progs/glsl/reflect.vert

   1 // Vertex shader for cube-texture reflection mapping
   2 // Brian Paul
   3
   4
   5 varying vec3 normal;
   6
   7 void main()
   8 {
   9    vec3 n = gl_NormalMatrix * gl_Normal;
  10    vec3 u = normalize(vec3(gl_ModelViewMatrix * gl_Vertex));
  11    float two_n_dot_u = 2.0 * dot(n, u);
  12    vec4 f;
  13    f.xyz = u - n * two_n_dot_u;
  14    f.w = 1.0;
  15
  16    // outputs
  17    normal = n;
  18    gl_TexCoord[0] = gl_TextureMatrix[0] * f;
  19    gl_Position = ftransform();
  20 }