include/basegfx/numeric/ftools.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #pragma once
  21
  22 #include <rtl/math.h>
  23 #include <cmath>
  24 #include <math.h>
  25 #include <basegfx/basegfxdllapi.h>
  26 #include <limits>
  27 #include <algorithm>
  28
  29
  30 // fTools defines
  31
  32 namespace basegfx
  33 {
  34     /** Round double to nearest integer
  35
  36         @return the nearest integer
  37     */
  38     inline sal_Int32 fround( double fVal )
  39     {
  40         if (fVal >= std::numeric_limits<sal_Int32>::max() - .5)
  41             return std::numeric_limits<sal_Int32>::max();
  42         else if (fVal <= std::numeric_limits<sal_Int32>::min() + .5)
  43             return std::numeric_limits<sal_Int32>::min();
  44         return fVal > 0.0 ? static_cast<sal_Int32>( fVal + .5 ) : static_cast<sal_Int32>( fVal - .5 );
  45     }
  46
  47     /** Round double to nearest integer
  48
  49         @return the nearest 64 bit integer
  50     */
  51     inline sal_Int64 fround64( double fVal )
  52     {
  53         return fVal > 0.0 ? static_cast<sal_Int64>( fVal + .5 ) : -static_cast<sal_Int64>( -fVal + .5 );
  54     }
  55
  56     /** Prune a small epsilon range around zero.
  57
  58         Use this method e.g. for calculating scale values. There, it
  59         is usually advisable not to set a scaling to 0.0, because that
  60         yields singular transformation matrices.
  61
  62         @param fVal
  63         An arbitrary, but finite and valid number
  64
  65         @return either fVal, or a small value slightly above (when
  66         fVal>0) or below (when fVal<0) zero.
  67      */
  68     inline double pruneScaleValue( double fVal )
  69     {
  70         if(fVal < 0.0)
  71             return std::min(fVal, -0.00001);
  72         else
  73             return std::max(fVal, 0.00001);
  74     }
  75
  76     /** Convert value from degrees to radians
  77      */
  78     template <int DegMultiple = 1> constexpr double deg2rad( double v )
  79     {
  80         // divide first, to get exact values for v being a multiple of
  81         // 90 degrees
  82         return v / (90.0 * DegMultiple) * M_PI_2;
  83     }
  84
  85     /** Convert value radians to degrees
  86      */
  87     template <int DegMultiple = 1> constexpr double rad2deg( double v )
  88     {
  89         // divide first, to get exact values for v being a multiple of
  90         // pi/2
  91         return v / M_PI_2 * (90.0 * DegMultiple);
  92     }
  93
  94     /** Snap v to nearest multiple of fStep, from negative and
  95         positive side.
  96
  97         Examples:
  98
  99         snapToNearestMultiple(-0.1, 0.5) = 0.0
 100         snapToNearestMultiple(0.1, 0.5) = 0.0
 101         snapToNearestMultiple(0.25, 0.5) = 0.0
 102         snapToNearestMultiple(0.26, 0.5) = 0.5
 103      */
 104     BASEGFX_DLLPUBLIC double snapToNearestMultiple(double v, const double fStep);
 105
 106     /** Snap v to the range [0.0 .. fWidth] using modulo
 107      */
 108     double snapToZeroRange(double v, double fWidth);
 109
 110     /** Snap v to the range [fLow .. fHigh] using modulo
 111      */
 112     double snapToRange(double v, double fLow, double fHigh);
 113
 114     /** return fValue with the sign of fSignCarrier, thus evtl. changed
 115     */
 116     inline double copySign(double fValue, double fSignCarrier)
 117     {
 118 #ifdef _WIN32
 119         return _copysign(fValue, fSignCarrier);
 120 #else
 121         return copysign(fValue, fSignCarrier);
 122 #endif
 123     }
 124
 125     /** RotateFlyFrame3: Normalize to range defined by [0.0 ... fRange[, independent
 126         if v is positive or negative.
 127
 128         Examples:
 129
 130         normalizeToRange(0.5, -1.0) = 0.0
 131         normalizeToRange(0.5, 0.0) = 0.0
 132         normalizeToRange(0.5, 1.0) = 0.5
 133         normalizeToRange(-0.5, 1.0) = 0.5
 134         normalizeToRange(-0.3, 1.0) = 0.7
 135         normalizeToRange(-0.7, 1.0) = 0.3
 136         normalizeToRange(3.5, 1.0) = 0.5
 137         normalizeToRange(3.3, 1.0) = 0.3
 138         normalizeToRange(3.7, 1.0) = 0.7
 139         normalizeToRange(-3.5, 1.0) = 0.5
 140         normalizeToRange(-3.3, 1.0) = 0.7
 141         normalizeToRange(-3.7, 1.0) = 0.3
 142      */
 143     BASEGFX_DLLPUBLIC double normalizeToRange(double v, const double fRange);
 144
 145     namespace fTools
 146     {
 147         /// Get threshold value for equalZero and friends
 148         inline double getSmallValue() { return 0.000000001f; }
 149
 150         /// Compare against small value
 151         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 152         inline bool equalZero(const T& rfVal)
 153         {
 154             return (fabs(rfVal) <= getSmallValue());
 155         }
 156
 157         /// Compare against given small value
 158         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 159         inline bool equalZero(const T& rfVal, const T& rfSmallValue)
 160         {
 161             return (fabs(rfVal) <= rfSmallValue);
 162         }
 163
 164         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 165         inline bool equal(T const& rfValA, T const& rfValB)
 166         {
 167             // changed to approxEqual usage for better numerical correctness
 168             return rtl_math_approxEqual(rfValA, rfValB);
 169         }
 170
 171         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 172         inline bool equal(const T& rfValA, const T& rfValB, const T& rfSmallValue)
 173         {
 174             return (fabs(rfValA - rfValB) <= rfSmallValue);
 175         }
 176
 177         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 178         inline bool less(const T& rfValA, const T& rfValB)
 179         {
 180             return (rfValA < rfValB && !equal(rfValA, rfValB));
 181         }
 182
 183         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 184         inline bool lessOrEqual(const T& rfValA, const T& rfValB)
 185         {
 186             return (rfValA < rfValB || equal(rfValA, rfValB));
 187         }
 188
 189         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 190         inline bool more(const T& rfValA, const T& rfValB)
 191         {
 192             return (rfValA > rfValB && !equal(rfValA, rfValB));
 193         }
 194
 195         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 196         inline bool moreOrEqual(const T& rfValA, const T& rfValB)
 197         {
 198             return (rfValA > rfValB || equal(rfValA, rfValB));
 199         }
 200
 201         template <typename T, std::enable_if_t<std::is_floating_point_v<T>, int> = 0>
 202         inline bool betweenOrEqualEither(const T& rfValA, const T& rfValB, const T& rfValC)
 203         {
 204             return (rfValA > rfValB && rfValA < rfValC) || equal(rfValA, rfValB) || equal(rfValA, rfValC);
 205         }
 206     };
 207 } // end of namespace basegfx
 208
 209 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */