title: Methods for implementing contour plotting
body: <p>I need to implement a contour plotting algorithm (as opposed to just using one). The input is a (continuous) function f: R^2 - > R (the function is defined over the entire domain, not just for certain inputs). The output should be in vector form, i.e. a set of splines or line segments.</p>
  
  <p>I'm looking for recommendations on how to implement this, preferably in the form of (scientific) papers.</p>
  
  <p>I found some references to algorithms developed in the 80s ("Level Tracing Algorithm"). Have there been any development in this area in the past 30 years? What's the standard method(s) used to solve this problem?</p>
  
  <p>The algorithm will be used for real-time visualization, so it needs to be fast while still producing decent results.</p>
  
  <p>(Small, self-contained and well tested C/C++ implementations would be welcomed as well.)</p>