Geometry.h

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// # Copyright (C) 2010 by ESO (in the framework of the ALMA collaboration)
// # Copyright (C) 1996,1997,1998,1999,2000,2001
// # Associated Universities, Inc. Washington DC, USA.
// #
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// # under the terms of the GNU Library General Public License as published by
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// # License for more details.
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#ifndef SCIMATH_GEOMETRY_H
#define SCIMATH_GEOMETRY_H
 
#include <casacore/casa/aips.h>
#include <casacore/casa/Quanta/Quantum.h>
#include <utility>
 
namespace casacore {  // # NAMESPACE CASACORE - BEGIN
 
// <summary>
// Geometry related methods.
// </summary>
 
// <use visibility=export>
 
// # <author>Dave Mehringer</author>
//  <reviewed reviewer="" date="yyyy/mm/dd" tests="" demos="">
//  </reviewed>
//  <etymology>
//  self-explanatory
//  </etymology>
 
// <synopsis>
// Various geometry related functions
// </synopsis>
 
// <motivation>
// Commonly used geometrical functions for various image and region
// applications.
// </motivation>
 
class Geometry {
 public:
  // Get result of rotating a 2-D vector counterclockwise through an angle
  // <src>theta</src>. The output pair will have x as the first
  // member and y as the second. <src>theta</src> must have angular units (no explicit
  // checking is done, but an exception will be thrown from the Quanta code if not).
  static std::pair<Double, Double> rotate2D(Double x, Double y, const Quantity& theta);
 
  // Determine if two coplanar line segments, a and b, intersect. Line segment a
  // has end points a0 and a1, and line segment b has endpoints b0 and b1.
  // Algorithm from
  // http://stackoverflow.com/questions/563198/how-do-you-detect-where-two-line-segments-intersect
  static Bool doLineSegmentsIntersect(Double a0x, Double a0y, Double a1x, Double a1y, Double b0x,
                                      Double b0y, Double b1x, Double b1y);
};
}  // namespace casacore
 
#endif