11 files changed, 416 insertions, 64 deletions

diff --git a/src/input_common/CMakeLists.txt b/src/input_common/CMakeLists.txt
index 56267c8a8..09361e37e 100644
--- a/src/input_common/CMakeLists.txt
+++ b/src/input_common/CMakeLists.txt
@@ -7,8 +7,12 @@ add_library(input_common STATIC
     main.h
     motion_emu.cpp
     motion_emu.h
+    motion_input.cpp
+    motion_input.h
     settings.cpp
     settings.h
+    touch_from_button.cpp
+    touch_from_button.h
     gcadapter/gc_adapter.cpp
     gcadapter/gc_adapter.h
     gcadapter/gc_poller.cpp
diff --git a/src/input_common/gcadapter/gc_adapter.cpp b/src/input_common/gcadapter/gc_adapter.cpp
index 74759ea7d..c6c423c4b 100644
--- a/src/input_common/gcadapter/gc_adapter.cpp
+++ b/src/input_common/gcadapter/gc_adapter.cpp
@@ -283,7 +283,7 @@ void Adapter::Reset() {
     }
 }
 
-bool Adapter::DeviceConnected(std::size_t port) {
+bool Adapter::DeviceConnected(std::size_t port) const {
     return adapter_controllers_status[port] != ControllerTypes::None;
 }
 
diff --git a/src/input_common/gcadapter/gc_adapter.h b/src/input_common/gcadapter/gc_adapter.h
index bed81915c..20e97d283 100644
--- a/src/input_common/gcadapter/gc_adapter.h
+++ b/src/input_common/gcadapter/gc_adapter.h
@@ -76,7 +76,7 @@ public:
     void EndConfiguration();
 
     /// Returns true if there is a device connected to port
-    bool DeviceConnected(std::size_t port);
+    bool DeviceConnected(std::size_t port) const;
 
     std::array<Common::SPSCQueue<GCPadStatus>, 4>& GetPadQueue();
     const std::array<Common::SPSCQueue<GCPadStatus>, 4>& GetPadQueue() const;
diff --git a/src/input_common/gcadapter/gc_poller.cpp b/src/input_common/gcadapter/gc_poller.cpp
index 71cd85eeb..92e9e8e89 100644
--- a/src/input_common/gcadapter/gc_poller.cpp
+++ b/src/input_common/gcadapter/gc_poller.cpp
@@ -15,7 +15,7 @@ namespace InputCommon {
 
 class GCButton final : public Input::ButtonDevice {
 public:
-    explicit GCButton(int port_, int button_, GCAdapter::Adapter* adapter)
+    explicit GCButton(int port_, int button_, const GCAdapter::Adapter* adapter)
         : port(port_), button(button_), gcadapter(adapter) {}
 
     ~GCButton() override;
@@ -30,15 +30,16 @@ public:
 private:
     const int port;
     const int button;
-    GCAdapter::Adapter* gcadapter;
+    const GCAdapter::Adapter* gcadapter;
 };
 
 class GCAxisButton final : public Input::ButtonDevice {
 public:
     explicit GCAxisButton(int port_, int axis_, float threshold_, bool trigger_if_greater_,
-                          GCAdapter::Adapter* adapter)
+                          const GCAdapter::Adapter* adapter)
         : port(port_), axis(axis_), threshold(threshold_), trigger_if_greater(trigger_if_greater_),
-          gcadapter(adapter), origin_value(adapter->GetOriginValue(port_, axis_)) {}
+          gcadapter(adapter),
+          origin_value(static_cast<float>(adapter->GetOriginValue(port_, axis_))) {}
 
     bool GetStatus() const override {
         if (gcadapter->DeviceConnected(port)) {
@@ -59,7 +60,7 @@ private:
     const int axis;
     float threshold;
     bool trigger_if_greater;
-    GCAdapter::Adapter* gcadapter;
+    const GCAdapter::Adapter* gcadapter;
     const float origin_value;
 };
 
@@ -148,11 +149,12 @@ void GCButtonFactory::EndConfiguration() {
 
 class GCAnalog final : public Input::AnalogDevice {
 public:
-    GCAnalog(int port_, int axis_x_, int axis_y_, float deadzone_, GCAdapter::Adapter* adapter,
-             float range_)
+    GCAnalog(int port_, int axis_x_, int axis_y_, float deadzone_,
+             const GCAdapter::Adapter* adapter, float range_)
         : port(port_), axis_x(axis_x_), axis_y(axis_y_), deadzone(deadzone_), gcadapter(adapter),
-          origin_value_x(adapter->GetOriginValue(port_, axis_x_)),
-          origin_value_y(adapter->GetOriginValue(port_, axis_y_)), range(range_) {}
+          origin_value_x(static_cast<float>(adapter->GetOriginValue(port_, axis_x_))),
+          origin_value_y(static_cast<float>(adapter->GetOriginValue(port_, axis_y_))),
+          range(range_) {}
 
     float GetAxis(int axis) const {
         if (gcadapter->DeviceConnected(port)) {
@@ -210,7 +212,7 @@ private:
     const int axis_x;
     const int axis_y;
     const float deadzone;
-    GCAdapter::Adapter* gcadapter;
+    const GCAdapter::Adapter* gcadapter;
     const float origin_value_x;
     const float origin_value_y;
     const float range;
diff --git a/src/input_common/main.cpp b/src/input_common/main.cpp
index 57e7a25fe..ea1a1cee6 100644
--- a/src/input_common/main.cpp
+++ b/src/input_common/main.cpp
@@ -11,6 +11,7 @@
 #include "input_common/keyboard.h"
 #include "input_common/main.h"
 #include "input_common/motion_emu.h"
+#include "input_common/touch_from_button.h"
 #include "input_common/udp/udp.h"
 #ifdef HAVE_SDL2
 #include "input_common/sdl/sdl.h"
@@ -32,6 +33,8 @@ struct InputSubsystem::Impl {
                                                     std::make_shared<AnalogFromButton>());
         motion_emu = std::make_shared<MotionEmu>();
         Input::RegisterFactory<Input::MotionDevice>("motion_emu", motion_emu);
+        Input::RegisterFactory<Input::TouchDevice>("touch_from_button",
+                                                   std::make_shared<TouchFromButtonFactory>());
 
 #ifdef HAVE_SDL2
         sdl = SDL::Init();
@@ -46,6 +49,7 @@ struct InputSubsystem::Impl {
         Input::UnregisterFactory<Input::AnalogDevice>("analog_from_button");
         Input::UnregisterFactory<Input::MotionDevice>("motion_emu");
         motion_emu.reset();
+        Input::UnregisterFactory<Input::TouchDevice>("touch_from_button");
 #ifdef HAVE_SDL2
         sdl.reset();
 #endif
@@ -171,6 +175,13 @@ const GCButtonFactory* InputSubsystem::GetGCButtons() const {
     return impl->gcbuttons.get();
 }
 
+void InputSubsystem::ReloadInputDevices() {
+    if (!impl->udp) {
+        return;
+    }
+    impl->udp->ReloadUDPClient();
+}
+
 std::vector<std::unique_ptr<Polling::DevicePoller>> InputSubsystem::GetPollers(
     Polling::DeviceType type) const {
 #ifdef HAVE_SDL2
diff --git a/src/input_common/main.h b/src/input_common/main.h
index 58e5dc250..f3fbf696e 100644
--- a/src/input_common/main.h
+++ b/src/input_common/main.h
@@ -115,6 +115,9 @@ public:
     /// Retrieves the underlying GameCube button handler.
     [[nodiscard]] const GCButtonFactory* GetGCButtons() const;
 
