Csharp/C Sharp/2D Graphics/Clip

Clip Draw

/*
GDI+ Programming in C# and VB .NET
by Nick Symmonds
Publisher: Apress
ISBN: 159059035X
*/
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
using System.Data;
namespace ClipDraw_c
{
    /// <summary>
    /// Summary description for ClipDraw_c.
    /// </summary>
    public class ClipDraw_c : System.Windows.Forms.Form
    {
        private System.Windows.Forms.Button B1;
        private System.Windows.Forms.Button B2;
        private System.Windows.Forms.Button B3;
        
        internal System.Windows.Forms.Button B4;
        internal System.Windows.Forms.Button B5;
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ruponentModel.Container components = null;
        public ClipDraw_c() {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
            this.MouseMove += new MouseEventHandler(this.ClipDraw_cMouse);
        }
        /// <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.B1 = new System.Windows.Forms.Button();
            this.B2 = new System.Windows.Forms.Button();
            this.B3 = new System.Windows.Forms.Button();
            this.B4 = new System.Windows.Forms.Button();
            this.B5 = new System.Windows.Forms.Button();
            this.SuspendLayout();
              // 
            // B1
            // 
            this.B1.Location = new System.Drawing.Point(16, 232);
            this.B1.Name = "B1";
            this.B1.Size = new System.Drawing.Size(56, 24);
            this.B1.TabIndex = 0;
            this.B1.Text = "Clip";
            this.B1.Click += new System.EventHandler(this.B1_Click);
            // 
            // B2
            // 
            this.B2.Location = new System.Drawing.Point(96, 232);
            this.B2.Name = "B2";
            this.B2.Size = new System.Drawing.Size(56, 24);
            this.B2.TabIndex = 1;
            this.B2.Text = "SetClip";
            this.B2.Click += new System.EventHandler(this.B2_Click);
            // 
            // B3
            // 
            this.B3.Location = new System.Drawing.Point(176, 232);
            this.B3.Name = "B3";
            this.B3.Size = new System.Drawing.Size(88, 24);
            this.B3.TabIndex = 2;
            this.B3.Text = "ExcludeClip";
            this.B3.Click += new System.EventHandler(this.B3_Click);
            // 
            // B4
            // 
            this.B4.Location = new System.Drawing.Point(176, 200);
            this.B4.Name = "B4";
            this.B4.Size = new System.Drawing.Size(88, 24);
            this.B4.TabIndex = 4;
            this.B4.Text = "Intersect";
            this.B4.Click += new System.EventHandler(this.B4_Click);
            // 
            // B5
            // 
            this.B5.Location = new System.Drawing.Point(280, 232);
            this.B5.Name = "B5";
            this.B5.Size = new System.Drawing.Size(88, 24);
            this.B5.TabIndex = 5;
            this.B5.Text = "IntersectClip";
            this.B5.Click += new System.EventHandler(this.B5_Click);
            // 
            // ClipDraw_c
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(376, 273);
            this.Controls.AddRange(new System.Windows.Forms.Control[] {
                                                                  this.B5,
                                                                  this.B4,
                                                                  this.B3,
                                                                  this.B2,
                                                                  this.B1});
            this.Name = "ClipDraw_c";
            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
            this.Text = "ClipDraw_c";
            this.Load += new System.EventHandler(this.ClipDraw_c_Load);
            this.ResumeLayout(false);
        }
        #endregion
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new ClipDraw_c());
        }
        private Graphics G_obj;
        private void ClipDraw_c_Load(object sender, System.EventArgs e)
        {
    
