The vertex shader is nearly identical to the one from the previous recipe, except that the Phong model is evaluated within a function, and we add another function to convert the position and the normal to camera coordinates:
// Uniform variables and attributes omitted... void getCamSpace( out vec3 norm, out vec3 position ) { norm = normalize( NormalMatrix * VertexNormal); position = (ModelViewMatrix * vec4(VertexPosition,1.0)).xyz;}vec3 phongModel( vec3 position, vec3 n ) { vec3 ambient = Light.La * Material.Ka; vec3 s = normalize( Light.Position.xyz - position ); float sDotN = max( dot(s,n), 0.0 ); vec3 diffuse = Light.Ld * Material.Kd * sDotN; vec3 spec = vec3(0.0); if( sDotN > 0.0 ) { vec3 v = normalize(-position.xyz); ...
