headers/libs/agg/agg_conv_adaptor_vcgen.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_CONV_ADAPTOR_VCGEN_INCLUDED
  17 #define AGG_CONV_ADAPTOR_VCGEN_INCLUDED
  18
  19 #include "agg_basics.h"
  20
  21 namespace agg
  22 {
  23     //------------------------------------------------------------null_markers
  24     struct null_markers
  25     {
  26         void remove_all() {}
  27         void add_vertex(double, double, unsigned) {}
  28         void prepare_src() {}
  29
  30         void rewind(unsigned) {}
  31         unsigned vertex(double*, double*) { return path_cmd_stop; }
  32     };
  33
  34
  35     //------------------------------------------------------conv_adaptor_vcgen
  36     template<class VertexSource,
  37              class Generator,
  38              class Markers=null_markers> class conv_adaptor_vcgen
  39     {
  40         enum status
  41         {
  42             initial,
  43             accumulate,
  44             generate
  45         };
  46
  47     public:
  48         conv_adaptor_vcgen(VertexSource& source) :
  49             m_source(&source),
  50             m_status(initial)
  51         {}
  52         void attach(VertexSource& source) { m_source = &source; }
  53
  54         Generator& generator() { return m_generator; }
  55         const Generator& generator() const { return m_generator; }
  56
  57         Markers& markers() { return m_markers; }
  58         const Markers& markers() const { return m_markers; }
  59
  60         void rewind(unsigned path_id)
  61         {
  62             m_source->rewind(path_id);
  63             m_status = initial;
  64         }
  65
  66         unsigned vertex(double* x, double* y);
  67
  68     private:
  69         // Prohibit copying
  70         conv_adaptor_vcgen(const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
  71         const conv_adaptor_vcgen<VertexSource, Generator, Markers>&
  72             operator = (const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
  73
  74         VertexSource* m_source;
  75         Generator     m_generator;
  76         Markers       m_markers;
  77         status        m_status;
  78         unsigned      m_last_cmd;
  79         double        m_start_x;
  80         double        m_start_y;
  81     };
  82
  83
  84
  85
  86
  87     //------------------------------------------------------------------------
  88     template<class VertexSource, class Generator, class Markers>
  89     unsigned conv_adaptor_vcgen<VertexSource, Generator, Markers>::vertex(double* x, double* y)
  90     {
  91         unsigned cmd = path_cmd_stop;
  92         bool done = false;
  93         while(!done)
  94         {
  95             switch(m_status)
  96             {
  97             case initial:
  98                 m_markers.remove_all();
  99                 m_last_cmd = m_source->vertex(&m_start_x, &m_start_y);
 100                 m_status = accumulate;
 101
 102             case accumulate:
 103                 if(is_stop(m_last_cmd)) return path_cmd_stop;
 104
 105                 m_generator.remove_all();
 106                 m_generator.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
 107                 m_markers.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
 108
 109                 for(;;)
 110                 {
 111                     cmd = m_source->vertex(x, y);
 112                     if(is_vertex(cmd))
 113                     {
 114                         m_last_cmd = cmd;
 115                         if(is_move_to(cmd))
 116                         {
 117                             m_start_x = *x;
 118                             m_start_y = *y;
 119                             break;
 120                         }
 121                         m_generator.add_vertex(*x, *y, cmd);
 122                         m_markers.add_vertex(*x, *y, path_cmd_line_to);
 123                     }
 124                     else
 125                     {
 126                         if(is_stop(cmd))
 127                         {
 128                             m_last_cmd = path_cmd_stop;
 129                             break;
 130                         }
 131                         if(is_end_poly(cmd))
 132                         {
 133                             m_generator.add_vertex(*x, *y, cmd);
 134                             break;
 135                         }
 136                     }
 137                 }
 138                 m_generator.rewind(0);
 139                 m_status = generate;
 140
 141             case generate:
 142                 cmd = m_generator.vertex(x, y);
 143                 if(is_stop(cmd))
 144                 {
 145                     m_status = accumulate;
 146                     break;
 147                 }
 148                 done = true;
 149                 break;
 150             }
 151         }
 152         return cmd;
 153     }
 154
 155 }
 156
 157 #endif