+    /// Reloads the input devices
+    void ReloadInputDevices();
+
     /// Get all DevicePoller from all backends for a specific device type
     [[nodiscard]] std::vector<std::unique_ptr<Polling::DevicePoller>> GetPollers(
         Polling::DeviceType type) const;
diff --git a/src/input_common/motion_input.cpp b/src/input_common/motion_input.cpp
new file mode 100644
index 000000000..22a849866
--- /dev/null
+++ b/src/input_common/motion_input.cpp
@@ -0,0 +1,181 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included
+
+#include "common/math_util.h"
+#include "input_common/motion_input.h"
+
+namespace InputCommon {
+
+MotionInput::MotionInput(f32 new_kp, f32 new_ki, f32 new_kd)
+    : kp(new_kp), ki(new_ki), kd(new_kd), quat{{0, 0, -1}, 0} {}
+
+void MotionInput::SetAcceleration(const Common::Vec3f& acceleration) {
+    accel = acceleration;
+}
+
+void MotionInput::SetGyroscope(const Common::Vec3f& gyroscope) {
+    gyro = gyroscope - gyro_drift;
+    if (gyro.Length2() < gyro_threshold) {
+        gyro = {};
+    }
+}
+
+void MotionInput::SetQuaternion(const Common::Quaternion<f32>& quaternion) {
+    quat = quaternion;
+}
+
+void MotionInput::SetGyroDrift(const Common::Vec3f& drift) {
+    gyro_drift = drift;
+}
+
+void MotionInput::SetGyroThreshold(f32 threshold) {
+    gyro_threshold = threshold;
+}
+
+void MotionInput::EnableReset(bool reset) {
+    reset_enabled = reset;
+}
+
+void MotionInput::ResetRotations() {
+    rotations = {};
+}
+
+bool MotionInput::IsMoving(f32 sensitivity) const {
+    return gyro.Length() >= sensitivity || accel.Length() <= 0.9f || accel.Length() >= 1.1f;
+}
+
+bool MotionInput::IsCalibrated(f32 sensitivity) const {
+    return real_error.Length() < sensitivity;
+}
+
+void MotionInput::UpdateRotation(u64 elapsed_time) {
+    const f32 sample_period = elapsed_time / 1000000.0f;
+    if (sample_period > 0.1f) {
+        return;
+    }
+    rotations += gyro * sample_period;
+}
+
+void MotionInput::UpdateOrientation(u64 elapsed_time) {
+    if (!IsCalibrated(0.1f)) {
+        ResetOrientation();
+    }
+    // Short name local variable for readability
+    f32 q1 = quat.w;
+    f32 q2 = quat.xyz[0];
+    f32 q3 = quat.xyz[1];
+    f32 q4 = quat.xyz[2];
+    const f32 sample_period = elapsed_time / 1000000.0f;
+
+    // ignore invalid elapsed time
+    if (sample_period > 0.1f) {
+        return;
+    }
+
+    const auto normal_accel = accel.Normalized();
+    auto rad_gyro = gyro * Common::PI * 2;
+    const f32 swap = rad_gyro.x;
+    rad_gyro.x = rad_gyro.y;
+    rad_gyro.y = -swap;
+    rad_gyro.z = -rad_gyro.z;
+
+    // Ignore drift correction if acceleration is not reliable
+    if (accel.Length() >= 0.75f && accel.Length() <= 1.25f) {
+        const f32 ax = -normal_accel.x;
+        const f32 ay = normal_accel.y;
+        const f32 az = -normal_accel.z;
+
+        // Estimated direction of gravity
+        const f32 vx = 2.0f * (q2 * q4 - q1 * q3);
+        const f32 vy = 2.0f * (q1 * q2 + q3 * q4);
+        const f32 vz = q1 * q1 - q2 * q2 - q3 * q3 + q4 * q4;
+
+        // Error is cross product between estimated direction and measured direction of gravity
+        const Common::Vec3f new_real_error = {az * vx - ax * vz, ay * vz - az * vy,
+                                              ax * vy - ay * vx};
+
+        derivative_error = new_real_error - real_error;
+        real_error = new_real_error;
+
+        // Prevent integral windup
+        if (ki != 0.0f && !IsCalibrated(0.05f)) {
+            integral_error += real_error;
+        } else {
+            integral_error = {};
+        }
+
+        // Apply feedback terms
+        rad_gyro += kp * real_error;
+        rad_gyro += ki * integral_error;
+        rad_gyro += kd * derivative_error;
+    }
+
+    const f32 gx = rad_gyro.y;
+    const f32 gy = rad_gyro.x;
+    const f32 gz = rad_gyro.z;
+
+    // Integrate rate of change of quaternion
+    const f32 pa = q2;
+    const f32 pb = q3;
+    const f32 pc = q4;
