/* * 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 . * * File author: Stefano D'Angelo */ /*! * module_type {{{ dsp }}} * version {{{ 0.5.0 }}} * requires {{{ * bw_common bw_config bw_gain bw_math bw_mm2 bw_one_pole bw_svf * }}} * description {{{ * Second-order peak filter with unitary gain at DC and asymptotically * as frequency increases. * * The quality factor of the underlying bandpass filter can be either * directly controlled via the Q parameter or indirectly through the * bandwidth parameter, which designates the distance in octaves between * midpoint gain frequencies, i.e., frequencies with gain = peak gain / 2 in * dB terms. The use_bandiwdth parameter allows you to choose which * parameterization to use. * }}} * changelog {{{ * * }}} */ #ifndef _BW_PEAK_H #define _BW_PEAK_H #ifdef __cplusplus extern "C" { #endif #include /*! api {{{ * #### bw_peak_coeffs * ```>>> */ typedef struct _bw_peak_coeffs bw_peak_coeffs; /*! <<<``` * Coefficients and related. * * #### bw_peak_state * ```>>> */ typedef struct _bw_peak_state bw_peak_state; /*! <<<``` * Internal state and related. * * #### bw_peak_init() * ```>>> */ static inline void bw_peak_init(bw_peak_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Initializes input parameter values in `coeffs`. * * #### bw_peak_set_sample_rate() * ```>>> */ static inline void bw_peak_set_sample_rate(bw_peak_coeffs *BW_RESTRICT coeffs, float sample_rate); /*! <<<``` * Sets the `sample_rate` (Hz) value in `coeffs`. * * #### bw_peak_reset_coeffs() * ```>>> */ static inline void bw_peak_reset_coeffs(bw_peak_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Resets coefficients in `coeffs` to assume their target values. * * #### bw_peak_reset_state() * ```>>> */ static inline void bw_peak_reset_state(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x0); /*! <<<``` * Resets the given `state` to its initial values using the given `coeffs` * and the quiescent/initial input value `x0`. * * #### bw_peak_update_coeffs_ctrl() * ```>>> */ static inline void bw_peak_update_coeffs_ctrl(bw_peak_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Triggers control-rate update of coefficients in `coeffs`. * * #### bw_peak_update_coeffs_audio() * ```>>> */ static inline void bw_peak_update_coeffs_audio(bw_peak_coeffs *BW_RESTRICT coeffs); /*! <<<``` * Triggers audio-rate update of coefficients in `coeffs`. * * #### bw_peak_process1() * ```>>> */ static inline float bw_peak_process1(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x); /*! <<<``` * Processes one input sample `x` using `coeffs`, while using and updating * `state`. Returns the corresponding output sample. * * #### bw_peak_process() * ```>>> */ static inline void bw_peak_process(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, const float *x, float *y, int n_samples); /*! <<<``` * Processes the first `n_samples` of the input buffer `x` and fills the * first `n_samples` of the output buffer `y`, while using and updating both * `coeffs` and `state` (control and audio rate). * * #### bw_peak_set_cutoff() * ```>>> */ static inline void bw_peak_set_cutoff(bw_peak_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the cutoff frequency `value` (Hz) in `coeffs`. * * Default value: `1e3f`. * * #### bw_peak_set_Q() * ```>>> */ static inline void bw_peak_set_Q(bw_peak_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the quality factor to the given `value` in `coeffs`. * * `value` must be equal or bigger than `0.5f`. * * Default value: `0.5f`. * * #### bw_peak_set_peak_gain_lin() * ```>>> */ static inline void bw_peak_set_peak_gain_lin(bw_peak_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the peak gain parameter to the given `value` (linear gain) in * `coeffs`. * * Default value: `0.f`. * * #### bw_peak_set_peak_gain_dB() * ```>>> */ static inline void bw_peak_set_peak_gain_dB(bw_peak_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the peak gain parameter to the given `value` (dB) in `coeffs`. * * Default value: `-INFINITY`. * * #### bw_peak_set_bandiwdth() * ```>>> */ static inline void bw_peak_set_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, float value); /*! <<<``` * Sets the bandwidth `value` (octaves) in `coeffs`. * * Default value: `0.5f`. * * #### bw_peak_set_use_bandwidth() * ```>>> */ static inline void