headers/libs/agg/agg_span_allocator.h

   1 //----------------------------------------------------------------------------
   2 // Anti-Grain Geometry - Version 2.4
   3 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
   4 //
   5 // Permission to copy, use, modify, sell and distribute this software
   6 // is granted provided this copyright notice appears in all copies.
   7 // This software is provided "as is" without express or implied
   8 // warranty, and with no claim as to its suitability for any purpose.
   9 //
  10 //----------------------------------------------------------------------------
  11 // Contact: mcseem@antigrain.com
  12 //          mcseemagg@yahoo.com
  13 //          http://www.antigrain.com
  14 //----------------------------------------------------------------------------
  15
  16 #ifndef AGG_SPAN_ALLOCATOR_INCLUDED
  17 #define AGG_SPAN_ALLOCATOR_INCLUDED
  18
  19 #include "agg_array.h"
  20
  21 namespace agg
  22 {
  23     //----------------------------------------------------------span_allocator
  24     template<class ColorT> class span_allocator
  25     {
  26     public:
  27         typedef ColorT color_type;
  28
  29         //--------------------------------------------------------------------
  30         AGG_INLINE color_type* allocate(unsigned span_len)
  31         {
  32             if(span_len > m_span.size())
  33             {
  34                 // To reduce the number of reallocs we align the
  35                 // span_len to 256 color elements.
  36                 // Well, I just like this number and it looks reasonable.
  37                 //-----------------------
  38                 m_span.resize(((span_len + 255) >> 8) << 8);
  39             }
  40             return &m_span[0];
  41         }
  42
  43         AGG_INLINE color_type* span()               { return &m_span[0]; }
  44         AGG_INLINE unsigned    max_span_len() const { return m_span.size(); }
  45
  46     private:
  47         pod_array<color_type> m_span;
  48     };
  49 }
  50
  51
  52 #endif
  53
  54