CAM: implement basic camera functions with a blank camera

src/core/frontend/camera/factory.h

@@ -0,0 +1,41 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include <string>
+#include "core/frontend/camera/interface.h"
+
+namespace Camera {
+
+class CameraFactory {
+public:
+    virtual ~CameraFactory();
+
+    /**
+     * Creates a camera object based on the configuration string.
+     * @params config Configuration string to create the camera. The implementation can decide the
+     *     meaning of this string.
+     * @returns a unique_ptr to the created camera object.
+     */
+    virtual std::unique_ptr<CameraInterface> Create(const std::string& config) const = 0;
+};
+
+/**
+ * Registers an external camera factory.
+ * @param name Identifier of the camera factory.
+ * @param factory Camera factory to register.
+ */
+void RegisterFactory(const std::string& name, std::unique_ptr<CameraFactory> factory);
+
+/**
+ * Creates a camera from the factory.
+ * @param name Identifier of the camera factory.
+ * @param config Configuration string to create the camera. The meaning of this string is
+ *     defined by the factory.
+ */
+std::unique_ptr<CameraInterface> CreateCamera(const std::string& name, const std::string& config);
+
+} // namespace Camera