mixer/pipewire: new plugin

src/mixer/plugins/PipeWireMixerPlugin.cxx

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2003-2021 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "PipeWireMixerPlugin.hxx"
+#include "mixer/MixerInternal.hxx"
+#include "mixer/Listener.hxx"
+#include "output/plugins/PipeWireOutputPlugin.hxx"
+
+#include <cmath>
+
+class PipeWireMixer final : public Mixer {
+	PipeWireOutput &output;
+
+	int volume = 100;
+
+public:
+	PipeWireMixer(PipeWireOutput &_output,
+		      MixerListener &_listener) noexcept
+		:Mixer(pipewire_mixer_plugin, _listener),
+		 output(_output)
+	{
+	}
+
+	PipeWireMixer(const PipeWireMixer &) = delete;
+	PipeWireMixer &operator=(const PipeWireMixer &) = delete;
+
+	void OnVolumeChanged(float new_volume) noexcept {
+		volume = std::lround(new_volume * 100.f);
+
+		listener.OnMixerVolumeChanged(*this, volume);
+	}
+
+	/* virtual methods from class Mixer */
+	void Open() override {
+	}
+
+	void Close() noexcept override {
+	}
+
+	int GetVolume() override;
+	void SetVolume(unsigned volume) override;
+};
+
+void
+pipewire_mixer_on_change(PipeWireMixer &pm, float new_volume) noexcept
+{
+	pm.OnVolumeChanged(new_volume);
+}
+
+int
+PipeWireMixer::GetVolume()
+{
+	return volume;
+}
+
+void
+PipeWireMixer::SetVolume(unsigned new_volume)
+{
+	pipewire_output_set_volume(output, float(new_volume) * 0.01f);
+	volume = new_volume;
+}
+
+static Mixer *
+pipewire_mixer_init([[maybe_unused]] EventLoop &event_loop, AudioOutput &ao,
+		    MixerListener &listener,
+		    const ConfigBlock &)
+{
+	auto &po = (PipeWireOutput &)ao;
+	return new PipeWireMixer(po, listener);
+}
+
+const MixerPlugin pipewire_mixer_plugin = {
+	pipewire_mixer_init,
+	true,
+};

src/mixer/plugins/PipeWireMixerPlugin.hxx

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2003-2021 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_PIPEWIRE_MIXER_PLUGIN_HXX
+#define MPD_PIPEWIRE_MIXER_PLUGIN_HXX
+
+struct MixerPlugin;
+class PipeWireMixer;
+
+extern const MixerPlugin pipewire_mixer_plugin;
+
+void
+pipewire_mixer_on_change(PipeWireMixer &pm, float new_volume) noexcept;
+
+#endif

src/mixer/plugins/meson.build

@@ -22,6 +22,10 @@ if is_darwin
   mixer_plugins_sources += 'OSXMixerPlugin.cxx'
 endif
 
+if pipewire_dep.found()
+  mixer_plugins_sources += 'PipeWireMixerPlugin.cxx'
+endif
+
 if pulse_dep.found()
   mixer_plugins_sources += 'PulseMixerPlugin.cxx'
 endif