Drawing Tools Subs or Functions with Demo

[TerryRitchie]

OK I am sorry I failed to mention the ratio width : height, 2:1, thing of image, that is important caveat; but the Sphere Radius, sr, should be anything you want (within reason of screen dimensions)? did I misunderstand?

If you use a smaller image it probably takes less time? (going by what you are saying) so take the image and shrink it before submitting to the sub, if time is an issue?

I'm not saying there is anything wrong with the code, quite the opposite as it works well for what is intended. Like I said, it's ingenious.

I contacted Paul Dunn and he said he adapted the code from an algorithm for mapping latitude and longitude coordinates to a rectangle. After he explained its origins it all makes sense now in how it works.

I have code now that can take any size image and create any size sphere. I'm putting it through its paces now to make sure I haven't missed any bugs.

Your thoughts about the magic numbers being related to PI were spot on. 1.5 is half Pi, 3 is Pi, and 6 is 2 * Pi. I used the reciprocal of Pi and 2 * Pi to remove as many divisions as I could from the code for speed.