--- a/AlsaBridge.cpp Fri Dec 18 23:58:03 2020 +0100
+++ b/AlsaBridge.cpp Sat Dec 19 17:33:16 2020 +0100
@@ -15,6 +15,9 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <iostream>
+#include <stdexcept>
+#include <thread>
+#include <atomic>
#include <alsa/asoundlib.h>
@@ -26,32 +29,63 @@
class AlsaBridgeImpl : public AlsaBridge, private djmfix::MidiSender {
private:
djmfix::DJMFix* djmFix;
+ snd_rawmidi_t* input;
+ snd_rawmidi_t* output;
+ std::thread receivingThread;
+ std::atomic<bool> stopped{false};
+
+ void run() {
+ while (!stopped) {
+ // TODO: poll
+ uint8_t buffer[256];
+ ssize_t length = snd_rawmidi_read(input, buffer, sizeof (buffer));
+ if (length > 0 && length <= sizeof (buffer)) {
+ // TODO: multiple messages combined together?
+ djmFix->receive(MidiMessage(buffer, buffer + length));
+ }
+
+ std::this_thread::sleep_for(std::chrono::milliseconds(100));
+ }
+ }
public:
- AlsaBridgeImpl(djmfix::DJMFix* djmFix) : djmFix(djmFix) {
+ AlsaBridgeImpl(djmfix::DJMFix* djmFix, const std::string& deviceName) : djmFix(djmFix) {
+ if (djmFix == nullptr) throw std::invalid_argument("need a djmFix for AlsaBridge");
+
+ int error = snd_rawmidi_open(&input, &output, deviceName.c_str(), SND_RAWMIDI_NONBLOCK);
+ if (error) throw std::invalid_argument("unable to open ALSA device");
+
+
djmFix->setMidiSender(this);
}
virtual ~AlsaBridgeImpl() {
+ // TODO: do not use raw/exclusive access to the device
+ snd_rawmidi_close(input);
+ snd_rawmidi_close(output);
std::cerr << "~AlsaBridgeImpl()" << std::endl; // TODO: do not mess STDIO
}
virtual void start() override {
djmFix->start();
+ receivingThread = std::thread(&AlsaBridgeImpl::run, this);
}
virtual void stop() override {
+ stopped = true;
+ receivingThread.join();
djmFix->stop();
}
virtual void send(MidiMessage midiMessage) override {
- std::cerr << "AlsaBridgeImpl::send()" << std::endl; // TODO: do not mess STDIO
+ ssize_t length = snd_rawmidi_write(output, midiMessage.data(), midiMessage.size());
+ std::cerr << "AlsaBridgeImpl::send(): length = " << length << std::endl; // TODO: do not mess STDIO
}
};
-AlsaBridge* create(djmfix::DJMFix* djmFix) {
- return new AlsaBridgeImpl(djmFix);
+AlsaBridge* create(djmfix::DJMFix* djmFix, const std::string& deviceName) {
+ return new AlsaBridgeImpl(djmFix, deviceName);
}
}