+    q1 = q1 + (-q2 * gx - q3 * gy - q4 * gz) * (0.5f * sample_period);
+    q2 = pa + (q1 * gx + pb * gz - pc * gy) * (0.5f * sample_period);
+    q3 = pb + (q1 * gy - pa * gz + pc * gx) * (0.5f * sample_period);
+    q4 = pc + (q1 * gz + pa * gy - pb * gx) * (0.5f * sample_period);
+
+    quat.w = q1;
+    quat.xyz[0] = q2;
+    quat.xyz[1] = q3;
+    quat.xyz[2] = q4;
+    quat = quat.Normalized();
+}
+
+std::array<Common::Vec3f, 3> MotionInput::GetOrientation() const {
+    const Common::Quaternion<float> quad{
+        .xyz = {-quat.xyz[1], -quat.xyz[0], -quat.w},
+        .w = -quat.xyz[2],
+    };
+    const std::array<float, 16> matrix4x4 = quad.ToMatrix();
+
+    return {Common::Vec3f(matrix4x4[0], matrix4x4[1], -matrix4x4[2]),
+            Common::Vec3f(matrix4x4[4], matrix4x4[5], -matrix4x4[6]),
+            Common::Vec3f(-matrix4x4[8], -matrix4x4[9], matrix4x4[10])};
+}
+
+Common::Vec3f MotionInput::GetAcceleration() const {
+    return accel;
+}
+
+Common::Vec3f MotionInput::GetGyroscope() const {
+    return gyro;
+}
+
+Common::Quaternion<f32> MotionInput::GetQuaternion() const {
+    return quat;
+}
+
+Common::Vec3f MotionInput::GetRotations() const {
+    return rotations;
+}
+
+void MotionInput::ResetOrientation() {
+    if (!reset_enabled) {
+        return;
+    }
+    if (!IsMoving(0.5f) && accel.z <= -0.9f) {
+        ++reset_counter;
+        if (reset_counter > 900) {
+            // TODO: calculate quaternion from gravity vector
+            quat.w = 0;
+            quat.xyz[0] = 0;
+            quat.xyz[1] = 0;
+            quat.xyz[2] = -1;
+            integral_error = {};
+            reset_counter = 0;
+        }
+    } else {
+        reset_counter = 0;
+    }
+}
+} // namespace InputCommon
diff --git a/src/input_common/motion_input.h b/src/input_common/motion_input.h
new file mode 100644
index 000000000..54b4439d9
--- /dev/null
+++ b/src/input_common/motion_input.h
@@ -0,0 +1,68 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included
+
+#pragma once
+
+#include "common/common_types.h"
+#include "common/quaternion.h"
+#include "common/vector_math.h"
+
+namespace InputCommon {
+
+class MotionInput {
+public:
+    MotionInput(f32 new_kp, f32 new_ki, f32 new_kd);
+
+    MotionInput(const MotionInput&) = default;
+    MotionInput& operator=(const MotionInput&) = default;
+
+    MotionInput(MotionInput&&) = default;
+    MotionInput& operator=(MotionInput&&) = default;
+
+    void SetAcceleration(const Common::Vec3f& acceleration);
+    void SetGyroscope(const Common::Vec3f& acceleration);
+    void SetQuaternion(const Common::Quaternion<f32>& quaternion);
+    void SetGyroDrift(const Common::Vec3f& drift);
+    void SetGyroThreshold(f32 threshold);
+
+    void EnableReset(bool reset);
+    void ResetRotations();
+
+    void UpdateRotation(u64 elapsed_time);
+    void UpdateOrientation(u64 elapsed_time);
+
+    std::array<Common::Vec3f, 3> GetOrientation() const;
+    Common::Vec3f GetAcceleration() const;
+    Common::Vec3f GetGyroscope() const;
+    Common::Vec3f GetRotations() const;
+    Common::Quaternion<f32> GetQuaternion() const;
+
+    bool IsMoving(f32 sensitivity) const;
+    bool IsCalibrated(f32 sensitivity) const;
+
+private:
+    void ResetOrientation();
+
+    // PID constants
+    const f32 kp;
+    const f32 ki;
+    const f32 kd;
+
+    // PID errors
+    Common::Vec3f real_error;
+    Common::Vec3f integral_error;
+    Common::Vec3f derivative_error;
+
+    Common::Quaternion<f32> quat;
+    Common::Vec3f rotations;
+    Common::Vec3f accel;
+    Common::Vec3f gyro;
+    Common::Vec3f gyro_drift;
+
+    f32 gyro_threshold = 0.0f;
+    u32 reset_counter = 0;
+    bool reset_enabled = true;
+};
+
+} // namespace InputCommon
diff --git a/src/input_common/sdl/sdl_impl.cpp b/src/input_common/sdl/sdl_impl.cpp
index c8d9eb2bc..a9e676f4b 100644
--- a/src/input_common/sdl/sdl_impl.cpp
+++ b/src/input_common/sdl/sdl_impl.cpp
@@ -3,6 +3,7 @@
 // Refer to the license.txt file included.
 
