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