_CheckedChanged);
			// 
			// checkBox3
			// 
			this.checkBox3.Location = new System.Drawing.Point(4, 84);
			this.checkBox3.Name = "checkBox3";
			this.checkBox3.Size = new System.Drawing.Size(72, 16);
			this.checkBox3.TabIndex = 8;
			this.checkBox3.Text = "Show Acc";
			this.checkBox3.CheckedChanged += new System.EventHandler(this.checkBox3_CheckedChanged);
			// 
			// textBox1
			// 
			this.textBox1.Location = new System.Drawing.Point(0, 152);
			this.textBox1.Name = "textBox1";
			this.textBox1.Size = new System.Drawing.Size(76, 20);
			this.textBox1.TabIndex = 9;
			this.textBox1.Text = "0";
			// 
			// label1
			// 
			this.label1.Location = new System.Drawing.Point(0, 136);
			this.label1.Name = "label1";
			this.label1.Size = new System.Drawing.Size(76, 16);
			this.label1.TabIndex = 10;
			this.label1.Text = "Vel X";
			// 
			// label2
			// 
			this.label2.Location = new System.Drawing.Point(0, 176);
			this.label2.Name = "label2";
			this.label2.Size = new System.Drawing.Size(76, 16);
			this.label2.TabIndex = 12;
			this.label2.Text = "Vel Y";
			// 
			// textBox2
			// 
			this.textBox2.Location = new System.Drawing.Point(0, 192);
			this.textBox2.Name = "textBox2";
			this.textBox2.Size = new System.Drawing.Size(76, 20);
			this.textBox2.TabIndex = 11;
			this.textBox2.Text = "0";
			// 
			// label3
			// 
			this.label3.Location = new System.Drawing.Point(0, 256);
			this.label3.Name = "label3";
			this.label3.Size = new System.Drawing.Size(76, 16);
			this.label3.TabIndex = 14;
			this.label3.Text = "Mass";
			// 
			// textBox3
			// 
			this.textBox3.Location = new System.Drawing.Point(0, 272);
			this.textBox3.Name = "textBox3";
			this.textBox3.Size = new System.Drawing.Size(76, 20);
			this.textBox3.TabIndex = 13;
			this.textBox3.Text = "100";
			// 
			// label4
			// 
			this.label4.Location = new System.Drawing.Point(0, 296);
			this.label4.Name = "label4";
			this.label4.Size = new System.Drawing.Size(76, 16);
			this.label4.TabIndex = 16;
			this.label4.Text = "Size";
			// 
			// textBox4
			// 
			this.textBox4.Location = new System.Drawing.Point(0, 312);
			this.textBox4.Name = "textBox4";
			this.textBox4.Size = new System.Drawing.Size(76, 20);
			this.textBox4.TabIndex = 15;
			this.textBox4.Text = "2";
			// 
			// label5
			// 
			this.label5.Location = new System.Drawing.Point(0, 216);
			this.label5.Name = "label5";
			this.label5.Size = new System.Drawing.Size(76, 16);
			this.label5.TabIndex = 18;
			this.label5.Text = "Vel Z";
			// 
			// textBox5
			// 
			this.textBox5.Location = new System.Drawing.Point(0, 232);
			this.textBox5.Name = "textBox5";
			this.textBox5.Size = new System.Drawing.Size(76, 20);
			this.textBox5.TabIndex = 17;
			this.textBox5.Text = "0";
			// 
			// button5
			// 
			this.button5.Location = new System.Drawing.Point(0, 336);
			this.button5.Name = "button5";
			this.button5.Size = new System.Drawing.Size(20, 20);
			this.button5.TabIndex = 19;
			this.button5.Text = "B";
			this.button5.Click += new System.EventHandler(this.button5_Click);
			// 
			// button6
			// 
			this.button6.Location = new System.Drawing.Point(28, 336);
			this.button6.Name = "button6";
			this.button6.Size = new System.Drawing.Size(20, 20);
			this.button6.TabIndex = 20;
			this.button6.Text = "M";
			this.button6.Click += new System.EventHandler(this.button6_Click);
			// 
			// button7
			// 
			this.button7.Location = new System.Drawing.Point(56, 336);
			this.button7.Name = "button7";
			this.button7.Size = new System.Drawing.Size(20, 20);
			this.button7.TabIndex = 21;
			this.button7.Text = "S";
			this.button7.Click += new System.EventHandler(this.button7_Click);
			// 
			// checkBox4
			// 
			this.checkBox4.Checked = true;
			this.checkBox4.CheckState = System.Windows.Forms.CheckState.Checked;
