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#ifndef DistanceLODEvaluator_INCLUDE_ONCE
#define DistanceLODEvaluator_INCLUDE_ONCE

#include <vlGraphics/Actor.hpp>

namespace vl
{
  //-----------------------------------------------------------------------------
  // DistanceLODEvaluator
  //-----------------------------------------------------------------------------
  /**
   * A LODEvaluator that computes the appropriate LOD based on the distance of an
   * Actor from the Camera.
   *
   * \sa
   * - LODEvaluator
   * - PixelLODEvaluator
  */
  class DistanceLODEvaluator: public LODEvaluator
  {
    VL_INSTRUMENT_CLASS(vl::DistanceLODEvaluator, LODEvaluator)

  public:
    DistanceLODEvaluator()
    {
      VL_DEBUG_SET_OBJECT_NAME()
    }
    virtual int evaluate(Actor* actor, Camera* camera)
    {
      if (mDistanceRangeSet.empty())
        return 0;

      vec3 center = actor->transform() ? actor->transform()->worldMatrix() * actor->lod(0)->boundingBox().center() : actor->lod(0)->boundingBox().center();
      double dist = (camera->modelingMatrix().getT() - center).length();

      // we assume the distances are sorted in increasing order
      int i=0;
      for(; i<(int)mDistanceRangeSet.size(); ++i)
      {
        if (dist<mDistanceRangeSet[i])
          return i;
      }

      return i; // == mDistanceRangeSet.size()
    }

    const std::vector<double>& distanceRangeSet() const { return mDistanceRangeSet; }

    std::vector<double>& distanceRangeSet() { return mDistanceRangeSet; }

  protected:
    std::vector<double> mDistanceRangeSet;
  };
}

#endif