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Diffstat (limited to 'demos/spectrum/3rdparty/fftreal/FFTRealPassDirect.hpp')
| -rw-r--r-- | demos/spectrum/3rdparty/fftreal/FFTRealPassDirect.hpp | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/demos/spectrum/3rdparty/fftreal/FFTRealPassDirect.hpp b/demos/spectrum/3rdparty/fftreal/FFTRealPassDirect.hpp new file mode 100644 index 0000000000..db9d568e61 --- /dev/null +++ b/demos/spectrum/3rdparty/fftreal/FFTRealPassDirect.hpp @@ -0,0 +1,204 @@ +/***************************************************************************** + + FFTRealPassDirect.hpp + Copyright (c) 2005 Laurent de Soras + +--- Legal stuff --- + +This library is free software; you can redistribute it and/or +modify it under the terms of the GNU Lesser General Public +License as published by the Free Software Foundation; either +version 2.1 of the License, or (at your option) any later version. + +This library 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 +Lesser General Public License for more details. + +You should have received a copy of the GNU Lesser General Public +License along with this library; if not, write to the Free Software +Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + +*Tab=3***********************************************************************/ + + + +#if defined (FFTRealPassDirect_CURRENT_CODEHEADER) + #error Recursive inclusion of FFTRealPassDirect code header. +#endif +#define FFTRealPassDirect_CURRENT_CODEHEADER + +#if ! defined (FFTRealPassDirect_CODEHEADER_INCLUDED) +#define FFTRealPassDirect_CODEHEADER_INCLUDED + + + +/*\\\ INCLUDE FILES \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ + +#include "FFTRealUseTrigo.h" + + + +/*\\\ PUBLIC \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ + + + +template <> +void FFTRealPassDirect <1>::process (long len, DataType dest_ptr [], DataType src_ptr [], const DataType x_ptr [], const DataType cos_ptr [], long cos_len, const long br_ptr [], OscType osc_list []) +{ + // First and second pass at once + const long qlen = len >> 2; + + long coef_index = 0; + do + { + // To do: unroll the loop (2x). + const long ri_0 = br_ptr [coef_index >> 2]; + const long ri_1 = ri_0 + 2 * qlen; // bit_rev_lut_ptr [coef_index + 1]; + const long ri_2 = ri_0 + 1 * qlen; // bit_rev_lut_ptr [coef_index + 2]; + const long ri_3 = ri_0 + 3 * qlen; // bit_rev_lut_ptr [coef_index + 3]; + + DataType * const df2 = dest_ptr + coef_index; + df2 [1] = x_ptr [ri_0] - x_ptr [ri_1]; + df2 [3] = x_ptr [ri_2] - x_ptr [ri_3]; + + const DataType sf_0 = x_ptr [ri_0] + x_ptr [ri_1]; + const DataType sf_2 = x_ptr [ri_2] + x_ptr [ri_3]; + + df2 [0] = sf_0 + sf_2; + df2 [2] = sf_0 - sf_2; + + coef_index += 4; + } + while (coef_index < len); +} + +template <> +void FFTRealPassDirect <2>::process (long len, DataType dest_ptr [], DataType src_ptr [], const DataType x_ptr [], const DataType cos_ptr [], long cos_len, const long br_ptr [], OscType osc_list []) +{ + // Executes "previous" passes first. Inverts source and destination buffers + FFTRealPassDirect <1>::process ( + len, + src_ptr, + dest_ptr, + x_ptr, + cos_ptr, + cos_len, + br_ptr, + osc_list + ); + + // Third pass + const DataType sqrt2_2 = DataType (SQRT2 * 0.5); + + long coef_index = 0; + do + { + dest_ptr [coef_index ] = src_ptr [coef_index] + src_ptr [coef_index + 4]; + dest_ptr [coef_index + 4] = src_ptr [coef_index] - src_ptr [coef_index + 4]; + dest_ptr [coef_index + 2] = src_ptr [coef_index + 2]; + dest_ptr [coef_index + 6] = src_ptr [coef_index + 6]; + + DataType v; + + v = (src_ptr [coef_index + 5] - src_ptr [coef_index + 7]) * sqrt2_2; + dest_ptr [coef_index + 1] = src_ptr [coef_index + 1] + v; + dest_ptr [coef_index + 3] = src_ptr [coef_index + 1] - v; + + v = (src_ptr [coef_index + 5] + src_ptr [coef_index + 7]) * sqrt2_2; + dest_ptr [coef_index + 5] = v + src_ptr [coef_index + 3]; + dest_ptr [coef_index + 7] = v - src_ptr [coef_index + 3]; + + coef_index += 8; + } + while (coef_index < len); +} + +template <int PASS> +void FFTRealPassDirect <PASS>::process (long len, DataType dest_ptr [], DataType src_ptr [], const DataType x_ptr [], const DataType cos_ptr [], long cos_len, const long br_ptr [], OscType osc_list []) +{ + // Executes "previous" passes first. Inverts source and destination buffers + FFTRealPassDirect <PASS - 1>::process ( + len, + src_ptr, + dest_ptr, + x_ptr, + cos_ptr, + cos_len, + br_ptr, + osc_list + ); + + const long dist = 1L << (PASS - 1); + const long c1_r = 0; + const long c1_i = dist; + const long c2_r = dist * 2; + const long c2_i = dist * 3; + const long cend = dist * 4; + const long table_step = cos_len >> (PASS - 1); + + enum { TRIGO_OSC = PASS - FFTRealFixLenParam::TRIGO_BD_LIMIT }; + enum { TRIGO_DIRECT = (TRIGO_OSC >= 0) ? 1 : 0 }; + + long coef_index = 0; + do + { + const DataType * const sf = src_ptr + coef_index; + DataType * const df = dest_ptr + coef_index; + + // Extreme coefficients are always real + df [c1_r] = sf [c1_r] + sf [c2_r]; + df [c2_r] = sf [c1_r] - sf [c2_r]; + df [c1_i] = sf [c1_i]; + df [c2_i] = sf [c2_i]; + + FFTRealUseTrigo <TRIGO_DIRECT>::prepare (osc_list [TRIGO_OSC]); + + // Others are conjugate complex numbers + for (long i = 1; i < dist; ++ i) + { + DataType c; + DataType s; + FFTRealUseTrigo <TRIGO_DIRECT>::iterate ( + osc_list [TRIGO_OSC], + c, + s, + cos_ptr, + i * table_step, + (dist - i) * table_step + ); + + const DataType sf_r_i = sf [c1_r + i]; + const DataType sf_i_i = sf [c1_i + i]; + + const DataType v1 = sf [c2_r + i] * c - sf [c2_i + i] * s; + df [c1_r + i] = sf_r_i + v1; + df [c2_r - i] = sf_r_i - v1; + + const DataType v2 = sf [c2_r + i] * s + sf [c2_i + i] * c; + df [c2_r + i] = v2 + sf_i_i; + df [cend - i] = v2 - sf_i_i; + } + + coef_index += cend; + } + while (coef_index < len); +} + + + +/*\\\ PROTECTED \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ + + + +/*\\\ PRIVATE \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ + + + +#endif // FFTRealPassDirect_CODEHEADER_INCLUDED + +#undef FFTRealPassDirect_CURRENT_CODEHEADER + + + +/*\\\ EOF \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\*/ |