headers/libs/agg/agg_path_length.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 #ifndef AGG_PATH_LENGTH_INCLUDED
  16 #define AGG_PATH_LENGTH_INCLUDED
  17
  18 #include "agg_math.h"
  19
  20 namespace agg
  21 {
  22     template<class VertexSource>
  23     double path_length(VertexSource& vs, unsigned path_id = 0)
  24     {
  25         double len = 0.0;
  26         double start_x = 0.0;
  27         double start_y = 0.0;
  28         double x1 = 0.0;
  29         double y1 = 0.0;
  30         double x2 = 0.0;
  31         double y2 = 0.0;
  32         bool first = true;
  33
  34         unsigned cmd;
  35         vs.rewind(path_id);
  36         while(!is_stop(cmd = vs.vertex(&x2, &y2)))
  37         {
  38             if(is_vertex(cmd))
  39             {
  40                 if(first || is_move_to(cmd))
  41                 {
  42                     start_x = x2;
  43                     start_y = y2;
  44                 }
  45                 else
  46                 {
  47                     len += calc_distance(x1, y1, x2, y2);
  48                 }
  49                 x1 = x2;
  50                 y1 = y2;
  51                 first = false;
  52             }
  53             else
  54             {
  55                 if(is_close(cmd) && !first)
  56                 {
  57                     len += calc_distance(x1, y1, start_x, start_y);
  58                 }
  59             }
  60         }
  61         return len;
  62     }
  63 }
  64
  65 #endif