include/basegfx/range/basicrange.hxx

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  19
  20 #ifndef INCLUDED_BASEGFX_RANGE_BASICRANGE_HXX
  21 #define INCLUDED_BASEGFX_RANGE_BASICRANGE_HXX
  22
  23 #include <sal/types.h>
  24 #include <float.h>
  25 #include <basegfx/numeric/ftools.hxx>
  26
  27
  28 namespace basegfx
  29 {
  30     template< typename T, typename Traits > class BasicRange
  31     {
  32     protected:
  33         T       mnMinimum;
  34         T       mnMaximum;
  35
  36     public:
  37         typedef T       ValueType;
  38         typedef Traits  TraitsType;
  39
  40         BasicRange() :
  41             mnMinimum(Traits::maxVal()),
  42             mnMaximum(Traits::minVal())
  43         {
  44         }
  45
  46         explicit BasicRange( T nValue ) :
  47             mnMinimum(nValue),
  48             mnMaximum(nValue)
  49         {
  50         }
  51
  52         void reset()
  53         {
  54             mnMinimum = Traits::maxVal();
  55             mnMaximum = Traits::minVal();
  56         }
  57
  58         bool isEmpty() const
  59         {
  60             return Traits::maxVal() == mnMinimum;
  61         }
  62
  63         T getMinimum() const { return mnMinimum; }
  64         T getMaximum() const { return mnMaximum; }
  65
  66         double getCenter() const
  67         {
  68             if(isEmpty())
  69             {
  70                 return 0.0;
  71             }
  72             else
  73             {
  74                 return ((mnMaximum + mnMinimum) / 2.0);
  75             }
  76         }
  77
  78         bool isInside(T nValue) const
  79         {
  80             if(isEmpty())
  81             {
  82                 return false;
  83             }
  84             else
  85             {
  86                 return (nValue >= mnMinimum) && (nValue <= mnMaximum);
  87             }
  88         }
  89
  90         bool isInside(const BasicRange& rRange) const
  91         {
  92             if(isEmpty())
  93             {
  94                 return false;
  95             }
  96             else
  97             {
  98                 if(rRange.isEmpty())
  99                 {
 100                     return false;
 101                 }
 102                 else
 103                 {
 104                     return (rRange.mnMinimum >= mnMinimum) && (rRange.mnMaximum <= mnMaximum);
 105                 }
 106             }
 107         }
 108
 109         bool overlaps(const BasicRange& rRange) const
 110         {
 111             if(isEmpty())
 112             {
 113                 return false;
 114             }
 115             else
 116             {
 117                 if(rRange.isEmpty())
 118                 {
 119                     return false;
 120                 }
 121                 else
 122                 {
 123                     return !((rRange.mnMaximum < mnMinimum) || (rRange.mnMinimum > mnMaximum));
 124                 }
 125             }
 126         }
 127
 128         bool overlapsMore(const BasicRange& rRange) const
 129         {
 130             if(isEmpty() || rRange.isEmpty())
 131                 return false;
 132             // returns true if the overlap is more than just a touching at the limits
 133             return ((rRange.mnMaximum > mnMinimum) && (rRange.mnMinimum < mnMaximum));
 134         }
 135
 136         bool operator==( const BasicRange& rRange ) const
 137         {
 138             return (mnMinimum == rRange.mnMinimum && mnMaximum == rRange.mnMaximum);
 139         }
 140
 141         bool operator!=( const BasicRange& rRange ) const
 142         {
 143             return (mnMinimum != rRange.mnMinimum || mnMaximum != rRange.mnMaximum);
 144         }
 145
 146         bool equal(const BasicRange& rRange) const
 147         {
 148             return (
 149                 fTools::equal(mnMinimum, rRange.mnMinimum) &&
 150                 fTools::equal(mnMaximum, rRange.mnMaximum));
 151         }
 152
 153         void expand(T nValue)
 154         {
 155             if(isEmpty())
 156             {
 157                 mnMinimum = mnMaximum = nValue;
 158             }
 159             else
 160             {
 161 // Silence over-eager warning emitted at least by GCC 4.9.2 in certain
 162 // instantiations:
 163 #if defined __GNUC__ && !defined __clang__
 164 #pragma GCC diagnostic push
 165 #pragma GCC diagnostic ignored "-Wstrict-overflow"
 166 #endif
 167                 if(nValue < mnMinimum)
 168 #if defined __GNUC__ && !defined __clang__
 169 #pragma GCC diagnostic pop
 170 #endif
 171                 {
 172                     mnMinimum = nValue;
 173                 }
 174
 175                 if(nValue > mnMaximum)
 176                 {
 177                     mnMaximum = nValue;
 178                 }
 179             }
 180         }
 181
 182         void expand(const BasicRange& rRange)
 183         {
 184             if(isEmpty())
 185             {
 186                 mnMinimum = rRange.mnMinimum;
 187                 mnMaximum = rRange.mnMaximum;
 188             }
 189             else
 190             {
 191                 if(!rRange.isEmpty())
 192                 {
 193                     if(rRange.mnMinimum < mnMinimum)
 194                     {
 195                         mnMinimum = rRange.mnMinimum;
 196                     }
 197
 198                     if(rRange.mnMaximum > mnMaximum)
 199                     {
 200                         mnMaximum = rRange.mnMaximum;
 201                     }
 202                 }
 203             }
 204         }
 205
 206         void intersect(const BasicRange& rRange)
 207         {
 208             // here, overlaps also tests all isEmpty() conditions already.
 209             if( !overlaps( rRange ) )
 210             {
 211                 reset();
 212             }
 213             else
 214             {
 215                 if(rRange.mnMinimum > mnMinimum)
 216                 {
 217                     mnMinimum = rRange.mnMinimum;
 218                 }
 219
 220                 if(rRange.mnMaximum < mnMaximum)
 221                 {
 222                     mnMaximum = rRange.mnMaximum;
 223                 }
 224             }
 225         }
 226
 227         void grow(T nValue)
 228         {
 229             if(!isEmpty())
 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
 251         typename Traits::DifferenceType getRange() const
 252         {
 253             if(isEmpty())
 254             {
 255                 return Traits::neutral();
 256             }
 257             else
 258             {
 259                 return (mnMaximum - mnMinimum);
 260             }
 261         }
 262     };
 263
 264     // some pre-fabricated traits
 265     struct DoubleTraits
 266     {
 267         static double minVal() { return DBL_MIN; };
 268         static double maxVal() { return DBL_MAX; };
 269         static double neutral() { return 0.0; };
 270
 271         typedef double DifferenceType;
 272     };
 273
 274     struct Int32Traits
 275     {
 276         static sal_Int32 minVal() { return SAL_MIN_INT32; };
 277         static sal_Int32 maxVal() { return SAL_MAX_INT32; };
 278         static sal_Int32 neutral() { return 0L; };
 279
 280         typedef sal_Int64 DifferenceType;
 281     };
 282
 283 } // end of namespace basegfx
 284
 285 #endif // INCLUDED_BASEGFX_RANGE_BASICRANGE_HXX
 286
 287 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */