#version 330

in vec4 pos_model;
in vec3 vec_normal;

out vec4 fragColor;

uniform vec4 couleur;
uniform vec4 lum_pos;
uniform mat4 view;
uniform vec4 lum_color;

void main() {
  const vec3 vue = vec3(0, 0, -1);
  const vec4 soleil_color = vec4(0.81f, 0.78f, 0.66f, 1.0f);
  vec3 torche = normalize(pos_model.xyz - lum_pos.xyz);
  float intensite_lumineuse = clamp(dot(vec_normal, -torche), 0., 1.);
  vec3 reflet = (transpose(inverse(view)) * vec4(reflect(torche, vec_normal), 0)).xyz;
  float intensite_specularite = pow(clamp(dot(reflet, -vue), 0., 1.), 10);

  fragColor = intensite_specularite * lum_color + 0.1 * soleil_color + 0.9 * intensite_lumineuse * couleur;
}