4f56b7646e
.. and account releasing notes at their sustain level until they're done. this ameliorates the effect where multiple releasing notes don't seem to actually be releasing, but stay at a constant volume.
110 lines
4.7 KiB
C
110 lines
4.7 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2021 Artyom Skrobov
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#pragma once
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#define SYNTHIO_BITS_PER_SAMPLE (16)
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#define SYNTHIO_BYTES_PER_SAMPLE (SYNTHIO_BITS_PER_SAMPLE / 8)
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#define SYNTHIO_MAX_DUR (256)
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#define SYNTHIO_SILENCE (mp_const_none)
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#define SYNTHIO_NOTE_IS_SIMPLE(note) (mp_obj_is_small_int(note))
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#define SYNTHIO_NOTE_IS_PLAYING(synth, i) ((synth)->envelope_state[(i)].state != SYNTHIO_ENVELOPE_STATE_RELEASE)
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#define SYNTHIO_FREQUENCY_SHIFT (16)
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#include "shared-module/audiocore/__init__.h"
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typedef struct {
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uint16_t dur;
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mp_obj_t note_obj[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
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} synthio_midi_span_t;
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typedef struct {
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// the number of attack or decay steps (signed) per sample
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// therefore the maximum time is 32767 samples or 0.68s at 48kHz
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// provided the level is maximum (this should be increased!)
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int16_t attack_step, decay_step, release_step;
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uint16_t attack_level, sustain_level;
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} synthio_envelope_definition_t;
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typedef enum {
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SYNTHIO_ENVELOPE_STATE_ATTACK, SYNTHIO_ENVELOPE_STATE_DECAY,
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SYNTHIO_ENVELOPE_STATE_SUSTAIN, SYNTHIO_ENVELOPE_STATE_RELEASE
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} envelope_state_e;
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typedef struct {
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int16_t level;
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uint16_t substep;
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envelope_state_e state;
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} synthio_envelope_state_t;
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typedef struct synthio_synth {
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uint32_t sample_rate;
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uint32_t total_envelope;
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int16_t *buffers[2];
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const int16_t *waveform;
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uint16_t buffer_length;
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uint16_t last_buffer_length;
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uint8_t other_channel, buffer_index, other_buffer_index;
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uint16_t waveform_length;
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synthio_envelope_definition_t envelope_definition;
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mp_obj_t envelope_obj;
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synthio_midi_span_t span;
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uint32_t accum[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
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synthio_envelope_state_t envelope_state[CIRCUITPY_SYNTHIO_MAX_CHANNELS];
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} synthio_synth_t;
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typedef struct {
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mp_float_t amplitude, frequency;
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} synthio_lfo_descr_t;
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typedef struct {
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uint32_t amplitude_scaled, offset_scaled, dds, phase;
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} synthio_lfo_state_t;
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void synthio_synth_synthesize(synthio_synth_t *synth, uint8_t **buffer, uint32_t *buffer_length, uint8_t channel);
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void synthio_synth_deinit(synthio_synth_t *synth);
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bool synthio_synth_deinited(synthio_synth_t *synth);
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void synthio_synth_init(synthio_synth_t *synth, uint32_t sample_rate, const int16_t *waveform, uint16_t waveform_length,
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mp_obj_t envelope);
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void synthio_synth_get_buffer_structure(synthio_synth_t *synth, bool single_channel_output,
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bool *single_buffer, bool *samples_signed, uint32_t *max_buffer_length, uint8_t *spacing);
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void synthio_synth_reset_buffer(synthio_synth_t *synth, bool single_channel_output, uint8_t channel);
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void synthio_synth_parse_waveform(mp_buffer_info_t *bufinfo_waveform, mp_obj_t waveform_obj);
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void synthio_synth_parse_envelope(uint16_t *envelope_sustain_index, mp_buffer_info_t *bufinfo_envelope, mp_obj_t envelope_obj, mp_obj_t envelope_hold_obj);
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bool synthio_span_change_note(synthio_synth_t *synth, mp_obj_t old_note, mp_obj_t new_note);
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void synthio_envelope_step(synthio_envelope_definition_t *definition, synthio_envelope_state_t *state, int n_samples);
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void synthio_envelope_definition_set(synthio_envelope_definition_t *envelope, mp_obj_t obj, uint32_t sample_rate);
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uint64_t synthio_frequency_convert_float_to_scaled(mp_float_t frequency_hz);
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uint32_t synthio_frequency_convert_float_to_dds(mp_float_t frequency_hz, int32_t sample_rate);
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uint32_t synthio_frequency_convert_scaled_to_dds(uint64_t frequency_scaled, int32_t sample_rate);
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void synthio_lfo_set(synthio_lfo_state_t *state, const synthio_lfo_descr_t *descr, uint32_t sample_rate);
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int synthio_lfo_step(synthio_lfo_state_t *state, uint16_t dur);
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