			this.checkBox4.Location = new System.Drawing.Point(4, 104);
			this.checkBox4.Name = "checkBox4";
			this.checkBox4.Size = new System.Drawing.Size(72, 16);
			this.checkBox4.TabIndex = 23;
			this.checkBox4.Text = "Acc Box";
			this.checkBox4.CheckedChanged += new System.EventHandler(this.checkBox4_CheckedChanged);
			// 
			// checkBox5
			// 
			this.checkBox5.Checked = true;
			this.checkBox5.CheckState = System.Windows.Forms.CheckState.Checked;
			this.checkBox5.Location = new System.Drawing.Point(4, 64);
			this.checkBox5.Name = "checkBox5";
			this.checkBox5.Size = new System.Drawing.Size(72, 16);
			this.checkBox5.TabIndex = 22;
			this.checkBox5.Text = "Vel Box";
			this.checkBox5.CheckedChanged += new System.EventHandler(this.checkBox5_CheckedChanged);
			// 
			// mainMenu1
			// 
			this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
            this.menuItem1});
			// 
			// menuItem1
			// 
			this.menuItem1.Index = 0;
			this.menuItem1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
            this.menuItem2,
            this.menuItem3,
            this.menuItem4});
			this.menuItem1.Text = "Simulation";
			// 
			// menuItem2
			// 
			this.menuItem2.Index = 0;
			this.menuItem2.Shortcut = System.Windows.Forms.Shortcut.CtrlE;
			this.menuItem2.Text = "Start";
			this.menuItem2.Click += new System.EventHandler(this.button3_Click);
			// 
			// menuItem3
			// 
			this.menuItem3.Index = 1;
			this.menuItem3.Shortcut = System.Windows.Forms.Shortcut.F2;
			this.menuItem3.Text = "Stop";
			this.menuItem3.Click += new System.EventHandler(this.button2_Click);
			// 
			// menuItem4
			// 
			this.menuItem4.Index = 2;
			this.menuItem4.Shortcut = System.Windows.Forms.Shortcut.F5;
			this.menuItem4.Text = "Pause";
			this.menuItem4.Click += new System.EventHandler(this.button4_Click);
			// 
			// checkBox6
			// 
			this.checkBox6.Checked = true;
			this.checkBox6.CheckState = System.Windows.Forms.CheckState.Checked;
			this.checkBox6.Location = new System.Drawing.Point(4, 24);
			this.checkBox6.Name = "checkBox6";
			this.checkBox6.Size = new System.Drawing.Size(72, 16);
			this.checkBox6.TabIndex = 24;
			this.checkBox6.Text = "Collisions";
			this.checkBox6.CheckedChanged += new System.EventHandler(this.checkBox6_CheckedChanged);
			// 
			// button1
			// 
			this.button1.Location = new System.Drawing.Point(0, 360);
			this.button1.Name = "button1";
			this.button1.Size = new System.Drawing.Size(76, 20);
			this.button1.TabIndex = 25;
			this.button1.Text = "Background";
			this.button1.Click += new System.EventHandler(this.button1_Click_1);
			// 
			// Form1
			// 
			this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
			this.ClientSize = new System.Drawing.Size(620, 465);
			this.Controls.Add(this.button1);
			this.Controls.Add(this.checkBox6);
			this.Controls.Add(this.checkBox4);
			this.Controls.Add(this.checkBox5);
			this.Controls.Add(this.button7);
			this.Controls.Add(this.button6);
			this.Controls.Add(this.button5);
			this.Controls.Add(this.label5);
			this.Controls.Add(this.textBox5);
			this.Controls.Add(this.label4);
			this.Controls.Add(this.textBox4);
			this.Controls.Add(this.label3);
			this.Controls.Add(this.textBox3);
			this.Controls.Add(this.label2);
			this.Controls.Add(this.textBox2);
			this.Controls.Add(this.label1);
			this.Controls.Add(this.textBox1);
			this.Controls.Add(this.checkBox3);
			this.Controls.Add(this.checkBox2);
			this.Controls.Add(this.checkBox1);
			this.Controls.Add(this.listView1);
			this.Controls.Add(this.pictureBox1);
			this.Menu = this.mainMenu1;
			this.Name = "Form1";
			this.Text = "Gravity Simulator";
			((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
			this.ResumeLayout(false);
			this.PerformLayout();