 #include <algorithm>
+#include <array>
 #include <atomic>
 #include <cmath>
 #include <functional>
@@ -358,7 +359,7 @@ public:
             return std::make_tuple(x / r * (r - deadzone) / (1 - deadzone),
                                    y / r * (r - deadzone) / (1 - deadzone));
         }
-        return std::make_tuple<float, float>(0.0f, 0.0f);
+        return {};
     }
 
     bool GetAnalogDirectionStatus(Input::AnalogDirection direction) const override {
@@ -574,10 +575,10 @@ std::vector<Common::ParamPackage> SDLState::GetInputDevices() {
 
 namespace {
 Common::ParamPackage BuildAnalogParamPackageForButton(int port, std::string guid, u8 axis,
-                                                      float value = 0.1) {
+                                                      float value = 0.1f) {
     Common::ParamPackage params({{"engine", "sdl"}});
     params.Set("port", port);
-    params.Set("guid", guid);
+    params.Set("guid", std::move(guid));
     params.Set("axis", axis);
     if (value > 0) {
         params.Set("direction", "+");
@@ -592,7 +593,7 @@ Common::ParamPackage BuildAnalogParamPackageForButton(int port, std::string guid
 Common::ParamPackage BuildButtonParamPackageForButton(int port, std::string guid, u8 button) {
     Common::ParamPackage params({{"engine", "sdl"}});
     params.Set("port", port);
-    params.Set("guid", guid);
+    params.Set("guid", std::move(guid));
     params.Set("button", button);
     return params;
 }
@@ -601,7 +602,7 @@ Common::ParamPackage BuildHatParamPackageForButton(int port, std::string guid, u
     Common::ParamPackage params({{"engine", "sdl"}});
 
     params.Set("port", port);
-    params.Set("guid", guid);
+    params.Set("guid", std::move(guid));
     params.Set("hat", hat);
     switch (value) {
     case SDL_HAT_UP:
@@ -670,55 +671,62 @@ Common::ParamPackage BuildParamPackageForAnalog(int port, const std::string& gui
 } // Anonymous namespace
 