        }
        private void ClipDraw_cMouse(System.Object sender , MouseEventArgs e) 
        {
            if (G_obj == null)
                return;
            if (G_obj.IsVisible(e.X, e.Y))
                G_obj.FillRectangle(Brushes.BlueViolet, e.X, e.Y, 1, 1);
        }
        private void B1_Click(object sender, System.EventArgs e)
        {
            Graphics G  = this.CreateGraphics();
            Rectangle R = new Rectangle(50, 50, 100, 100);
            G.Clear(Color.Gainsboro);
            //Outline the rectangle and create the clipping region
            G.DrawRectangle(Pens.Black, R);
            G.Clip = new Region(R);
            //Draw line the sidth of the form
            G.DrawLine(Pens.Blue, 0, 75, this.Width, 75);
            //Draw a circle 1/4 inside clipping region
            G.FillEllipse(Brushes.LawnGreen, new Rectangle(75, 75, 150, 150));
            G.Dispose();    
        }
        private void B2_Click(object sender, System.EventArgs e)
        {
            Graphics G = this.CreateGraphics();
            Rectangle R = new Rectangle(20, 20, 100, 100);
            GraphicsPath path = new GraphicsPath();
            G.Clear(Color.Gainsboro);
            path.AddEllipse(R);
            G.DrawPath(Pens.Black, path);
            G.SetClip(path);
            // Draw some clipped strings.
            Font F = new Font("Arial", 16);
            G.DrawString("ABCDEFGHIJKLM", F, Brushes.DeepPink, 15, 25);
            G.DrawString("NOPQRSTUVWXYZ", F, Brushes.DeepPink, 15, 68);
            path.Dispose();
        }
        private void B3_Click(object sender, System.EventArgs e)
        {
            Graphics G = this.CreateGraphics();
            Rectangle R = new Rectangle(40, 20, 100, 100);
            GraphicsPath path = new GraphicsPath();
            G.Clear(Color.Gainsboro);
            path.AddEllipse(R);
            G.DrawPath(Pens.Black, path);
            G.ExcludeClip(new Region(path));
            // Draw some clipped strings.
            Font F = new Font("Arial", 16);
            G.DrawString("ABCDEFGHIJKLM", F, Brushes.DeepPink, 15, 25);
            G.DrawString("NOPQRSTUVWXYZ", F, Brushes.DeepPink, 15, 68);
            path.Dispose();    
            F.Dispose();
        }
        private void B4_Click(object sender, System.EventArgs e)
        {
      Graphics G = this.CreateGraphics();
      Rectangle R = new Rectangle(40, 20, 100, 100);
      Rectangle R2 = new Rectangle(60, 20, 120, 120);
      GraphicsPath P1 = new GraphicsPath();
      GraphicsPath P2 = new GraphicsPath();
      G.Clear(Color.Gainsboro);
      P1.AddEllipse(R);
      G.DrawPath(Pens.Black, P1);
      P2.AddEllipse(R2);
      G.DrawPath(Pens.Black, P2);
      G.SetClip(P1);
      G.SetClip(P2, CombineMode.Intersect);
      // Draw some clipped strings.
      Font F = new Font("Arial", 16);
      G.DrawString("ABCDEFGHIJKLM", F, Brushes.DeepPink, 15, 25);
      G.DrawString("NOPQRSTUVWXYZ", F, Brushes.DeepPink, 15, 68);
      G_obj = G;
      F.Dispose();
      P1.Dispose();     
      P2.Dispose();     
    }
    private void B5_Click(object sender, System.EventArgs e)
    {
      //Bail out if not set
      if (G_obj == null )
        return;
      Rectangle R2 = new Rectangle(75, 75, 150, 150);
      G_obj.IntersectClip(R2);
      G_obj.FillRectangle(new SolidBrush(Color.Blue), 0, 0, 500, 500);
    }
    }
}

Clipping

/*
Professional Windows GUI Programming Using C#
by Jay Glynn, Csaba Torok, Richard Conway, Wahid Choudhury, 
   Zach Greenvoss, Shripad Kulkarni, Neil Whitlow
Publisher: Peer Information
ISBN: 1861007663
*/
using System;
using System.Drawing;
using System.Collections;
using System.ruponentModel;
using System.Windows.Forms;
using System.Data;
using System.Drawing.Drawing2D;
namespace Clipping
{
    /// <summary>
    /// Summary description for Clipping.
    /// </summary>
    public class Clipping : System.Windows.Forms.Form
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ruponentModel.Container components = null;
        GraphicsPath gP;
        public Clipping()
        {
            //
            // Required for Windows Form Designer support
            //
            InitializeComponent();
            this.Text = "Transform and Clip";
            //
            // TODO: Add any constructor code after InitializeComponent call
            //
        }
        /// <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()
        {
            // 
            // Clipping
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(292, 149);
            this.Name = "Clipping";
            this.Text = "Clipping";
        }
        #endregion
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() 
        {
            Application.Run(new Clipping());
        }
        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            DrawPathTransform(g);
            //DrawClip(g);
            g.Dispose();
        }
        void AddStringToPath(string s)
        {
            int fSt = (int)FontStyle.Regular;
            Point xy = new Point(50, 10);
            FontFamily fF = new FontFamily("Times new roman");
            StringFormat sFr = StringFormat.GenericDefault;
            gP.AddString(s, fF, fSt, 100, xy, sFr);  // add the string to the path
        }
        void DrawPathTransform(Graphics g)
        {
            gP = new GraphicsPath();  // create a new path
            AddStringToPath("C#");
            g.FillPath(Brushes.Gray, gP);  // draw the path to the surface
            Matrix m = new Matrix();
            m.Translate(5, 5);
            gP.Transform(m);
            g.FillPath(Brushes.Yellow, gP);  // draw the path to the surface
            g.DrawPath(Pens.Red, gP);  // draw the path to the surface
        }
        void DrawClip(Graphics g)
        {
            gP = new GraphicsPath();  // create a new path
            AddStringToPath("C#");
            g.SetClip(gP);
            g.TranslateClip(-5, -5);
            RectangleF rc = gP.GetBounds();
            rc.Offset(-5, -5);
            g.FillRectangle(Brushes.Gray, rc);  // results in gray C#
            g.ResetClip();
            g.FillPath(Brushes.Yellow, gP);  // draw the path to the surface
            g.DrawPath(Pens.Red, gP);  // draw the path to the surface
        }
    }
}

