   cg and opengl
  Hy.I'm try to create and compile cg shader from fx composer , but i have some problem , then i pass to compile with cgc.What are the specific?1)I must call my shader only "main" for the fragment or vertex shader?2)i must separate the vertex and the fragment shader?3)if i separate the vertex and fragment shader how i can send values for ex from the vshader to the fragment shader? is automatically?4)how i can access light created in opengl?is possible?5)how is better declare the constans vars in cg in a struct?   
  up   