2D Graphics

Perform a Screen Capture

Posted on by coder 
   
 


using System;
using System.Drawing;
using System.Runtime.InteropServices;
using System.Windows.Forms;

public class DesktopCapture {

    [DllImport("user32.dll")]
    private extern static IntPtr GetDesktopWindow();

    [DllImport("user32.dll")]
    private extern static IntPtr GetDC(IntPtr windowHandle);

    [DllImport("gdi32.dll")]
    private extern static IntPtr GetCurrentObject(IntPtr hdc,
      ushort objectType);

    [DllImport("user32.dll")]
    private extern static void ReleaseDC( IntPtr hdc );

    const int OBJ_BITMAP = 7;

    public static Bitmap Capture() {
        IntPtr desktopWindow = GetDesktopWindow();
        IntPtr desktopDC = GetDC( desktopWindow );
        IntPtr desktopBitmap = GetCurrentObject(desktopDC, OBJ_BITMAP);
        Bitmap desktopImage = Image.FromHbitmap( desktopBitmap );
        ReleaseDC(desktopDC);
        return desktopImage;
    }
}

Get Screen Resolution

Posted on by coder 


   


  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;
      Bitmap bmp = new Bitmap("winter.jpg");
      g.DrawImage(bmp, 0, 0);

      Console.WriteLine("Screen resolution: " + g.DpiX + "DPI");
      Console.WriteLine("Image resolution: " + bmp.HorizontalResolution + "DPI");
      Console.WriteLine("Image Width: " + bmp.Width);
      Console.WriteLine("Image Height: " + bmp.Height);

      SizeF s = new SizeF(bmp.Width * (g.DpiX / bmp.HorizontalResolution),
                bmp.Height * (g.DpiY / bmp.VerticalResolution));
      Console.WriteLine("Display size of image: " + s);
    }

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

Scale subsequent operations by 3x horizontally and 2x vertically

Posted on by coder 


   



  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);

      g.DrawRectangle(Pens.Black, 10, 10, 50, 50);
      g.DrawEllipse(Pens.Black, 10, 10, 20, 20);

      // Now apply the scaling transformation
      // This will scale subsequent operations by 3x horizontally
      // and 2x vertically
      g.ScaleTransform(3.0f, 2.0f);

      // Now draw the same rectangle and circle, 
      // but with the scaling transformation 
      g.DrawRectangle(Pens.Black, 10, 10, 50, 50);
      g.DrawEllipse(Pens.Black, 10, 10, 20, 20);
    }

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

Fill region

Posted on by coder 


   


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


public class Form1 : System.Windows.Forms.Form
{
  private System.ComponentModel.Container components = null;

  public Form1()
  {
    InitializeComponent();
  }

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

    protected override void OnPaint ( PaintEventArgs e) {
      Rectangle r1 = new Rectangle(10, 10, 50, 50);
      Rectangle r2 = new Rectangle(40, 40, 50, 50);
      Region r = new Region(r1);
      r.Union(r2);

      GraphicsPath path = new GraphicsPath(new Point[] {new Point(45, 45),
                                                        new Point(145, 55),
                                                        new Point(200, 150),
                                                        new Point(75, 150),
                                                        new Point(45, 45)
                                                       }, new byte[] {  (byte)PathPointType.Start,
                                                                        (byte)PathPointType.Bezier,
                                                                        (byte)PathPointType.Bezier,
                                                                        (byte)PathPointType.Bezier,
                                                                        (byte)PathPointType.Line
                                                                     });
      r.Union(path);
      e.Graphics.FillRegion(Brushes.Blue, r);
    }

   private void InitializeComponent() {
      this.components = new System.ComponentModel.Container();
      this.Size = new System.Drawing.Size(300,300);
      this.Text = "Form1";
    }
    static void Main() {
    Application.Run(new Form1());
  }
}

Get repainted regions

Posted on by coder

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);

SizeF sizeF = g.MeasureString(“AA”, this.Font);
StringFormat sf = new StringFormat();
sf.LineAlignment = StringAlignment.Center;

// Set properties of the grid
int cellHeight = (int)sizeF.Height + 200;
int cellWidth = 200;
int nbrColumns = 50;
int nbrRows = 50;

// Output general info to console
Console.WriteLine(“——————————————-“);
Console.WriteLine(“e.ClipRectangle = ” + e.ClipRectangle);
Console.WriteLine(“The following cells need to be redrawn ” +
“(in whole or in part):”);
// Draw the cells and the output to console
for (int row = 0; row < nbrRows; ++row) { for (int col = 0; col < nbrColumns; ++col) { Point cellLocation = new Point(col * cellWidth, row * cellHeight); Rectangle cellRect = new Rectangle(cellLocation.X, cellLocation.Y, cellWidth, cellHeight); if (cellRect.IntersectsWith(e.ClipRectangle)) { Console.WriteLine("Row:{0} Col:{1}", row, col); g.FillRectangle(Brushes.White, cellRect); g.DrawRectangle(Pens.Black, cellRect); String s = String.Format("{0},{1}", col, row); g.DrawString(s, this.Font, Brushes.Black, cellRect, sf); } } } } private void Form1_Resize(object sender, System.EventArgs e) { Invalidate(); } } [/csharp]

Get Clipping region painted

Posted on by coder 


   


  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

Posted on by coder 


   


  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();
    }
  }