faster_corner_utilities.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 |
   +------------------------------------------------------------------------+ */

// ---------------------------------------------------------------------------
// LICENSING: This file is a slightly-modified version of part of libcvd,
//             released under LGPL 2.1 by Edward Rosten
// ---------------------------------------------------------------------------

#ifndef MRPT_CVD_INTERNAL_INC_FAST_CORNER_UTILITIES_H
#define MRPT_CVD_INTERNAL_INC_FAST_CORNER_UTILITIES_H

#include <mrpt/utils/SSE_types.h>

namespace mrpt
{
struct Less
{
        template <class T1, class T2>
        static bool eval(const T1 a, const T2 b)
        {
                return a < b;
        }
        static int prep_t(int pixel_val, int barrier)
        {
                return pixel_val - barrier;
        }
};
struct Greater
{
        template <class T1, class T2>
        static bool eval(const T1 a, const T2 b)
        {
                return a > b;
        }
        static int prep_t(int pixel_val, int barrier)
        {
                return pixel_val + barrier;
        }
};

#if MRPT_HAS_SSE2

#define CHECK_BARRIER(lo, hi, other, flags)                                    \
        {                                                                          \
                __m128i diff = _mm_subs_epu8(lo, other);                               \
                __m128i diff2 = _mm_subs_epu8(other, hi);                              \
                __m128i z = _mm_setzero_si128();                                       \
                diff = _mm_cmpeq_epi8(diff, z);                                        \
                diff2 = _mm_cmpeq_epi8(diff2, z);                                      \
                flags = ~(_mm_movemask_epi8(diff) | (_mm_movemask_epi8(diff2) << 16)); \
        }

template <bool Aligned>
inline __m128i load_si128(const void* addr)
{
        return _mm_loadu_si128((const __m128i*)addr);
}
template <>
inline __m128i load_si128<true>(const void* addr)
{
        return _mm_load_si128((const __m128i*)addr);
}

#endif
}
#endif