title: GLSL How to ensure largest possible float value without overflow
body: <p>From what I understand, there are no FLT_MAX type constants in GLSL. </p>
  
  <p>Is there any way to ensure that a float represents the largest possible value without overflow?</p>
  
  <p>EDIT:</p>
  
  <p>Since it was asked what Im using this for:</p>
  
  <p>I'm basically scaling a point out into "infinity". Its for 2D shadow casting, where I completely reshape the triangle strip shadows on the GPU. As I can only control deal with a single vertex at a time the w component stores whether it stays on the hull or is projected to infinity.</p>
  
  <p>In the case that both 'shadow boundary' points on are the same edge, and the light is almost colinear with that edge, I need to ensure that the triangle still covers the entire screen. Its hard to describe.</p>