Dogcows Code - chaz/rasterize/blob - sphere.hh

   1
   2 /*
   3  * CS5600 University of Utah
   4  * Charles McGarvey
   5  * mcgarvey@eng.utah.edu
   6  */
   7
   8 #ifndef _SPHERE_HH_
   9 #define _SPHERE_HH_
  10
  11 #include "color.hh"
  12 #include "element.hh"
  13
  14
  15 namespace rt {
  16
  17
  18 /*
  19  * A class for a sphere object.
  20  */
  21 class sphere : public element
  22 {
  23 public:
  24
  25     color_t material;
  26     vec_t   origin;
  27     scal_t  radius;
  28
  29     sphere(vec_t o, scal_t r = S(1.0), color_t color = COLOR_WHITE) :
  30         origin(o), radius(r), material(color)
  31     {}
  32
  33     virtual ~sphere()
  34     {}
  35
  36     virtual bool intersect(ray_t ray, contact_t& hit) const
  37     {
  38         vec_t   b = vec_sub(origin, ray.o);
  39                 scal_t  z = vec_dot(b, ray.d);
  40
  41                 // check if the sphere is behind the ray
  42                 if (z < S(0.0)) {
  43             return false;
  44         }
  45
  46                 scal_t d2 = vec_dot(b, b) - z * z;
  47                 scal_t r2 = radius * radius;
  48
  49                 // check for an intersection
  50                 if (r2 < d2) {
  51             return false;
  52         }
  53
  54                 hit.d = z - std::sqrt(r2 - d2);
  55                 if (hit.d < S(0.0)) {
  56             return false;
  57         }
  58
  59         hit.p = ray_solve(ray, hit.d);
  60         hit.n = vec_sub(hit.p, origin);
  61                 return true;
  62     }
  63
  64     virtual color_t color(vec_t point) const
  65     {
  66         return material;
  67     }
  68 };
  69
  70
  71 /*
  72  * Destroy a new'd sphere, releasing its memory.
  73  */
  74 INLINE_MAYBE
  75 void sphere_destroy(sphere* s)
  76 {
  77     delete s;
  78 }
  79
  80
  81 } // namespace rt
  82
  83 #endif // _SPHERE_HH_
  84