		}
		#endregion

		[STAThread]
		static void Main() {
			Application.Run(new Form1());
		}

		private ParticleSystem ps;

		private void button2_Click(object sender, System.EventArgs e) {
			ps.Stop();
			timer1.Enabled = false;
			menuItem3.Enabled = false;
			menuItem4.Enabled = false;
			menuItem4.Text = "Pause";
		}

		private void pictureBox1_Resize(object sender, EventArgs e) {
			blank = new Bitmap(pictureBox1.Width, pictureBox1.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
			using (Graphics g = Graphics.FromImage(blank)) {
				g.Clear(Color.FromArgb(20, 255, 255, 255));
			}
		}

		private int ticks;
		private Bitmap blank;
		private void timer1_Tick(object sender, System.EventArgs e) {
			menuItem3.Enabled = true;
			menuItem4.Enabled = true;
			if (!ps.IsRunning) {
				timer1.Enabled = false;
				menuItem3.Enabled = false;
				MessageBox.Show(this, "Done");
			}

			using (Bitmap bmp = new Bitmap(pictureBox1.Width, pictureBox1.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb)) {
				//if (blank == null) {
				//    blank = new Bitmap(pictureBox1.Width, pictureBox1.Height);
				//    using (Graphics g = Graphics.FromImage(blank)) {
				//        g.Clear(Color.FromArgb(20, 255, 255, 255));
				//    }
				//}

				using (Graphics g = Graphics.FromImage(bmp)) {
					ps.Draw(g, pictureBox1.ClientRectangle);
				}
				using (Graphics g = pictureBox1.CreateGraphics()) {
					//if (checkBox1.Checked) {
					//    //System.Drawing.Imaging.ImageAttributes middleImageAttributes = new System.Drawing.Imaging.ImageAttributes();
					//    //System.Drawing.Imaging.ColorMatrix middleColorMatrix = new System.Drawing.Imaging.ColorMatrix();
					//    //middleColorMatrix.Matrix33 = 0.1f;
					//    //middleImageAttributes.SetColorMatrix(middleColorMatrix, System.Drawing.Imaging.ColorMatrixFlag.Default, System.Drawing.Imaging.ColorAdjustType.Bitmap);
					//    //g.DrawImage(blank, pictureBox1.ClientRectangle, 0, 0, pictureBox1.Width, pictureBox1.Height, GraphicsUnit.Pixel, middleImageAttributes);
					//    ////g.FillRectangle(fadeBrush, pictureBox1.ClientRectangle);
					//    g.DrawImage(blank, 0, 0);
					//}
					g.DrawImage(bmp, 0, 0);
				}
			}

			//Graphics g = pictureBox1.CreateGraphics();
			//ps.Draw(g, pictureBox1.Bounds);

			//if (ps.Particles.Count < 50) {
			//    ticks++;
			//    if (ticks > 50) {
			//        listView1.Items.Clear();
			//        foreach (Particle p in ps.Particles) {
			//            ListViewItem lvi = new ListViewItem(p.Mass.ToString());
			//            lvi.ForeColor = p.Color;
			//            lvi.SubItems.Add(p.Location.X.ToString());
			//            lvi.SubItems.Add(p.Location.Y.ToString());
			//            lvi.SubItems.Add(p.Location.Z.ToString());
			//            lvi.SubItems.Add(p.Velocity.X.ToString());
			//            lvi.SubItems.Add(p.Velocity.Y.ToString());
			//            lvi.SubItems.Add(p.Velocity.Z.ToString());
			//            lvi.Tag = p;
			//            listView1.Items.Add(lvi);
			//        }
			//        ticks = 0;
			//    }
			//} else {
			//    if (listView1.Items.Count > 0) { listView1.Items.Clear(); }
			//}
		}

		private void button1_Click(object sender, System.EventArgs e) {
			ps = new SingleParticle(new Particle(new Vector(2, 40, 0), new Vector(0.4f, 0, 0), 2, 2, Color.Black));
			Graphics g = pictureBox1.CreateGraphics();
			ps.Start(g, pictureBox1.Bounds);
			timer1.Enabled = true;
		}

		private void button3_Click(object sender, System.EventArgs e) {
			ps = new GravityParticles();
			ps.BackgroundColor = pictureBox1.BackColor;
			Graphics g = pictureBox1.CreateGraphics();
			ps.Start(g, pictureBox1.Bounds);
			timer1.Enabled = true;
			ps.Trace = checkBox1.Checked;
			ps.ShowVelocityVectors = checkBox2.Checked;
			ps.ShowAccelerationVectors = checkBox3.Checked;
			ps.ShowVelocityBox = checkBox5.Checked;
			ps.ShowAccelerationBox = checkBox4.Checked;
			ps.DetectCollisions = checkBox6.Checked;
		}

