flower/offset.cc

   1 /*
   2   offset.cc -- implement Offset
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997 Han-Wen Nienhuys <hanwen@stack.nl>
   7 */
   8 #include <math.h>
   9
  10 #include "string.hh"
  11 #include "offset.hh"
  12
  13
  14 #ifndef STANDALONE
  15 String
  16 Offset::str () const
  17 {
  18   String s;
  19   s = String("(") + coordinate_a_[X_AXIS] + ", " + coordinate_a_[Y_AXIS] + ")";
  20   return s;
  21 }
  22 #endif
  23
  24 Offset
  25 complex_multiply (Offset z1, Offset z2)
  26 {
  27   Offset z;
  28   z[X_AXIS] = z1[X_AXIS] * z2[X_AXIS] - z1[Y_AXIS]*z2[Y_AXIS];
  29   z[Y_AXIS] = z1[X_AXIS] * z2[Y_AXIS] + z1[Y_AXIS] * z2[X_AXIS];
  30   return z;
  31 }
  32
  33 Offset
  34 complex_exp (Offset o)
  35 {
  36   Real s = sin (o[Y_AXIS]);
  37   Real c = cos (o[Y_AXIS]);
  38
  39   Real r = exp (o[X_AXIS]);
  40
  41   return Offset(r*c, r*s);
  42 }
  43
  44 Real
  45 Offset::arg () const
  46 {
  47   return atan2 (y (), x());
  48 }
  49
  50 /**
  51    euclidian vector length / complex modulus
  52  */
  53 Real
  54 Offset::length () const
  55 {
  56   return sqrt (sqr (x()) + sqr (y()));
  57 }
  58 void
  59 Offset::mirror (Axis a)
  60 {
  61   coordinate_a_[a] = - coordinate_a_[a];
  62 }