flower/offset.cc

   1 /*
   2   offset.cc -- implement Offset
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c)  1997--1999 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8 #include <math.h>
   9
  10 #ifndef STANDALONE
  11 #include "string.hh"
  12 #endif
  13 #include "offset.hh"
  14
  15
  16 #ifndef STANDALONE
  17 String
  18 Offset::str () const
  19 {
  20   String s;
  21   s = String("(") + to_str (coordinate_a_[X_AXIS]) + ", "
  22     + to_str (coordinate_a_[Y_AXIS]) + ")";
  23   return s;
  24 }
  25 #endif
  26
  27
  28 bool
  29 isinf_b (Real r)
  30 {
  31   return (fabs (r) > 1e20);
  32 }
  33
  34 /*
  35   free bsd fix by John Galbraith
  36  */
  37
  38 Offset
  39 complex_multiply (Offset z1, Offset z2)
  40 {
  41   Offset z;
  42   if(!isinf_b(z2[Y_AXIS]))
  43   {
  44       z[X_AXIS] = z1[X_AXIS] * z2[X_AXIS] - z1[Y_AXIS]*z2[Y_AXIS];
  45       z[Y_AXIS] = z1[X_AXIS] * z2[Y_AXIS] + z1[Y_AXIS] * z2[X_AXIS];
  46   }
  47   return z;
  48 }
  49
  50
  51
  52 Offset
  53 complex_exp (Offset o)
  54 {
  55   Real s = sin (o[Y_AXIS]);
  56   Real c = cos (o[Y_AXIS]);
  57
  58   Real r = exp (o[X_AXIS]);
  59
  60   return Offset(r*c, r*s);
  61 }
  62
  63 Real
  64 Offset::arg () const
  65 {
  66   return atan2 (y (), x());
  67 }
  68
  69 /**
  70    euclidian vector length / complex modulus
  71  */
  72 Real
  73 Offset::length () const
  74 {
  75   return sqrt (sqr (x()) + sqr (y()));
  76 }
  77 void
  78 Offset::mirror (Axis a)
  79 {
  80   coordinate_a_[a] = - coordinate_a_[a];
  81 }