fragmentShader_Minnaert.txt

varying vec3 N;
varying vec3 v;  
varying vec2 texture_coordinate; 

uniform sampler2D my_color_texture;

void main (void)  
{  
   gl_FragColor = gl_FrontLightModelProduct.sceneColor;
   vec3 l, h;
   const float k = 0.8;
   
   for (int i = 0; i < 3; i++) {
        l = gl_LightSource[i].position.xyz - v;
        h = l + v ;
    
        vec3  n2   = normalize ( N );
        vec3  l2   = normalize ( l );
        vec3  v2   = normalize ( v );
        float d1 = pow ( max ( dot ( n2, l2 ), 0.0 ), 1.0 + k );
        float d2 = pow ( 1.0 - dot ( n2, v2 ), 1.0 - k );
    
        vec4 Iamb = gl_FrontLightProduct[i].ambient;     
        vec4 Idiff = gl_FrontLightProduct[i].diffuse;    
        vec4 Ispec = gl_FrontLightProduct[i].specular;

        gl_FragColor += Idiff * d1 * d2;
   }
   //gl_FragColor *= texture2D(my_color_texture, texture_coordinate);
}