Csharp/C Sharp/2D Graphics/Polygon

Draw Polygon

/*
C# Programming Tips & Techniques
by Charles Wright, Kris Jamsa
Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/
using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
using System.Data;
namespace Poly
{
  /// <summary>
  /// Summary description for Form1.
  /// </summary>
  public class PolyclsMain : System.Windows.Forms.Form
  {
    private System.Windows.Forms.MainMenu mainMenu1;
    private System.Windows.Forms.MenuItem menuItem1;
    private System.Windows.Forms.MenuItem mnuFileExit;
    private System.Windows.Forms.Label label1;
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ruponentModel.Container components = null;
    public PolyclsMain()
    {
      //
      // Required for Windows Form Designer support
      //
      InitializeComponent();
      InitForm ();
      //
      // TODO: Add any constructor code after InitializeComponent call
      //
    }
    clsPoint pt = new clsPoint (50, 50);
    clsEllipse ellipse = new clsEllipse (200, 150, 150, 75, 450);
    clsCircle circle = new clsCircle (400, 150, 150);
    clsLine line = new clsLine (400, 150, 150, 450);
//    clsShape [] Shapes;
    private void InitForm ()
    {
//    Shapes = new clsShape [] {pt, ellipse, circle, line};
      pt.color = Color.Red;
      this.MaximumSize = new Size (this.Bounds.Width, this.Bounds.Height);
      this.MinimumSize = this.MaximumSize;
      ellipse.color = Color.DarkOrange;
      line.color = Color.Blue;
    }
    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    protected override void Dispose( bool disposing )
    {
      if( disposing )
      {
        if (components != null) 
        {
          components.Dispose();
        }
      }
      base.Dispose( disposing );
    }
    #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
            this.label1 = new System.Windows.Forms.Label();
            this.mnuFileExit = new System.Windows.Forms.MenuItem();
            this.menuItem1 = new System.Windows.Forms.MenuItem();
            this.mainMenu1 = new System.Windows.Forms.MainMenu();
            this.SuspendLayout();
            // 
            // label1
            // 
            this.label1.BackColor = System.Drawing.SystemColors.Window;
            this.label1.Dock = System.Windows.Forms.DockStyle.Fill;
            this.label1.Name = "label1";
            this.label1.Size = new System.Drawing.Size(680, 341);
            this.label1.TabIndex = 0;
            this.label1.Paint += new System.Windows.Forms.PaintEventHandler(this.label1_Paint);
            // 
            // mnuFileExit
            // 
            this.mnuFileExit.Index = 0;
            this.mnuFileExit.Text = "Exit";
            this.mnuFileExit.Click += new System.EventHandler(this.mnuFileExit_Click);
            // 
            // menuItem1
            // 
            this.menuItem1.Index = 0;
            this.menuItem1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
                        this.mnuFileExit});
            this.menuItem1.Text = "File";
            // 
            // mainMenu1
            // 
            this.mainMenu1.MenuItems.AddRange(new System.Windows.Forms.MenuItem[] {
                        this.menuItem1});
            // 
            // clsMain
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(680, 341);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                        this.label1});
            this.Menu = this.mainMenu1;
            this.MinimizeBox = false;
            this.Name = "Poly";
            this.Text = "Poly";
            this.ResumeLayout(false);
        }
        #endregion
    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    [STAThread]
    static void Main() 
    {
      Application.Run(new PolyclsMain());
    }
    private void mnuFileExit_Click(object sender, System.EventArgs e)
    {
      this.Close (); 
    }
    int m_cx = 100;
    int m_cy = 50;
    private void label1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {
//    foreach (clsShape shape in Shapes)
//      shape.Show (e);
      pt.Show(e);
      ellipse.Show (e);
      circle.Show (e);
      line.Show (e);
    }
  }
  abstract public class clsShape
  {
    protected clsShape() { }
    ~clsShape ()
    {
      if (m_Pen != null)
        m_Pen.Dispose ();
      if (m_Brush != null)
        m_Brush.Dispose ();
    }
    protected Pen m_Pen = null;
    protected SolidBrush m_Brush = null;
    public Color color
    {
      get
      {
        if (m_Brush == null)
          m_Brush = new SolidBrush (Color.Black);
        return (m_Brush.Color);
      }
      set
      {
        if (m_Brush != null)
          m_Brush.Dispose ();
        m_Brush = new SolidBrush (value);
      }
    }
    protected virtual SolidBrush brush
    {
      get
      {
        if (m_Brush == null)
          m_Brush = new SolidBrush (Color.Black);
        return (m_Brush);
      }
    }
    protected virtual Pen pen
    {
      get
      {
        if (m_Pen == null)
          SetPen();
        return (m_Pen);
      }
      set {SetPen ();}
    }
    private void SetPen ()
    {
      if (m_Brush == null)
        m_Brush = new SolidBrush (Color.Black);
      if (m_Pen != null)
        m_Pen.Dispose ();
      m_Pen = new Pen (m_Brush, 2);
    }
    public void Show (PaintEventArgs e)
    {
      Draw (e);
    }
    virtual protected void Draw (PaintEventArgs e)
    {
    }
    protected void Rotate (int angle, Point ptCenter, Point [] ptControl)
    {
            // If the angle is 0, there"s nothing to do
      if (angle == 0)
        return;
            
            // The angle is in tenths of a degree. Convert to radians
      double fAngle = (angle / 10.0) / 57.29578;
            
            // Calculate the sine of the angle
      double fSine = Math.Sin (fAngle);
            
            // Calculate the cosing of the angle
      double fCosine = Math.Cos (fAngle);
            
            // Translate the center point so it can be the center of rotation
      double fRotateX = ptCenter.X - ptCenter.X * fCosine - ptCenter.Y * fSine;
      double fRotateY = ptCenter.Y + ptCenter.X * fSine - ptCenter.Y * fCosine;
      for (int x = 0; x <  ptControl.Length; ++x)
      {
                // Rotate the control point and add the translated center point
        double fNewX = ptControl[x].X * fCosine + ptControl[x].Y *fSine + fRotateX;
        double fNewY = -ptControl[x].X * fSine + ptControl[x].Y *fCosine + fRotateY;
                
                // Put the new values in the control point
        ptControl[x].X = (int) fNewX;
        ptControl[x].Y = (int) fNewY;
      }
    }
  }
  public class clsPoint : clsShape
  {
    protected clsPoint () { }
    public clsPoint (int cx, int cy)
    {
      m_cx = cx;
      m_cy = cy;
    }
    public int cx
    {
      get {return(m_cx);}
      set {m_cx = value;}
    }
    public int cy
    {
      get {return(m_cy);}
      set {m_cy = value;}
    }
    protected int m_cx;
    protected int m_cy;
    override protected void Draw (PaintEventArgs e)
    {
      Point pt1 = new Point (m_cx, m_cy - 1);
      Point pt2 = new Point (m_cx, m_cy + 1);
      e.Graphics.DrawLine (pen, pt1, pt2);
      pt1.X = m_cx - 1;
      pt2.X = m_cx + 1;
      pt1.Y = pt2.Y = m_cy;
      e.Graphics.DrawLine (pen, pt1, pt2);
      e.Graphics.DrawRectangle (pen, m_cx - 3, m_cy - 3, 6, 6);
    }
  }
  public class clsLine : clsShape
  {
    protected clsLine () { }
    public clsLine (int cx, int cy, int length, int angle)
    {
      m_Start = new Point (cx, cy);
      m_End = new Point (cx + length, cy);
      m_Angle = angle;
    }
    protected Point m_End;
    protected Point m_Start;
    protected int m_Angle;
    override protected void Draw (PaintEventArgs e)
    {
      Point ptStart = new Point (m_Start.X, m_Start.Y);
      Point [] ptEnd = new Point[1] {new Point (m_End.X, m_End.Y)};
      Rotate (m_Angle, ptStart, ptEnd);
      e.Graphics.DrawLine (pen, ptStart, ptEnd[0]);
    }
  }
  public class clsCircle : clsPoint
  {
    protected clsCircle () { }
    public clsCircle (int cx, int cy, int radius)
    {
      m_cx = cx;
      m_cy = cy;
      m_Radius = radius;
    }
    protected int m_Radius;
    override protected void Draw (PaintEventArgs e)
    {
      e.Graphics.DrawEllipse (pen, m_cx - m_Radius, m_cy - m_Radius, 2 * m_Radius, 2 * m_Radius);
      DrawCenter (e);
    }
    public void DrawCenter (PaintEventArgs e)
    {
      base.Draw (e);
    }
  }
  /// <summary>
  /// Draws an ellipse using Bezier points
  /// </summary>
  public class clsEllipse : clsCircle, IDisposable
  {
    protected clsEllipse () { }
    public void Dispose ()
    {
    }
    public clsEllipse (int cx, int cy, int horiz, int vert, int rotate)
    {
      m_cx = cx;
      m_cy = cy;
      m_Radius = horiz;
      m_Vert = vert;
      m_Rotate = rotate;
    }
    protected double m_Eccentric;
    protected int m_Vert;
    protected int m_Rotate;
        /// <summary>
        /// Overridden from the clsCircle class
        /// </summary>
        /// <param name="e"></param>
    override protected void Draw (PaintEventArgs e)
    {
      int OffsetX = (int) (2 * m_Radius * (2 * (Math.Sqrt(2) - 1) / 3) + 0.5);
      int OffsetY = (int) (2 * m_Vert * (2 * (Math.Sqrt(2) - 1) / 3) + 0.5);
      Point [] ptEllipse = new Point [13]
          {
          new Point (m_cx + m_Radius, m_cy),
          new Point (m_cx + m_Radius, m_cy - OffsetY),
          new Point (m_cx + OffsetX,  m_cy - m_Vert),
          new Point (m_cx,            m_cy - m_Vert),
          new Point (m_cx - OffsetX,  m_cy - m_Vert),
          new Point (m_cx - m_Radius, m_cy - OffsetY),
          new Point (m_cx - m_Radius, m_cy),
          new Point (m_cx - m_Radius, m_cy + OffsetY),
          new Point (m_cx - OffsetX,  m_cy + m_Vert),
          new Point (m_cx,            m_cy + m_Vert),
          new Point (m_cx + OffsetX,  m_cy + m_Vert),
          new Point (m_cx + m_Radius, m_cy + OffsetY),
          new Point (m_cx + m_Radius, m_cy)
          };
      Point ptCenter = new Point (m_cx, m_cy);
      Rotate (m_Rotate, ptCenter, ptEllipse);
      e.Graphics.DrawBeziers (pen, ptEllipse);
      base.DrawCenter (e);
    }
  }
}