text: // Geometric Tools, LLC
  // Copyright (c) 1998-2014
  // Distributed under the Boost Software License, Version 1.0.
  // http://www.boost.org/LICENSE_1_0.txt
  // http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
  //
  // File Version: 5.0.1 (2010/10/01)
  
  #ifndef WM5CURVESEGMENT_H
  #define WM5CURVESEGMENT_H
  
  #include "Wm5GraphicsLIB.h"
  #include "Wm5Object.h"
  #include "Wm5APoint.h"
  
  namespace Wm5
  {
  
  class WM5_GRAPHICS_ITEM CurveSegment : public Object
  {
      WM5_DECLARE_RTTI;
      WM5_DECLARE_NAMES;
      WM5_DECLARE_STREAM(CurveSegment);
  
  protected:
      // Construction.
      CurveSegment (float umin, float umax);
  public:
      // Abstract base class.
      virtual ~CurveSegment ();
  
      // The parametric domain is umin <= u <= umax.
      float GetUMin () const;
      float GetUMax () const;
  
      // Position and derivatives up to third order.
      virtual APoint P (float u) const = 0;
      virtual AVector PU (float u) const = 0;
      virtual AVector PUU (float u) const = 0;
      virtual AVector PUUU (float u) const = 0;
  
      // Differential geometric quantities.
      AVector Tangent (float u) const;
      AVector Normal (float u) const;
      AVector Binormal (float u) const;
      void GetFrame (float u, APoint& position, AVector& tangent,
          AVector& normal, AVector& binormal) const;
      float Curvature (float u) const;
      float Torsion (float u) const;
  
  protected:
      float mUMin, mUMax;
  };
  
  WM5_REGISTER_STREAM(CurveSegment);
  typedef Pointer0<CurveSegment> CurveSegmentPtr;
  
  }
  
  #endif
  