Triangle.cxx

   1 #include "Triangle.hxx"
   2
   3 Triangle::Triangle(const Vec3f& a,
   4                    const Vec3f& b,
   5                    const Vec3f& c)
   6   : m_a(a),
   7     m_b(b),
   8     m_c(c)
   9 {
  10 }
  11
  12 Triangle::~Triangle()
  13 {
  14 }
  15
  16 bool
  17 Triangle::Intersect(Ray& ray)
  18 {
  19   const Vec3f edge1 = m_b-m_a;
  20   const Vec3f edge2 = m_c-m_a;
  21
  22   const Vec3f pvec = ray.direction().cross(edge2);
  23
  24   const float det = edge1.dot(pvec);
  25   if (fabs(det) < Epsilon) return false;
  26
  27   const float inv_det = 1.0f / det;
  28
  29   const Vec3f tvec = ray.origin()-m_a;
  30   float lambda = tvec.dot( pvec );
  31   lambda *= inv_det;
  32
  33   if (lambda < 0.0f || lambda > 1.0f)
  34     return false;
  35
  36   const Vec3f qvec = tvec.cross(edge1);
  37   float mue = ray.direction().dot(qvec);
  38   mue *= inv_det;
  39
  40   if (mue < 0.0f || mue+lambda > 1.0f)
  41     return false;
  42
  43   float f = edge2.dot(qvec);
  44   f *= inv_det;
  45   if (ray.t() <= f || f <  1e-4  )
  46     return false;
  47
  48   ray.setT(f);
  49
  50   return true;
  51 }