dolphin/Source/Core/Common/MathUtil.h
2019-04-23 19:02:41 -05:00

126 lines
2.5 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#pragma once
#include <algorithm>
#include <vector>
#include "Common/CommonTypes.h"
#ifdef _MSC_VER
#include <intrin.h>
#endif
namespace MathUtil
{
constexpr double TAU = 6.2831853071795865;
constexpr double PI = TAU / 2;
template <class T>
constexpr T Clamp(const T val, const T& min, const T& max)
{
return std::max(min, std::min(max, val));
}
template <typename T>
constexpr auto Sign(const T& val) -> decltype((T{} < val) - (val < T{}))
{
return (T{} < val) - (val < T{});
}
template <typename T, typename F>
constexpr auto Lerp(const T& x, const T& y, const F& a) -> decltype(x + (y - x) * a)
{
return x + (y - x) * a;
}
template <typename T>
constexpr bool IsPow2(T imm)
{
return imm > 0 && (imm & (imm - 1)) == 0;
}
constexpr u32 NextPowerOf2(u32 value)
{
--value;
value |= value >> 1;
value |= value >> 2;
value |= value >> 4;
value |= value >> 8;
value |= value >> 16;
++value;
return value;
}
template <class T>
struct Rectangle
{
T left{};
T top{};
T right{};
T bottom{};
constexpr Rectangle() = default;
constexpr Rectangle(T theLeft, T theTop, T theRight, T theBottom)
: left(theLeft), top(theTop), right(theRight), bottom(theBottom)
{
}
constexpr bool operator==(const Rectangle& r) const
{
return left == r.left && top == r.top && right == r.right && bottom == r.bottom;
}
T GetWidth() const { return abs(right - left); }
T GetHeight() const { return abs(bottom - top); }
// If the rectangle is in a coordinate system with a lower-left origin, use
// this Clamp.
void ClampLL(T x1, T y1, T x2, T y2)
{
left = Clamp(left, x1, x2);
right = Clamp(right, x1, x2);
top = Clamp(top, y2, y1);
bottom = Clamp(bottom, y2, y1);
}
// If the rectangle is in a coordinate system with an upper-left origin,
// use this Clamp.
void ClampUL(T x1, T y1, T x2, T y2)
{
left = Clamp(left, x1, x2);
right = Clamp(right, x1, x2);
top = Clamp(top, y1, y2);
bottom = Clamp(bottom, y1, y2);
}
};
} // namespace MathUtil
float MathFloatVectorSum(const std::vector<float>&);
// Rounds down. 0 -> undefined
inline int IntLog2(u64 val)
{
#if defined(__GNUC__)
return 63 - __builtin_clzll(val);
#elif defined(_MSC_VER)
unsigned long result = ULONG_MAX;
_BitScanReverse64(&result, val);
return result;
#else
int result = -1;
while (val != 0)
{
val >>= 1;
++result;
}
return result;
#endif
}