mapnik/deps/agg/src/agg_vpgen_clip_polyline.cpp

77 lines
2.4 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
//----------------------------------------------------------------------------
#include "agg_vpgen_clip_polyline.h"
#include "agg_clip_liang_barsky.h"
namespace agg
{
//----------------------------------------------------------------------------
void vpgen_clip_polyline::reset()
{
m_vertex = 0;
m_num_vertices = 0;
m_move_to = false;
}
//----------------------------------------------------------------------------
void vpgen_clip_polyline::move_to(double x, double y)
{
m_vertex = 0;
m_num_vertices = 0;
m_x1 = x;
m_y1 = y;
m_move_to = true;
}
//----------------------------------------------------------------------------
void vpgen_clip_polyline::line_to(double x, double y)
{
double x2 = x;
double y2 = y;
unsigned flags = clip_line_segment(&m_x1, &m_y1, &x2, &y2, m_clip_box);
m_vertex = 0;
m_num_vertices = 0;
if((flags & 4) == 0)
{
if((flags & 1) != 0 || m_move_to)
{
m_x[0] = m_x1;
m_y[0] = m_y1;
m_cmd[0] = path_cmd_move_to;
m_num_vertices = 1;
}
m_x[m_num_vertices] = x2;
m_y[m_num_vertices] = y2;
m_cmd[m_num_vertices++] = path_cmd_line_to;
m_move_to = (flags & 2) != 0;
}
m_x1 = x;
m_y1 = y;
}
//----------------------------------------------------------------------------
unsigned vpgen_clip_polyline::vertex(double* x, double* y)
{
if(m_vertex < m_num_vertices)
{
*x = m_x[m_vertex];
*y = m_y[m_vertex];
return m_cmd[m_vertex++];
}
return path_cmd_stop;
}
}