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/*
cw_binaural~: a binaural synthesis external for pure data
by David Doukhan - david.doukhan@gmail.com - http://perso.limsi.fr/doukhan
and Anne Sedes - sedes.anne@gmail.com
Copyright (C) 2009-2011 David Doukhan and Anne Sedes
For more details, see CW_binaural~, a binaural synthesis external for Pure Data
David Doukhan and Anne Sedes, PDCON09
This program 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 3 of the License, or
(at your option) any later version.
This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef HRTFCONT_HPP_
# define HRTFCONT_HPP_
# include <map>
# include "ir_key.hpp"
# include "interpolation_candidates.hpp"
// atomic element
// contains a buffer for a right and left impulse response
// corresponding to a given azimuth and elevation
typedef struct
{
float *lbuf; // left buffer
float *rbuf; // right buffer
// string fname;
} ir_buffer;
// each HRTF is indexed by two angles in degree: azimuth and elevation
// Depending on the HRTF dabase considered, those angles may be expressed
// in a different coordinate system
//
// For the Listen Database, azimuth and elevation are expressed
// in the Vertical-polar coordinate system (most common spherical coordinate system)
// azimuth is in the range [0,360[ and distance between 2 azimuth is circular
// elevation is in the range [-90,+90]
// Consequently, database expressed in Vertical-polar coordinate system
// will be indexed by elevation first, and then azimuth
//
// For the CIPIC Database, azimuth and elevation are expressed
// in the Interaural-polar coordinate system
// elevation is in the range [0,360[ and distance between 2 elevations is circular
// azimuth is in the range [-90,+90]
// Consequently, database expressed in Interoral-polar coordinate system
// will be indexed by elevation first, and then azimuth
// store impulse responses indexed by an angle whose values are in [0,360[ degree
// azimuth in vertical-polar coords, or elevation in interaural-polar coords
// corresponds to the second index of the storage map
typedef map<float, ir_buffer> angle2_cont;
// const interator on the second angle index
typedef angle2_cont::const_iterator angle2_cit;
// type used to store HRTFs corresponding of a given subject
// indexed by an angle in [-90,+90[ first and then by an angle in [0,360[
typedef map<float, angle2_cont> hrtf_map;
// const interator on the first angle angle index
typedef map<float, angle2_cont>::const_iterator angle1_cit;
// HRTF Container
class HrtfCont
{
public:
HrtfCont(const ir_key& k);
// return the map indexing all available impulse responses
map<float, map<float, ir_buffer> >* map_get() {return &_m;}
inline size_t ir_length_get() const {return _ir_length;}
// update and interpolation structure containing the candidates to be interpolated
void set_candidates(interp_cdts& ic, float az, float el);
// called from set_candidates, for a fixed angle index 1
// add the angle index2 candidates
void add_a2_candidates(interp_cdts& ic, float a1_key, float a2, float weight);
// update filter coefficients from interpolation candidates
void update_from_candidates(const interp_cdts& ic, float* left, float* right);
protected:
// normalize vertical polar coordinates expressed in degree
// ie: set elevation in [-90, +90], and azimuth in [-180, 180[
void normalize_vertpolar_coords(float& azimuth, float& elevation) const;
// angular distance (ie dist(350,0) == 10)
float angular_dist(float a1, float a2) const;
// convert an azimuth/elevation couple expressed in
// vertical polar coordinates to interaural polar coordinates
void vertpol2interaurpol(float& az, float& el) const;
size_t _ir_length;
hrtf_map _m;
const bool _vert_pol_coords;
};
#endif
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