// fbc_cv is free software and uses the same licence as OpenCV
// Email: fengbingchun@163.com

#ifndef FBC_CV_CORE_SATURATE_HPP_
#define FBC_CV_CORE_SATURATE_HPP_

// reference: include/opencv2/core/saturate.hpp

#include <algorithm>
#include <limits.h>

#include "fbcdef.hpp"
#include "interface.hpp"
#include "fast_math.hpp"

namespace yt_tinycv
{
template<typename _Tp> static inline _Tp saturate_cast(uchar v)    { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(schar v)    { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(ushort v)   { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(short v)    { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(unsigned int v) { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(int v)      { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(float v)    { return _Tp(v); }
template<typename _Tp> static inline _Tp saturate_cast(double v)   { return _Tp(v); }

template<> inline uchar saturate_cast<uchar>(schar v)        { return (uchar)std::max((int)v, 0); }
template<> inline uchar saturate_cast<uchar>(ushort v)       { return (uchar)std::min((unsigned)v, (unsigned)UCHAR_MAX); }
template<> inline uchar saturate_cast<uchar>(int v)          { return (uchar)((unsigned)v <= UCHAR_MAX ? v : v > 0 ? UCHAR_MAX : 0); }
template<> inline uchar saturate_cast<uchar>(short v)        { return saturate_cast<uchar>((int)v); }
template<> inline uchar saturate_cast<uchar>(unsigned int v) { return (uchar)std::min(v, (unsigned)UCHAR_MAX); }
template<> inline uchar saturate_cast<uchar>(float v)        { int iv = fbcRound(v); return saturate_cast<uchar>(iv); }
template<> inline uchar saturate_cast<uchar>(double v)       { int iv = fbcRound(v); return saturate_cast<uchar>(iv); }

template<> inline schar saturate_cast<schar>(uchar v)        { return (schar)std::min((int)v, SCHAR_MAX); }
template<> inline schar saturate_cast<schar>(ushort v)       { return (schar)std::min((unsigned)v, (unsigned)SCHAR_MAX); }
template<> inline schar saturate_cast<schar>(int v)          { return (schar)((unsigned)(v-SCHAR_MIN) <= (unsigned)UCHAR_MAX ? v : v > 0 ? SCHAR_MAX : SCHAR_MIN); }
template<> inline schar saturate_cast<schar>(short v)        { return saturate_cast<schar>((int)v); }
template<> inline schar saturate_cast<schar>(unsigned v)     { return (schar)std::min(v, (unsigned)SCHAR_MAX); }
template<> inline schar saturate_cast<schar>(float v)        { int iv = fbcRound(v); return saturate_cast<schar>(iv); }
template<> inline schar saturate_cast<schar>(double v)       { int iv = fbcRound(v); return saturate_cast<schar>(iv); }

template<> inline ushort saturate_cast<ushort>(schar v)      { return (ushort)std::max((int)v, 0); }
template<> inline ushort saturate_cast<ushort>(short v)      { return (ushort)std::max((int)v, 0); }
template<> inline ushort saturate_cast<ushort>(int v)        { return (ushort)((unsigned)v <= (unsigned)USHRT_MAX ? v : v > 0 ? USHRT_MAX : 0); }
template<> inline ushort saturate_cast<ushort>(unsigned v)   { return (ushort)std::min(v, (unsigned)USHRT_MAX); }
template<> inline ushort saturate_cast<ushort>(float v)      { int iv = fbcRound(v); return saturate_cast<ushort>(iv); }
template<> inline ushort saturate_cast<ushort>(double v)     { int iv = fbcRound(v); return saturate_cast<ushort>(iv); }

template<> inline short saturate_cast<short>(ushort v)       { return (short)std::min((int)v, SHRT_MAX); }
template<> inline short saturate_cast<short>(int v)          { return (short)((unsigned)(v - SHRT_MIN) <= (unsigned)USHRT_MAX ? v : v > 0 ? SHRT_MAX : SHRT_MIN); }
template<> inline short saturate_cast<short>(unsigned v)     { return (short)std::min(v, (unsigned)SHRT_MAX); }
template<> inline short saturate_cast<short>(float v)        { int iv = fbcRound(v); return saturate_cast<short>(iv); }
template<> inline short saturate_cast<short>(double v)       { int iv = fbcRound(v); return saturate_cast<short>(iv); }

template<> inline int saturate_cast<int>(float v)            { return fbcRound(v); }
template<> inline int saturate_cast<int>(double v)           { return fbcRound(v); }

template<> inline unsigned saturate_cast<unsigned>(float v)  { return fbcRound(v); }
template<> inline unsigned saturate_cast<unsigned>(double v) { return fbcRound(v); }

} // yt_tinycv

#endif // FBC_CV_CORE_SATURATE_HPP_