math.hpp

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#pragma once
#include <ossia/detail/config.hpp>
 
#include <ossia/detail/ssize.hpp>
 
#include <cmath>
 
#include <algorithm>
#include <cinttypes>
#include <utility>
namespace ossia
{
#if defined(__ANDROID_API__)
using ::asinh;
using ::exp2;
using ::fma;
using ::llround;
using ::log1p;
using ::remainder;
#else
using std::asinh;
using std::exp2;
using std::fma;
using std::llround;
using std::log1p;
using std::remainder;
#endif
const constexpr auto pi = 3.141592653589793238462643383279502884;
const constexpr auto two_pi = 6.283185307179586476925286766559005768;
const constexpr auto half_pi = 1.570796326794896619231321691639751442;
const constexpr auto rad_to_deg = 5.729577951308232087679815481410517033e+01;
const constexpr auto deg_to_rad = 1.745329251994329576923690768488612713e-02;
const constexpr auto ln_2 = 6.931471805599453094172321214581765680e-01;
const constexpr auto sqrt_2 = 1.414213562373095048801688724209698078e+00;
 
template <typename T>
T ipow(T x, int N) noexcept
{
  T res = x;
  for(int i = 1; i < N; i++)
  {
    res *= x;
  }
  return res;
}
 
template <typename T>
auto norm(T x, T y) noexcept
{
  return std::sqrt(ipow(x, 2) + ipow(y, 2));
}
 
template <typename T>
auto norm(T x, T y, T z) noexcept
{
  return std::sqrt(ipow(x, 2) + ipow(y, 2) + ipow(z, 2));
}
 
inline constexpr size_t constexpr_log2(size_t n) noexcept
{
  return ((n < 2) ? 0 : 1 + constexpr_log2(n / 2));
}
 
template <typename T>
inline constexpr size_t constexpr_abs(T n) noexcept
{
  return n < 0 ? -n : n;
}
 
// https://github.com/a2flo/floor/blob/master/constexpr/const_math.hpp#L251
template <typename T>
inline constexpr int64_t constexpr_floor(T val) noexcept
{
  const auto val_int = (int64_t)val;
  const T fval_int = (T)val_int;
  return (val >= (T)0 ? fval_int : (val == fval_int ? val : fval_int - 1));
}
 
template <typename T>
inline constexpr int64_t constexpr_ceil(T f)
{
  const int64_t i = f;
  return f > i ? i + 1 : i;
}
 
template <class T, class U>
OSSIA_INLINE constexpr auto max(const T a, const U b) noexcept ->
    typename std::conditional<(sizeof(T) > sizeof(U)), T, U>::type
{
  static_assert(std::is_integral_v<T> && std::is_integral_v<U>);
  static_assert(std::is_signed_v<T> == std::is_signed_v<U>);
  return a < b ? b : a;
}
 
static OSSIA_INLINE constexpr float max(float a, const float b) noexcept
{
  return a < b ? b : a;
}
static OSSIA_INLINE constexpr double max(double a, const double b) noexcept
{
  return a < b ? b : a;
}
static OSSIA_INLINE constexpr double max(float a, const double b) noexcept
{
  return a < b ? b : a;
}
static OSSIA_INLINE constexpr double max(double a, const float b) noexcept
{
  return a < b ? b : a;
}
 
template <class T, class U>
OSSIA_INLINE constexpr auto min(const T a, const U b) noexcept ->
    typename std::conditional<(sizeof(T) > sizeof(U)), T, U>::type
{
  static_assert(std::is_integral_v<T> && std::is_integral_v<U>);
  static_assert(std::is_signed_v<T> == std::is_signed_v<U>);
  return a > b ? b : a;
}
 
static OSSIA_INLINE constexpr float min(float a, const float b) noexcept
{
  return a > b ? b : a;
}
static OSSIA_INLINE constexpr double min(double a, const double b) noexcept
{
  return a > b ? b : a;
}
static OSSIA_INLINE constexpr double min(float a, const double b) noexcept
{
  return a > b ? b : a;
}
static OSSIA_INLINE constexpr double min(double a, const float b) noexcept
{
  return a > b ? b : a;
}
 
template <class T>
OSSIA_INLINE constexpr T clamp(T d, const T min, const T max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
 
static OSSIA_INLINE constexpr int64_t
clamp(int64_t d, const int64_t min, const int64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int64_t d, const int32_t min, const int64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int64_t d, const int32_t min, const int32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int64_t d, const int64_t min, const int32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int32_t
clamp(int32_t d, const int32_t min, const int32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int32_t d, const int64_t min, const int64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int32_t d, const int32_t min, const int64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr int64_t
clamp(int32_t d, const int64_t min, const int32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
 
static OSSIA_INLINE constexpr uint64_t
clamp(uint64_t d, const uint64_t min, const uint64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint64_t d, const uint32_t min, const uint64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint64_t d, const uint32_t min, const uint32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint64_t d, const uint64_t min, const uint32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint32_t
clamp(uint32_t d, const uint32_t min, const uint32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint32_t d, const uint64_t min, const uint64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint32_t d, const uint32_t min, const uint64_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr uint64_t
clamp(uint32_t d, const uint64_t min, const uint32_t max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
 
static OSSIA_INLINE constexpr double
clamp(double d, const double min, const double max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(double d, const float min, const double max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(double d, const float min, const float max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(double d, const double min, const float max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr float
clamp(float d, const float min, const float max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(float d, const double min, const double max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(float d, const float min, const double max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
static OSSIA_INLINE constexpr double
clamp(float d, const double min, const float max) noexcept
{
  return ossia::max(ossia::min(d, max), min);
}
 
// Wrap & Fold code taken from Jamoma TTLimits.h.
// Credits : Nils Peters, Nov. 2008
template <class T>
OSSIA_INLINE constexpr T wrap(const T val, const T low, const T high) noexcept
{
  if((val >= low) && (val < high))
    return val;
  else if(val >= low)
    return low + std::fmod(val - low, std::fabs(low - high));
  else
    return high - std::fmod(low - val, std::fabs(low - high));
}
 
template <class T>
OSSIA_INLINE constexpr T fold(const T val, const T low, const T high) noexcept
{
  if((val >= low) && (val <= high))
    return val;
  else
  {
    return low + std::fabs(ossia::remainder(val - low, 2. * std::fabs(low - high)));
  }
}
 
template <class T>
OSSIA_INLINE constexpr std::pair<T, T> div(T num, T denom) noexcept
{
  return {num / denom, num % denom};
}
 
// normalized means x in [min, min + range] => f(x) in [0; 1] with log increase
OSSIA_INLINE float log_to_normalized(float min, float range, float val) noexcept
{
  return val <= min ? 0.f : std::log1pf(val - min) / std::log1pf(range);
}
OSSIA_INLINE float normalized_to_log(float min, float range, float val) noexcept
{
  const float res = std::expm1f(val * std::log1pf(range)) + min;
  return std::min(res, min + range);
}
 
template <typename T, typename R>
constexpr OSSIA_INLINE bool valid_index(T idx, const R& range) noexcept
{
  using range_size_type = typename R::size_type;
  if constexpr(std::is_signed_v<T>)
  {
    if constexpr(std::is_signed_v<range_size_type>)
      return idx >= 0 && idx < range.size();
    else
      return idx >= 0 && idx < std::ssize(range);
  }
  else
  {
    if constexpr(std::is_signed_v<range_size_type>)
      return idx < static_cast<std::size_t>(range.size());
    else
      return idx < range.size();
  }
}
 
}