Nautilus Spiral: A bit complicated

[Boleeman]

I made a Nautilus Spiral in Lazarus

Used a bgrabmp for the rendering.


Not sure exactly why but there is a part in the code I had to "trial and error" to get the expected curve.

Code: Pascal  [Select][+][-]

1.     if (i <= 12) or ((i >= 29) and (i <= 44)) then
2.       perp := PointF(perp.X, perp.Y);
3.  
4.     arcCenter := PointF(
5.       midPt.X + perp.X * hh,
6.       midPt.Y + perp.Y * hh
7.     );

Would be nice to make a 3D version, but not really sure how to go about it.
Found a JavaScript 3D version that looks good.

Enjoy.