title: C : send different structures for one function argument
body: <p>I have a function that draws a circle using OpenGL, I would like to pass it a structure containing the x and y coordinates and the radius. The problem is this same function has to be used with 3 different structures all containing the coordinates, radius and some other things that the draw function doesn't use. </p>
  
  <p>Is there some way to only have one argument for 3 different structures (only one is sent at a time).</p>
  
  <p>I hope I've been enough precise.</p>
  
  <p>PS : the functions have to be "abstract".</p>