Shader for painting cube faces with respect to the direction of the vertex normal . ( March 2012 )

rubixcubefragmentshader.fsh

//Copyright © 2015 Manoj M J
//All Rights Reserved

//Why I do copyright the code that I provide at gist.github.com 
//( https://gist.github.com/mmj-the-fighter/bccd0a7ff57c638beee8 )

//Development History:
//Authored on : Monday, July 04, 2011 using ShaderDesigner
//Posted to my blog on, July 05, 2011  http://www.gamedev1001.blogspot.in/2011/07/gpu-programming.html
//Posted to gamedev.net on March 25, 2012 http://www.gamedev.net/topic/622385-a-free-shader/
//Updated the blog later: http://www.gamedev1001.blogspot.in/2011/07/gpu-programming.html


varying vec4 color;
void main()
{

  gl_FragColor = color;
}

rubixcubevertexshader.vsh

//Copyright © 2015 Manoj M J
//All Rights Reserved

//Why I do copyright the code that I provide at gist.github.com 
//( https://gist.github.com/mmj-the-fighter/bccd0a7ff57c638beee8 )

//Development History:
//Authored on : Monday, July 04, 2011 using ShaderDesigner
//Posted to my blog on, July 05, 2011  http://www.gamedev1001.blogspot.in/2011/07/gpu-programming.html
//Posted to gamedev.net on March 25, 2012 http://www.gamedev.net/topic/622385-a-free-shader/
//Updated the blog later: http://www.gamedev1001.blogspot.in/2011/07/gpu-programming.html


varying vec4 color;
const mat4 pal0 =
mat4(1,0.55,0,1,0,0.9,0,1,1,0,0,1,0,0,0.8,1);
const mat4 pal1 =
mat4(1,1,1,1,1,1,0,1,0,0,0,0,0,0,0,0);

void colorRubix()
{
if( abs(gl_Normal.x) > 0.5 )
{
  if(sign(gl_Normal.x) > 0.0)
  {
    color = pal0[0]; //orange;
  }
  else
  {
   color = pal0[1]; //green
  }
}
else if( abs(gl_Normal.y) >  0.5 )
{
  if(sign(gl_Normal.y) > 0.0)
  {
   color = pal0[2]; //red
  }
  else
  {
   color = pal0[3];//blue;
  }
}
else if(abs(gl_Normal.z) >  0.5 )
{
  if(sign(gl_Normal.z) > 0.0)
  {
   color = pal1[0];//white
  }
  else
  {
   color = pal1[1];//yellow
  }
}
}
void colorNormalDebug()
{
color = vec4( clamp(abs( (gl_Normal + 1.0) * 0.5),0.0,1.0), 1.0 );
}
void colorHashed()
{
  //Note:under construction, experimental
  vec3 n =  (gl_Normal + 1.0);
  float k = 4.0 * n.y + n.z;
  k += 2.0*n.x;
  k += 5.0;
  k = clamp(k,0.0, 6.0);
  //use k as an index to fetch a color;
}
void main()
{
  color = vec4(1,1,1,1);
  colorRubix();
  ///colorNormalDebug();
  gl_Position = ftransform();
}