AnimTestbed/3rdparty/ozz-animation/include/ozz/base/maths/math_ex.h

126 lines
4.3 KiB
C
Raw Normal View History

2021-11-11 21:22:24 +01:00
//----------------------------------------------------------------------------//
// //
// ozz-animation is hosted at http://github.com/guillaumeblanc/ozz-animation //
// and distributed under the MIT License (MIT). //
// //
// Copyright (c) Guillaume Blanc //
// //
// Permission is hereby granted, free of charge, to any person obtaining a //
// copy of this software and associated documentation files (the "Software"), //
// to deal in the Software without restriction, including without limitation //
// the rights to use, copy, modify, merge, publish, distribute, sublicense, //
// and/or sell copies of the Software, and to permit persons to whom the //
// Software is furnished to do so, subject to the following conditions: //
// //
// The above copyright notice and this permission notice shall be included in //
// all copies or substantial portions of the Software. //
// //
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR //
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, //
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL //
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER //
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING //
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER //
// DEALINGS IN THE SOFTWARE. //
// //
//----------------------------------------------------------------------------//
#ifndef OZZ_OZZ_BASE_MATHS_MATH_EX_H_
#define OZZ_OZZ_BASE_MATHS_MATH_EX_H_
#include <cassert>
#include <cmath>
#include "ozz/base/platform.h"
namespace ozz {
namespace math {
// Returns the linear interpolation of _a and _b with coefficient _f.
// _f is not limited to range [0,1].
OZZ_INLINE float Lerp(float _a, float _b, float _f) {
return (_b - _a) * _f + _a;
}
// Returns the minimum of _a and _b. Comparison's based on operator <.
template <typename _Ty>
OZZ_INLINE _Ty Min(_Ty _a, _Ty _b) {
return (_a < _b) ? _a : _b;
}
// Returns the maximum of _a and _b. Comparison's based on operator <.
template <typename _Ty>
OZZ_INLINE _Ty Max(_Ty _a, _Ty _b) {
return (_b < _a) ? _a : _b;
}
// Clamps _x between _a and _b. Comparison's based on operator <.
// Result is unknown if _a is not less or equal to _b.
template <typename _Ty>
OZZ_INLINE _Ty Clamp(_Ty _a, _Ty _x, _Ty _b) {
const _Ty min = _x < _b ? _x : _b;
return min < _a ? _a : min;
}
// Implements int selection, avoiding branching.
OZZ_INLINE int Select(bool _b, int _true, int _false) {
return _false ^ (-static_cast<int>(_b) & (_true ^ _false));
}
// Implements float selection, avoiding branching.
OZZ_INLINE float Select(bool _b, float _true, float _false) {
union {
float f;
int32_t i;
} t = {_true};
union {
float f;
int32_t i;
} f = {_false};
union {
int32_t i;
float f;
} r = {f.i ^ (-static_cast<int32_t>(_b) & (t.i ^ f.i))};
return r.f;
}
// Implements pointer selection, avoiding branching.
template <typename _Ty>
OZZ_INLINE _Ty* Select(bool _b, _Ty* _true, _Ty* _false) {
union {
_Ty* p;
intptr_t i;
} t = {_true};
union {
_Ty* p;
intptr_t i;
} f = {_false};
union {
intptr_t i;
_Ty* p;
} r = {f.i ^ (-static_cast<intptr_t>(_b) & (t.i ^ f.i))};
return r.p;
}
// Implements const pointer selection, avoiding branching.
template <typename _Ty>
OZZ_INLINE const _Ty* Select(bool _b, const _Ty* _true, const _Ty* _false) {
union {
const _Ty* p;
intptr_t i;
} t = {_true};
union {
const _Ty* p;
intptr_t i;
} f = {_false};
union {
intptr_t i;
const _Ty* p;
} r = {f.i ^ (-static_cast<intptr_t>(_b) & (t.i ^ f.i))};
return r.p;
}
} // namespace math
} // namespace ozz
#endif // OZZ_OZZ_BASE_MATHS_MATH_EX_H_