virtualx-engine/thirdparty/oidn/core/math.h
2021-01-14 18:02:07 +01:00

78 lines
2.6 KiB
C++

// ======================================================================== //
// Copyright 2009-2019 Intel Corporation //
// //
// Licensed under the Apache License, Version 2.0 (the "License"); //
// you may not use this file except in compliance with the License. //
// You may obtain a copy of the License at //
// //
// http://www.apache.org/licenses/LICENSE-2.0 //
// //
// Unless required by applicable law or agreed to in writing, software //
// distributed under the License is distributed on an "AS IS" BASIS, //
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. //
// See the License for the specific language governing permissions and //
// limitations under the License. //
// ======================================================================== //
#pragma once
#include "common/platform.h"
namespace oidn {
constexpr float minVectorLength = 1e-10f;
constexpr float minVectorLengthSqr = minVectorLength * minVectorLength;
using std::log;
using std::log2;
using std::exp;
using std::exp2;
using std::pow;
using std::isfinite;
using std::isnan;
__forceinline float sqr(float x)
{
return x * x;
}
__forceinline float rcp(float x)
{
__m128 r = _mm_rcp_ss(_mm_set_ss(x));
return _mm_cvtss_f32(_mm_sub_ss(_mm_add_ss(r, r), _mm_mul_ss(_mm_mul_ss(r, r), _mm_set_ss(x))));
}
__forceinline float rsqrt(float x)
{
__m128 r = _mm_rsqrt_ss(_mm_set_ss(x));
return _mm_cvtss_f32(_mm_add_ss(_mm_mul_ss(_mm_set_ss(1.5f), r),
_mm_mul_ss(_mm_mul_ss(_mm_mul_ss(_mm_set_ss(x), _mm_set_ss(-0.5f)), r), _mm_mul_ss(r, r))));
}
__forceinline float maxSafe(float value, float minValue)
{
return isfinite(value) ? max(value, minValue) : minValue;
}
__forceinline float clampSafe(float value, float minValue, float maxValue)
{
return isfinite(value) ? clamp(value, minValue, maxValue) : minValue;
}
// Returns ceil(a / b) for non-negative integers
template<class Int>
__forceinline constexpr Int ceilDiv(Int a, Int b)
{
//assert(a >= 0);
//assert(b > 0);
return (a + b - 1) / b;
}
// Returns a rounded up to multiple of b
template<class Int>
__forceinline constexpr Int roundUp(Int a, Int b)
{
return ceilDiv(a, b) * b;
}
} // namespace oidn