#ifndef TEXTURE_HPP
#define TEXTURE_HPP
#include <Eigen/Core>
#include <memory>
#include "warping.hpp"
using Color = Eigen::Vector3f;
struct texture{
    virtual Eigen::Vector3f eval(float u, float v)const{
        return Eigen::Vector3f(1,1,1);
    }
};
struct uni_texture : texture{
    Color c;
    uni_texture(const Color& _c) : c(_c){}
    virtual Eigen::Vector3f eval(float u, float v)const override{
        return c;
    }
};
struct bsdf{
    virtual Color eval(const Eigen::Vector3f& in, const Eigen::Vector3f& out, const Eigen::Vector3f& normal)const{
        throw 5;
        return Eigen::Vector3f(1,1,1);
    }
};
struct lambertian_bsdf : bsdf{
    virtual Color eval(const Eigen::Vector3f& in, const Eigen::Vector3f& out, const Eigen::Vector3f& normal)const override{
        float x = in.dot(-normal);
        return Eigen::Vector3f(x,x,x);
    }
};
struct microfacet_bsdf : bsdf{
    const float alpha;
    microfacet_bsdf() : alpha(0.1f){}
    microfacet_bsdf(float _alpha) : alpha(_alpha){}
    virtual Color eval(const Eigen::Vector3f& in, const Eigen::Vector3f& out, const Eigen::Vector3f& normal)const override{
        //float x = in.dot(-normal);
        //return Eigen::Vector3f(x,x,x);
        Eigen::Vector3f mirror_ref = in + normal * (in.dot(normal));
        //float x = beckmann_eval(mirror_ref, alpha);
        float x = 1.0f * std::exp(mirror_ref.dot(out) - 1);
        return Color(x,x,x);
    }
};
struct material{
    std::unique_ptr<texture> tex;
    std::unique_ptr<bsdf> m_bsdf;
    material() : material(Color(1,1,1)){

    }
    material(const Color& c, std::unique_ptr<bsdf>&& bsdf) : tex(std::make_unique<uni_texture>(c)), m_bsdf(std::move(bsdf)){
        
    }
    material(const Color& c) : tex(std::make_unique<uni_texture>(c)), m_bsdf(std::make_unique<lambertian_bsdf>()){
        
    }
};
#endif