title: Is there a way to determine how many pixels will be written to, per GL_LINE element?
body: <p>I'm trying to approximate a "trajectory density", by rendering to an FBO with additive blending to count the total number of times each pixel is written to. </p>
  
  <p>The problem is that (1) elements with large displacement will be counted more times due to longer lines, and (2) there is an artifact caused by the fact that the number of pixels used to draw a line also depends on the angle of the line.  </p>
  
  <p>I would like to weight the count of the pixels drawn for each element by the number of pixels used to draw the line. So is there some way to accomplish this? In worst case, I can send length and angle as attributes and estimate pixel count. Is there a better way to do this? Or is there a good alternative way to accomplish what I want to do?</p>