agg/source/agg_trans_warp_magnifier.cpp

   1 //----------------------------------------------------------------------------
   2 // Anti-Grain Geometry - Version 2.3
   3 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
   4 //
   5 // Permission to copy, use, modify, sell and distribute this software
   6 // is granted provided this copyright notice appears in all copies.
   7 // This software is provided "as is" without express or implied
   8 // warranty, and with no claim as to its suitability for any purpose.
   9 //
  10 //----------------------------------------------------------------------------
  11 // Contact: mcseem@antigrain.com
  12 //          mcseemagg@yahoo.com
  13 //          http://www.antigrain.com
  14 //----------------------------------------------------------------------------
  15
  16 #include <math.h>
  17 #include "agg_trans_warp_magnifier.h"
  18
  19 namespace agg
  20 {
  21
  22     //------------------------------------------------------------------------
  23     void trans_warp_magnifier::transform(double* x, double* y) const
  24     {
  25         double dx = *x - m_xc;
  26         double dy = *y - m_yc;
  27         double r = sqrt(dx * dx + dy * dy);
  28         if(r < m_radius)
  29         {
  30             *x = m_xc + dx * m_magn;
  31             *y = m_yc + dy * m_magn;
  32             return;
  33         }
  34
  35         double m = (r + m_radius * (m_magn - 1.0)) / r;
  36         *x = m_xc + dx * m;
  37         *y = m_yc + dy * m;
  38     }
  39
  40     //------------------------------------------------------------------------
  41     void trans_warp_magnifier::inverse_transform(double* x, double* y) const
  42     {
  43         trans_warp_magnifier t(*this);
  44         t.magnification(1.0 / m_magn);
  45         t.radius(m_radius * m_magn);
  46         t.transform(x, y);
  47     }
  48
  49
  50 }