size_t closestPointToRay(const V3f* points, size_t nPoints,
const V3f& rayOrigin, const V3f& rayDirection,
double longitudinalScale, double* distance)
{
const V3f T = rayDirection.normalized();
const double f = longitudinalScale*longitudinalScale - 1;
size_t nearestIdx = -1;
double nearestDist2 = DBL_MAX;
for(size_t i = 0; i < nPoints; ++i)
{
const V3f v = points[i] - rayOrigin; // vector from ray origin to point
const double a = v.dot(T); // distance along ray to point of closest approach to test point
const double r2 = v.length2() + f*a*a;
if(r2 < nearestDist2)
{
// new closest angle to axis
nearestDist2 = r2;
nearestIdx = i;
}
}
if(distance)
{
if(nPoints == 0)
*distance = DBL_MAX;
else
*distance = sqrt(nearestDist2);
}
return nearestIdx;
}
bool SpherePrimitiveEvaluator::closestPoint( const V3f &p, PrimitiveEvaluator::Result *result ) const
{
assert( dynamic_cast<Result *>( result ) );
Result *sr = static_cast<Result *>( result );
sr->m_p = p.normalized() * m_sphere->radius();
return true;
}
int ImagePrimitiveEvaluator::intersectionPoints( const V3f &origin, const V3f &direction,
std::vector<PrimitiveEvaluator::ResultPtr> &results, float maxDistance ) const
{
results.clear();
V3f hitPoint;
Box3f bound = m_image->bound();
bool hit = boxIntersects( bound , origin, direction.normalized(), hitPoint );
if ( hit )
{
if ( ( origin - hitPoint ).length2() < maxDistance * maxDistance )
{
ResultPtr result = staticPointerCast< Result >( createResult() );
result->m_p = hitPoint;
results.push_back( result );
}
}
return results.size();
}
