mapnik/deps/agg/include/agg_trans_lens.h

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//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.1
// 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
//----------------------------------------------------------------------------
#ifndef AGG_WARP_MAGNIFIER_INCLUDED
#define AGG_WARP_MAGNIFIER_INCLUDED
#include <cmath>
#include "agg_basics.h"
namespace agg
{
class trans_warp_magnifier
{
public:
trans_warp_magnifier() : m_xc(0.0), m_yc(0.0), m_magn(1.0), m_radius(1.0), m_warp(false) {}
void center(double x, double y) { m_xc = x; m_yc = y; }
void magnification(double m) { m_magn = m; }
void radius(double r) { m_radius = r; }
void warp(bool w) { m_warp = w; }
void transform(double* x, double* y) const
{
double dx = *x - m_xc;
double dy = *y - m_yc;
double r = sqrt(dx * dx + dy * dy);
double rm = m_radius / m_magn;
if(r < rm)
{
*x = m_xc + dx * m_magn;
*y = m_yc + dy * m_magn;
return;
}
if(m_warp)
{
double m = (r + rm * (m_magn - 1.0)) / r;
*x = m_xc + dx * m;
*y = m_yc + dy * m;
return;
}
if(r < m_radius)
{
double m = m_radius / r;
*x = m_xc + dx * m;
*y = m_yc + dy * m;
}
}
private:
double m_xc;
double m_yc;
double m_magn;
double m_radius;
bool m_warp;
};
}
#endif