Applications: Move to Userland/Applications/

Userland/Applications/Piano/Track.cpp

@@ -0,0 +1,369 @@
+/*
+ * 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 "Track.h"
+#include <AK/NumericLimits.h>
+#include <LibAudio/Loader.h>
+#include <math.h>
+
+Track::Track(const u32& time)
+    : m_time(time)
+{
+    set_sustain_impl(1000);
+    set_attack(5);
+    set_decay(1000);
+    set_release(5);
+}
+
+Track::~Track()
+{
+}
+
+void Track::fill_sample(Sample& sample)
+{
+    Audio::Sample new_sample;
+
+    for (size_t note = 0; note < note_count; ++note) {
+        if (!m_roll_iters[note].is_end()) {
+            if (m_roll_iters[note]->on_sample == m_time) {
+                set_note(note, On);
+            } else if (m_roll_iters[note]->off_sample == m_time) {
+                set_note(note, Off);
+                ++m_roll_iters[note];
+                if (m_roll_iters[note].is_end())
+                    m_roll_iters[note] = m_roll_notes[note].begin();
+            }
+        }
+
+        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 note_sample;
+        switch (m_wave) {
+        case Wave::Sine:
+            note_sample = sine(note);
+            break;
+        case Wave::Saw:
+            note_sample = saw(note);
+            break;
+        case Wave::Square:
+            note_sample = square(note);
+            break;
+        case Wave::Triangle:
+            note_sample = triangle(note);
+            break;
+        case Wave::Noise:
+            note_sample = noise();
+            break;
+        case Wave::RecordedSample:
+            note_sample = recorded_sample(note);
+            break;
+        default:
+            ASSERT_NOT_REACHED();
+        }
+        new_sample.left += note_sample.left * m_power[note] * volume;
+        new_sample.right += note_sample.right * m_power[note] * volume;
+    }
+
+    if (m_delay) {
+        new_sample.left += m_delay_buffer[m_delay_index].left * 0.333333;
+        new_sample.right += m_delay_buffer[m_delay_index].right * 0.333333;
+        m_delay_buffer[m_delay_index].left = new_sample.left;
+        m_delay_buffer[m_delay_index].right = new_sample.right;
+        if (++m_delay_index >= m_delay_samples)
+            m_delay_index = 0;
+    }
+
+    sample.left += new_sample.left;
+    sample.right += new_sample.right;
+}
+
+void Track::reset()
+{
+    memset(m_delay_buffer.data(), 0, m_delay_buffer.size() * sizeof(Sample));
+    m_delay_index = 0;
+
+    memset(m_note_on, 0, sizeof(m_note_on));
+    memset(m_power, 0, sizeof(m_power));
+    memset(m_envelope, 0, sizeof(m_envelope));
+}
+
+String Track::set_recorded_sample(const StringView& path)
+{
+    NonnullRefPtr<Audio::Loader> loader = Audio::Loader::create(path);
+    if (loader->has_error())
+        return String(loader->error_string());
+    auto buffer = 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(buffer->sample_count());
+
+    double peak = 0;
+    for (int i = 0; i < buffer->sample_count(); ++i) {
+        double left_abs = fabs(buffer->samples()[i].left);
+        double right_abs = fabs(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 < buffer->sample_count(); ++i) {
+            m_recorded_sample[i].left = buffer->samples()[i].left / peak;
+            m_recorded_sample[i].right = buffer->samples()[i].right / peak;
+        }
+    }
+
+    return String::empty();
+}
+
+// All of the information for these waves is on Wikipedia.
+
+Audio::Sample Track::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 Track::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 Track::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 Track::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 Track::noise() const
+{
+    double random_percentage = static_cast<double>(rand()) / RAND_MAX;
+    double w = (random_percentage * 2) - 1;
+    return w;
+}
+
+Audio::Sample Track::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 Track::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] != NumericLimits<u8>::max());
+    ASSERT(m_power[note] >= 0);
+}
+
+void Track::sync_roll(int note)
+{
+    auto it = m_roll_notes[note].find_if([&](auto& roll_note) { return roll_note.off_sample > m_time; });
+    if (it.is_end())
+        m_roll_iters[note] = m_roll_notes[note].begin();
+    else
+        m_roll_iters[note] = it;
+}
+
+void Track::set_roll_note(int note, u32 on_sample, u32 off_sample)
+{
+    RollNote new_roll_note = { on_sample, off_sample };
+
+    ASSERT(note >= 0 && note < note_count);
+    ASSERT(new_roll_note.off_sample < roll_length);
+    ASSERT(new_roll_note.length() >= 2);
+
+    for (auto it = m_roll_notes[note].begin(); !it.is_end();) {
+        if (it->on_sample > new_roll_note.off_sample) {
+            m_roll_notes[note].insert_before(it, new_roll_note);
+            sync_roll(note);
+            return;
+        }
+        if (it->on_sample <= new_roll_note.on_sample && it->off_sample >= new_roll_note.on_sample) {
+            if (m_time >= it->on_sample && m_time <= it->off_sample)
+                set_note(note, Off);
+            m_roll_notes[note].remove(it);
+            sync_roll(note);
+            return;
+        }
+        if ((new_roll_note.on_sample == 0 || it->on_sample >= new_roll_note.on_sample - 1) && it->on_sample <= new_roll_note.off_sample) {
+            if (m_time >= new_roll_note.off_sample && m_time <= it->off_sample)
+                set_note(note, Off);
+            m_roll_notes[note].remove(it);
+            it = m_roll_notes[note].begin();
+            continue;
+        }
+        ++it;
+    }
+
+    m_roll_notes[note].append(new_roll_note);
+    sync_roll(note);
+}
+
+void Track::set_wave(int wave)
+{
+    ASSERT(wave >= first_wave && wave <= last_wave);
+    m_wave = wave;
+}
+
+void Track::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 Track::set_attack(int attack)
+{
+    ASSERT(attack >= 0);
+    m_attack = attack;
+    m_attack_step = calculate_step(1, m_attack);
+}
+
+void Track::set_decay(int decay)
+{
+    ASSERT(decay >= 0);
+    m_decay = decay;
+    m_decay_step = calculate_step(1 - m_sustain_level, m_decay);
+}
+
+void Track::set_sustain_impl(int sustain)
+{
+    ASSERT(sustain >= 0);
+    m_sustain = sustain;
+    m_sustain_level = sustain / 1000.0;
+}
+
+void Track::set_sustain(int sustain)
+{
+    set_sustain_impl(sustain);
+    set_decay(m_decay);
+}
+
+void Track::set_release(int release)
+{
+    ASSERT(release >= 0);
+    m_release = release;
+}
+
+void Track::set_delay(int delay)
+{
+    ASSERT(delay >= 0);
+    m_delay = delay;
+    m_delay_samples = m_delay == 0 ? 0 : (sample_rate / (beats_per_minute / 60)) / m_delay;
+    m_delay_buffer.resize(m_delay_samples);
+    memset(m_delay_buffer.data(), 0, m_delay_buffer.size() * sizeof(Sample));
+    m_delay_index = 0;
+}