bw_peak_set_use_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, char value); /*! <<<``` * Sets whether the quality factor should be controlled via the bandwidth * parameter (`value` non-`0`) or via the Q parameter (`0`). * * Default value: non-`0` (use bandwidth parameter). * }}} */ /*** 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 #include struct _bw_peak_coeffs { // Sub-components bw_mm2_coeffs mm2_coeffs; // Coefficients float bw_k; // Parameters float peak_gain; float Q; float bandwidth; char use_bandwidth; int param_changed; }; struct _bw_peak_state { bw_mm2_state mm2_state; }; #define _BW_PEAK_PARAM_PEAK_GAIN 1 #define _BW_PEAK_PARAM_Q (1<<1) #define _BW_PEAK_PARAM_BANDWIDTH (1<<2) static inline void bw_peak_init(bw_peak_coeffs *BW_RESTRICT coeffs) { bw_mm2_init(&coeffs->mm2_coeffs); coeffs->peak_gain = 1.f; coeffs->Q = 0.5f; coeffs->bandwidth = 2.543106606327224f; coeffs->use_bandwidth = 1; } static inline void bw_peak_set_sample_rate(bw_peak_coeffs *BW_RESTRICT coeffs, float sample_rate) { bw_mm2_set_sample_rate(&coeffs->mm2_coeffs, sample_rate); } static inline void _bw_peak_update_mm2_params(bw_peak_coeffs *BW_RESTRICT coeffs) { if (coeffs->param_changed) { if (coeffs->use_bandwidth) { if (coeffs->param_changed & (_BW_PEAK_PARAM_PEAK_GAIN | _BW_PEAK_PARAM_BANDWIDTH)) { if (coeffs->param_changed & _BW_PEAK_PARAM_BANDWIDTH) coeffs->bw_k = bw_pow2f_3(coeffs->bandwidth); const float Q = bw_sqrtf_2(coeffs->bw_k * coeffs->peak_gain) * bw_rcpf_2(coeffs->bw_k - 1.f); bw_mm2_set_Q(&coeffs->mm2_coeffs, Q); bw_mm2_set_coeff_bp(&coeffs->mm2_coeffs, (coeffs->peak_gain - 1.f) * bw_rcpf_2(Q)); } } else { if (coeffs->param_changed & (_BW_PEAK_PARAM_PEAK_GAIN | _BW_PEAK_PARAM_Q)) { if (coeffs->param_changed & _BW_PEAK_PARAM_Q) bw_mm2_set_Q(&coeffs->mm2_coeffs, coeffs->Q); bw_mm2_set_coeff_bp(&coeffs->mm2_coeffs, (coeffs->peak_gain - 1.f) * bw_rcpf_2(coeffs->Q)); } } coeffs->param_changed = 0; } } static inline void bw_peak_reset_coeffs(bw_peak_coeffs *BW_RESTRICT coeffs) { coeffs->param_changed = ~0; _bw_peak_update_mm2_params(coeffs); bw_mm2_reset_coeffs(&coeffs->mm2_coeffs); } static inline void bw_peak_reset_state(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x0) { bw_mm2_reset_state(&coeffs->mm2_coeffs, &state->mm2_state, x0); } static inline void bw_peak_update_coeffs_ctrl(bw_peak_coeffs *BW_RESTRICT coeffs) { _bw_peak_update_mm2_params(coeffs); bw_mm2_update_coeffs_ctrl(&coeffs->mm2_coeffs); } static inline void bw_peak_update_coeffs_audio(bw_peak_coeffs *BW_RESTRICT coeffs) { bw_mm2_update_coeffs_audio(&coeffs->mm2_coeffs); } static inline float bw_peak_process1(const bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, float x) { return bw_mm2_process1(&coeffs->mm2_coeffs, &state->mm2_state, x); } static inline void bw_peak_process(bw_peak_coeffs *BW_RESTRICT coeffs, bw_peak_state *BW_RESTRICT state, const float *x, float *y, int n_samples) { bw_peak_update_coeffs_ctrl(coeffs); for (int i = 0; i < n_samples; i++) { bw_peak_update_coeffs_audio(coeffs); y[i] = bw_peak_process1(coeffs, state, x[i]); } } static inline void bw_peak_set_cutoff(bw_peak_coeffs *BW_RESTRICT coeffs, float value) { bw_mm2_set_cutoff(&coeffs->mm2_coeffs, value); } static inline void bw_peak_set_Q(bw_peak_coeffs *BW_RESTRICT coeffs, float value) { if (coeffs->Q != value) { coeffs->Q = value; coeffs->param_changed |= _BW_PEAK_PARAM_Q; } } static inline void bw_peak_set_peak_gain_lin(bw_peak_coeffs *BW_RESTRICT coeffs, float value) { if (coeffs->peak_gain != value) { coeffs->peak_gain = value; coeffs->param_changed |= _BW_PEAK_PARAM_PEAK_GAIN; } } static inline void bw_peak_set_peak_gain_dB(bw_peak_coeffs *BW_RESTRICT coeffs, float value) { bw_peak_set_peak_gain_lin(coeffs, bw_dB2linf_3(value)); } static inline void bw_peak_set_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, float value) { if (coeffs->bandwidth != value) { coeffs->bandwidth = value; coeffs->param_changed |= _BW_PEAK_PARAM_BANDWIDTH; } } static inline void bw_peak_set_use_bandwidth(bw_peak_coeffs *BW_RESTRICT coeffs, char value) { if ((coeffs->use_bandwidth && !value) || (!coeffs->use_bandwidth && value)) { coeffs->use_bandwidth = value; coeffs->param_changed |= _BW_PEAK_PARAM_Q | _BW_PEAK_PARAM_BANDWIDTH; } } #undef _BW_PEAK_PARAM_PEAK_GAIN #undef _BW_PEAK_PARAM_Q #undef _BW_PEAK_PARAM_BANDWIDTH #ifdef __cplusplus } #endif #endif