agg/include/agg_shorten_path.h

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2021-12-27 20:14:31 +01:00
//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
#ifndef AGG_SHORTEN_PATH_INCLUDED
#define AGG_SHORTEN_PATH_INCLUDED
#include "agg_basics.h"
#include "agg_vertex_sequence.h"
namespace agg
{
//===========================================================shorten_path
template<class VertexSequence>
void shorten_path(VertexSequence& vs, double s, unsigned closed = 0)
{
typedef typename VertexSequence::value_type vertex_type;
if(s > 0.0 && vs.size() > 1)
{
double d;
int n = int(vs.size() - 2);
while(n)
{
d = vs[n].dist;
if(d > s) break;
vs.remove_last();
s -= d;
--n;
}
if(vs.size() < 2)
{
vs.remove_all();
}
else
{
n = vs.size() - 1;
vertex_type& prev = vs[n-1];
vertex_type& last = vs[n];
d = (prev.dist - s) / prev.dist;
double x = prev.x + (last.x - prev.x) * d;
double y = prev.y + (last.y - prev.y) * d;
last.x = x;
last.y = y;
if(!prev(last)) vs.remove_last();
vs.close(closed != 0);
}
}
}
}
#endif