		private void button4_Click(object sender, System.EventArgs e) {
			ps.IsRunning = !ps.IsRunning;
			timer1.Enabled = ps.IsRunning;
			menuItem4.Text = ps.IsRunning ? "Pause" : "Resume";
			if (!ps.IsRunning) {
				listView1.Items.Clear();
				foreach (Particle p in ps.Particles) {
					ListViewItem lvi = new ListViewItem(p.Mass.ToString());
					lvi.ForeColor = p.Color;
					lvi.SubItems.Add(p.Location.X.ToString());
					lvi.SubItems.Add(p.Location.Y.ToString());
					lvi.SubItems.Add(p.Location.Z.ToString());
					lvi.SubItems.Add(p.Velocity.X.ToString());
					lvi.SubItems.Add(p.Velocity.Y.ToString());
					lvi.SubItems.Add(p.Velocity.Z.ToString());
					lvi.Tag = p;
					listView1.Items.Add(lvi);
				}
			} else {
				if (listView1.Items.Count > 0) { listView1.Items.Clear(); }
			}
		}

		private void pictureBox1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) {
			if (ps == null) { return; }
			Point pt = new Point(e.X, e.Y);
			float vx = 0; try { vx = float.Parse(textBox1.Text); } catch {}
			float vy = 0; try { vy = float.Parse(textBox2.Text); } catch {}
			float vz = 0; try { vz = float.Parse(textBox5.Text); } catch {}
			float m = 0; try { m = float.Parse(textBox3.Text); } catch {}
			float s = 0; try { s = float.Parse(textBox4.Text); } catch {}
			ps.Particles.Add(new Particle(new Vector(pt.X, pt.Y, 0), new Vector(vx, vy, vz), m, s, NewColor()));
		}
		private Color NewColor() {
			Random r = new Random(Environment.TickCount);
			return Color.FromArgb(r.Next(0, 255), r.Next(0, 255), r.Next(0, 255));
		}

		private void checkBox1_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.Trace = checkBox1.Checked;
		}

		private void checkBox2_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.ShowVelocityVectors = checkBox2.Checked;
		}

		private void checkBox5_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.ShowVelocityBox = checkBox5.Checked;
		}

		private void checkBox3_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.ShowAccelerationVectors = checkBox3.Checked;
		}

		private void checkBox4_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.ShowAccelerationBox = checkBox4.Checked;
		}

		private void checkBox6_CheckedChanged(object sender, System.EventArgs e) {
			if (ps == null) { return; }
			ps.DetectCollisions = checkBox6.Checked;
		}

		private void button5_Click(object sender, System.EventArgs e) {
			textBox3.Text = "100000000"; //mass 10000000
			textBox4.Text = "8"; //size
			textBox1.Text = "0"; //vx
			textBox2.Text = "0"; //vy
			textBox5.Text = "0"; //vz
		}

		private void button6_Click(object sender, System.EventArgs e) {
			textBox3.Text = "1000"; //mass
			textBox4.Text = "6"; //size
			textBox1.Text = "2"; //vx 7
			textBox2.Text = "0"; //vy
			textBox5.Text = "0"; //vz
		}

		private void button7_Click(object sender, System.EventArgs e) {
			textBox3.Text = "100"; //mass
			textBox4.Text = "4"; //size
			textBox1.Text = "2"; //vx 9
			textBox2.Text = "0"; //vy
			textBox5.Text = "0"; //vz
		}

		private void listView1_KeyUp(object sender, System.Windows.Forms.KeyEventArgs e) {
			if (ps == null) { return; }
			ArrayList pp = new ArrayList();
			ArrayList ls = new ArrayList();
			if (e.KeyCode == Keys.Delete) {
				foreach (ListViewItem lvi in listView1.SelectedItems) {
					Particle p = lvi.Tag as Particle;
					if (p != null) { pp.Add(p); ls.Add(lvi); }
				}
			}
			foreach (Particle p in pp) {
				ps.Particles.Remove(p);
			}
			foreach (ListViewItem lvi in ls) {
				listView1.Items.Remove(lvi);
			}
		}

		private void pictureBox1_BackColorChanged(object sender, System.EventArgs e) {
			if (ps != null) {
				ps.BackgroundColor = pictureBox1.BackColor;
			}
		}

		private void button1_Click_1(object sender, System.EventArgs e) {
			ColorDialog cd = new ColorDialog();
			if (cd.ShowDialog(this) == DialogResult.OK) {
				if (ps != null) {
					ps.BackgroundColor = cd.Color;
				}
				pictureBox1.BackColor = cd.Color;
				fadeBrush = new SolidBrush(Color.FromArgb(10, pictureBox1.BackColor.R, pictureBox1.BackColor.G, pictureBox1.BackColor.B));
			}
		}
	}
}