dmd/complex_t.h

   1
   2 // Compiler implementation of the D programming language
   3 // Copyright (c) 1999-2006 by Digital Mars
   4 // All Rights Reserved
   5 // written by Walter Bright and Burton Radons
   6 // http://www.digitalmars.com
   7 // License for redistribution is by either the Artistic License
   8 // in artistic.txt, or the GNU General Public License in gnu.txt.
   9 // See the included readme.txt for details.
  10
  11 #ifndef DMD_COMPLEX_T_H
  12 #define DMD_COMPLEX_T_H
  13
  14 /* Roll our own complex type for compilers that don't support complex
  15  */
  16
  17 struct complex_t
  18 {
  19     long double re;
  20     long double im;
  21
  22     complex_t() { this->re = 0; this->im = 0; }
  23     complex_t(long double re) { this->re = re; this->im = 0; }
  24     complex_t(long double re, long double im) { this->re = re; this->im = im; }
  25
  26     complex_t operator + (complex_t y) { complex_t r; r.re = re + y.re; r.im = im + y.im; return r; }
  27     complex_t operator - (complex_t y) { complex_t r; r.re = re - y.re; r.im = im - y.im; return r; }
  28     complex_t operator - () { complex_t r; r.re = -re; r.im = -im; return r; }
  29     complex_t operator * (complex_t y) { return complex_t(re * y.re - im * y.im, im * y.re + re * y.im); }
  30
  31     complex_t operator / (complex_t y)
  32     {
  33         long double abs_y_re = y.re < 0 ? -y.re : y.re;
  34         long double abs_y_im = y.im < 0 ? -y.im : y.im;
  35         long double r, den;
  36
  37         if (abs_y_re < abs_y_im)
  38         {
  39             r = y.re / y.im;
  40             den = y.im + r * y.re;
  41             return complex_t((re * r + im) / den,
  42                              (im * r - re) / den);
  43         }
  44         else
  45         {
  46             r = y.im / y.re;
  47             den = y.re + r * y.im;
  48             return complex_t((re + r * im) / den,
  49                              (im - r * re) / den);
  50         }
  51     }
  52
  53     operator bool () { return re || im; }
  54
  55     int operator == (complex_t y) { return re == y.re && im == y.im; }
  56     int operator != (complex_t y) { return re != y.re || im != y.im; }
  57 };
  58
  59 inline complex_t operator * (long double x, complex_t y) { return complex_t(x) * y; }
  60 inline complex_t operator * (complex_t x, long double y) { return x * complex_t(y); }
  61 inline complex_t operator / (complex_t x, long double y) { return x / complex_t(y); }
  62
  63
  64 inline long double creall(complex_t x)
  65 {
  66     return x.re;
  67 }
  68
  69 inline long double cimagl(complex_t x)
  70 {
  71     return x.im;
  72 }
  73
  74 #endif