title: Scatter plots with OpenGL: how to style markers
body: <p>I'm experimenting with OpenGL (for performance reasons) for drawing scatterplots. I'm interested in both 2D and 3D.</p>
  
  <p>What options do I have for <em>styling</em> markers, to make e.g. different groups visible?</p>
  
  <p>Obviously I can vary the color. But in "traditional" scatterplots, one also uses circles, plusses, Xes, boxes etc. - how do I best achieve these in OpenGL scatterplots?</p>
  
  <p>Should I render desired 2D markers to a small texture and then draw one triangles with the texture for each marker? Can I use a texture for alpha only, but use a dynamic color? (to e.g. have texture = class, color = other score)?</p>
  
  <p>Are there any extra cool ways for styling markers in OpenGL that I don't have in regular plotting libraries (say, gnuplot)?</p>
  
  <p>Any hints for performance? Display lists or vertex buffers?</p>