 ButtonMapping SDLState::GetButtonMappingForDevice(const Common::ParamPackage& params) {
-    // This list is missing ZL/ZR since those are not considered buttons in SDL GameController.
-    // We will add those afterwards
-    // This list also excludes Screenshot since theres not really a mapping for that
-    std::unordered_map<Settings::NativeButton::Values, SDL_GameControllerButton>
-        switch_to_sdl_button = {
-            {Settings::NativeButton::A, SDL_CONTROLLER_BUTTON_B},
-            {Settings::NativeButton::B, SDL_CONTROLLER_BUTTON_A},
-            {Settings::NativeButton::X, SDL_CONTROLLER_BUTTON_Y},
-            {Settings::NativeButton::Y, SDL_CONTROLLER_BUTTON_X},
-            {Settings::NativeButton::LStick, SDL_CONTROLLER_BUTTON_LEFTSTICK},
-            {Settings::NativeButton::RStick, SDL_CONTROLLER_BUTTON_RIGHTSTICK},
-            {Settings::NativeButton::L, SDL_CONTROLLER_BUTTON_LEFTSHOULDER},
-            {Settings::NativeButton::R, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER},
-            {Settings::NativeButton::Plus, SDL_CONTROLLER_BUTTON_START},
-            {Settings::NativeButton::Minus, SDL_CONTROLLER_BUTTON_BACK},
-            {Settings::NativeButton::DLeft, SDL_CONTROLLER_BUTTON_DPAD_LEFT},
-            {Settings::NativeButton::DUp, SDL_CONTROLLER_BUTTON_DPAD_UP},
-            {Settings::NativeButton::DRight, SDL_CONTROLLER_BUTTON_DPAD_RIGHT},
-            {Settings::NativeButton::DDown, SDL_CONTROLLER_BUTTON_DPAD_DOWN},
-            {Settings::NativeButton::SL, SDL_CONTROLLER_BUTTON_LEFTSHOULDER},
-            {Settings::NativeButton::SR, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER},
-            {Settings::NativeButton::Home, SDL_CONTROLLER_BUTTON_GUIDE},
-        };
     if (!params.Has("guid") || !params.Has("port")) {
         return {};
     }
     const auto joystick = GetSDLJoystickByGUID(params.Get("guid", ""), params.Get("port", 0));
-    auto controller = joystick->GetSDLGameController();
-    if (!controller) {
+    auto* controller = joystick->GetSDLGameController();
+    if (controller == nullptr) {
         return {};
     }
 
-    ButtonMapping mapping{};
+    // This list is missing ZL/ZR since those are not considered buttons in SDL GameController.
+    // We will add those afterwards
+    // This list also excludes Screenshot since theres not really a mapping for that
+    using ButtonBindings =
+        std::array<std::pair<Settings::NativeButton::Values, SDL_GameControllerButton>, 17>;
+    static constexpr ButtonBindings switch_to_sdl_button{{
+        {Settings::NativeButton::A, SDL_CONTROLLER_BUTTON_B},
+        {Settings::NativeButton::B, SDL_CONTROLLER_BUTTON_A},
+        {Settings::NativeButton::X, SDL_CONTROLLER_BUTTON_Y},
+        {Settings::NativeButton::Y, SDL_CONTROLLER_BUTTON_X},
+        {Settings::NativeButton::LStick, SDL_CONTROLLER_BUTTON_LEFTSTICK},
+        {Settings::NativeButton::RStick, SDL_CONTROLLER_BUTTON_RIGHTSTICK},
+        {Settings::NativeButton::L, SDL_CONTROLLER_BUTTON_LEFTSHOULDER},
+        {Settings::NativeButton::R, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER},
+        {Settings::NativeButton::Plus, SDL_CONTROLLER_BUTTON_START},
+        {Settings::NativeButton::Minus, SDL_CONTROLLER_BUTTON_BACK},
+        {Settings::NativeButton::DLeft, SDL_CONTROLLER_BUTTON_DPAD_LEFT},
+        {Settings::NativeButton::DUp, SDL_CONTROLLER_BUTTON_DPAD_UP},
+        {Settings::NativeButton::DRight, SDL_CONTROLLER_BUTTON_DPAD_RIGHT},
+        {Settings::NativeButton::DDown, SDL_CONTROLLER_BUTTON_DPAD_DOWN},
+        {Settings::NativeButton::SL, SDL_CONTROLLER_BUTTON_LEFTSHOULDER},
+        {Settings::NativeButton::SR, SDL_CONTROLLER_BUTTON_RIGHTSHOULDER},
+        {Settings::NativeButton::Home, SDL_CONTROLLER_BUTTON_GUIDE},
+    }};
+
+    // Add the missing bindings for ZL/ZR
+    using ZBindings =
+        std::array<std::pair<Settings::NativeButton::Values, SDL_GameControllerAxis>, 2>;
+    static constexpr ZBindings switch_to_sdl_axis{{
+        {Settings::NativeButton::ZL, SDL_CONTROLLER_AXIS_TRIGGERLEFT},
+        {Settings::NativeButton::ZR, SDL_CONTROLLER_AXIS_TRIGGERRIGHT},
+    }};
+
+    ButtonMapping mapping;
+    mapping.reserve(switch_to_sdl_button.size() + switch_to_sdl_axis.size());
+
     for (const auto& [switch_button, sdl_button] : switch_to_sdl_button) {
         const auto& binding = SDL_GameControllerGetBindForButton(controller, sdl_button);
-        mapping[switch_button] =
-            BuildParamPackageForBinding(joystick->GetPort(), joystick->GetGUID(), binding);
+        mapping.insert_or_assign(
+            switch_button,
+            BuildParamPackageForBinding(joystick->GetPort(), joystick->GetGUID(), binding));
     }
-
-    // Add the missing bindings for ZL/ZR
-    std::unordered_map<Settings::NativeButton::Values, SDL_GameControllerAxis> switch_to_sdl_axis =
-        {
-            {Settings::NativeButton::ZL, SDL_CONTROLLER_AXIS_TRIGGERLEFT},
-            {Settings::NativeButton::ZR, SDL_CONTROLLER_AXIS_TRIGGERRIGHT},
-        };
     for (const auto& [switch_button, sdl_axis] : switch_to_sdl_axis) {
         const auto& binding = SDL_GameControllerGetBindForAxis(controller, sdl_axis);
-        mapping[switch_button] =
-            BuildParamPackageForBinding(joystick->GetPort(), joystick->GetGUID(), binding);
+        mapping.insert_or_assign(
+            switch_button,
+            BuildParamPackageForBinding(joystick->GetPort(), joystick->GetGUID(), binding));
     }
 
     return mapping;
@@ -729,8 +737,8 @@ AnalogMapping SDLState::GetAnalogMappingForDevice(const Common::ParamPackage& pa
         return {};
     }
     const auto joystick = GetSDLJoystickByGUID(params.Get("guid", ""), params.Get("port", 0));
-    auto controller = joystick->GetSDLGameController();
-    if (!controller) {
+    auto* controller = joystick->GetSDLGameController();
+    if (controller == nullptr) {
         return {};
     }
 
@@ -739,16 +747,18 @@ AnalogMapping SDLState::GetAnalogMappingForDevice(const Common::ParamPackage& pa
         SDL_GameControllerGetBindForAxis(controller, SDL_CONTROLLER_AXIS_LEFTX);
     const auto& binding_left_y =
         SDL_GameControllerGetBindForAxis(controller, SDL_CONTROLLER_AXIS_LEFTY);
-    mapping[Settings::NativeAnalog::LStick] =
-        BuildParamPackageForAnalog(joystick->GetPort(), joystick->GetGUID(),
-                                   binding_left_x.value.axis, binding_left_y.value.axis);
+    mapping.insert_or_assign(Settings::NativeAnalog::LStick,
+                             BuildParamPackageForAnalog(joystick->GetPort(), joystick->GetGUID(),
+                                                        binding_left_x.value.axis,
+                                                        binding_left_y.value.axis));
     const auto& binding_right_x =
         SDL_GameControllerGetBindForAxis(controller, SDL_CONTROLLER_AXIS_RIGHTX);
     const auto& binding_right_y =
         SDL_GameControllerGetBindForAxis(controller, SDL_CONTROLLER_AXIS_RIGHTY);
-    mapping[Settings::NativeAnalog::RStick] =
-        BuildParamPackageForAnalog(joystick->GetPort(), joystick->GetGUID(),
-                                   binding_right_x.value.axis, binding_right_y.value.axis);
+    mapping.insert_or_assign(Settings::NativeAnalog::RStick,
+                             BuildParamPackageForAnalog(joystick->GetPort(), joystick->GetGUID(),
+                                                        binding_right_x.value.axis,
+                                                        binding_right_y.value.axis));
     return mapping;
 }
 
