very, very simple WP with midi CC out

2024-10-09 02:01:23 +02:00
commit 3d6fc151f1
126 changed files with 19539 additions and 0 deletions
@@ -0,0 +1,174 @@
+#pragma once
+#include <libremidi/backends/alsa_seq/config.hpp>
+#include <libremidi/backends/alsa_seq/helpers.hpp>
+#include <libremidi/detail/midi_out.hpp>
+
+namespace libremidi::alsa_seq
+{
+
+class midi_out_impl final
+    : public midi1::out_api
+    , private alsa_data
+    , public error_handler
+{
+public:
+  struct
+      : libremidi::output_configuration
+      , alsa_seq::output_configuration
+  {
+  } configuration;
+
+  midi_out_impl(libremidi::output_configuration&& conf, alsa_seq::output_configuration&& apiconf)
+      : configuration{std::move(conf), std::move(apiconf)}
+  {
+    if (init_client(configuration) < 0)
+    {
+      error<driver_error>(
+          this->configuration,
+          "midi_in_alsa::initialize: error creating ALSA sequencer client "
+          "object.");
+      return;
+    }
+
+    if (snd.midi.event_new(this->bufferSize, &this->coder) < 0)
+    {
+      error<driver_error>(
+          this->configuration,
+          "midi_out_alsa::initialize: error initializing MIDI event "
+          "parser.");
+      return;
+    }
+    snd.midi.event_init(this->coder);
+  }
+
+  ~midi_out_impl() override
+  {
+    // Close a connection if it exists.
+    midi_out_impl::close_port();
+
+    // Cleanup.
+    if (this->vport >= 0)
+      snd.seq.delete_port(this->seq, this->vport);
+    if (this->coder)
+      snd.midi.event_free(this->coder);
+
+    if (!configuration.context)
+      snd.seq.close(this->seq);
+  }
+
+  libremidi::API get_current_api() const noexcept override { return libremidi::API::ALSA_SEQ; }
+
+  [[nodiscard]] int create_port(std::string_view portName)
+  {
+    return alsa_data::create_port(
+        *this, portName, SND_SEQ_PORT_CAP_READ | SND_SEQ_PORT_CAP_SUBS_READ,
+        SND_SEQ_PORT_TYPE_MIDI_GENERIC | SND_SEQ_PORT_TYPE_APPLICATION, std::nullopt);
+  }
+
+  bool open_port(const output_port& p, std::string_view portName) override
+  {
+    unsigned int nSrc = this->get_port_count(SND_SEQ_PORT_CAP_WRITE | SND_SEQ_PORT_CAP_SUBS_WRITE);
+    if (nSrc < 1)
+    {
+      error<no_devices_found_error>(
+          this->configuration, "midi_out_alsa::open_port: no MIDI output sources found!");
+      return false;
+    }
+
+    auto sink = get_port_info(p);
+    if (!sink)
+      return false;
+
+    if (int err = create_port(portName); err < 0)
+    {
+      error<driver_error>(configuration, "midi_out_alsa::create_port: ALSA error creating port.");
+      return false;
+    }
+
+    snd_seq_addr_t source{
+        .client = (unsigned char)snd.seq.client_id(this->seq), .port = (unsigned char)this->vport};
+    if (int err = create_connection(*this, source, *sink, true); err < 0)
+    {
+      error<driver_error>(
+          configuration, "midi_out_alsa::create_port: ALSA error making port connection.");
+      return false;
+    }
+
+    return true;
+  }
+
+  bool open_virtual_port(std::string_view portName) override
+  {
+    if (int err = create_port(portName); err < 0)
+      return false;
+    return true;
+  }
+
+  void close_port() override { unsubscribe(); }
+
+  void set_client_name(std::string_view clientName) override
+  {
+    alsa_data::set_client_name(clientName);
+  }
+
+  void set_port_name(std::string_view portName) override { alsa_data::set_port_name(portName); }
+
+  void send_message(const unsigned char* message, std::size_t size) override
+  {
+    int64_t result{};
+    if (size > this->bufferSize)
+    {
+      this->bufferSize = size;
+      result = snd.midi.event_resize_buffer(this->coder, size);
+      if (result != 0)
+      {
+        error<driver_error>(
+            this->configuration,
+            "midi_out_alsa::send_message: ALSA error resizing MIDI event "
+            "buffer.");
+        return;
+      }
+    }
+
+    std::size_t offset = 0;
+    while (offset < size)
+    {
+      snd_seq_event_t ev;
+      snd_seq_ev_clear(&ev);
+      snd_seq_ev_set_source(&ev, this->vport);
+      snd_seq_ev_set_subs(&ev);
+      // FIXME direct is set but snd_seq_event_output_direct is not used...
+      snd_seq_ev_set_direct(&ev);
+
+      const int64_t nBytes = size; // signed to avoir potential overflow with size - offset below
+      result = snd.midi.event_encode(this->coder, message + offset, (long)(nBytes - offset), &ev);
+      if (result < 0)
+      {
+        warning(this->configuration, "midi_out_alsa::send_message: event parsing error!");
+        return;
+      }
+
+      if (ev.type == SND_SEQ_EVENT_NONE)
+      {
+        warning(this->configuration, "midi_out_alsa::send_message: incomplete message!");
+        return;
+      }
+
+      offset += result;
+
+      result = snd.seq.event_output(this->seq, &ev);
+      if (result < 0)
+      {
+        warning(
+            this->configuration,
+            "midi_out_alsa::send_message: error sending MIDI message to port.");
+        return;
+      }
+    }
+    snd.seq.drain_output(this->seq);
+  }
+
+private:
+  uint64_t bufferSize{32};
+};
+}