Get Clipping region painted


   


  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);

      String s = "Create the necessary objects to draw the text string";
      Font f = new Font("Times New Roman", 12);
      SizeF sf = g.MeasureString(s, f, 100);
      RectangleF rf = new RectangleF(10, 10, sf.Width, sf.Height);

      g.DrawString(s, f, Brushes.Black, rf);
      f.Dispose();

      Console.WriteLine("Clipping region painted: " + e.ClipRectangle);
    }

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


           
          


Region Unions


   


  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 reg = new Region();
      reg.MakeEmpty();

      GraphicsPath gp = new GraphicsPath();
      gp.AddEllipse(10, 10, 50, 50);
      reg.Union(gp);

      gp.Reset();
      gp.AddLine(40, 40, 70, 10);
      gp.AddLine(70, 10, 140, 140);
      gp.CloseFigure();
      reg.Union(gp);

      reg.Union(new Rectangle(40, 50, 60, 60));

      // Set the clipping region
      g.SetClip(reg, CombineMode.Replace);

      g.FillRectangle(Brushes.Green, this.ClientRectangle);

      gp.Dispose();
      reg.Dispose();
    }

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


           
          


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();
    }
  }