223 lines
7.4 KiB
C
223 lines
7.4 KiB
C
/*
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* Brickworks
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*
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* Copyright (C) 2022 Orastron Srl unipersonale
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*
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* Brickworks is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, version 3 of the License.
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*
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* Brickworks is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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*
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* File author: Stefano D'Angelo
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*/
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/*!
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* module_type {{{ dsp }}}
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* version {{{ 0.2.0 }}}
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* requires {{{ bw_config bw_common bw_math bw_one_pole }}}
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* description {{{
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* Envelope follower made of a full-wave rectifier followed by
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* [bw_one_pole](bw_one_pole) one-pole filter (6 dB/oct).
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* }}}
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* changelog {{{
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* <ul>
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* <li>Version <strong>0.2.0</strong>:
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* <ul>
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* <li>Refactored API.</li>
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* </ul>
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* </li>
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* <li>Version <strong>0.1.0</strong>:
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* <ul>
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* <li>First release.</li>
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* </ul>
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* </li>
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* </ul>
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* }}}
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*/
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#ifndef _BW_ENV_FOLLOW_H
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#define _BW_ENV_FOLLOW_H
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#ifdef __cplusplus
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extern "C" {
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#endif
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#include <bw_common.h>
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/*! api {{{
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* #### bw_env_follow_coeffs
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* ```>>> */
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typedef struct _bw_env_follow_coeffs bw_env_follow_coeffs;
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/*! <<<```
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* Coefficients and related.
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*
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* #### bw_env_follow_state
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* ```>>> */
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typedef struct _bw_env_follow_state bw_env_follow_state;
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/*! <<<```
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* Internal state and related.
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*
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* #### bw_env_follow_init()
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* ```>>> */
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static inline void bw_env_follow_init(bw_env_follow_coeffs *BW_RESTRICT coeffs);
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/*! <<<```
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* Initializes input parameter values in `coeffs`.
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*
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* #### bw_env_follow_set_sample_rate()
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* ```>>> */
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static inline void bw_env_follow_set_sample_rate(bw_env_follow_coeffs *BW_RESTRICT coeffs, float sample_rate);
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/*! <<<```
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* Sets the `sample_rate` (Hz) value in `coeffs`.
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*
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* #### bw_env_follow_reset_coeffs()
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* ```>>> */
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static inline void bw_env_follow_reset_coeffs(bw_env_follow_coeffs *BW_RESTRICT coeffs);
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/*! <<<```
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* Resets coefficients in `coeffs` to assume their target values.
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*
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* #### bw_env_follow_reset_state()
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* ```>>> */
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static inline void bw_env_follow_reset_state(const bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state);
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/*! <<<```
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* Resets the given `state` to its initial values using the given `coeffs`.
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*
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* #### bw_env_follow_update_coeffs_ctrl()
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* ```>>> */
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static inline void bw_env_follow_update_coeffs_ctrl(bw_env_follow_coeffs *BW_RESTRICT coeffs);
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/*! <<<```
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* Triggers control-rate update of coefficients in `coeffs`.
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*
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* #### bw_env_follow_update_coeffs_audio()
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* ```>>> */
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static inline void bw_env_follow_update_coeffs_audio(bw_env_follow_coeffs *BW_RESTRICT coeffs);
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/*! <<<```
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* Triggers audio-rate update of coefficients in `coeffs`.
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*
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* #### bw_env_follow_process1()
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* ```>>> */
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static inline float bw_env_follow_process1(const bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state, float x);
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/*! <<<```
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* Processes one input sample `x` using `coeffs` and updating `state` (audio
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* rate only). Returns the corresponding output sample.
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*
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* #### bw_env_follow_process()
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* ```>>> */
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static inline void bw_env_follow_process(bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state, const float *x, float *y, int n_samples);
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/*! <<<```
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* Processes the first `n_samples` of the input buffer `x` and fills the
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* first `n_samples` of the output buffer `y`, while using and updating both
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* `coeffs` and `state` (control and audio rate).
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*
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* `y` may be `NULL`.
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*
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* #### bw_env_follow_set_attack_tau()
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* ```>>> */
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static inline void bw_env_follow_set_attack_tau(bw_env_follow_coeffs *BW_RESTRICT coeffs, float value);
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/*! <<<```
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* Sets the upgoing (attack)
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* <a href="https://en.wikipedia.org/wiki/Time_constant" target="_blank">time
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* constant</a> in `coeffs` of the one-pole filter to `value` (s).
