OverlaySlide takes an image and draws it. It then takes another image, and from left to right, draws it on top of the first image, either
in a narrow band (as above) or in a solid sweep. Transparent images enable you to do some really cool stuff with this.
OverlaySlide takes a number of parameters:
- Speed (1-1000)
- Higher is faster. About 20 is what you typically want.
- The base image
- The overlayed image
- wid (optional)
- If set, this is the width, in pixels of the band of the overlay to use. A value of 12 is used above.