/home/hauberg/Dokumenter/Capture/humim-tracker-0.1/src/OpenTissue/OpenTissue/core/spline/spline_compute_knot_span.h

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#ifndef OPENTISSUE_CORE_SPLINE_SPLINE_COMPUTE_KNOT_SPAN_H
#define OPENTISSUE_CORE_SPLINE_SPLINE_COMPUTE_KNOT_SPAN_H
//
// OpenTissue Template Library
// - A generic toolbox for physics-based modeling and simulation.
// Copyright (C) 2008 Department of Computer Science, University of Copenhagen.
//
// OTTL is licensed under zlib: http://opensource.org/licenses/zlib-license.php
//
#include <OpenTissue/configuration.h>

#include <stdexcept>

namespace OpenTissue
{
  namespace spline
  {
    namespace detail
    {
      template <typename knot_container>
      inline int compute_knot_span(
        typename knot_container::value_type const & u
        , int const & k
        , knot_container const & U
        )
      {
        if(k < 1)
          throw std::invalid_argument("order must be greater than zero");

        if(U.size() < 2u*k)
          throw std::invalid_argument("knot vector was too small or order was too high");

        int const m = U.size() - 1;
        int const n = m-k;

        if (u >= U[n+1])
        {
          return n;
        }

        if (u <= U[k-1])
        {
          return k-1;
        }

        int low  = k-1;
        int high = n+1;
        int mid  = (low+high)/2;

        while(u < U[mid] || u >= U[mid+1])
        {
          if (u < U[mid])
          {
            high = mid;
          }
          else
          {
            low = mid;
          }
          mid = (low+high)/2;
        }
        return mid;

      }

    } // namespace detail
  } // namespace spline
} // namespace OpenTissue

//OPENTISSUE_CORE_SPLINE_SPLINE_COMPUTE_KNOT_SPAN_H
#endif