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serenity/Applications/Piano/AudioEngine.cpp

378 lines
11 KiB
C++

/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* Copyright (c) 2019-2020, William McPherson <willmcpherson2@gmail.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "AudioEngine.h"
#include <LibAudio/WavLoader.h>
#include <limits>
#include <math.h>
AudioEngine::AudioEngine()
{
set_sustain_impl(1000);
set_attack(5);
set_decay(1000);
set_release(5);
}
AudioEngine::~AudioEngine()
{
}
void AudioEngine::fill_buffer(FixedArray<Sample>& buffer)
{
memset(buffer.data(), 0, buffer_size);
if (m_time == 0)
set_notes_from_roll();
for (size_t i = 0; i < buffer.size(); ++i) {
for (size_t note = 0; note < note_count; ++note) {
switch (m_envelope[note]) {
case Done:
continue;
case Attack:
m_power[note] += m_attack_step;
if (m_power[note] >= 1) {
m_power[note] = 1;
m_envelope[note] = Decay;
}
break;
case Decay:
m_power[note] -= m_decay_step;
if (m_power[note] < m_sustain_level)
m_power[note] = m_sustain_level;
break;
case Release:
m_power[note] -= m_release_step[note];
if (m_power[note] <= 0) {
m_power[note] = 0;
m_envelope[note] = Done;
continue;
}
break;
default:
ASSERT_NOT_REACHED();
}
Audio::Sample sample;
switch (m_wave) {
case Wave::Sine:
sample = sine(note);
break;
case Wave::Saw:
sample = saw(note);
break;
case Wave::Square:
sample = square(note);
break;
case Wave::Triangle:
sample = triangle(note);
break;
case Wave::Noise:
sample = noise();
break;
case Wave::RecordedSample:
sample = recorded_sample(note);
break;
default:
ASSERT_NOT_REACHED();
}
buffer[i].left += sample.left * m_power[note] * volume;
buffer[i].right += sample.right * m_power[note] * volume;
}
}
if (m_delay) {
if (m_delay_buffers.size() >= m_delay) {
auto to_blend = m_delay_buffers.dequeue();
for (size_t i = 0; i < to_blend->size(); ++i) {
buffer[i].left += (*to_blend)[i].left * 0.333333;
buffer[i].right += (*to_blend)[i].right * 0.333333;
}
}
auto delay_buffer = make<FixedArray<Sample>>(buffer.size());
memcpy(delay_buffer->data(), buffer.data(), buffer_size);
m_delay_buffers.enqueue(move(delay_buffer));
}
if (++m_time == m_tick) {
m_time = 0;
update_roll();
}
memcpy(m_back_buffer_ptr->data(), buffer.data(), buffer_size);
swap(m_front_buffer_ptr, m_back_buffer_ptr);
}
void AudioEngine::reset()
{
memset(m_front_buffer.data(), 0, buffer_size);
memset(m_back_buffer.data(), 0, buffer_size);
m_front_buffer_ptr = &m_front_buffer;
m_back_buffer_ptr = &m_back_buffer;
m_delay_buffers.clear();
memset(m_note_on, 0, sizeof(m_note_on));
memset(m_power, 0, sizeof(m_power));
memset(m_envelope, 0, sizeof(m_envelope));
m_time = 0;
m_current_column = 0;
m_previous_column = horizontal_notes - 1;
}
String AudioEngine::set_recorded_sample(const StringView& path)
{
Audio::WavLoader wav_loader(path);
if (wav_loader.has_error())
return String(wav_loader.error_string());
auto wav_buffer = wav_loader.get_more_samples(60 * sample_rate * sizeof(Sample)); // 1 minute maximum
if (!m_recorded_sample.is_empty())
m_recorded_sample.clear();
m_recorded_sample.resize(wav_buffer->sample_count());
double peak = 0;
for (int i = 0; i < wav_buffer->sample_count(); ++i) {
double left_abs = fabs(wav_buffer->samples()[i].left);
double right_abs = fabs(wav_buffer->samples()[i].right);
if (left_abs > peak)
peak = left_abs;
if (right_abs > peak)
peak = right_abs;
}
if (peak) {
for (int i = 0; i < wav_buffer->sample_count(); ++i) {
m_recorded_sample[i].left = wav_buffer->samples()[i].left / peak;
m_recorded_sample[i].right = wav_buffer->samples()[i].right / peak;
}
}
return String::empty();
}
// All of the information for these waves is on Wikipedia.