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*
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* Default value: `0.f`.
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*
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* #### bw_env_follow_set_release_tau()
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* ```>>> */
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static inline void bw_env_follow_set_release_tau(bw_env_follow_coeffs *BW_RESTRICT coeffs, float value);
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/*! <<<```
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* Sets the downgoing (release)
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* <a href="https://en.wikipedia.org/wiki/Time_constant" target="_blank">time
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* constant</a> in `coeffs` of the one-pole filter to `value` (s).
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*
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* Default value: `0.f`.
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*
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* #### bw_env_follow_get_y_z1()
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* ```>>> */
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static inline float bw_env_follow_get_y_z1(const bw_env_follow_state *BW_RESTRICT state);
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/*! <<<```
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* Returns the last output sample as stored in `state`.
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* }}} */
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/*** Implementation ***/
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#include <bw_math.h>
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#include <bw_one_pole.h>
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/* WARNING: This part of the file is not part of the public API. Its content may
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* change at any time in future versions. Please, do not use it directly. */
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struct _bw_env_follow_coeffs {
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// Sub-components
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bw_one_pole_coeffs one_pole_coeffs;
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};
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struct _bw_env_follow_state {
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bw_one_pole_state one_pole_state;
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};
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static inline void bw_env_follow_init(bw_env_follow_coeffs *BW_RESTRICT coeffs) {
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bw_one_pole_init(&coeffs->one_pole_coeffs);
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}
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static inline void bw_env_follow_set_sample_rate(bw_env_follow_coeffs *BW_RESTRICT coeffs, float sample_rate) {
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bw_one_pole_set_sample_rate(&coeffs->one_pole_coeffs, sample_rate);
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}
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static inline void bw_env_follow_reset_coeffs(bw_env_follow_coeffs *BW_RESTRICT coeffs) {
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bw_one_pole_reset_coeffs(&coeffs->one_pole_coeffs);
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}
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static inline void bw_env_follow_reset_state(const bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state) {
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bw_one_pole_reset_state(&coeffs->one_pole_coeffs, &state->one_pole_state, 0.f);
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}
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static inline void bw_env_follow_update_coeffs_ctrl(bw_env_follow_coeffs *BW_RESTRICT coeffs) {
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bw_one_pole_update_coeffs_ctrl(&coeffs->one_pole_coeffs);
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}
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static inline void bw_env_follow_update_coeffs_audio(bw_env_follow_coeffs *BW_RESTRICT coeffs) {
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bw_one_pole_update_coeffs_audio(&coeffs->one_pole_coeffs);
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}
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static inline float bw_env_follow_process1(const bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state, float x) {
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x = bw_absf(x);
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return bw_one_pole_process1_asym(&coeffs->one_pole_coeffs, &state->one_pole_state, x);
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}
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static inline void bw_env_follow_process(bw_env_follow_coeffs *BW_RESTRICT coeffs, bw_env_follow_state *BW_RESTRICT state, const float *x, float *y, int n_samples) {
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bw_env_follow_update_coeffs_ctrl(coeffs);
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if (y != NULL)
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for (int i = 0; i < n_samples; i++) {
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bw_env_follow_update_coeffs_audio(coeffs);
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y[i] = bw_env_follow_process1(coeffs, state, x[i]);
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}
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else
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for (int i = 0; i < n_samples; i++) {
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bw_env_follow_update_coeffs_audio(coeffs);
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bw_env_follow_process1(coeffs, state, x[i]);
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}
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}
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static inline void bw_env_follow_set_attack_tau(bw_env_follow_coeffs *BW_RESTRICT coeffs, float value) {
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bw_one_pole_set_tau_up(&coeffs->one_pole_coeffs, value);
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}
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static inline void bw_env_follow_set_release_tau(bw_env_follow_coeffs *BW_RESTRICT coeffs, float value) {
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bw_one_pole_set_tau_down(&coeffs->one_pole_coeffs, value);
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}
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static inline float bw_env_follow_get_y_z1(const bw_env_follow_state *BW_RESTRICT state) {
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return bw_one_pole_get_y_z1(&state->one_pole_state);
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}
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#ifdef __cplusplus
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}
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#endif
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#endif
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