progs/vpglsl/if.glsl

   1
   2 void main() {
   3     gl_FrontColor = gl_Color;
   4     gl_Position = gl_Vertex;
   5     if (gl_Position.x < 0.5)
   6         gl_FrontColor = vec4(1.0, 0.0, 0.0, 1.0);
   7 }