path: root/hw5/src/bumpMap.cpp

/******************************************************************/
/* 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 <cassert>
#include <algorithm>
#include "bumpMap.h"
#include "coordinateTransform.h"

//////////////////
// Constructors //
//////////////////
bumpMap::bumpMap(const std::shared_ptr<const texture_base>& map, float scale, unsigned int channel, const std::shared_ptr<const shader_base>& shader)
  : shadingFrameTransformation(shader)
{
  _map = map;
  _scale = scale;
  _channel = std::max(channel, 2u);
}

/////////////
// Methods //
/////////////
transformation3d bumpMap::_transformation(const vec2d& textureCoord) const
{
  // HW5-BONUS: Implement a bump map. The bump map specifies a 'bump' as a an offset in the 
  //      Z direction (i.e., which aligns to N in the local shading frame). The variable
  //      '_channel' indicates which channel in the '_map' encodes the height offset.
  //      The variable '_scale' determines the relative height of the bump with respect to
  //      the texel size. I.e., the height of a bump is _map(u,v)*_scale.  From the bump
  //      you need to compute the new surface normal, and from this the shading frame
  //      transformation.
  // Modifies: nothing
  // Returns: transformation3d
  return transformation3d();
}


void bumpMap::_print(std::ostream& s) const
{
  s << "bumpMap (" << _scale << " x " << *_map << "[" << _channel << "]) -> {" << *_shader << "}";
}