Audio::Sample AudioEngine::sine(size_t note)
{
double pos = note_frequencies[note] / sample_rate;
double sin_step = pos * 2 * M_PI;
double w = sin(m_pos[note]);
m_pos[note] += sin_step;
return w;
}
Audio::Sample AudioEngine::saw(size_t note)
{
double saw_step = note_frequencies[note] / sample_rate;
double t = m_pos[note];
double w = (0.5 - (t - floor(t))) * 2;
m_pos[note] += saw_step;
return w;
}
Audio::Sample AudioEngine::square(size_t note)
{
double pos = note_frequencies[note] / sample_rate;
double square_step = pos * 2 * M_PI;
double w = sin(m_pos[note]) >= 0 ? 1 : -1;
m_pos[note] += square_step;
return w;
}
Audio::Sample AudioEngine::triangle(size_t note)
{
double triangle_step = note_frequencies[note] / sample_rate;
double t = m_pos[note];
double w = fabs(fmod((4 * t) + 1, 4) - 2) - 1;
m_pos[note] += triangle_step;
return w;
}
Audio::Sample AudioEngine::noise() const
{
double random_percentage = static_cast<double>(rand()) / RAND_MAX;
double w = (random_percentage * 2) - 1;
return w;
}
Audio::Sample AudioEngine::recorded_sample(size_t note)
{
int t = m_pos[note];
if (t >= static_cast<int>(m_recorded_sample.size()))
return 0;
double w_left = m_recorded_sample[t].left;
double w_right = m_recorded_sample[t].right;
if (t + 1 < static_cast<int>(m_recorded_sample.size())) {
double t_fraction = m_pos[note] - t;
w_left += (m_recorded_sample[t + 1].left - m_recorded_sample[t].left) * t_fraction;
w_right += (m_recorded_sample[t + 1].right - m_recorded_sample[t].right) * t_fraction;
}
double recorded_sample_step = note_frequencies[note] / middle_c;
m_pos[note] += recorded_sample_step;
return { w_left, w_right };
}
static inline double calculate_step(double distance, int milliseconds)
{
if (milliseconds == 0)
return distance;
constexpr double samples_per_millisecond = sample_rate / 1000.0;
double samples = milliseconds * samples_per_millisecond;
double step = distance / samples;
return step;
}
void AudioEngine::set_note(int note, Switch switch_note)
{
ASSERT(note >= 0 && note < note_count);
if (switch_note == On) {
if (m_note_on[note] == 0) {
m_pos[note] = 0;
m_envelope[note] = Attack;
}
++m_note_on[note];
} else {
if (m_note_on[note] >= 1) {
if (m_note_on[note] == 1) {
m_release_step[note] = calculate_step(m_power[note], m_release);
m_envelope[note] = Release;
}
--m_note_on[note];
}
}
ASSERT(m_note_on[note] != std::numeric_limits<u8>::max());
ASSERT(m_power[note] >= 0);
}
void AudioEngine::set_note_current_octave(int note, Switch switch_note)
{
set_note(note + octave_base(), switch_note);
}
void AudioEngine::set_roll_note(int y, int x, Switch switch_note)
{
ASSERT(x >= 0 && x < horizontal_notes);
ASSERT(y >= 0 && y < note_count);
m_roll_notes[y][x] = switch_note;
if (x == m_current_column && switch_note == Off) // If you turn off a note that is playing.
set_note((note_count - 1) - y, Off);
}
void AudioEngine::update_roll()
{
if (++m_current_column == horizontal_notes)
m_current_column = 0;
if (++m_previous_column == horizontal_notes)
m_previous_column = 0;
}
void AudioEngine::set_notes_from_roll()
{
for (int note = 0; note < note_count; ++note) {
if (m_roll_notes[note][m_previous_column] == On)
set_note((note_count - 1) - note, Off);
if (m_roll_notes[note][m_current_column] == On)
set_note((note_count - 1) - note, On);
}
}
void AudioEngine::set_octave(Direction direction)
{
if (direction == Up) {
if (m_octave < octave_max)
++m_octave;
} else {
if (m_octave > octave_min)
--m_octave;
}
}
void AudioEngine::set_wave(int wave)
{
ASSERT(wave >= first_wave && wave <= last_wave);
m_wave = wave;
}
void AudioEngine::set_wave(Direction direction)
{
if (direction == Up) {
if (++m_wave > last_wave)
m_wave = first_wave;
} else {
if (--m_wave < first_wave)
m_wave = last_wave;
}
}
void AudioEngine::set_attack(int attack)
{
ASSERT(attack >= 0);
m_attack = attack;
m_attack_step = calculate_step(1, m_attack);
}
void AudioEngine::set_decay(int decay)
{
ASSERT(decay >= 0);
m_decay = decay;
m_decay_step = calculate_step(1 - m_sustain_level, m_decay);
}
void AudioEngine::set_sustain_impl(int sustain)
{
ASSERT(sustain >= 0);
m_sustain = sustain;
m_sustain_level = sustain / 1000.0;
}
void AudioEngine::set_sustain(int sustain)
{
set_sustain_impl(sustain);
set_decay(m_decay);
}
void AudioEngine::set_release(int release)
{
ASSERT(release >= 0);
m_release = release;
}
void AudioEngine::set_delay(int delay)
{
ASSERT(delay >= 0);
m_delay_buffers.clear();
m_delay = delay;
}