#version 330 core

// Output data
out vec3 color;

// Interpolated values from the vertex shaders
in vec3 Normal_cameraspace;
in vec3 LightDirection_cameraspace;
in vec3 tangent_cameraspace;
in vec3 bitangent_cameraspace;
in vec2 UV;
in vec3 EyeDirection_cameraspace;

// Values that stay constant for the entire mesh
uniform sampler2D tangentnm;
uniform sampler2D diffuse;
uniform sampler2D specular;

void main() {
    vec3 n = normalize(Normal_cameraspace);  // Normal of the computed fragment, in camera space

    // Darboux frame for tangent space normal mapping
		// tangent space normal mapping
		mat3 D = mat3(normalize(tangent_cameraspace), normalize(bitangent_cameraspace), n); 
    n = normalize((D*normalize(texture(tangentnm, UV).rgb * 2 - 1)));                   

    vec3 l = normalize(LightDirection_cameraspace); // Direction of the light (from the fragment to the light)
    float cosTheta = clamp(dot(n,l), 0, 1);         // Cosine of the angle between the normal and the light direction, 

    vec3 E = normalize(EyeDirection_cameraspace); // Eye vector (towards the camera)
    vec3 R = -reflect(l,n);                       // Direction in which the triangle reflects the light
    float cosAlpha = clamp(dot(E,R), 0, 1);       // Cosine of the angle between the Eye vector and the Reflect vector,

    //color =  texture(diffuse, UV).xyz*(0.1 +                                                //  ambient lighting
    //                                   1.3*cosTheta  +                                      //  diffuse lighting
    //                                   2.0*pow(cosAlpha, texture(specular, UV).r*250+10));  // specular lighting
    color =  vec3(0,1,1);
}