flower/offset.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "offset.hh"
  21
  22 #ifndef STANDALONE
  23 string
  24 Offset::to_string () const
  25 {
  26   string s;
  27   s = string (" (") + ::to_string (coordinate_a_[X_AXIS]) + ", "
  28     + ::to_string (coordinate_a_[Y_AXIS]) + ")";
  29   return s;
  30 }
  31 #endif
  32
  33 /*
  34   free bsd fix by John Galbraith
  35 */
  36
  37 Offset
  38 complex_multiply (Offset z1, Offset z2)
  39 {
  40   Offset z;
  41   if (!isinf (z2[Y_AXIS]))
  42     {
  43       z[X_AXIS] = z1[X_AXIS] * z2[X_AXIS] - z1[Y_AXIS] * z2[Y_AXIS];
  44       z[Y_AXIS] = z1[X_AXIS] * z2[Y_AXIS] + z1[Y_AXIS] * z2[X_AXIS];
  45     }
  46   return z;
  47 }
  48
  49 Offset
  50 complex_conjugate (Offset o)
  51 {
  52   o[Y_AXIS] = -o[Y_AXIS];
  53   return o;
  54 }
  55
  56 Offset
  57 complex_divide (Offset z1, Offset z2)
  58 {
  59   z2 = complex_conjugate (z2);
  60   Offset z = complex_multiply (z1, z2);
  61   z *= 1 / z2.length ();
  62   return z;
  63 }
  64
  65 Offset
  66 complex_exp (Offset o)
  67 {
  68   Real s = sin (o[Y_AXIS]);
  69   Real c = cos (o[Y_AXIS]);
  70
  71   Real r = exp (o[X_AXIS]);
  72
  73   return Offset (r * c, r * s);
  74 }
  75
  76 Real
  77 Offset::arg () const
  78 {
  79   return atan2 (coordinate_a_[Y_AXIS], coordinate_a_[X_AXIS]);
  80 }
  81
  82 Real
  83 Offset::angle_degrees () const
  84 {
  85   return arg () * 180 / M_PI;
  86 }
  87 /**
  88    euclidian vector length / complex modulus
  89 */
  90 Real
  91 Offset::length () const
  92 {
  93   return sqrt (sqr (coordinate_a_[X_AXIS])
  94                     + sqr (coordinate_a_[Y_AXIS]));
  95 }
  96
  97 bool
  98 Offset::is_sane () const
  99 {
 100   return !isnan (coordinate_a_[X_AXIS])
 101     && !isnan (coordinate_a_ [Y_AXIS])
 102     && !isinf (coordinate_a_[X_AXIS])
 103     && !isinf (coordinate_a_[Y_AXIS]);
 104 }
 105
 106 Offset
 107 Offset::direction () const
 108 {
 109   Offset d = *this;
 110   d /= length ();
 111   return d;
 112 }
 113
 114 Offset
 115 Offset::swapped () const
 116 {
 117   return Offset (coordinate_a_[Y_AXIS], coordinate_a_[X_AXIS]);
 118 }