@@ -784,7 +794,7 @@ public:
         }
         return {};
     }
-    std::optional<Common::ParamPackage> FromEvent(const SDL_Event& event) {
+    [[nodiscard]] std::optional<Common::ParamPackage> FromEvent(const SDL_Event& event) const {
         switch (event.type) {
         case SDL_JOYAXISMOTION:
             if (std::abs(event.jaxis.value / 32767.0) < 0.5) {
@@ -795,7 +805,7 @@ public:
         case SDL_JOYHATMOTION:
             return {SDLEventToButtonParamPackage(state, event)};
         }
-        return {};
+        return std::nullopt;
     }
 };
 
diff --git a/src/input_common/touch_from_button.cpp b/src/input_common/touch_from_button.cpp
new file mode 100644
index 000000000..98da0ef1a
--- /dev/null
+++ b/src/input_common/touch_from_button.cpp
@@ -0,0 +1,50 @@
+// Copyright 2020 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/frontend/framebuffer_layout.h"
+#include "core/settings.h"
+#include "input_common/touch_from_button.h"
+
+namespace InputCommon {
+
+class TouchFromButtonDevice final : public Input::TouchDevice {
+public:
+    TouchFromButtonDevice() {
+        for (const auto& config_entry :
+             Settings::values.touch_from_button_maps[Settings::values.touch_from_button_map_index]
+                 .buttons) {
+            const Common::ParamPackage package{config_entry};
+            map.emplace_back(
+                Input::CreateDevice<Input::ButtonDevice>(config_entry),
+                std::clamp(package.Get("x", 0), 0, static_cast<int>(Layout::ScreenUndocked::Width)),
+                std::clamp(package.Get("y", 0), 0,
+                           static_cast<int>(Layout::ScreenUndocked::Height)));
+        }
+    }
+
+    std::tuple<float, float, bool> GetStatus() const override {
+        for (const auto& m : map) {
+            const bool state = std::get<0>(m)->GetStatus();
+            if (state) {
+                const float x = static_cast<float>(std::get<1>(m)) /
+                                static_cast<int>(Layout::ScreenUndocked::Width);
+                const float y = static_cast<float>(std::get<2>(m)) /
+                                static_cast<int>(Layout::ScreenUndocked::Height);
+                return {x, y, true};
+            }
+        }
+        return {};
+    }
+
+private:
+    // A vector of the mapped button, its x and its y-coordinate
+    std::vector<std::tuple<std::unique_ptr<Input::ButtonDevice>, int, int>> map;
+};
+
+std::unique_ptr<Input::TouchDevice> TouchFromButtonFactory::Create(
+    const Common::ParamPackage& params) {
+    return std::make_unique<TouchFromButtonDevice>();
+}
+
+} // namespace InputCommon
diff --git a/src/input_common/touch_from_button.h b/src/input_common/touch_from_button.h
new file mode 100644
index 000000000..8b4d1aa96
--- /dev/null
+++ b/src/input_common/touch_from_button.h
@@ -0,0 +1,23 @@
+// Copyright 2020 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 {
+
+/**
+ * A touch device factory that takes a list of button devices and combines them into a touch device.
+ */
+class TouchFromButtonFactory final : public Input::Factory<Input::TouchDevice> {
+public:
+    /**
+     * Creates a touch device from a list of button devices
+     */
+    std::unique_ptr<Input::TouchDevice> Create(const Common::ParamPackage& params) override;
+};
+
+} // namespace InputCommon