Color 1 is the Surround Color for the 'unlit' state, Color 2 is the Centre Color for the 'unlit' state AND the Surround Color for the 'lit' state, and Color 3 is the Centre Color for the 'lit' state. There are fifteen LEDs, each of which uses three colors. In short, we size each LED so that fifteen will fit nicely within the size of the control, build a 3D border round them, and light them with a PathGradientBrush according to the Volume property. The control inherits from, and overrides the OnPaint method.
It doesn't do anything at all with Digital Signal Processing, so apologies to anyone who was hoping it would, but I think it looks really nice, so it became the subject of my first submission to The Code Project. As is often the case, it was easier than I had first thought. Having thought about writing my own TrackBar control, but discovering that someone else had already done it, I decided to use my new-found knowledge and try to create an LED vu Meter, such as is found in PC and Mac music recording systems. After a considerable amount of brain-wringing, I managed to get to grips with the basics of Matrix and Transform. Here, I learned all about the PathGradientBrush. While researching a small project to develop round 3D buttons, I came across the very excellent Bob Powell site.
