/******************************************************************/
/* This file is part of the homework assignments for CSCI-427/527 */
/* at The College of William & Mary and authored by Pieter Peers. */
/* No part of this file, whether altered or in original form, can */
/* be distributed or used outside the context of CSCI-427/527     */
/* without consent of either the College of William & Mary or     */
/* Pieter Peers.                                                  */
/******************************************************************/
#ifndef _SHADER_BASE_H_
#define _SHADER_BASE_H_

#include <memory>
#include <ostream>

#include "vec2d.h"
#include "vec3d.h"
#include "color.h"
#include "brdfSample.h"
#include "shaderProperties.h"
#include "intersectionPoint.h"


class shader_base 
{
 public:
  //////////////////
  // Constructors //
  //////////////////
  shader_base(void) {}
  shader_base(const shader_base&) = delete;

  ///////////////
  // Operators //
  ///////////////
  shader_base& operator=(const shader_base&) = delete;

  /////////////
  // Methods //
  /////////////
  virtual color shade(const intersectionPoint& ip, const vec3d& light_dir) const = 0;

  virtual color reflectance(const intersectionPoint& ip, const vec3d& light_dir) const = 0;
  virtual brdfSample sample(const intersectionPoint& ip, float r1, float r2) const = 0;
  virtual float reflectivity(const intersectionPoint& ip) const = 0;
  virtual color emittance(const intersectionPoint& ip) const = 0;

  virtual shaderProperties properties(const intersectionPoint& ip) const = 0;

  /////////////
  // Friends //
  /////////////
  friend std::ostream& operator<<(std::ostream& s, const shader_base& shader)
  {
    shader._print(s);
    return s;
  }

 protected:
  ///////////////////////
  // Protected Methods //
  ///////////////////////
  virtual void _print(std::ostream& s) const = 0;
};

#endif /* _SHADER_BASE_H_ */