ultimatepp/uppdev/aggdraw/agg_vpgen_segmentator.cpp

76 lines
2.3 KiB
C++

//----------------------------------------------------------------------------
// Anti-Grain Geometry (AGG) - Version 2.5
// A high quality rendering engine for C++
// Copyright (C) 2002-2006 Maxim Shemanarev
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://antigrain.com
//
// AGG is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// AGG is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with AGG; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
// MA 02110-1301, USA.
//----------------------------------------------------------------------------
#include <math.h>
#include "agg_vpgen_segmentator.h"
namespace agg
{
void vpgen_segmentator::move_to(double x, double y)
{
m_x1 = x;
m_y1 = y;
m_dx = 0.0;
m_dy = 0.0;
m_dl = 2.0;
m_ddl = 2.0;
m_cmd = path_cmd_move_to;
}
void vpgen_segmentator::line_to(double x, double y)
{
m_x1 += m_dx;
m_y1 += m_dy;
m_dx = x - m_x1;
m_dy = y - m_y1;
double len = sqrt(m_dx * m_dx + m_dy * m_dy) * m_approximation_scale;
if(len < 1e-30) len = 1e-30;
m_ddl = 1.0 / len;
m_dl = (m_cmd == path_cmd_move_to) ? 0.0 : m_ddl;
if(m_cmd == path_cmd_stop) m_cmd = path_cmd_line_to;
}
unsigned vpgen_segmentator::vertex(double* x, double* y)
{
if(m_cmd == path_cmd_stop) return path_cmd_stop;
unsigned cmd = m_cmd;
m_cmd = path_cmd_line_to;
if(m_dl >= 1.0 - m_ddl)
{
m_dl = 1.0;
m_cmd = path_cmd_stop;
*x = m_x1 + m_dx;
*y = m_y1 + m_dy;
return cmd;
}
*x = m_x1 + m_dx * m_dl;
*y = m_y1 + m_dy * m_dl;
m_dl += m_ddl;
return cmd;
}
}