include/tools/helpers.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   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 #ifndef INCLUDED_TOOLS_HELPERS_HXX
  10 #define INCLUDED_TOOLS_HELPERS_HXX
  11
  12 #include <sal/config.h>
  13 #include <sal/types.h>
  14 #include <o3tl/safeint.hxx>
  15 #include <cassert>
  16 #include <type_traits>
  17
  18 template<typename T>
  19 inline
  20 typename std::enable_if<
  21              std::is_signed<T>::value || std::is_floating_point<T>::value, long >::type
  22 MinMax(T nVal, long nMin, long nMax)
  23 {
  24     assert(nMin <= nMax);
  25     if (nVal >= nMin)
  26     {
  27         if (nVal <= nMax)
  28             return static_cast<long>(nVal);
  29         else
  30            return nMax;
  31     }
  32     else
  33     {
  34         return nMin;
  35     }
  36 }
  37
  38 template<typename T>
  39 inline
  40 typename std::enable_if<
  41              std::is_unsigned<T>::value, long >::type
  42 MinMax(T nVal, long nMin, long nMax)
  43 {
  44     assert(nMin <= nMax);
  45     if (nMax < 0)
  46     {
  47         return nMax;
  48     }
  49     else
  50     {
  51         if (nMin < 0 || nVal >= static_cast<unsigned long>(nMin))
  52         {
  53             if (nVal <= static_cast<unsigned long>(nMax))
  54                 return static_cast<long>(nVal);
  55             else
  56                 return nMax;
  57         }
  58         else
  59         {
  60             return nMin;
  61         }
  62     }
  63 }
  64
  65 inline sal_uInt32 AlignedWidth4Bytes(sal_uInt32 nWidthBits)
  66 {
  67     if (nWidthBits > SAL_MAX_UINT32 - 31)
  68         nWidthBits = SAL_MAX_UINT32;
  69     else
  70         nWidthBits += 31;
  71     return (nWidthBits >> 5) << 2;
  72 }
  73
  74 inline long FRound( double fVal )
  75 {
  76     return fVal > 0.0 ? static_cast<long>( fVal + 0.5 ) : -static_cast<long>( -fVal + 0.5 );
  77 }
  78
  79 //valid range:  (-180,180]
  80 template <typename T>
  81 [[nodiscard]] inline typename std::enable_if<std::is_signed<T>::value, T>::type
  82 NormAngle180(T angle)
  83 {
  84     while (angle <= -180)
  85         angle += 360;
  86     while (angle > 180)
  87         angle -= 360;
  88     return angle;
  89 }
  90
  91 //valid range:  [0,360)
  92 template <typename T> [[nodiscard]] inline T NormAngle360(T angle)
  93 {
  94     while (angle < 0)
  95         angle += 360;
  96     while (angle >= 360)
  97         angle -= 360;
  98     return angle;
  99 }
 100
 101 /** Convert 100th-mm to twips
 102
 103     A twip is 1/20 of a point, one inch is equal to 72 points, and
 104     one inch is 2,540 100th-mm.
 105
 106     Thus:
 107         twips = n * 72 / 2,540 / 20
 108               = n * 72 / 127
 109
 110     Adding 63 (half of 127) fixes truncation issues in int arithmetic.
 111
 112     This formula is (n>=0) ? (n*72+63) / 127 : (n*72-63) / 127
 113  */
 114 inline sal_Int64 sanitiseMm100ToTwip(sal_Int64 n)
 115 {
 116     if (n >= 0)
 117     {
 118         if (o3tl::checked_multiply<sal_Int64>(n, 72, n) || o3tl::checked_add<sal_Int64>(n, 63, n))
 119             n = SAL_MAX_INT64;
 120     }
 121     else
 122     {
 123         if (o3tl::checked_multiply<sal_Int64>(n, 72, n) || o3tl::checked_sub<sal_Int64>(n, 63, n))
 124             n = SAL_MIN_INT64;
 125     }
 126     return n / 127; // 127 is 2,540 100th-mm divided by 20pts
 127 }
 128
 129 #endif
 130
 131 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */