diff options
Diffstat (limited to 'gnuradio-core/src/lib/general/gr_fxpt.cc')
-rw-r--r-- | gnuradio-core/src/lib/general/gr_fxpt.cc | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/gnuradio-core/src/lib/general/gr_fxpt.cc b/gnuradio-core/src/lib/general/gr_fxpt.cc new file mode 100644 index 0000000000..62ed8bd67a --- /dev/null +++ b/gnuradio-core/src/lib/general/gr_fxpt.cc @@ -0,0 +1,57 @@ +/* -*- c++ -*- */ +/* + * Copyright 2004 Free Software Foundation, Inc. + * + * This file is part of GNU Radio + * + * GNU Radio is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * GNU Radio is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Radio; see the file COPYING. If not, write to + * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include <gr_fxpt.h> + +const float gr_fxpt::s_sine_table[1 << NBITS][2] = { +#include "sine_table.h" +}; + +// gcc 4.x fix +const float gr_fxpt::TWO_TO_THE_31; +const float gr_fxpt::PI; + +#if 0 +/* + * Compute sine using table lookup with linear interpolation. + * Each table entry contains slope and intercept. + */ +float +gr_fxpt::sin (gr_int32 x) +{ + gr_uint32 ux = x; + int index = ux >> (WORDBITS - NBITS); + return s_sine_table[index][0] * (ux >> 1) + s_sine_table[index][1]; +} + +float +gr_fxpt::cos (gr_int32 x) +{ + gr_uint32 ux = x + 0x40000000; + int index = ux >> (WORDBITS - NBITS); + return s_sine_table[index][0] * (ux >> 1) + s_sine_table[index][1]; +} +#endif |