include/basegfx/range/basicrange.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 <sal/types.h>
  23 #include <float.h>
  24 #include <basegfx/numeric/ftools.hxx>
  25
  26
  27 namespace basegfx
  28 {
  29     template< typename T, typename Traits > class BasicRange
  30     {
  31     protected:
  32         T mnMinimum;
  33         T mnMaximum;
  34
  35     public:
  36         typedef T       ValueType;
  37         typedef Traits  TraitsType;
  38
  39         BasicRange() :
  40             mnMinimum(Traits::maxVal()),
  41             mnMaximum(Traits::minVal())
  42         {
  43         }
  44
  45         explicit BasicRange( T nValue ) :
  46             mnMinimum(nValue),
  47             mnMaximum(nValue)
  48         {
  49         }
  50
  51         void reset()
  52         {
  53             mnMinimum = Traits::maxVal();
  54             mnMaximum = Traits::minVal();
  55         }
  56
  57         bool isEmpty() const
  58         {
  59             return Traits::maxVal() == mnMinimum;
  60         }
  61
  62         T getMinimum() const { return mnMinimum; }
  63         T getMaximum() const { return mnMaximum; }
  64
  65         double getCenter() const
  66         {
  67             if(isEmpty())
  68             {
  69                 return 0.0;
  70             }
  71             else
  72             {
  73                 return ((mnMaximum + mnMinimum) / 2.0);
  74             }
  75         }
  76
  77         bool isInside(T nValue) const
  78         {
  79             if(isEmpty())
  80             {
  81                 return false;
  82             }
  83             else
  84             {
  85                 return (nValue >= mnMinimum) && (nValue <= mnMaximum);
  86             }
  87         }
  88
  89         bool isInside(const BasicRange& rRange) const
  90         {
  91             if(isEmpty())
  92             {
  93                 return false;
  94             }
  95             else
  96             {
  97                 if(rRange.isEmpty())
  98                 {
  99                     return false;
 100                 }
 101                 else
 102                 {
 103                     return (rRange.mnMinimum >= mnMinimum) && (rRange.mnMaximum <= mnMaximum);
 104                 }
 105             }
 106         }
 107
 108         bool overlaps(const BasicRange& rRange) const
 109         {
 110             if(isEmpty())
 111             {
 112                 return false;
 113             }
 114             else
 115             {
 116                 if(rRange.isEmpty())
 117                 {
 118                     return false;
 119                 }
 120                 else
 121                 {
 122                     return (rRange.mnMaximum >= mnMinimum) && (rRange.mnMinimum <= mnMaximum);
 123                 }
 124             }
 125         }
 126
 127         bool overlapsMore(const BasicRange& rRange) const
 128         {
 129             if(isEmpty() || rRange.isEmpty())
 130                 return false;
 131             // returns true if the overlap is more than just a touching at the limits
 132             return ((rRange.mnMaximum > mnMinimum) && (rRange.mnMinimum < mnMaximum));
 133         }
 134
 135         bool operator==( const BasicRange& rRange ) const
 136         {
 137             return (mnMinimum == rRange.mnMinimum && mnMaximum == rRange.mnMaximum);
 138         }
 139
 140         bool operator!=( const BasicRange& rRange ) const
 141         {
 142             return (mnMinimum != rRange.mnMinimum || mnMaximum != rRange.mnMaximum);
 143         }
 144
 145         bool equal(const BasicRange& rRange) const
 146         {
 147             return (
 148                 fTools::equal(mnMinimum, rRange.mnMinimum) &&
 149                 fTools::equal(mnMaximum, rRange.mnMaximum));
 150         }
 151
 152         void expand(T nValue)
 153         {
 154             if(isEmpty())
 155             {
 156                 mnMinimum = mnMaximum = nValue;
 157             }
 158             else
 159             {
 160 // Silence over-eager warning emitted at least by GCC 4.9.2 in certain
 161 // instantiations:
 162 #if defined __GNUC__ && !defined __clang__
 163 #pragma GCC diagnostic push
 164 #pragma GCC diagnostic ignored "-Wstrict-overflow"
 165 #endif
 166                 if(nValue < mnMinimum)
 167 #if defined __GNUC__ && !defined __clang__
 168 #pragma GCC diagnostic pop
 169 #endif
 170                 {
 171                     mnMinimum = nValue;
 172                 }
 173
 174                 if(nValue > mnMaximum)
 175                 {
 176                     mnMaximum = nValue;
 177                 }
 178             }
 179         }
 180
 181         void expand(const BasicRange& rRange)
 182         {
 183             if(isEmpty())
 184             {
 185                 mnMinimum = rRange.mnMinimum;
 186                 mnMaximum = rRange.mnMaximum;
 187             }
 188             else
 189             {
 190                 if(!rRange.isEmpty())
 191                 {
 192                     if(rRange.mnMinimum < mnMinimum)
 193                     {
 194                         mnMinimum = rRange.mnMinimum;
 195                     }
 196
 197                     if(rRange.mnMaximum > mnMaximum)
 198                     {
 199                         mnMaximum = rRange.mnMaximum;
 200                     }
 201                 }
 202             }
 203         }
 204
 205         void intersect(const BasicRange& rRange)
 206         {
 207             // here, overlaps also tests all isEmpty() conditions already.
 208             if( !overlaps( rRange ) )
 209             {
 210                 reset();
 211             }
 212             else
 213             {
 214                 if(rRange.mnMinimum > mnMinimum)
 215                 {
 216                     mnMinimum = rRange.mnMinimum;
 217                 }
 218
 219                 if(rRange.mnMaximum < mnMaximum)
 220                 {
 221                     mnMaximum = rRange.mnMaximum;
 222                 }
 223             }
 224         }
 225
 226         void grow(T nValue)
 227         {
 228             if(isEmpty())
 229                 return;
 230
 231             bool bLessThanZero(nValue < 0);
 232
 233             if(nValue > 0 || bLessThanZero)
 234             {
 235                 mnMinimum -= nValue;
 236                 mnMaximum += nValue;
 237
 238                 if(bLessThanZero)
 239                 {
 240                     // test if range did collapse
 241                     if(mnMinimum > mnMaximum)
 242                     {
 243                         // if yes, collapse to center
 244                         mnMinimum = mnMaximum = (mnMinimum + mnMaximum) / 2;
 245                     }
 246                 }
 247             }
 248         }
 249
 250         T clamp(T nValue) const
 251         {
 252             if(isEmpty())
 253             {
 254                 return nValue;
 255             }
 256             else
 257             {
 258                 if(nValue < mnMinimum)
 259                 {
 260                     return mnMinimum;
 261                 }
 262
 263                 if(nValue > mnMaximum)
 264                 {
 265                     return mnMaximum;
 266                 }
 267
 268                 return nValue;
 269             }
 270         }
 271
 272 #if defined _MSC_VER && defined(_M_ARM64)
 273 #pragma warning(push)
 274 #pragma warning(disable: 4723) /* ignore: warning for (C4723) potential divide by 0 on windows arm64 build */
 275 #endif
 276         typename Traits::DifferenceType getRange() const
 277         {
 278             if(isEmpty())
 279             {
 280                 return Traits::neutral();
 281             }
 282             else
 283             {
 284                 return (mnMaximum - mnMinimum);
 285             }
 286         }
 287 #if defined _MSC_VER && defined(_M_ARM64)
 288 #pragma warning( pop )
 289 #endif
 290     };
 291
 292     // some pre-fabricated traits
 293     struct DoubleTraits
 294     {
 295         static constexpr double minVal() { return DBL_MIN; };
 296         static constexpr double maxVal() { return DBL_MAX; };
 297         static constexpr double neutral() { return 0.0; };
 298
 299         typedef double DifferenceType;
 300     };
 301
 302     struct Int32Traits
 303     {
 304         static constexpr sal_Int32 minVal() { return SAL_MIN_INT32; };
 305         static constexpr sal_Int32 maxVal() { return SAL_MAX_INT32; };
 306         static constexpr sal_Int32 neutral() { return 0; };
 307
 308         typedef sal_Int64 DifferenceType;
 309     };
 310
 311 } // end of namespace basegfx
 312
 313 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */