orastron/brickworks
2
1
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases 9 Wiki Activity
fc91d59f57
brickworks/include/bw_osc_pulse.h

626 lines
20 KiB
C++
Raw Blame History

/*
* Brickworks
*
* Copyright (C) 2022, 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 {{{ 1.0.0 }}}
* requires {{{ bw_common bw_math bw_one_pole }}}
* description {{{
* Pulse oscillator waveshaper with variable pulse width (actually, duty
* cycle) and PolyBLEP antialiasing.
*
* It turns a normalized phase signal, such as that geneated by
* [bw\_phase\_gen](bw_phase_gen), into a pulse wave.
*
* The antialiasing algorithm is based on
*
* V. Valimaki and A. Huovilainen, "Antialiasing Oscillators in Subtractive
* Synthesis", IEEE Signal Processing Magazine, vol. 24, no. 2, pp. 116-125,
* March 2007.
* }}}
* changelog {{{
* <ul>
* <li>Version <strong>1.0.0</strong>:
* <ul>
* <li><code>bw_osc_pulse_process()</code> and
* <code>bw_osc_pulse_process_multi()</code> now use
* <code>size_t</code> to count samples and channels.</li>
* <li>Added more <code>const</code> specifiers to input
* arguments.</li>
* <li>Moved C++ code to C header.</li>
* <li>Added overloaded C++ <code>process()</code> function taking
* C-style arrays as arguments.</li>
* <li>Removed usage of reserved identifiers.</li>
* <li>Clearly specified validity ranges for audio-rate signals.</li>
* <li>Added debugging code.</li>
* </ul>
* </li>
* <li>Version <strong>0.6.0</strong>:
* <ul>
* <li>Removed dependency on bw_config.</li>
* </ul>
* </li>
* <li>Version <strong>0.5.0</strong>:
* <ul>
* <li>Added <code>bw_osc_pulse_process_multi()</code>.</li>
* <li>Added C++ wrapper.</li>
* </ul>
* </li>
* <li>Version <strong>0.4.0</strong>:
* <ul>
* <li>Fixed unused parameter warnings.</li>
* </ul>
* </li>
* <li>Version <strong>0.2.0</strong>:
* <ul>
* <li>Refactored API.</li>
* </ul>
* </li>
* <li>Version <strong>0.1.0</strong>:
* <ul>
* <li>First release.</li>
* </ul>
* </li>
* </ul>
* }}}
*/
#ifndef BW_OSC_PULSE_H
#define BW_OSC_PULSE_H
#include <bw_common.h>
#ifdef __cplusplus
extern "C" {
#endif
/*! api {{{
* #### bw_osc_pulse_coeffs
* ```>>> */
typedef struct bw_osc_pulse_coeffs bw_osc_pulse_coeffs;
/*! <<<```
* Coefficients and related.
*
* #### bw_osc_pulse_init()
* ```>>> */
static inline void bw_osc_pulse_init(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs);
/*! <<<```
* Initializes input parameter values in `coeffs`.
*
* #### bw_osc_pulse_set_sample_rate()
* ```>>> */
static inline void bw_osc_pulse_set_sample_rate(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float sample_rate);
/*! <<<```
* Sets the `sample_rate` (Hz) value in `coeffs`.
*
* #### bw_osc_pulse_reset_coeffs()
* ```>>> */
static inline void bw_osc_pulse_reset_coeffs(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs);
/*! <<<```
* Resets coefficients in `coeffs` to assume their target values.
*
* #### bw_osc_pulse_update_coeffs_ctrl()
* ```>>> */
static inline void bw_osc_pulse_update_coeffs_ctrl(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs);
/*! <<<```
* Triggers control-rate update of coefficients in `coeffs`.
*
* #### bw_osc_pulse_update_coeffs_audio()
* ```>>> */
static inline void bw_osc_pulse_update_coeffs_audio(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs);
/*! <<<```
* Triggers audio-rate update of coefficients in `coeffs`.
*
* #### bw_osc_pulse_process1\*()
* ```>>> */
static inline float bw_osc_pulse_process1(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float x);
static inline float bw_osc_pulse_process1_antialias(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float x,
float x_inc);
/*! <<<```
* These function process one input sample `x`, representing the normalized
* phase, using `coeffs`. They return the corresponding output sample.
*
* In particular:
* * `bw_osc_pulse_process1()` assumes that antialiasing is disabled;
* * `bw_osc_pulse_process1_antialias()` assumes that antialiasing is
* enabled and requires the corresponding phase increment value to be
* passed via `x_inc`.
*
* Whether antialiasing is enabled or not is unchecked even for debugging
* purposes.
*
* `x` must be in [`0.f`, `1.f`).
*
* `x_inc` must be in [`-0.5f`, `0.5f`].
*
* #### bw_osc_pulse_process()
* ```>>> */
static inline void bw_osc_pulse_process(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
const float * x,
const float * x_inc,
float * y,
size_t n_samples);
/*! <<<```
* Processes the first `n_samples` of the input buffer `x`, containing the
* normalized phase signal, and fills the first `n_samples` of the output
* buffer `y`, while using and updating `coeffs` (control and audio rate).
*
* If antialiasing is enabled, `x_inc` must contain phase increment
* values, otherwise it is ignored and can be `NULL`.
*
* All samples in `x` must be in [`0.f`, `1.f`).
*
* All samples is `x_inc`, if not ignored, must be in [`-0.5f`, `0.5f`].
*
* #### bw_osc_pulse_process_multi()
* ```>>> */
static inline void bw_osc_pulse_process_multi(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
const float * const * x,
const float * const * x_inc,
float * const * y,
size_t n_channels,
size_t n_samples);
/*! <<<```
* Processes the first `n_samples` of the `n_channels` input buffers `x`,
* containing the normalized phase signals, and fills the first `n_samples`
* of the `n_channels` output buffers `y`, while using and updating the
* common `coeffs` (control and audio rate).
*
* If antialiasing is enabled, each of the `n_channels` buffers pointed by
* `x_inc` must contain phase increment values, otherwise `x_inc` is ignored
* and can be `NULL`.
*
* All samples in `x` must be in [`0.f`, `1.f`).
*
* All samples is `x_inc`, if not ignored, must be in [`-0.5f`, `0.5f`].
*
* #### bw_osc_pulse_set_antialiasing()
* ```>>> */
static inline void bw_osc_pulse_set_antialiasing(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
char value);
/*! <<<```
* Sets whether the antialiasing is on (`value` non-`0`) or off (`0`) in
* `coeffs`.
*
* Default value: `0` (off).
*
* #### bw_osc_pulse_set_pulse_width()
* ```>>> */
static inline void bw_osc_pulse_set_pulse_width(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float value);
/*! <<<```
* Sets the pulse width (actually, the duty cycle) to `value` in `coeffs`.
*
* Valid range: [`0.f` (0% duty cycle), `1.f` (100% duty cycle)].
*
* Default value: `0.5f`.
*
* #### bw_osc_pulse_coeffs_is_valid()
* ```>>> */
static inline char bw_osc_pulse_coeffs_is_valid(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs);
/*! <<<```
* Tries to determine whether `coeffs` is valid and returns non-`0` if it
* seems to be the case and `0` if it is certainly not. False positives are
* possible, false negatives are not.
*
* `coeffs` must at least point to a readable memory block of size greater
* than or equal to that of `bw_osc_pulse_coeffs`.
* }}} */
#ifdef __cplusplus
}
#endif
/*** 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_one_pole.h>
#ifdef __cplusplus
extern "C" {
#endif
#ifdef BW_DEBUG_DEEP
enum bw_osc_pulse_coeffs_state {
bw_osc_pulse_coeffs_state_invalid,
bw_osc_pulse_coeffs_state_init,
bw_osc_pulse_coeffs_state_set_sample_rate,
bw_osc_pulse_coeffs_state_reset_coeffs
};
#endif
struct bw_osc_pulse_coeffs {
#ifdef BW_DEBUG_DEEP
uint32_t hash;
enum bw_osc_pulse_coeffs_state state;
#endif
// Sub-components
bw_one_pole_coeffs smooth_coeffs;
bw_one_pole_state smooth_state;
// Parameters
char antialiasing;
float pulse_width;
};
static inline void bw_osc_pulse_init(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs) {
BW_ASSERT(coeffs != NULL);
bw_one_pole_init(&coeffs->smooth_coeffs);
bw_one_pole_set_tau(&coeffs->smooth_coeffs, 0.005f);
coeffs->antialiasing = 0;
coeffs->pulse_width = 0.5f;
#ifdef BW_DEBUG_DEEP
coeffs->hash = bw_hash_sdbm("bw_osc_pulse_coeffs");
coeffs->state = bw_osc_pulse_coeffs_state_init;
#endif
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state == bw_osc_pulse_coeffs_state_init);
}
static inline void bw_osc_pulse_set_sample_rate(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float sample_rate) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_init);
BW_ASSERT(bw_is_finite(sample_rate) && sample_rate > 0.f);
bw_one_pole_set_sample_rate(&coeffs->smooth_coeffs, sample_rate);
bw_one_pole_reset_coeffs(&coeffs->smooth_coeffs);
#ifdef BW_DEBUG_DEEP
coeffs->state = bw_osc_pulse_coeffs_state_set_sample_rate;
#endif
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state == bw_osc_pulse_coeffs_state_set_sample_rate);
}
static inline void bw_osc_pulse_reset_coeffs(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_set_sample_rate);
bw_one_pole_reset_state(&coeffs->smooth_coeffs, &coeffs->smooth_state, coeffs->pulse_width);
#ifdef BW_DEBUG_DEEP
coeffs->state = bw_osc_pulse_coeffs_state_reset_coeffs;
#endif
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state == bw_osc_pulse_coeffs_state_reset_coeffs);
}
static inline void bw_osc_pulse_update_coeffs_ctrl(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
(void)coeffs;
}
static inline void bw_osc_pulse_update_coeffs_audio(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
bw_one_pole_process1(&coeffs->smooth_coeffs, &coeffs->smooth_state, coeffs->pulse_width);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
}
static inline float bw_osc_pulse_process1(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float x) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 0.f && x < 1.f);
const float pw = bw_one_pole_get_y_z1(&coeffs->smooth_state);
const float y = bw_signf(pw - x);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(bw_is_finite(y));
return y;
}
// PolyBLEP residual based on Parzen window (4th-order B-spline), one-sided (x in [0, 2])
static inline float bw_osc_pulse_blep_diff(
float x) {
return x < 1.f
? x * ((0.25f * x - 0.6666666666666666f) * x * x + 1.333333333333333f) - 1.f
: x * (x * ((0.6666666666666666f - 0.08333333333333333f * x) * x - 2.f) + 2.666666666666667f) - 1.333333333333333f;
}
static inline float bw_osc_pulse_process1_antialias(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float x,
float x_inc) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(bw_is_finite(x));
BW_ASSERT(x >= 0.f && x < 1.f);
BW_ASSERT(bw_is_finite(x_inc));
BW_ASSERT(x_inc >= -0.5f && x_inc <= 0.5f);
const float pw = bw_one_pole_get_y_z1(&coeffs->smooth_state);
const float pw_m_phase = pw - x;
float v = bw_copysignf(1.f, pw_m_phase); // pw = phase case should be properly compensated by the AA
const float a_inc = bw_absf(x_inc);
if (a_inc > 1e-6f) {
const float phase_inc_2 = a_inc + a_inc;
const float phase_inc_rcp = bw_rcpf(a_inc);
const float phase_2 = 0.5f * v + 0.5f - pw_m_phase;
const float s_1_m_phase = 1.f - x;
const float s_1_m_phase_2 = 1.f - phase_2;
if (s_1_m_phase < phase_inc_2)
v -= bw_osc_pulse_blep_diff(s_1_m_phase * phase_inc_rcp);
if (s_1_m_phase_2 < phase_inc_2)
v += bw_osc_pulse_blep_diff(s_1_m_phase_2 * phase_inc_rcp);
if (x < phase_inc_2)
v += bw_osc_pulse_blep_diff(x * phase_inc_rcp);
if (phase_2 < phase_inc_2)
v -= bw_osc_pulse_blep_diff(phase_2 * phase_inc_rcp);
}
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(bw_is_finite(v));
return v;
}
static inline void bw_osc_pulse_process(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
const float * x,
const float * x_inc,
float * y,
size_t n_samples) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(x != NULL);
BW_ASSERT_DEEP(bw_has_only_finite(x, n_samples));
BW_ASSERT(coeffs->antialiasing ? x_inc != NULL : 1);
BW_ASSERT_DEEP(coeffs->antialiasing ? bw_has_only_finite(x_inc, n_samples) : 1);
BW_ASSERT(y != NULL);
if (coeffs->antialiasing)
for (size_t i = 0; i < n_samples; i++) {
bw_osc_pulse_update_coeffs_audio(coeffs);
y[i] = bw_osc_pulse_process1_antialias(coeffs, x[i], x_inc[i]);
}
else
for (size_t i = 0; i < n_samples; i++) {
bw_osc_pulse_update_coeffs_audio(coeffs);
y[i] = bw_osc_pulse_process1(coeffs, x[i]);
}
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT_DEEP(bw_has_only_finite(y, n_samples));
}
static inline void bw_osc_pulse_process_multi(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
const float * const * x,
const float * const * x_inc,
float * const * y,
size_t n_channels,
size_t n_samples) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
BW_ASSERT(x != NULL);
BW_ASSERT(y != NULL);
if (coeffs->antialiasing)
for (size_t i = 0; i < n_samples; i++) {
bw_osc_pulse_update_coeffs_audio(coeffs);
for (size_t j = 0; j < n_channels; j++)
y[j][i] = bw_osc_pulse_process1_antialias(coeffs, x[j][i], x_inc[j][i]);
}
else
for (size_t i = 0; i < n_samples; i++) {
bw_osc_pulse_update_coeffs_audio(coeffs);
for (size_t j = 0; j < n_channels; j++)
y[j][i] = bw_osc_pulse_process1(coeffs, x[j][i]);
}
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_reset_coeffs);
}
static inline void bw_osc_pulse_set_antialiasing(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
char value) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_init);
coeffs->antialiasing = value;
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_init);
}
static inline void bw_osc_pulse_set_pulse_width(
bw_osc_pulse_coeffs * BW_RESTRICT coeffs,
float value) {
BW_ASSERT(coeffs != NULL);
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_init);
BW_ASSERT(bw_is_finite(value));
BW_ASSERT(value >= 0.f && value <= 1.f);
coeffs->pulse_width = value;
BW_ASSERT_DEEP(bw_osc_pulse_coeffs_is_valid(coeffs));
BW_ASSERT_DEEP(coeffs->state >= bw_osc_pulse_coeffs_state_init);
}
static inline char bw_osc_pulse_coeffs_is_valid(
const bw_osc_pulse_coeffs * BW_RESTRICT coeffs) {
BW_ASSERT(coeffs != NULL);
#ifdef BW_DEBUG_DEEP
if (coeffs->hash != bw_hash_sdbm("bw_osc_pulse_coeffs"))
return 0;
if (coeffs->state < bw_osc_pulse_coeffs_state_init || coeffs->state > bw_osc_pulse_coeffs_state_reset_coeffs)
return 0;
#endif
return bw_is_finite(coeffs->pulse_width) && coeffs->pulse_width >= 0.f && coeffs->pulse_width <= 1.f;
}
#ifdef __cplusplus
}
#include <array>
namespace Brickworks {
/*** Public C++ API ***/
/*! api_cpp {{{
* ##### Brickworks::OscPulse
* ```>>> */
template<size_t N_CHANNELS>
class OscPulse {
public:
OscPulse();
void setSampleRate(
float sampleRate);
void reset();
void process(
const float * const * x,
const float * const * x_inc,
float * const * y,
size_t nSamples);
void process(
std::array<const float *, N_CHANNELS> x,
std::array<const float *, N_CHANNELS> x_inc,
std::array<float *, N_CHANNELS> y,
size_t nSamples);
void setAntialiasing(
bool value);
void setPulseWidth(
float value);
/*! <<<...
* }
* ```
* }}} */
/*** 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. */
private:
bw_osc_pulse_coeffs coeffs;
};
template<size_t N_CHANNELS>
inline OscPulse<N_CHANNELS>::OscPulse() {
bw_osc_pulse_init(&coeffs);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::setSampleRate(
float sampleRate) {
bw_osc_pulse_set_sample_rate(&coeffs, sampleRate);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::reset() {
bw_osc_pulse_reset_coeffs(&coeffs);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::process(
const float * const * x,
const float * const * x_inc,
float * const * y,
size_t nSamples) {
bw_osc_pulse_process_multi(&coeffs, x, x_inc, y, N_CHANNELS, nSamples);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::process(
std::array<const float *, N_CHANNELS> x,
std::array<const float *, N_CHANNELS> x_inc,
std::array<float *, N_CHANNELS> y,
size_t nSamples) {
process(x.data(), x_inc.data(), y.data(), nSamples);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::setAntialiasing(
bool value) {
bw_osc_pulse_set_antialiasing(&coeffs, value);
}
template<size_t N_CHANNELS>
inline void OscPulse<N_CHANNELS>::setPulseWidth(
float value) {
bw_osc_pulse_set_pulse_width(&coeffs, value);
}
}
#endif
#endif
Reference in New Issue View Git Blame Copy Permalink