Add AudioNode interface and implementation

include/AudioNode.h

@@ -0,0 +1,84 @@
+/*
+ * AudioSoure.h
+ *
+ * Copyright (c) 2024 saker <[email protected]>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * 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 (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#ifndef LMMS_AUDIO_NODE_H
+#define LMMS_AUDIO_NODE_H
+
+#include <optional>
+#include <vector>
+
+#include "lmms_basics.h"
+#include "lmms_export.h"
+
+namespace lmms {
+
+class LMMS_EXPORT AudioNode
+{
+public:
+	struct Buffer
+	{
+		const sampleFrame* buffer;
+		size_t size;
+	};
+
+	class Processor
+	{
+	public:
+		//! Creates a `Processor` for node `currentNode`.
+		Processor(AudioNode* currentNode);
+
+		//! First runs any dependencies for this node, then runs itself.
+		auto run() -> std::optional<Buffer>;
+
+		//! Add another node as a dependency to this node.
+		void addDependency(AudioNode* node);
+
+		//! Remove another node as a dependency to this node.
+		void removeDependency(AudioNode* node);
+
+		//! Add a buffer as input to this node.
+		void addInput(Buffer input);
+
+		//! Take all inputs from this node.
+		auto inputs() -> std::vector<Buffer>;
+
+	private:
+		std::vector<AudioNode*> m_dependencies;
+		std::vector<Buffer> m_inputs;
+		AudioNode* m_currentNode;
+	};
+
+	virtual ~AudioNode() = default;
+
+	//! Returns the processor for this node.
+	virtual auto processor() -> Processor& = 0;
+
+private:
+	//! Internal processing meant to be implemented by subclasses.
+	virtual auto process() -> std::optional<Buffer> = 0;
+	friend class Processor;
+};
+} // namespace lmms
+
+#endif // LMMS_AUDIO_NODE_H

src/core/AudioNode.cpp

@@ -0,0 +1,69 @@
+/*
+ * AudioSoure.cpp
+ *
+ * Copyright (c) 2024 saker <[email protected]>
+ *
+ * This file is part of LMMS - https://lmms.io
+ *
+ * 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 (see COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ * Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include "AudioNode.h"
+
+#include <algorithm>
+
+namespace lmms {
+AudioNode::Processor::Processor(AudioNode* currentNode)
+	: m_currentNode(currentNode)
+{
+}
+
+auto AudioNode::Processor::run() -> std::optional<Buffer>
+{
+	for (auto& dependency : m_dependencies)
+	{
+		auto buffer = dependency->processor().run();
+		if (buffer) { m_currentNode->processor().addInput(buffer.value()); }
+	}
+	return m_currentNode->process();
+}
+
+void AudioNode::Processor::addInput(Buffer input)
+{
+    m_inputs.push_back(input);
+}
+
+auto AudioNode::Processor::inputs() -> std::vector<Buffer>
+{
+    const auto inputs = m_inputs;
+    m_inputs.clear();
+    return inputs;
+}
+
+void AudioNode::Processor::addDependency(AudioNode* node)
+{
+	if (std::find(m_dependencies.begin(), m_dependencies.end(), node) != m_dependencies.end()) { return; }
+	m_dependencies.push_back(node);
+}
+
+void AudioNode::Processor::removeDependency(AudioNode* node)
+{
+	if (std::find(m_dependencies.begin(), m_dependencies.end(), node) == m_dependencies.end()) { return; }
+	m_dependencies.erase(std::remove(m_dependencies.begin(), m_dependencies.end(), node), m_dependencies.end());
+}
+
+} // namespace lmms

src/core/CMakeLists.txt

@@ -4,6 +4,7 @@ set(LMMS_SRCS
 	core/AudioEngine.cpp
 	core/AudioEngineProfiler.cpp
 	core/AudioEngineWorkerThread.cpp
+	core/AudioNode.cpp
 	core/AudioResampler.cpp
 	core/AutomatableModel.cpp
 	core/AutomationClip.cpp