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Diffstat (limited to 'agg/source/agg_trans_affine.cpp')
-rwxr-xr-x | agg/source/agg_trans_affine.cpp | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/agg/source/agg_trans_affine.cpp b/agg/source/agg_trans_affine.cpp new file mode 100755 index 000000000000..f81050d3e42f --- /dev/null +++ b/agg/source/agg_trans_affine.cpp @@ -0,0 +1,195 @@ +//---------------------------------------------------------------------------- +// Anti-Grain Geometry - Version 2.3 +// 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 +//---------------------------------------------------------------------------- +// +// Affine transformations +// +//---------------------------------------------------------------------------- +#include "agg_trans_affine.h" + + + +namespace agg +{ + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::parl_to_parl(const double* src, + const double* dst) + { + m0 = src[2] - src[0]; + m1 = src[3] - src[1]; + m2 = src[4] - src[0]; + m3 = src[5] - src[1]; + m4 = src[0]; + m5 = src[1]; + invert(); + multiply(trans_affine(dst[2] - dst[0], dst[3] - dst[1], + dst[4] - dst[0], dst[5] - dst[1], + dst[0], dst[1])); + return *this; + } + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::rect_to_parl(double x1, double y1, + double x2, double y2, + const double* parl) + { + double src[6]; + src[0] = x1; src[1] = y1; + src[2] = x2; src[3] = y1; + src[4] = x2; src[5] = y2; + parl_to_parl(src, parl); + return *this; + } + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::parl_to_rect(const double* parl, + double x1, double y1, + double x2, double y2) + { + double dst[6]; + dst[0] = x1; dst[1] = y1; + dst[2] = x2; dst[3] = y1; + dst[4] = x2; dst[5] = y2; + parl_to_parl(parl, dst); + return *this; + } + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::multiply(const trans_affine& m) + { + double t0 = m0 * m.m0 + m1 * m.m2; + double t2 = m2 * m.m0 + m3 * m.m2; + double t4 = m4 * m.m0 + m5 * m.m2 + m.m4; + m1 = m0 * m.m1 + m1 * m.m3; + m3 = m2 * m.m1 + m3 * m.m3; + m5 = m4 * m.m1 + m5 * m.m3 + m.m5; + m0 = t0; + m2 = t2; + m4 = t4; + return *this; + } + + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::invert() + { + double d = determinant(); + + double t0 = m3 * d; + m3 = m0 * d; + m1 = -m1 * d; + m2 = -m2 * d; + + double t4 = -m4 * t0 - m5 * m2; + m5 = -m4 * m1 - m5 * m3; + + m0 = t0; + m4 = t4; + return *this; + } + + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::flip_x() + { + m0 = -m0; + m1 = -m1; + m4 = -m4; + return *this; + } + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::flip_y() + { + m2 = -m2; + m3 = -m3; + m5 = -m5; + return *this; + } + + //------------------------------------------------------------------------ + const trans_affine& trans_affine::reset() + { + m0 = m3 = 1.0; + m1 = m2 = m4 = m5 = 0.0; + return *this; + } + + //------------------------------------------------------------------------ + inline bool is_equal_eps(double v1, double v2, double epsilon) + { + return fabs(v1 - v2) < epsilon; + } + + //------------------------------------------------------------------------ + bool trans_affine::is_identity(double epsilon) const + { + return is_equal_eps(m0, 1.0, epsilon) && + is_equal_eps(m1, 0.0, epsilon) && + is_equal_eps(m2, 0.0, epsilon) && + is_equal_eps(m3, 1.0, epsilon) && + is_equal_eps(m4, 0.0, epsilon) && + is_equal_eps(m5, 0.0, epsilon); + } + + //------------------------------------------------------------------------ + bool trans_affine::is_equal(const trans_affine& m, double epsilon) const + { + return is_equal_eps(m0, m.m0, epsilon) && + is_equal_eps(m1, m.m1, epsilon) && + is_equal_eps(m2, m.m2, epsilon) && + is_equal_eps(m3, m.m3, epsilon) && + is_equal_eps(m4, m.m4, epsilon) && + is_equal_eps(m5, m.m5, epsilon); + } + + //------------------------------------------------------------------------ + double trans_affine::rotation() const + { + double x1 = 0.0; + double y1 = 0.0; + double x2 = 1.0; + double y2 = 0.0; + transform(&x1, &y1); + transform(&x2, &y2); + return atan2(y2-y1, x2-x1); + } + + //------------------------------------------------------------------------ + void trans_affine::translation(double* dx, double* dy) const + { + trans_affine t(*this); + t *= trans_affine_rotation(-rotation()); + t.transform(dx, dy); + } + + //------------------------------------------------------------------------ + void trans_affine::scaling(double* sx, double* sy) const + { + double x1 = 0.0; + double y1 = 0.0; + double x2 = 1.0; + double y2 = 1.0; + trans_affine t(*this); + t *= trans_affine_rotation(-rotation()); + t.transform(&x1, &y1); + t.transform(&x2, &y2); + *sx = x2 - x1; + *sy = y2 - y1; + } + + +} + |