mirror of
https://github.com/alliedmodders/amxmodx.git
synced 2024-12-26 06:45:37 +03:00
140 lines
3.9 KiB
C++
140 lines
3.9 KiB
C++
// vim: set sts=8 ts=2 sw=2 tw=99 et:
|
|
//
|
|
// Copyright (C) 2013, David Anderson and AlliedModders LLC
|
|
// All rights reserved.
|
|
//
|
|
// Redistribution and use in source and binary forms, with or without
|
|
// modification, are permitted provided that the following conditions are met:
|
|
//
|
|
// * Redistributions of source code must retain the above copyright notice, this
|
|
// list of conditions and the following disclaimer.
|
|
// * Redistributions in binary form must reproduce the above copyright notice,
|
|
// this list of conditions and the following disclaimer in the documentation
|
|
// and/or other materials provided with the distribution.
|
|
// * Neither the name of AlliedModders LLC nor the names of its contributors
|
|
// may be used to endorse or promote products derived from this software
|
|
// without specific prior written permission.
|
|
//
|
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
// POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
#ifndef _include_amtl_float_h_
|
|
#define _include_amtl_float_h_
|
|
|
|
#include <math.h>
|
|
#include <float.h>
|
|
|
|
namespace ke {
|
|
|
|
static const uint32_t kFloat32ExponentMask = 0x7F800000;
|
|
static const uint64_t kFloat64ExponentMask = 0x7FFF000000000000ULL;
|
|
|
|
struct float32_bits
|
|
{
|
|
static const uint32_t kExponentMask = kFloat32ExponentMask;
|
|
|
|
typedef uint32_t Bits;
|
|
|
|
union layout {
|
|
uint32_t bits;
|
|
float value;
|
|
};
|
|
|
|
static layout to_layout(float value) {
|
|
layout impl;
|
|
impl.value = value;
|
|
return impl;
|
|
}
|
|
};
|
|
|
|
struct float64_bits
|
|
{
|
|
static const uint64_t kExponentMask = kFloat64ExponentMask;
|
|
|
|
typedef uint64_t Bits;
|
|
|
|
union layout {
|
|
uint64_t bits;
|
|
float value;
|
|
};
|
|
|
|
static layout to_layout(float value) {
|
|
layout impl;
|
|
impl.value = value;
|
|
return impl;
|
|
}
|
|
};
|
|
|
|
template <typename T>
|
|
struct float_bits;
|
|
template <>
|
|
struct float_bits<float> : public float32_bits {};
|
|
template <>
|
|
struct float_bits<double> : public float64_bits {};
|
|
|
|
template <typename T>
|
|
static inline bool
|
|
IsNaN(T v)
|
|
{
|
|
#ifdef _MSC_VER
|
|
return !!_isnan(v);
|
|
#else
|
|
return isnan(v);
|
|
#endif
|
|
}
|
|
|
|
template <typename T> static inline bool
|
|
IsInfinite(T value)
|
|
{
|
|
typedef float_bits<T> Properties;
|
|
typedef typename Properties::Bits Bits;
|
|
Bits bits = Properties::to_layout(value).bits;
|
|
return (bits & Properties::kExponentMask) == Properties::kExponentMask;
|
|
};
|
|
|
|
// Performs the operation (x % y) where x and y are floating-point values.
|
|
//
|
|
// To compute a floating point modulus, this function returns "r", where r
|
|
// satisfies the following equation:
|
|
//
|
|
// x = (I * y) + r
|
|
//
|
|
// Where I is an integer <= x, and r is a value less than y. If no such
|
|
// integer I exists, the result is NaN.
|
|
//
|
|
// If x or y are NaN, the result is NaN.
|
|
// If x is +/-Infinity, the result is NaN.
|
|
// If y is 0, the result is NaN (as a divide by zero is implied).
|
|
//
|
|
// If y is Infinity, then r = x (and I = 0).
|
|
// If x is +/-0, then r = +/-0.
|
|
template <typename T> static inline T
|
|
FloatModulo(T left, T right)
|
|
{
|
|
#if defined(KE_WINDOWS)
|
|
// Windows fmod() does not follow the contract above, in that:
|
|
// 42 % Infinity => NaN, instead of 42, and
|
|
// -0 % -N => 0, instead of -0.
|
|
if ((!IsInfinite(left) && IsInfinite(right)) ||
|
|
(left == 0 && !IsInfinite(right)))
|
|
{
|
|
return left;
|
|
}
|
|
#endif
|
|
|
|
return fmod(left, right);
|
|
}
|
|
|
|
} // namespace ke
|
|
|
|
#endif // _include_amtl_float_h_
|