mapnik/deps/agg/src/agg_vcgen_stroke.cpp

213 lines
6.8 KiB
C++

//----------------------------------------------------------------------------
// 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
//----------------------------------------------------------------------------
//
// Stroke generator
//
//----------------------------------------------------------------------------
#include <math.h>
#include "agg_vcgen_stroke.h"
#include "agg_shorten_path.h"
namespace agg
{
//------------------------------------------------------------------------
vcgen_stroke::vcgen_stroke() :
m_stroker(),
m_src_vertices(),
m_out_vertices(),
m_shorten(0.0),
m_closed(0),
m_status(initial),
m_src_vertex(0),
m_out_vertex(0)
{
}
//------------------------------------------------------------------------
void vcgen_stroke::remove_all()
{
m_src_vertices.remove_all();
m_closed = 0;
m_status = initial;
}
//------------------------------------------------------------------------
void vcgen_stroke::add_vertex(double x, double y, unsigned cmd)
{
m_status = initial;
if(is_move_to(cmd))
{
m_src_vertices.modify_last(vertex_dist(x, y));
}
else
{
if(is_vertex(cmd))
{
m_src_vertices.add(vertex_dist(x, y));
}
else
{
m_closed = get_close_flag(cmd);
}
}
}
//------------------------------------------------------------------------
void vcgen_stroke::rewind(unsigned)
{
if(m_status == initial)
{
m_src_vertices.close(m_closed != 0);
shorten_path(m_src_vertices, m_shorten, m_closed);
if(m_src_vertices.size() < 3) m_closed = 0;
}
m_status = ready;
m_src_vertex = 0;
m_out_vertex = 0;
}
//------------------------------------------------------------------------
unsigned vcgen_stroke::vertex(double* x, double* y)
{
unsigned cmd = path_cmd_line_to;
while(!is_stop(cmd))
{
switch(m_status)
{
case initial:
rewind(0);
case ready:
if(m_src_vertices.size() < 2 + unsigned(m_closed != 0))
{
cmd = path_cmd_stop;
break;
}
m_status = m_closed ? outline1 : cap1;
cmd = path_cmd_move_to;
m_src_vertex = 0;
m_out_vertex = 0;
break;
case cap1:
m_stroker.calc_cap(m_out_vertices,
m_src_vertices[0],
m_src_vertices[1],
m_src_vertices[0].dist);
m_src_vertex = 1;
m_prev_status = outline1;
m_status = out_vertices;
m_out_vertex = 0;
break;
case cap2:
m_stroker.calc_cap(m_out_vertices,
m_src_vertices[m_src_vertices.size() - 1],
m_src_vertices[m_src_vertices.size() - 2],
m_src_vertices[m_src_vertices.size() - 2].dist);
m_prev_status = outline2;
m_status = out_vertices;
m_out_vertex = 0;
break;
case outline1:
if(m_closed)
{
if(m_src_vertex >= m_src_vertices.size())
{
m_prev_status = close_first;
m_status = end_poly1;
break;
}
}
else
{
if(m_src_vertex >= m_src_vertices.size() - 1)
{
m_status = cap2;
break;
}
}
m_stroker.calc_join(m_out_vertices,
m_src_vertices.prev(m_src_vertex),
m_src_vertices.curr(m_src_vertex),
m_src_vertices.next(m_src_vertex),
m_src_vertices.prev(m_src_vertex).dist,
m_src_vertices.curr(m_src_vertex).dist);
++m_src_vertex;
m_prev_status = m_status;
m_status = out_vertices;
m_out_vertex = 0;
break;
case close_first:
m_status = outline2;
cmd = path_cmd_move_to;
case outline2:
if(m_src_vertex <= unsigned(m_closed == 0))
{
m_status = end_poly2;
m_prev_status = stop;
break;
}
--m_src_vertex;
m_stroker.calc_join(m_out_vertices,
m_src_vertices.next(m_src_vertex),
m_src_vertices.curr(m_src_vertex),
m_src_vertices.prev(m_src_vertex),
m_src_vertices.curr(m_src_vertex).dist,
m_src_vertices.prev(m_src_vertex).dist);
m_prev_status = m_status;
m_status = out_vertices;
m_out_vertex = 0;
break;
case out_vertices:
if(m_out_vertex >= m_out_vertices.size())
{
m_status = m_prev_status;
}
else
{
const point_d& c = m_out_vertices[m_out_vertex++];
*x = c.x;
*y = c.y;
return cmd;
}
break;
case end_poly1:
m_status = m_prev_status;
return path_cmd_end_poly | path_flags_close | path_flags_ccw;
case end_poly2:
m_status = m_prev_status;
return path_cmd_end_poly | path_flags_close | path_flags_cw;
case stop:
cmd = path_cmd_stop;
break;
}
}
return cmd;
}
}