InputCommon: add AnalogFromButton

src/input_common/analog_from_button.h

@@ -0,0 +1,31 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <memory>
+#include "core/frontend/input.h"
+
+namespace InputCommon {
+
+/**
+ * An analog device factory that takes direction button devices and combines them into a analog
+ * device.
+ */
+class AnalogFromButton final : public Input::Factory<Input::AnalogDevice> {
+public:
+    /**
+     * Creates an analog device from direction button devices
+     * @param params contains parameters for creating the device:
+     *     - "up": a serialized ParamPackage for creating a button device for up direction
+     *     - "down": a serialized ParamPackage for creating a button device for down direction
+     *     - "left": a serialized ParamPackage for creating a button device for left direction
+     *     - "right": a serialized ParamPackage  for creating a button device for right direction
+     *     - "modifier": a serialized ParamPackage for creating a button device as the modifier
+     *     - "modifier_scale": a float for the multiplier the modifier gives to the position
+     */
+    std::unique_ptr<Input::AnalogDevice> Create(const Common::ParamPackage& params) override;
+};
+
+} // namespace InputCommon