How to draw Windows 7 taskbar like Shaded Buttons

Question

Windows 7 taskbar buttons are drawn on a shaded background. The color shade somehow reacts on where the mouse is over the button.

I\'d like to use such buttons in my

Answer 1

I believe they're implemented as shader programs on the GPU. Just a simple program which takes the cursor position, and computes a brightness for each pixel based on the distance from that position.