5 files changed, 113 insertions, 0 deletions

diff --git a/src/input_common/CMakeLists.txt b/src/input_common/CMakeLists.txt
index ac1ad45a9..9f4422269 100644
--- a/src/input_common/CMakeLists.txt
+++ b/src/input_common/CMakeLists.txt
@@ -1,9 +1,11 @@
 set(SRCS
+            analog_from_button.cpp
             keyboard.cpp
             main.cpp
             )
 
 set(HEADERS
+            analog_from_button.h
             keyboard.h
             main.h
             )
diff --git a/src/input_common/analog_from_button.cpp b/src/input_common/analog_from_button.cpp
new file mode 100755
index 000000000..e1a260762
--- /dev/null
+++ b/src/input_common/analog_from_button.cpp
@@ -0,0 +1,58 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "input_common/analog_from_button.h"
+
+namespace InputCommon {
+
+class Analog final : public Input::AnalogDevice {
+public:
+    using Button = std::unique_ptr<Input::ButtonDevice>;
+
+    Analog(Button up_, Button down_, Button left_, Button right_, Button modifier_,
+           float modifier_scale_)
+        : up(std::move(up_)), down(std::move(down_)), left(std::move(left_)),
+          right(std::move(right_)), modifier(std::move(modifier_)),
+          modifier_scale(modifier_scale_) {}
+
+    std::tuple<float, float> GetStatus() const override {
+        constexpr float SQRT_HALF = 0.707106781f;
+        int x = 0, y = 0;
+
+        if (right->GetStatus())
+            ++x;
+        if (left->GetStatus())
+            --x;
+        if (up->GetStatus())
+            ++y;
+        if (down->GetStatus())
+            --y;
+
+        float coef = modifier->GetStatus() ? modifier_scale : 1.0f;
+        return std::make_tuple(x * coef * (y == 0 ? 1.0f : SQRT_HALF),
+                               y * coef * (x == 0 ? 1.0f : SQRT_HALF));
+    }
+
+private:
+    Button up;
+    Button down;
+    Button left;
+    Button right;
+    Button modifier;
+    float modifier_scale;
+};
+
+std::unique_ptr<Input::AnalogDevice> AnalogFromButton::Create(const Common::ParamPackage& params) {
+    const std::string null_engine = Common::ParamPackage{{"engine", "null"}}.Serialize();
+    auto up = Input::CreateDevice<Input::ButtonDevice>(params.Get("up", null_engine));
+    auto down = Input::CreateDevice<Input::ButtonDevice>(params.Get("down", null_engine));
+    auto left = Input::CreateDevice<Input::ButtonDevice>(params.Get("left", null_engine));
+    auto right = Input::CreateDevice<Input::ButtonDevice>(params.Get("right", null_engine));
+    auto modifier = Input::CreateDevice<Input::ButtonDevice>(params.Get("modifier", null_engine));
+    auto modifier_scale = params.Get("modifier_scale", 0.5f);
+    return std::make_unique<Analog>(std::move(up), std::move(down), std::move(left),
+                                    std::move(right), std::move(modifier), modifier_scale);
+}
+
+} // namespace InputCommon
diff --git a/src/input_common/analog_from_button.h b/src/input_common/analog_from_button.h
new file mode 100755
index 000000000..bbd583dd9
--- /dev/null
+++ b/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
diff --git a/src/input_common/main.cpp b/src/input_common/main.cpp
index ff25220b4..8455fdc17 100644
--- a/src/input_common/main.cpp
+++ b/src/input_common/main.cpp
@@ -4,6 +4,7 @@
 
 #include <memory>
 #include "common/param_package.h"
+#include "input_common/analog_from_button.h"
 #include "input_common/keyboard.h"
 #include "input_common/main.h"
 
@@ -14,11 +15,14 @@ static std::shared_ptr<Keyboard> keyboard;
 void Init() {
     keyboard = std::make_shared<InputCommon::Keyboard>();
     Input::RegisterFactory<Input::ButtonDevice>("keyboard", keyboard);
+    Input::RegisterFactory<Input::AnalogDevice>("analog_from_button",
+                                                std::make_shared<InputCommon::AnalogFromButton>());
 }
 
 void Shutdown() {
     Input::UnregisterFactory<Input::ButtonDevice>("keyboard");
     keyboard.reset();
+    Input::UnregisterFactory<Input::AnalogDevice>("analog_from_button");
 }
 
 Keyboard* GetKeyboard() {
@@ -32,4 +36,18 @@ std::string GenerateKeyboardParam(int key_code) {
     return param.Serialize();
 }
 
+std::string GenerateAnalogParamFromKeys(int key_up, int key_down, int key_left, int key_right,
+                                        int key_modifier, float modifier_scale) {
+    Common::ParamPackage circle_pad_param{
+        {"engine", "analog_from_button"},
+        {"up", GenerateKeyboardParam(key_up)},
+        {"down", GenerateKeyboardParam(key_down)},
+        {"left", GenerateKeyboardParam(key_left)},
+        {"right", GenerateKeyboardParam(key_right)},
+        {"modifier", GenerateKeyboardParam(key_modifier)},
+        {"modifier_scale", std::to_string(modifier_scale)},
+    };
+    return circle_pad_param.Serialize();
+}
+
 } // namespace InputCommon
diff --git a/src/input_common/main.h b/src/input_common/main.h
index a490dd829..140bbd014 100644
--- a/src/input_common/main.h
+++ b/src/input_common/main.h
@@ -22,4 +22,8 @@ Keyboard* GetKeyboard();
 /// Generates a serialized param package for creating a keyboard button device
 std::string GenerateKeyboardParam(int key_code);
 
+/// Generates a serialized param package for creating an analog device taking input from keyboard
+std::string GenerateAnalogParamFromKeys(int key_up, int key_down, int key_left, int key_right,
+                                        int key_modifier, float modifier_scale);
+
 } // namespace InputCommon