1 2 //---------------------------------------------------------------------------- 3 // Anti-Grain Geometry - Version 2.3 4 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com) 5 // 6 // Permission to copy, use, modify, sell and distribute this software 7 // is granted provided this copyright notice appears in all copies. 8 // This software is provided "as is" without express or implied 9 // warranty, and with no claim as to its suitability for any purpose. 10 // 11 //---------------------------------------------------------------------------- 12 // Contact: mcseem (at) antigrain.com 13 // mcseemagg (at) yahoo.com 14 // http://www.antigrain.com 15 //---------------------------------------------------------------------------- 16 #ifndef AGG_SHORTEN_PATH_INCLUDED 17 #define AGG_SHORTEN_PATH_INCLUDED 18 #include "agg_basics.h" 19 #include "agg_vertex_sequence.h" 20 namespace agg 21 { 22 template<class VertexSequence> 23 void shorten_path(VertexSequence& vs, FX_FLOAT s, unsigned closed = 0) 24 { 25 typedef typename VertexSequence::value_type vertex_type; 26 if(s > 0 && vs.size() > 1) { 27 FX_FLOAT d; 28 int n = int(vs.size() - 2); 29 while(n) { 30 d = vs[n].dist; 31 if(d > s) { 32 break; 33 } 34 vs.remove_last(); 35 s -= d; 36 --n; 37 } 38 if(vs.size() < 2) { 39 vs.remove_all(); 40 } else { 41 n = vs.size() - 1; 42 vertex_type& prev = vs[n - 1]; 43 vertex_type& last = vs[n]; 44 d = (prev.dist - s) / prev.dist; 45 FX_FLOAT x = prev.x + (last.x - prev.x) * d; 46 FX_FLOAT y = prev.y + (last.y - prev.y) * d; 47 last.x = x; 48 last.y = y; 49 if(!prev(last)) { 50 vs.remove_last(); 51 } 52 vs.close(closed != 0); 53 } 54 } 55 } 56 } 57 #endif 58
