Eyes

• Download VS2008 source - 29.9 KB
• Download VS2005 source - 29.76 KB

Introduction

This article demonstrates how to create a perfect, useless control using C# WinForms and .NET 2.0. The control uses pure managed code, and all visual elements can be adjusted through its properties.

Background

Is it not all developer's deepest desire to create something living? Well, not me! This was solely to have fun playing with the graphics. So, don't expect to see a mouth, nose, or brains in the future.

The Graphics

Above are the basic elements of the eye: background, iris, shadow, pupil, reflex, and the eye-lid. The eye is drawn in this order.

Architecture

The Eye is a single class that inherits from the System.Windows.Forms.Control. Below are the properties and methods of the Eye class.

Using the Code

Using the Eye class is straightforward, but some properties may need some explanation.

• BlinkStep is the rate in which the eye will close when blinking.
• FocusPoint is the point the eye will look, in screen coordinates.
• FocusAngle and FocusDistance are derived (read only) from FocusPoint.
• LidOffset is used when TypeOfEye is Left or Right.

  The offset in pixels is the width of the iris divided by the value. Minimum is 3.

• SlitSize is a percentage of the eye height.
• TypeOfEye is an enum, and can take the values Left, Right, and Cyclops (default).
• Blink() starts a new thread that will blink the eye.

The detailed iris is done using a color blend:

using (var path = new GraphicsPath())
{
  path.AddEllipse(rect);
  using (var gradientBrush = new PathGradientBrush(path))
  {
    gradientBrush.CenterPoint = centerPoint;
    var cb = new ColorBlend(4)
               {
                 Colors = irisColors,
                 Positions = new[] { 0.0F, 0.05F, 0.1F, 1.0F }
               };
    if (cb.Colors == null) return;
    gradientBrush.InterpolationColors = cb;
    g.FillPath(gradientBrush, path);
  }
}

Points of Interest

I attempted to squeeze the iris rectangle to make it more eye-like when going to the edge, but it never quite looked right.

History and Credits

This is the first version - 1.0.