obs/CSinCosLookUpTableFor2DScans.h

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/* +---------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)               |
   |                          http://www.mrpt.org/                             |
   |                                                                           |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file        |
   | See: http://www.mrpt.org/Authors - All rights reserved.                   |
   | Released under BSD License. See details in http://www.mrpt.org/License    |
   +---------------------------------------------------------------------------+ */
#ifndef CSinCosLookUpTableFor2DScans_H
#define CSinCosLookUpTableFor2DScans_H

#include <mrpt/utils/types_math.h>
#include <mrpt/synch/CCriticalSection.h>
#include <mrpt/obs/T2DScanProperties.h>
#include <mrpt/obs/link_pragmas.h>
#include <map>

namespace mrpt
{
namespace obs
{
        // Frwd decl:
        class CObservation2DRangeScan;


        /** A smart look-up-table (LUT) of sin/cos values for 2D laser scans.
          *  Refer to the main method CSinCosLookUpTableFor2DScans::getSinCosForScan()
          *
          *  This class is used in mrpt::maps::CPointsMap
         * \ingroup mrpt_obs_grp
          */
        class OBS_IMPEXP CSinCosLookUpTableFor2DScans
        {
        public:
                CSinCosLookUpTableFor2DScans() {}
                /** Do NOT copy neither the cache nor the mutex */
                CSinCosLookUpTableFor2DScans(const CSinCosLookUpTableFor2DScans&) {}
                CSinCosLookUpTableFor2DScans & operator =(const CSinCosLookUpTableFor2DScans &)
                {
                        return *this;
                }

                /** A pair of vectors with the cos and sin values. */
                struct TSinCosValues {
                        mrpt::math::CVectorFloat ccos, csin;
                };

                /** Return two vectors with the cos and the sin of the angles for each of the
                  * rays in a scan, computing them only the first time and returning a cached copy the rest.
                  *  Usage:
                  * \code
                  *   CSinCosLookUpTableFor2DScans cache;
                  *   ...
                  *   const CSinCosLookUpTableFor2DScans::TSinCosValues & sincos_vals = cache.getSinCosForScan( scan );
                  * \endcode
                  */
                const TSinCosValues & getSinCosForScan(const CObservation2DRangeScan &scan) const;
                /** \overload */
                const TSinCosValues & getSinCosForScan(const T2DScanProperties &scan_prop) const;

        private:
                mutable std::map<T2DScanProperties,TSinCosValues>  m_cache; //!< The cache of known scans and their sin/cos tables.
                mutable mrpt::synch::CCriticalSection m_cache_cs;
        };


} // end NS obs
} // end NS mrpt

#endif