recently, I was building a test application that needed some basic graphic drawing to show some physical values in real time. I wanted to do it simple and fast, so I didn´t want to deal with all the DirectX stuff (devices, resources, etc). That´s why I went into the simple Windows Forms GDI solution.
I wrote the program and run fine but, as expected, flickering appeared all around when animation came into scene. This is something that was obviously going to happen, so I decided to remember the old times and search for a double buffer drawing solution.
It is very simple to fix this behavior, just draw everything appart, to a different surface, and then dump the whole picture to the screen. Among the different solutions I found over the internet, one of the best and most simple is the code included below (NT Almond. 2003):
Just include it in a class and perform all the rendering through its Graphics object.
et voilá!
using System;
using System.Drawing;
namespace GDIDB
{
///
/// Class to implement Double Buffering
/// NT Almond
/// 24 July 2003
///
///
public class DBGraphics
{
private Graphics graphics;
private Bitmap memoryBitmap;
private int width;
private int height;
///
/// Default constructor
///
public DBGraphics()
{
width = 0;
height = 0;
}
///
/// Creates double buffer object
///
/// Window forms Graphics Object
/// width of paint area
/// height of paint area
///
public bool CreateDoubleBuffer( Graphics g, int width, int height )
{
if ( width <= 0 height <= 0 ) return false; if ( width != this.width height != this.height memoryBitmap == null graphics == null ) { if ( memoryBitmap != null ) { memoryBitmap.Dispose(); memoryBitmap = null; } if ( graphics != null ) { graphics.Dispose(); graphics = null; } this.width = width; this.height = height; memoryBitmap = new Bitmap( width, height ); graphics = Graphics.FromImage( memoryBitmap ); } return true; } ///
/// Renders the double buffer to the screen
///
/// Window forms Graphics Object
public void Render( Graphics g )
{
if ( memoryBitmap != null )
g.DrawImage( memoryBitmap, new Rectangle( 0, 0, width, height ), 0, 0, width, height, GraphicsUnit.Pixel );
}
///
///
///
///
public bool CanDoubleBuffer()
{
return graphics != null;
}
///
/// Accessor for memory graphics object
///
public Graphics g
{
get
{
return graphics;
}
}
}
}
Code found here, among other sites:
http://www.koders.com/csharp/fid8D1742BF7E30AEB520A0548A95C99DD48CDAA645.aspx