PerspectiveCamera.cxx

   1 #include <limits>
   2 #include <iostream>
   3
   4 #include "PerspectiveCamera.hxx"
   5
   6 PerspectiveCamera::PerspectiveCamera()
   7   : Camera()
   8 {
   9 }
  10
  11 PerspectiveCamera::PerspectiveCamera(const Vec3f& pos,
  12                                      const Vec3f& dir,
  13                                      const Vec3f& up,
  14                                      float angle,
  15                                      int resX,
  16                                      int resY)
  17   : Camera(resX,resY),
  18     m_pos(pos),
  19     m_dir(dir),
  20     m_up(up),
  21     m_angle(angle)
  22 {
  23   // preprocess the values and fill the rest of the member variables here
  24
  25   // compute local coordinate system
  26   m_zAxis = dir;
  27   m_xAxis = dir.cross(up);
  28   m_yAxis = m_xAxis.cross(m_zAxis);
  29
  30   m_xAxis.normalize();
  31   m_yAxis.normalize();
  32   m_zAxis.normalize();
  33
  34   m_aspect = resX/static_cast<float>(resY);
  35
  36   // derive focal length from opening angle
  37   float angle_in_rad = angle * M_PI / 180.0f;
  38   m_focus = 1.0 / tan(angle_in_rad * 0.5);
  39 }
  40
  41 PerspectiveCamera::~PerspectiveCamera()
  42 {
  43 }
  44
  45 PerspectiveCamera::PerspectiveCamera(const PerspectiveCamera& )
  46 {
  47
  48 }
  49
  50 PerspectiveCamera&
  51 PerspectiveCamera::operator=(const PerspectiveCamera& )
  52 {
  53   return *this;
  54 }
  55
  56 bool
  57 PerspectiveCamera::InitRay(float x, //!< pixel x-coordinate
  58                            float y, //!< pixel y-coordinate
  59                            Ray& ray //!< should be filled by this function
  60                            ) const
  61 {
  62   // define direction,position and maximum hit distance of Ray here
  63   Vec3f dir = m_xAxis * ( 2.0f * ((x/static_cast<float>(m_resX) - 0.5 ) * m_aspect ) )
  64     + m_yAxis * ( 2.0f * (y/static_cast<float>(m_resY) - 0.5 ) )
  65     + ( m_zAxis * m_focus );
  66   dir.normalize();
  67
  68   ray.setDir(dir);
  69   ray.setOrigin(m_pos);
  70   float t = std::numeric_limits<float>::max();
  71   ray.setT(t);
  72
  73   return true;
  74 }