include/tools/degree.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  */
   9 #pragma once
  10
  11 #include <sal/config.h>
  12
  13 #include <basegfx/numeric/ftools.hxx>
  14 #include <sal/types.h>
  15 #include <o3tl/strong_int.hxx>
  16 #include <o3tl/unit_conversion.hxx>
  17 #include <cstdlib>
  18 #include <math.h>
  19 #include <numeric>
  20
  21 template <int N> struct FractionTag;
  22 // 1/Nth fraction of a degree
  23 template <typename I, int N> using Degree = o3tl::strong_int<I, FractionTag<N>>;
  24
  25 template <typename I, int N> char (&NofDegree(Degree<I, N>))[N]; // helper
  26 // Nof<DegreeN> gives compile-time constant N, needed in templates
  27 template <class D> constexpr int Nof = sizeof(NofDegree(std::declval<D>()));
  28
  29 /** tenths of a Degree, normally rotation */
  30 typedef Degree<sal_Int16, 10> Degree10;
  31
  32 /** custom literal */
  33 constexpr Degree10 operator""_deg10(unsigned long long n) { return Degree10{ n }; }
  34
  35 /** hundredths of a Degree, normally rotation */
  36 typedef Degree<sal_Int32, 100> Degree100;
  37
  38 // Android has trouble calling the correct overload of std::abs
  39 #ifdef ANDROID
  40 inline Degree100 abs(Degree100 x) { return Degree100(std::abs(static_cast<int>(x.get()))); }
  41 #else
  42 inline Degree100 abs(Degree100 x) { return Degree100(std::abs(x.get())); }
  43 #endif
  44
  45 /** custom literal */
  46 constexpr Degree100 operator""_deg100(unsigned long long n) { return Degree100{ n }; }
  47
  48 /** conversion functions */
  49
  50 template <class To, typename IofFrom, int NofFrom> inline To to(Degree<IofFrom, NofFrom> x)
  51 {
  52     constexpr sal_Int64 m = Nof<To> / std::gcd(Nof<To>, NofFrom);
  53     constexpr sal_Int64 d = NofFrom / std::gcd(Nof<To>, NofFrom);
  54     return To{ o3tl::convert(x.get(), m, d) };
  55 }
  56
  57 template <class D> inline double toRadians(D x) { return basegfx::deg2rad<Nof<D>>(x.get()); }
  58 template <class D> inline double toDegrees(D x) { return x.get() / static_cast<double>(Nof<D>); }
  59
  60 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */