/******************************************************************/
/* 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.                                                  */
/******************************************************************/
#include "shadingFrameTransformation.h"


//////////////////
// Constructors //
//////////////////
shadingFrameTransformation::shadingFrameTransformation(const std::shared_ptr<const shader_base>& shader)
  : shader_base()
{
  _shader = shader;
}


/////////////
// Methods //
/////////////
color shadingFrameTransformation::shade(const intersectionPoint& ip, const vec3d& light_dir) const 
{
  // transform to local shading frame
  intersectionPoint localIp(ip);
  localIp.inverseTransformShadingFrame( _transformation(ip.textureCoordinate()) );

  // Done.
  return _shader->shade(localIp, light_dir);
}


color shadingFrameTransformation::reflectance(const intersectionPoint& ip, const vec3d& light_dir) const
{
  // transform to local shading frame
  intersectionPoint localIp(ip);
  localIp.inverseTransformShadingFrame( _transformation(ip.textureCoordinate()) );

  // Done.
  return _shader->reflectance(localIp, light_dir);
}


brdfSample shadingFrameTransformation::sample(const intersectionPoint& ip, float r1, float r2) const
{
  // transform to local shading frame
  intersectionPoint localIp(ip);
  transformation3d ct = _transformation(ip.textureCoordinate());
  localIp.inverseTransformShadingFrame(ct);

  //get sample (in local shading frame)
  brdfSample sample = _shader->sample(localIp, r1, r2);

  // transform to global shading frame
  return sample.transform(ct);
}


float shadingFrameTransformation::reflectivity(const intersectionPoint& ip) const
{
  return _shader->reflectivity(ip);
}


color shadingFrameTransformation::emittance(const intersectionPoint& ip) const
{
  // transform to local shading frame
  intersectionPoint localIp(ip);
  localIp.inverseTransformShadingFrame( _transformation(ip.textureCoordinate()) );

  // Done.
  return _shader->emittance(localIp);
}


shaderProperties shadingFrameTransformation::properties(const intersectionPoint& ip) const
{
  return _shader->properties(ip);
}