94 lines
2.5 KiB
C++
94 lines
2.5 KiB
C++
#pragma once
|
|
#include "ivoice.h"
|
|
#include "midi_event.h"
|
|
#include "voice_allocator.h"
|
|
#include <cstring>
|
|
#include <memory>
|
|
#include <vector>
|
|
|
|
namespace trnr {
|
|
|
|
// a generic midi synth base class with sample accurate event handling.
|
|
// the templated type t_voice must derive from ivoice
|
|
template <typename t_voice, typename t_sample>
|
|
class midi_synth : public voice_allocator<t_voice, t_sample> {
|
|
public:
|
|
midi_synth()
|
|
: m_voices_active {false}
|
|
{
|
|
// checks whether template derives from ivoice
|
|
typedef t_voice assert_at_compile_time[is_convertible<t_voice, t_sample>::value ? 1 : -1];
|
|
}
|
|
|
|
void set_samplerate_blocksize(double _samplerate, int _block_size)
|
|
{
|
|
m_block_size = _block_size;
|
|
voice_allocator<t_voice, t_sample>::set_samplerate(_samplerate);
|
|
}
|
|
|
|
void process_block(t_sample** _outputs, int _n_frames)
|
|
{
|
|
// clear outputs
|
|
for (auto i = 0; i < 2; i++) { memset(_outputs[i], 0, _n_frames * sizeof(t_sample)); }
|
|
|
|
// sample accurate event handling based on the iPlug2 synth by Oli Larkin
|
|
if (m_voices_active || !m_event_queue.empty()) {
|
|
int block_size = m_block_size;
|
|
int samples_remaining = _n_frames;
|
|
int start_index = 0;
|
|
|
|
while (samples_remaining > 0) {
|
|
|
|
if (samples_remaining < block_size) block_size = samples_remaining;
|
|
|
|
while (!m_event_queue.empty()) {
|
|
midi_event event = m_event_queue.front();
|
|
|
|
// we assume the messages are in chronological order. If we find one later than the current block we
|
|
// are done.
|
|
if (event.offset > start_index + block_size) break;
|
|
|
|
// send performance messages to the voice allocator
|
|
// message offset is relative to the start of this process_samples() block
|
|
event.offset -= start_index;
|
|
voice_allocator<t_voice, t_sample>::add_event(event);
|
|
|
|
m_event_queue.erase(m_event_queue.begin());
|
|
}
|
|
|
|
voice_allocator<t_voice, t_sample>::process_samples(_outputs, start_index, block_size);
|
|
|
|
samples_remaining -= block_size;
|
|
start_index += block_size;
|
|
}
|
|
|
|
m_voices_active = voice_allocator<t_voice, t_sample>::voices_active();
|
|
|
|
flush_event_queue(_n_frames);
|
|
} else {
|
|
for (int s = 0; s < _n_frames; s++) {
|
|
_outputs[0][s] = 0.;
|
|
_outputs[1][s] = 0.;
|
|
}
|
|
}
|
|
}
|
|
|
|
void add_event(midi_event event)
|
|
{
|
|
if (event.type == midi_event_type::note_on) m_voices_active = true;
|
|
|
|
m_event_queue.push_back(event);
|
|
}
|
|
|
|
void flush_event_queue(int frames)
|
|
{
|
|
for (int i = 0; i < m_event_queue.size(); i++) { m_event_queue.at(i).offset -= frames; }
|
|
}
|
|
|
|
private:
|
|
std::vector<midi_event> m_event_queue;
|
|
int m_block_size;
|
|
bool m_voices_active;
|
|
};
|
|
} // namespace trnr
|