Clipping Combinations

 
using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
   
class ClippingCombinations: Form
{
     string   strCaption = "CombineMode = ";
     MenuItem miCombineMode;
   
     public static void Main()
     {
          Application.Run(new ClippingCombinations());
     }
     protected override void OnPaint(PaintEventArgs pea)
     {
          DoPage(pea.Graphics, ForeColor,ClientSize.Width, ClientSize.Height);
     }      
     public ClippingCombinations()
     {
          ResizeRedraw = true;
   
          Menu = new MainMenu();
          Menu.MenuItems.Add("&CombineMode");
   
          EventHandler ehClick = new EventHandler(MenuCombineModeOnClick);
          
          for (int i = 0; i < 6; i++)
          {
               MenuItem mi   = new MenuItem("&" + (CombineMode)i);
               mi.Click     += ehClick;
               mi.RadioCheck = true;
   
               Menu.MenuItems[0].MenuItems.Add(mi);
          }
          miCombineMode = Menu.MenuItems[0].MenuItems[0];
          miCombineMode.Checked = true;
     }
     void MenuCombineModeOnClick(object obj, EventArgs ea)
     {
          miCombineMode.Checked = false;
          miCombineMode = (MenuItem) obj;
          miCombineMode.Checked = true;
   
          Text = strCaption + (CombineMode)miCombineMode.Index;
          Invalidate();
     }
     protected void DoPage(Graphics grfx, Color clr, int cx, int cy)
     {
          GraphicsPath path = new GraphicsPath();
          path.AddEllipse(0, 0, 2 * cx / 3, cy);
          grfx.SetClip(path);
   
          path.Reset();
          path.AddEllipse(cx / 3, 0, 2 * cx / 3, cy);
          grfx.SetClip(path, (CombineMode)miCombineMode.Index);
   
          grfx.FillRectangle(Brushes.Red, 0, 0, cx, cy);
     }
}

draw something onto the drawing surface (with the clipping region applied)

 
using System;
using System.Collections.Generic;
using System.ruponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Text;
using System.Windows.Forms;
public class Form1 : Form {
    protected override void OnPaint(PaintEventArgs e) {
    Graphics g = e.Graphics;
    g.FillRectangle(Brushes.White, this.ClientRectangle);
    Rectangle rect = new Rectangle(10, 10, 80, 50);
    g.DrawRectangle(Pens.Black, rect);
    g.SetClip(rect);
    g.FillEllipse(Brushes.Blue, 20, 20, 100, 100);
    }
    public static void Main() {
        Application.Run(new Form1());
    }
}

Write info about the clipping rectangle to the console window

 
using System;
using System.Collections.Generic;
using System.ruponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
public class Form1 : Form {
    protected override void OnPaint(PaintEventArgs e) {
    Graphics g = e.Graphics;
    g.FillRectangle(Brushes.White, this.ClientRectangle);
    String s = "text";
    Font f = new Font("Times New Roman", 12);
    SizeF sf = g.MeasureString(s, f, 400);
    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);
    }
    public static void Main() {
        Application.Run(new Form1());
    }
}