ultimatepp/uppdev/aggdraw/agg_trans_warp_magnifier.cpp

79 lines
2.5 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_trans_warp_magnifier.h"
namespace agg
{
//------------------------------------------------------------------------
void trans_warp_magnifier::transform(double* x, double* y) const
{
double dx = *x - m_xc;
double dy = *y - m_yc;
double r = sqrt(dx * dx + dy * dy);
if(r < m_radius)
{
*x = m_xc + dx * m_magn;
*y = m_yc + dy * m_magn;
return;
}
double m = (r + m_radius * (m_magn - 1.0)) / r;
*x = m_xc + dx * m;
*y = m_yc + dy * m;
}
//------------------------------------------------------------------------
void trans_warp_magnifier::inverse_transform(double* x, double* y) const
{
// New version by Andrew Skalkin
//-----------------
double dx = *x - m_xc;
double dy = *y - m_yc;
double r = sqrt(dx * dx + dy * dy);
if(r < m_radius * m_magn)
{
*x = m_xc + dx / m_magn;
*y = m_yc + dy / m_magn;
}
else
{
double rnew = r - m_radius * (m_magn - 1.0);
*x = m_xc + rnew * dx / r;
*y = m_yc + rnew * dy / r;
}
// Old version
//-----------------
//trans_warp_magnifier t(*this);
//t.magnification(1.0 / m_magn);
//t.radius(m_radius * m_magn);
//t.transform(x, y);
}
}