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music-synthesizer-for-android/cpp/src/synth_unit.cc

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/*
* Copyright 2012 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifdef VERBOSE
#include <iostream>
#endif
#ifdef __ANDROID__
#include <android/log.h>
#define LOGI(...) __android_log_print(ANDROID_LOG_INFO, "synth", __VA_ARGS__)
#endif
#include <string.h>
#include "synth.h"
#include "freqlut.h"
#include "sin.h"
#include "exp2.h"
#include "pitchenv.h"
#include "patch.h"
#include "synth_unit.h"
#include "aligned_buf.h"
char epiano[] = {
95, 29, 20, 50, 99, 95, 0, 0, 41, 0, 19, 0, 115, 24, 79, 2, 0,
95, 20, 20, 50, 99, 95, 0, 0, 0, 0, 0, 0, 3, 0, 99, 2, 0,
95, 29, 20, 50, 99, 95, 0, 0, 0, 0, 0, 0, 59, 24, 89, 2, 0,
95, 20, 20, 50, 99, 95, 0, 0, 0, 0, 0, 0, 59, 8, 99, 2, 0,
95, 50, 35, 78, 99, 75, 0, 0, 0, 0, 0, 0, 59, 28, 58, 28, 0,
96, 25, 25, 67, 99, 75, 0, 0, 0, 0, 0, 0, 83, 8, 99, 2, 0,
94, 67, 95, 60, 50, 50, 50, 50, 4, 6, 34, 33, 0, 0, 56, 24,
69, 46, 80, 73, 65, 78, 79, 32, 49, 32
};
void SynthUnit::Init(double sample_rate) {
Freqlut::init(sample_rate);
Exp2::init();
Tanh::init();
Sin::init();
Lfo::init(sample_rate);
PitchEnv::init(sample_rate);
}
SynthUnit::SynthUnit(RingBuffer *ring_buffer) {
ring_buffer_ = ring_buffer;
for (int note = 0; note < max_active_notes; ++note) {
active_note_[note].dx7_note = new Dx7Note;
active_note_[note].keydown = false;
active_note_[note].sustained = false;
active_note_[note].live = false;
}
input_buffer_index_ = 0;
memcpy(patch_data_, epiano, sizeof(epiano));
ProgramChange(0);
current_note_ = 0;
filter_control_[0] = 258847126;
filter_control_[1] = 0;
filter_control_[2] = 0;
controllers_.values_[kControllerPitch] = 0x2000;
sustain_ = false;
extra_buf_size_ = 0;
}
// Transfer as many bytes as possible from ring buffer to input buffer.
// Note that this implementation has a fair amount of copying - we'd probably
// do it a bit differently if it were bulk data, but in this case we're
// optimizing for simplicity of implementation.
void SynthUnit::TransferInput() {
size_t bytes_available = ring_buffer_->BytesAvailable();
int bytes_to_read = min(bytes_available,
sizeof(input_buffer_) - input_buffer_index_);
if (bytes_to_read > 0) {
ring_buffer_->Read(bytes_to_read, input_buffer_ + input_buffer_index_);
input_buffer_index_ += bytes_to_read;
}
}
void SynthUnit::ConsumeInput(int n_input_bytes) {
if (n_input_bytes < input_buffer_index_) {
memmove(input_buffer_, input_buffer_ + n_input_bytes,
input_buffer_index_ - n_input_bytes);
}
input_buffer_index_ -= n_input_bytes;
}
int SynthUnit::AllocateNote() {
int note = current_note_;
for (int i = 0; i < max_active_notes; i++) {
if (!active_note_[note].keydown) {
current_note_ = (note + 1) % max_active_notes;
return note;
}
note = (note + 1) % max_active_notes;
}
return -1;
}
void SynthUnit::ProgramChange(int p) {
current_patch_ = p;
const uint8_t *patch = patch_data_ + 128 * current_patch_;
UnpackPatch((const char *)patch, unpacked_patch_);
lfo_.reset(unpacked_patch_ + 137);
}
void SynthUnit::SetController(int controller, int value) {
controllers_.values_[controller] = value;
}
int SynthUnit::ProcessMidiMessage(const uint8_t *buf, int buf_size) {
uint8_t cmd = buf[0];
uint8_t cmd_type = cmd & 0xf0;
//LOGI("got %d midi: %02x %02x %02x", buf_size, buf[0], buf[1], buf[2]);
if (cmd_type == 0x80 || (cmd_type == 0x90 && buf[2] == 0)) {
if (buf_size >= 3) {
// note off
for (int note = 0; note < max_active_notes; ++note) {
if (active_note_[note].midi_note == buf[1] &&
active_note_[note].keydown) {
if (sustain_) {
active_note_[note].sustained = true;
} else {
