agg/inc/agg_conv_close_polygon.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
  16 #ifndef AGG_CONV_CLOSE_POLYGON_INCLUDED
  17 #define AGG_CONV_CLOSE_POLYGON_INCLUDED
  18
  19 #include "agg_basics.h"
  20 #include "agg_vertex_iterator.h"
  21
  22 namespace agg
  23 {
  24
  25     //======================================================conv_close_polygon
  26     template<class VertexSource> class conv_close_polygon
  27     {
  28     public:
  29         conv_close_polygon(VertexSource& vs) : m_source(&vs) {}
  30
  31         void set_source(VertexSource& source) { m_source = &source; }
  32
  33         void rewind(unsigned path_id);
  34         unsigned vertex(double* x, double* y);
  35
  36         typedef conv_close_polygon<VertexSource> source_type;
  37         typedef vertex_iterator<source_type> iterator;
  38         iterator begin(unsigned id) { return iterator(*this, id); }
  39         iterator end() { return iterator(path_cmd_stop); }
  40
  41     private:
  42         conv_close_polygon(const conv_close_polygon<VertexSource>&);
  43         const conv_close_polygon<VertexSource>&
  44             operator = (const conv_close_polygon<VertexSource>&);
  45
  46         VertexSource* m_source;
  47         unsigned      m_cmd[2];
  48         double        m_x[2];
  49         double        m_y[2];
  50         unsigned      m_vertex;
  51         bool          m_line_to;
  52     };
  53
  54
  55
  56     //------------------------------------------------------------------------
  57     template<class VertexSource>
  58     void conv_close_polygon<VertexSource>::rewind(unsigned path_id)
  59     {
  60         m_source->rewind(path_id);
  61         m_vertex = 2;
  62         m_line_to = false;
  63     }
  64
  65
  66
  67     //------------------------------------------------------------------------
  68     template<class VertexSource>
  69     unsigned conv_close_polygon<VertexSource>::vertex(double* x, double* y)
  70     {
  71         unsigned cmd = path_cmd_stop;
  72         for(;;)
  73         {
  74             if(m_vertex < 2)
  75             {
  76                 *x = m_x[m_vertex];
  77                 *y = m_y[m_vertex];
  78                 cmd = m_cmd[m_vertex];
  79                 ++m_vertex;
  80                 break;
  81             }
  82
  83             cmd = m_source->vertex(x, y);
  84
  85             if(is_end_poly(cmd))
  86             {
  87                 cmd |= path_flags_close;
  88                 break;
  89             }
  90
  91             if(is_stop(cmd))
  92             {
  93                 if(m_line_to)
  94                 {
  95                     m_cmd[0]  = path_cmd_end_poly | path_flags_close;
  96                     m_cmd[1]  = path_cmd_stop;
  97                     m_vertex  = 0;
  98                     m_line_to = false;
  99                     continue;
 100                 }
 101                 break;
 102             }
 103
 104             if(is_move_to(cmd))
 105             {
 106                 if(m_line_to)
 107                 {
 108                     m_x[0]    = 0.0;
 109                     m_y[0]    = 0.0;
 110                     m_cmd[0]  = path_cmd_end_poly | path_flags_close;
 111                     m_x[1]    = *x;
 112                     m_y[1]    = *y;
 113                     m_cmd[1]  = cmd;
 114                     m_vertex  = 0;
 115                     m_line_to = false;
 116                     continue;
 117                 }
 118                 break;
 119             }
 120
 121             if(is_vertex(cmd))
 122             {
 123                 m_line_to = true;
 124                 break;
 125             }
 126         }
 127         return cmd;
 128     }
 129
 130 }
 131
 132 #endif