How to shade a picture (image)?

The object of the exercise is to draw a sizeable colored map of the World, and to show on it the Grayline curve (where is sunshine, where is darkness), the daylight terminator (where is twilight), and some orbiting satellite footprints. The areas are dynamic, and recalculated every few seconds.

The math is done, the plots are accurate, but the graphics stinks.

I needed the map to be sizeable as the form is resized, so I used an image. For my initial (very unsatisfactory) graphics, I saved the curves I had calculated is an array of POINTAPI, and use the
SetPolyFillMode and Polygon APIs on the form to draw the curves and fill the areas.

Anyone willing to work with me (this could take a while) on how to do this more elegantly (considering how bad mine looks, that shouldn't be too hard).

Again, the object of the exercise to shade irregular areas of a coloredpicture (on an Image Control), and to periodically update the size, shape, and position of the shaded areas.

Thanks,

Why don't you try Jotaf98's Special Effects Module,
His post can be found here: Post

Thanks. Let me play with this and see what I can do.