agg/src/agg_vcgen_dash.cpp

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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
//----------------------------------------------------------------------------
//
// Line dash generator
//
//----------------------------------------------------------------------------
#include <cmath>
#include "agg_vcgen_dash.h"
#include "agg_shorten_path.h"
namespace agg
{
//------------------------------------------------------------------------
vcgen_dash::vcgen_dash() :
m_total_dash_len(0.0),
m_num_dashes(0),
m_dash_start(0.0),
m_shorten(0.0),
m_curr_dash_start(0.0),
m_curr_dash(0),
m_src_vertices(),
m_closed(0),
m_status(initial),
m_src_vertex(0)
{
}
//------------------------------------------------------------------------
void vcgen_dash::remove_all_dashes()
{
m_total_dash_len = 0.0;
m_num_dashes = 0;
m_curr_dash_start = 0.0;
m_curr_dash = 0;
}
//------------------------------------------------------------------------
void vcgen_dash::add_dash(double dash_len, double gap_len)
{
if(m_num_dashes < max_dashes)
{
m_total_dash_len += dash_len + gap_len;
m_dashes[m_num_dashes++] = dash_len;
m_dashes[m_num_dashes++] = gap_len;
}
}
//------------------------------------------------------------------------
void vcgen_dash::dash_start(double ds)
{
m_dash_start = ds;
calc_dash_start(std::fabs(ds));
}
//------------------------------------------------------------------------
void vcgen_dash::calc_dash_start(double ds)
{
m_curr_dash = 0;
m_curr_dash_start = 0.0;
while(ds > 0.0)
{
if(ds > m_dashes[m_curr_dash])
{
ds -= m_dashes[m_curr_dash];
++m_curr_dash;
m_curr_dash_start = 0.0;
if(m_curr_dash >= m_num_dashes) m_curr_dash = 0;
}
else
{
m_curr_dash_start = ds;
ds = 0.0;
}
}
}
//------------------------------------------------------------------------
void vcgen_dash::remove_all()
{
m_status = initial;
m_src_vertices.remove_all();
m_closed = 0;
}
//------------------------------------------------------------------------
void vcgen_dash::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_dash::rewind(unsigned)
{
if(m_status == initial)
{
m_src_vertices.close(m_closed != 0);
shorten_path(m_src_vertices, m_shorten, m_closed);
}
m_status = ready;
m_src_vertex = 0;
}
//------------------------------------------------------------------------
unsigned vcgen_dash::vertex(double* x, double* y)
{
unsigned cmd = path_cmd_move_to;
while(!is_stop(cmd))
{
switch(m_status)
{
case initial:
rewind(0);
case ready:
if(m_num_dashes < 2 || m_src_vertices.size() < 2)
{
cmd = path_cmd_stop;
break;
}
m_status = polyline;
m_src_vertex = 1;
m_v1 = &m_src_vertices[0];
m_v2 = &m_src_vertices[1];
m_curr_rest = m_v1->dist;
*x = m_v1->x;
*y = m_v1->y;
if(m_dash_start >= 0.0) calc_dash_start(m_dash_start);
return path_cmd_move_to;
case polyline:
{
double dash_rest = m_dashes[m_curr_dash] - m_curr_dash_start;
unsigned cmd = (m_curr_dash & 1) ?
path_cmd_move_to :
path_cmd_line_to;
if(m_curr_rest > dash_rest)
{
m_curr_rest -= dash_rest;
++m_curr_dash;
if(m_curr_dash >= m_num_dashes) m_curr_dash = 0;
m_curr_dash_start = 0.0;
*x = m_v2->x - (m_v2->x - m_v1->x) * m_curr_rest / m_v1->dist;
*y = m_v2->y - (m_v2->y - m_v1->y) * m_curr_rest / m_v1->dist;
}
else
{
m_curr_dash_start += m_curr_rest;
*x = m_v2->x;
*y = m_v2->y;
++m_src_vertex;
m_v1 = m_v2;
m_curr_rest = m_v1->dist;
if(m_closed)
{
if(m_src_vertex > m_src_vertices.size())
{
m_status = stop;
}
else
{
m_v2 = &m_src_vertices
[
(m_src_vertex >= m_src_vertices.size()) ? 0 :
m_src_vertex
];
}
}
else
{
if(m_src_vertex >= m_src_vertices.size())
{
m_status = stop;
}
else
{
m_v2 = &m_src_vertices[m_src_vertex];
}
}
}
return cmd;
}
break;
case stop:
cmd = path_cmd_stop;
break;
}
}
return path_cmd_stop;
}
}