agg/source/agg_vcgen_markers_term.cpp

   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 // Terminal markers generator (arrowhead/arrowtail)
  17 //
  18 //----------------------------------------------------------------------------
  19
  20 #include "agg_vcgen_markers_term.h"
  21
  22 namespace agg
  23 {
  24
  25     //------------------------------------------------------------------------
  26     void vcgen_markers_term::remove_all()
  27     {
  28         m_markers.remove_all();
  29     }
  30
  31
  32     //------------------------------------------------------------------------
  33     void vcgen_markers_term::add_vertex(double x, double y, unsigned cmd)
  34     {
  35         if(is_move_to(cmd))
  36         {
  37             if(m_markers.size() & 1)
  38             {
  39                 // Initial state, the first coordinate was added.
  40                 // If two of more calls of start_vertex() occures
  41                 // we just modify the last one.
  42                 m_markers.modify_last(coord_type(x, y));
  43             }
  44             else
  45             {
  46                 m_markers.add(coord_type(x, y));
  47             }
  48         }
  49         else
  50         {
  51             if(is_vertex(cmd))
  52             {
  53                 if(m_markers.size() & 1)
  54                 {
  55                     // Initial state, the first coordinate was added.
  56                     // Add three more points, 0,1,1,0
  57                     m_markers.add(coord_type(x, y));
  58                     m_markers.add(m_markers[m_markers.size() - 1]);
  59                     m_markers.add(m_markers[m_markers.size() - 3]);
  60                 }
  61                 else
  62                 {
  63                     if(m_markers.size())
  64                     {
  65                         // Replace two last points: 0,1,1,0 -> 0,1,2,1
  66                         m_markers[m_markers.size() - 1] = m_markers[m_markers.size() - 2];
  67                         m_markers[m_markers.size() - 2] = coord_type(x, y);
  68                     }
  69                 }
  70             }
  71         }
  72     }
  73
  74
  75     //------------------------------------------------------------------------
  76     void vcgen_markers_term::rewind(unsigned id)
  77     {
  78         m_curr_id = id * 2;
  79         m_curr_idx = m_curr_id;
  80     }
  81
  82
  83     //------------------------------------------------------------------------
  84     unsigned vcgen_markers_term::vertex(double* x, double* y)
  85     {
  86         if(m_curr_id > 2 || m_curr_idx >= m_markers.size())
  87         {
  88             return path_cmd_stop;
  89         }
  90         const coord_type& c = m_markers[m_curr_idx];
  91         *x = c.x;
  92         *y = c.y;
  93         if(m_curr_idx & 1)
  94         {
  95             m_curr_idx += 3;
  96             return path_cmd_line_to;
  97         }
  98         ++m_curr_idx;
  99         return path_cmd_move_to;
 100     }
 101
 102
 103 }