UNIFORMS

varying mediump vec3 FS_eye;
varying mediump vec3 FS_normal;
VARYINGS

void main(void)
{
    vec3 n = normalize(FS_normal);
    float diffuse = clamp(dot(LIGHT, n)*_DIFFUSE, 0., 1.);
    float ambient = _AMBIENT + .25*n.z;
    vec4 color = vec4(.4, .4, .4, 1.);

    vec3 e = normalize(FS_eye);
    vec3 R = normalize(reflect(LIGHT, n));
    float specular = pow(clamp(max(dot(R, e), .0), .0, 1.), 12.);

    float shadow = SHADOW;

    gl_FragColor = specular*vec4(.3, .3, .3, 1.)*shadow + shadow * color * diffuse + color * ambient;
}