/*
* Brickworks
*
* Copyright (C) 2023 Orastron Srl unipersonale
*
* Brickworks 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, version 3 of the License.
*
* Brickworks 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 Brickworks. If not, see <http://www.gnu.org/licenses/>.
*
* File author: Stefano D'Angelo
*/
/*!
* module_type {{{ dsp }}}
* version {{{ 0.3.0 }}}
* requires {{{ bw_common bw_config bw_gain bw_math bw_one_pole }}}
* description {{{
* Stereo panner.
* }}}
* changelog {{{
* <ul>
* <li>Version <strong>0.5.0</strong>:
* <ul>
* <li>Added <code>bw_pan_process_multi()</code>.</li>
* <li><code>bw_pan_process()</code> does not accept <code>NULL</code>
* buffers anymore.</li>
* </ul>
* </li>
* <li>Version <strong>0.3.0</strong>:
* <ul>
* <li>First release.</li>
* </ul>
* </li>
* </ul>
* }}}
*/
#ifndef _BW_PAN_H
#define _BW_PAN_H
#ifdef __cplusplus
extern "C" {
#endif
#include <bw_common.h>
/*! api {{{
* #### bw_pan_coeffs
* ```>>> */
typedef struct _bw_pan_coeffs bw_pan_coeffs;
/*! <<<```
* Coefficients and related.
*
* #### bw_pan_init()
* ```>>> */
static inline void bw_pan_init(bw_pan_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Initializes input parameter values in `coeffs`.
*
* #### bw_pan_set_sample_rate()
* ```>>> */
static inline void bw_pan_set_sample_rate(bw_pan_coeffs *BW_RESTRICT coeffs, float sample_rate);
/*! <<<```
* Sets the `sample_rate` (Hz) value in `coeffs`.
*
* #### bw_pan_reset_coeffs()
* ```>>> */
static inline void bw_pan_reset_coeffs(bw_pan_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Resets coefficients in `coeffs` to assume their target values.
*
* #### bw_pan_update_coeffs_ctrl()
* ```>>> */
static inline void bw_pan_update_coeffs_ctrl(bw_pan_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Triggers control-rate update of coefficients in `coeffs`.
*
* #### bw_pan_update_coeffs_audio()
* ```>>> */
static inline void bw_pan_update_coeffs_audio(bw_pan_coeffs *BW_RESTRICT coeffs);
/*! <<<```
* Triggers audio-rate update of coefficients in `coeffs`.
*
* #### bw_pan_process1()
* ```>>> */
static inline void bw_pan_process1(const bw_pan_coeffs *BW_RESTRICT coeffs, float x, float *BW_RESTRICT y_l, float *BW_RESTRICT y_r);
/*! <<<```
* Processes one input sample `x` using `coeffs`, while using and updating
* `state`. The left and right output samples are put into `y_l` (left) and
* `y_r` (right) respectively.
*
* #### bw_pan_process()
* ```>>> */
static inline void bw_pan_process(bw_pan_coeffs *BW_RESTRICT coeffs, const float *x, float *y_l, float *y_r, int n_samples);
/*! <<<```
* Processes the first `n_samples` of the input buffer `x` and fills the
* first `n_samples` of the output buffers `y_l` (left) and `y_r` (right),
* while using and updating `coeffs` (control and audio rate).
*
* #### bw_pan_process_multi()
* ```>>> */
static inline void bw_pan_process_multi(bw_pan_coeffs *BW_RESTRICT coeffs, const float **x, float **y_l, float **y_r, int n_channels, int n_samples);
/*! <<<```
* Processes the first `n_samples` of the `n_channels` input buffers `x` and
* fills the first `n_samples` of the `n_channels` output buffers `y_l`
* (left) and `y_r` (right), while using and updating the common `coeffs`
* (control and audio rate).
*
* #### bw_pan_set_pan()
* ```>>> */
static inline void bw_pan_set_pan(bw_pan_coeffs *BW_RESTRICT coeffs, float value);
/*! <<<```
* Sets the panning `value`, where `-1.f` corresponds to hard left pan, `0.f`
* to center pan, and `1.f` to hard right pan.
*
* Default value: `0.f`.
* }}} */
/*** Implementation ***/
/* WARNING: This part of the file is not part of the public API. Its content may
* change at any time in future versions. Please, do not use it directly. */
#include <bw_math.h>
#include <bw_gain.h>
struct _bw_pan_coeffs {
// Sub-components
bw_gain_coeffs l_coeffs;
bw_gain_coeffs r_coeffs;
// Parameters
float pan;
float pan_prev;
};
static inline void bw_pan_init(bw_pan_coeffs *BW_RESTRICT coeffs) {
bw_gain_init(&coeffs->l_coeffs);
bw_gain_init(&coeffs->r_coeffs);
coeffs->pan = 0.f;
}
static inline void bw_pan_set_sample_rate(bw_pan_coeffs *BW_RESTRICT coeffs, float sample_rate) {
bw_gain_set_sample_rate(&coeffs->l_coeffs, sample_rate);
bw_gain_set_sample_rate(&coeffs->r_coeffs, sample_rate);
}
static inline void _bw_pan_do_update_coeffs(bw_pan_coeffs *BW_RESTRICT coeffs, char force) {
if (force || coeffs->pan != coeffs->pan_prev) {
const float k = 0.125f * coeffs->pan + 0.125f;
bw_gain_set_gain_lin(&coeffs->l_coeffs, bw_cos2pif_3(k));
bw_gain_set_gain_lin(&coeffs->r_coeffs, bw_sin2pif_3(k));
coeffs->pan_prev = coeffs->pan;
}
}
static inline void bw_pan_reset_coeffs(bw_pan_coeffs *BW_RESTRICT coeffs) {
_bw_pan_do_update_coeffs(coeffs, 1);
bw_gain_reset_coeffs(&coeffs->l_coeffs);
bw_gain_reset_coeffs(&coeffs->r_coeffs);
}
static inline void bw_pan_update_coeffs_ctrl(bw_pan_coeffs *BW_RESTRICT coeffs) {
_bw_pan_do_update_coeffs(coeffs, 0);
bw_gain_update_coeffs_ctrl(&coeffs->l_coeffs);
bw_gain_update_coeffs_ctrl(&coeffs->r_coeffs);
}
static inline void bw_pan_update_coeffs_audio(bw_pan_coeffs *BW_RESTRICT coeffs) {
bw_gain_update_coeffs_audio(&coeffs->l_coeffs);
bw_gain_update_coeffs_audio(&coeffs->r_coeffs);
}
static inline void bw_pan_process1(const bw_pan_coeffs *BW_RESTRICT coeffs, float x, float *BW_RESTRICT y_l, float *BW_RESTRICT y_r) {
*y_l = bw_gain_process1(&coeffs->l_coeffs, x);
*y_r = bw_gain_process1(&coeffs->r_coeffs, x);
}
static inline void bw_pan_process(bw_pan_coeffs *BW_RESTRICT coeffs, const float *x, float *y_l, float *y_r, int n_samples) {
bw_pan_update_coeffs_ctrl(coeffs);
for (int i = 0; i < n_samples; i++) {
bw_pan_update_coeffs_audio(coeffs);
bw_pan_process1(coeffs, x[i], y_l + i, y_r + i);
}
}
static inline void bw_pan_process_multi(bw_pan_coeffs *BW_RESTRICT coeffs, const float **x, float **y_l, float **y_r, int n_channels, int n_samples) {
bw_pan_update_coeffs_ctrl(coeffs);
for (int i = 0; i < n_samples; i++) {
bw_pan_update_coeffs_audio(coeffs);
for (int j = 0; j < n_channels; j++)
bw_pan_process1(coeffs, x[j][i], y_l[j] + i, y_r[j] + i);
}
}
static inline void bw_pan_set_pan(bw_pan_coeffs *BW_RESTRICT coeffs, float value) {
coeffs->pan = value;
}
#ifdef __cplusplus
}
#endif
#endif