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