include/basegfx/range/basicrange.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
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  19
  20 #ifndef _BGFX_RANGE_BASICRANGE_HXX
  21 #define _BGFX_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                 if(nValue < mnMinimum)
 162                 {
 163                     mnMinimum = nValue;
 164                 }
 165
 166                 if(nValue > mnMaximum)
 167                 {
 168                     mnMaximum = nValue;
 169                 }
 170             }
 171         }
 172
 173         void expand(const BasicRange& rRange)
 174         {
 175             if(isEmpty())
 176             {
 177                 mnMinimum = rRange.mnMinimum;
 178                 mnMaximum = rRange.mnMaximum;
 179             }
 180             else
 181             {
 182                 if(!rRange.isEmpty())
 183                 {
 184                     if(rRange.mnMinimum < mnMinimum)
 185                     {
 186                         mnMinimum = rRange.mnMinimum;
 187                     }
 188
 189                     if(rRange.mnMaximum > mnMaximum)
 190                     {
 191                         mnMaximum = rRange.mnMaximum;
 192                     }
 193                 }
 194             }
 195         }
 196
 197         void intersect(const BasicRange& rRange)
 198         {
 199             // here, overlaps also tests all isEmpty() conditions already.
 200             if( !overlaps( rRange ) )
 201             {
 202                 reset();
 203             }
 204             else
 205             {
 206                 if(rRange.mnMinimum > mnMinimum)
 207                 {
 208                     mnMinimum = rRange.mnMinimum;
 209                 }
 210
 211                 if(rRange.mnMaximum < mnMaximum)
 212                 {
 213                     mnMaximum = rRange.mnMaximum;
 214                 }
 215             }
 216         }
 217
 218         void grow(T nValue)
 219         {
 220             if(!isEmpty())
 221             {
 222                 bool bLessThanZero(nValue < 0);
 223
 224                 if(nValue > 0 || bLessThanZero)
 225                 {
 226                     mnMinimum -= nValue;
 227                     mnMaximum += nValue;
 228
 229                     if(bLessThanZero)
 230                     {
 231                         // test if range did collapse
 232                         if(mnMinimum > mnMaximum)
 233                         {
 234                             // if yes, collapse to center
 235                             mnMinimum = mnMaximum = (mnMinimum + mnMaximum) / 2;
 236                         }
 237                     }
 238                 }
 239             }
 240         }
 241
 242         typename Traits::DifferenceType getRange() const
 243         {
 244             if(isEmpty())
 245             {
 246                 return Traits::neutral();
 247             }
 248             else
 249             {
 250                 return (mnMaximum - mnMinimum);
 251             }
 252         }
 253     };
 254
 255     // some pre-fabricated traits
 256     struct DoubleTraits
 257     {
 258         static double minVal() { return DBL_MIN; };
 259         static double maxVal() { return DBL_MAX; };
 260         static double neutral() { return 0.0; };
 261
 262         typedef double DifferenceType;
 263     };
 264
 265     struct Int32Traits
 266     {
 267         static sal_Int32 minVal() { return SAL_MIN_INT32; };
 268         static sal_Int32 maxVal() { return SAL_MAX_INT32; };
 269         static sal_Int32 neutral() { return 0L; };
 270
 271         typedef sal_Int64 DifferenceType;
 272     };
 273
 274 } // end of namespace basegfx
 275
 276 #endif /* _BGFX_RANGE_BASICRANGE_HXX */
 277
 278 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */