agg/inc/agg_span_subdiv_adaptor.h

   1 //----------------------------------------------------------------------------
   2 // Anti-Grain Geometry - Version 2.3
   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 #ifndef AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
  16 #define AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
  17
  18 #include "agg_basics.h"
  19
  20 namespace agg
  21 {
  22
  23     //=================================================span_subdiv_adaptor
  24     template<class Interpolator, unsigned SubpixelShift = 8>
  25     class span_subdiv_adaptor
  26     {
  27     public:
  28         typedef Interpolator interpolator_type;
  29         typedef typename interpolator_type::trans_type trans_type;
  30
  31         enum
  32         {
  33             subpixel_shift = SubpixelShift,
  34             subpixel_size  = 1 << subpixel_shift
  35         };
  36
  37
  38         //----------------------------------------------------------------
  39         span_subdiv_adaptor() :
  40             m_subdiv_shift(4),
  41             m_subdiv_size(1 << m_subdiv_shift),
  42             m_subdiv_mask(m_subdiv_size - 1) {}
  43
  44         span_subdiv_adaptor(interpolator_type& interpolator,
  45                              unsigned subdiv_shift = 4) :
  46             m_subdiv_shift(subdiv_shift),
  47             m_subdiv_size(1 << m_subdiv_shift),
  48             m_subdiv_mask(m_subdiv_size - 1),
  49             m_interpolator(&interpolator) {}
  50
  51         span_subdiv_adaptor(interpolator_type& interpolator,
  52                              double x, double y, unsigned len,
  53                              unsigned subdiv_shift = 4) :
  54             m_subdiv_shift(subdiv_shift),
  55             m_subdiv_size(1 << m_subdiv_shift),
  56             m_subdiv_mask(m_subdiv_size - 1),
  57             m_interpolator(&interpolator)
  58         {
  59             begin(x, y, len);
  60         }
  61
  62
  63         //----------------------------------------------------------------
  64         const interpolator_type& interpolator() const { return *m_interpolator; }
  65         void interpolator(interpolator_type& intr) { m_interpolator = &intr; }
  66
  67         //----------------------------------------------------------------
  68         const trans_type& transformer() const
  69         {
  70             return *m_interpolator->transformer();
  71         }
  72         void transformer(const trans_type& trans)
  73         {
  74             m_interpolator->transformer(trans);
  75         }
  76
  77         //----------------------------------------------------------------
  78         unsigned subdiv_shift() const { return m_subdiv_shift; }
  79         void subdiv_shift(unsigned shift)
  80         {
  81             m_subdiv_shift = shift;
  82             m_subdiv_size = 1 << m_subdiv_shift;
  83             m_subdiv_mask = m_subdiv_size - 1;
  84         }
  85
  86         //----------------------------------------------------------------
  87         void begin(double x, double y, unsigned len)
  88         {
  89             m_pos   = 1;
  90             m_src_x = int(x * subpixel_size) + subpixel_size;
  91             m_src_y = y;
  92             m_len   = len;
  93             if(len > m_subdiv_size) len = m_subdiv_size;
  94             m_interpolator->begin(x, y, len);
  95         }
  96
  97         //----------------------------------------------------------------
  98         void operator++()
  99         {
 100             ++(*m_interpolator);
 101             if(m_pos >= m_subdiv_size)
 102             {
 103                 unsigned len = m_len;
 104                 if(len > m_subdiv_size) len = m_subdiv_size;
 105                 m_interpolator->resynchronize(double(m_src_x) / double(subpixel_size) + len,
 106                                               m_src_y,
 107                                               len);
 108                 m_pos = 0;
 109             }
 110             m_src_x += subpixel_size;
 111             ++m_pos;
 112             --m_len;
 113         }
 114
 115         //----------------------------------------------------------------
 116         void coordinates(int* x, int* y) const
 117         {
 118             m_interpolator->coordinates(x, y);
 119         }
 120
 121         //----------------------------------------------------------------
 122         void local_scale(int* x, int* y) const
 123         {
 124             m_interpolator->local_scale(x, y);
 125         }
 126
 127
 128     private:
 129         unsigned m_subdiv_shift;
 130         unsigned m_subdiv_size;
 131         unsigned m_subdiv_mask;
 132         interpolator_type* m_interpolator;
 133         int      m_src_x;
 134         double   m_src_y;
 135         unsigned m_pos;
 136         unsigned m_len;
 137     };
 138
 139 }
 140
 141 #endif