Region Clips


   


  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Rectangle rect = new Rectangle(10, 10, 80, 80);

      g.DrawRectangle(Pens.Black, rect);

      g.SetClip(rect);

      g.FillEllipse(Brushes.Blue, 20, 20, 100, 100);
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }


           
          


Is this Rectangle visible to the Region


   



  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);

      Rectangle rect = new Rectangle(25, 65, 5, 5);
      g.DrawRectangle(Pens.Black, rect);
      Console.WriteLine((r.IsVisible(rect) ? " - is visible"
                         : " - is invisible")
                + " in the rectangle shown");
      r.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

           
          


Is a point visible to a Region


   


  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);

      PointF pf = new PointF(35.0f, 30.0f);
      Console.WriteLine((r.IsVisible(pf) ? " - includes"
                         : " - excludes")
                + " the point (35.0, 50.0)");
      r.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }


           
          


Is Region Empty


   


  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);

      Console.WriteLine(r.IsEmpty(g) ? " - is empty"
                       : " - is non-empty");

      r.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }


           
          


Is Region finite


   


  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);

      Console.WriteLine(r.IsInfinite(g) ? " - is infinite"
                        : " - is finite");

      r.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }


           
          


Region Excludes


   



  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      Region r = new Region(new Rectangle(30, 30, 30, 60));
      r.Exclude(new Rectangle(40, 40, 10, 10));
      g.FillRegion(Brushes.Orange, r);

      r.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }

           
          


Fill a Region


   


  using System;
  using System.Drawing;
  using System.Drawing.Drawing2D;
  using System.Collections;
  using System.ComponentModel;
  using System.Windows.Forms;
  using System.Data;
  using System.Drawing.Imaging;

  public class Form1 : System.Windows.Forms.Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    private void InitializeComponent()
    {
      this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
      this.ClientSize = new System.Drawing.Size(292, 273);
      this.Text = "";
      this.Resize += new System.EventHandler(this.Form1_Resize);
      this.Paint += new System.Windows.Forms.PaintEventHandler(this.Form1_Paint);

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

    private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e)
    {      
      Graphics g = e.Graphics;
      g.FillRectangle(Brushes.White, this.ClientRectangle);

      GraphicsPath gp = new GraphicsPath();

      gp.AddLine(10, 10, 10, 50);
      gp.AddBezier(10, 50, 120, 55, 25, 70, 30, 70);
      gp.AddLine(30, 70, 60, 70);
      gp.AddBezier(60, 70, 305, 70, 90, 55, 90, 50);
      gp.AddLine(90, 50, 90, 30);

      gp.StartFigure();
      gp.AddLine(60, 110, 40, 160);
      gp.AddLine(40, 160, 60, 180);

      // Create a Region whose boundary is the above GraphicsPath 
      Region reg = new Region(gp);

      g.FillRegion(Brushes.Green, reg);
      reg.Dispose();
      gp.Dispose();
    }

    private void Form1_Resize(object sender, System.EventArgs e)
    {
      Invalidate();
    }
  }