active_note_[note].dx7_note->keyup();
}
active_note_[note].keydown = false;
}
}
return 3;
}
return 0;
} else if (cmd_type == 0x90) {
if (buf_size >= 3) {
// note on
int note_ix = AllocateNote();
if (note_ix >= 0) {
lfo_.keydown(); // TODO: should only do this if # keys down was 0
active_note_[note_ix].midi_note = buf[1];
active_note_[note_ix].keydown = true;
active_note_[note_ix].sustained = sustain_;
active_note_[note_ix].live = true;
active_note_[note_ix].dx7_note->init(unpacked_patch_, buf[1], buf[2]);
}
return 3;
}
return 0;
} else if (cmd_type == 0xb0) {
if (buf_size >= 3) {
// controller
// TODO: move more logic into SetController
int controller = buf[1];
int value = buf[2];
if (controller == 1) {
filter_control_[0] = 142365917 + value * 917175;
} else if (controller == 2) {
filter_control_[1] = value * 528416;
} else if (controller == 3) {
filter_control_[2] = value * 528416;
} else if (controller == 64) {
sustain_ = value != 0;
if (!sustain_) {
for (int note = 0; note < max_active_notes; note++) {
if (active_note_[note].sustained && !active_note_[note].keydown) {
active_note_[note].dx7_note->keyup();
active_note_[note].sustained = false;
}
}
}
}
return 3;
} return 0;
} else if (cmd_type == 0xc0) {
if (buf_size >= 2) {
// program change
int program_number = buf[1];
ProgramChange(min(program_number, 31));
char name[11];
memcpy(name, unpacked_patch_ + 145, 10);
name[10] = 0;
#ifdef VERBOSE
std::cout << "Loaded patch " << current_patch_ << ": " << name << "\r";
std::cout.flush();
#endif
return 2;
}
return 0;
} else if (cmd == 0xe0) {
// pitch bend
SetController(kControllerPitch, buf[1] | (buf[2] << 7));
return 3;
} else if (cmd == 0xf0) {
// sysex
if (buf_size >= 6 && buf[1] == 0x43 && buf[2] == 0x00 && buf[3] == 0x09 &&
buf[4] == 0x20 && buf[5] == 0x00) {
if (buf_size >= 4104) {
// TODO: check checksum?
memcpy(patch_data_, buf + 6, 4096);
ProgramChange(current_patch_);
return 4104;
}
return 0;
}
}
// TODO: more robust handling
#ifdef VERBOSE
std::cout << "Unknown message " << std::hex << (int)cmd <<
", skipping " << std::dec << buf_size << " bytes" << std::endl;
#endif
return buf_size;
}
void SynthUnit::GetSamples(int n_samples, int16_t *buffer) {
TransferInput();
size_t input_offset;
for (input_offset = 0; input_offset < input_buffer_index_; ) {
int bytes_available = input_buffer_index_ - input_offset;
int bytes_consumed = ProcessMidiMessage(input_buffer_ + input_offset,
bytes_available);
if (bytes_consumed == 0) {
break;
}
input_offset += bytes_consumed;
}
ConsumeInput(input_offset);
int i;
for (i = 0; i < n_samples && i < extra_buf_size_; i++) {
buffer[i] = extra_buf_[i];
}
if (extra_buf_size_ > n_samples) {
for (int j = 0; j < extra_buf_size_ - n_samples; j++) {
extra_buf_[j] = extra_buf_[j + n_samples];
}
extra_buf_size_ -= n_samples;
return;
}
for (; i < n_samples; i += N) {
AlignedBuf<int32_t, N> audiobuf;
AlignedBuf<int32_t, N> audiobuf2;
for (int j = 0; j < N; ++j) {
audiobuf.get()[j] = 0;
}
int32_t lfovalue = lfo_.getsample();
int32_t lfodelay = lfo_.getdelay();
for (int note = 0; note < max_active_notes; ++note) {
if (active_note_[note].live) {
active_note_[note].dx7_note->compute(audiobuf.get(), lfovalue, lfodelay,
&controllers_);
}
}
const int32_t *bufs[] = { audiobuf.get() };
int32_t *bufs2[] = { audiobuf2.get() };
filter_.process(bufs, filter_control_, filter_control_, bufs2);
int jmax = n_samples - i;
for (int j = 0; j < N; ++j) {
int32_t val = audiobuf2.get()[j] >> 4;
int clip_val = val < -(1 << 24) ? 0x8000 : val >= (1 << 24) ? 0x7fff :
val >> 9;
// TODO: maybe some dithering?
if (j < jmax) {
buffer[i + j] = clip_val;
} else {
extra_buf_[j - jmax] = clip_val;
}
}
}
extra_buf_size_ = i - n_samples;
}