#version 330

in vec4 mvpos;
in vec3 N;

out vec4 fragColor;

uniform vec4 scolor;
uniform vec4 lcolor;
uniform vec4 lumpos;

void main() {
  vec4 ambient = 0.15f * lcolor * scolor;
  vec3 Ld = normalize(mvpos.xyz - lumpos.xyz);
  float ild = clamp(dot(normalize(N), -normalize(Ld)), 0, 1);
  vec4 diffus = (ild * lcolor) * scolor;
  vec3 R = reflect(Ld, N);
  vec3 Vue = vec3(0, 0, -1);
  float ils = pow(clamp(dot(R, -Vue), 0, 1), 10);
  vec4 spec = ils * lcolor;
  fragColor = ambient + diffus + spec;
}