How do I blit image along path in pygame?

Question

Here's an image of what I'm trying to achieve: http://bit.ly/cabifI Basically I want the blue circle to move along the curve path back and forth when I press the right and left arrow keys.

I know I have to blit the image but is there a way to automatically determine the x,y coordinates of the path and blit the image into there while pressing the keys?

Or is there some king of algorithm/techniques that needs to be used?

Answer 1

I assume you know the paths coordinates.

Given a single point along the path, place the ball on the same x but let y = y - ballRadius - (lineWidth / 2).

A very simple approximation; you will probably have some intersections, especially on steep slopes, but it might do the trick.