#include "light/light.h"
#include "scene/scene.h"
#include "shader/materialshader.h"
#include <cmath>

Vector3d tangentToWorldSpace(const Vector3d &surfaceNormal, const Vector3d &surfaceTangent, const Vector3d &surfaceBitangent, const Vector3d &textureNormal) {
  return textureNormal.x * surfaceTangent + textureNormal.y * surfaceBitangent + textureNormal.z * surfaceNormal;
}

MaterialShader::MaterialShader() : opacity(1.0f), normalCoefficient(1.0f), diffuseCoefficient(0.5f), reflectance(0.0f), specularCoefficient(0.5f), shininessExponent(8) {}

Color MaterialShader::shade(Scene const &scene, Ray const &ray) const {
  Color fragmentColor;

  // IMPLEMENT ME

  // (Normal Map) Calculate the new normal vector

  // (Diffuse-/Specular Map) Accumulate the light over all light sources

  // (Reflection Map) Calculate the reflectance, create a reflection ray

  // (Alpha Map) Calculate the opacity, create a background ray

  return fragmentColor;
}

bool MaterialShader::isTransparent() const { return this->opacity < 1.0f || this->alphaMap; }