Merge remote-tracking branch 'upstream/master' into int-flags

13 files changed, 252 insertions, 158 deletions

diff --git a/src/core/frontend/applets/controller.cpp b/src/core/frontend/applets/controller.cpp
index 4505da758..03bbedf8b 100644
--- a/src/core/frontend/applets/controller.cpp
+++ b/src/core/frontend/applets/controller.cpp
@@ -4,7 +4,6 @@
 
 #include "common/assert.h"
 #include "common/logging/log.h"
-#include "core/core.h"
 #include "core/frontend/applets/controller.h"
 #include "core/hle/service/hid/controllers/npad.h"
 #include "core/hle/service/hid/hid.h"
@@ -14,32 +13,33 @@ namespace Core::Frontend {
 
 ControllerApplet::~ControllerApplet() = default;
 
+DefaultControllerApplet::DefaultControllerApplet(Service::SM::ServiceManager& service_manager_)
+    : service_manager{service_manager_} {}
+
 DefaultControllerApplet::~DefaultControllerApplet() = default;
 
 void DefaultControllerApplet::ReconfigureControllers(std::function<void()> callback,
-                                                     ControllerParameters parameters) const {
+                                                     const ControllerParameters& parameters) const {
     LOG_INFO(Service_HID, "called, deducing the best configuration based on the given parameters!");
 
     auto& npad =
-        Core::System::GetInstance()
-            .ServiceManager()
-            .GetService<Service::HID::Hid>("hid")
+        service_manager.GetService<Service::HID::Hid>("hid")
             ->GetAppletResource()
             ->GetController<Service::HID::Controller_NPad>(Service::HID::HidController::NPad);
 
-    auto& players = Settings::values.players;
+    auto& players = Settings::values.players.GetValue();
 
     const std::size_t min_supported_players =
         parameters.enable_single_mode ? 1 : parameters.min_players;
 
     // Disconnect Handheld first.
-    npad.DisconnectNPadAtIndex(8);
+    npad.DisconnectNpadAtIndex(8);
 
     // Deduce the best configuration based on the input parameters.
     for (std::size_t index = 0; index < players.size() - 2; ++index) {
         // First, disconnect all controllers regardless of the value of keep_controllers_connected.
         // This makes it easy to connect the desired controllers.
-        npad.DisconnectNPadAtIndex(index);
+        npad.DisconnectNpadAtIndex(index);
 
         // Only connect the minimum number of required players.
         if (index >= min_supported_players) {
@@ -66,7 +66,7 @@ void DefaultControllerApplet::ReconfigureControllers(std::function<void()> callb
                     npad.MapSettingsTypeToNPad(Settings::ControllerType::RightJoycon), index);
             }
         } else if (index == 0 && parameters.enable_single_mode && parameters.allow_handheld &&
-                   !Settings::values.use_docked_mode) {
+                   !Settings::values.use_docked_mode.GetValue()) {
             // We should *never* reach here under any normal circumstances.
             npad.AddNewControllerAt(npad.MapSettingsTypeToNPad(Settings::ControllerType::Handheld),
                                     index);
diff --git a/src/core/frontend/applets/controller.h b/src/core/frontend/applets/controller.h
index a227f15cd..dff71d8d9 100644
--- a/src/core/frontend/applets/controller.h
+++ b/src/core/frontend/applets/controller.h
@@ -8,6 +8,10 @@
 
 #include "common/common_types.h"
 
+namespace Service::SM {
+class ServiceManager;
+}
+
 namespace Core::Frontend {
 
 using BorderColor = std::array<u8, 4>;
@@ -34,15 +38,19 @@ public:
     virtual ~ControllerApplet();
 
     virtual void ReconfigureControllers(std::function<void()> callback,
-                                        ControllerParameters parameters) const = 0;
+                                        const ControllerParameters& parameters) const = 0;
 };
 
 class DefaultControllerApplet final : public ControllerApplet {
 public:
+    explicit DefaultControllerApplet(Service::SM::ServiceManager& service_manager_);
     ~DefaultControllerApplet() override;
 
     void ReconfigureControllers(std::function<void()> callback,
-                                ControllerParameters parameters) const override;
+                                const ControllerParameters& parameters) const override;
+
+private:
+    Service::SM::ServiceManager& service_manager;
 };
 
 } // namespace Core::Frontend
diff --git a/src/core/frontend/applets/error.cpp b/src/core/frontend/applets/error.cpp
index 4002a9211..dceb20ff8 100644
--- a/src/core/frontend/applets/error.cpp
+++ b/src/core/frontend/applets/error.cpp
@@ -2,6 +2,7 @@
 // Licensed under GPLv2 or any later version
 // Refer to the license.txt file included.
 
+#include "common/logging/log.h"
 #include "core/frontend/applets/error.h"
 
 namespace Core::Frontend {
@@ -10,7 +11,7 @@ ErrorApplet::~ErrorApplet() = default;
 
 void DefaultErrorApplet::ShowError(ResultCode error, std::function<void()> finished) const {
     LOG_CRITICAL(Service_Fatal, "Application requested error display: {:04}-{:04} (raw={:08X})",
-                 static_cast<u32>(error.module.Value()), error.description.Value(), error.raw);
+                 error.module.Value(), error.description.Value(), error.raw);
 }
 
 void DefaultErrorApplet::ShowErrorWithTimestamp(ResultCode error, std::chrono::seconds time,
@@ -18,7 +19,7 @@ void DefaultErrorApplet::ShowErrorWithTimestamp(ResultCode error, std::chrono::s
     LOG_CRITICAL(
         Service_Fatal,
         "Application requested error display: {:04X}-{:04X} (raw={:08X}) with timestamp={:016X}",
-        static_cast<u32>(error.module.Value()), error.description.Value(), error.raw, time.count());
+        error.module.Value(), error.description.Value(), error.raw, time.count());
 }
 
 void DefaultErrorApplet::ShowCustomErrorText(ResultCode error, std::string main_text,
@@ -26,7 +27,7 @@ void DefaultErrorApplet::ShowCustomErrorText(ResultCode error, std::string main_
                                              std::function<void()> finished) const {
     LOG_CRITICAL(Service_Fatal,
                  "Application requested custom error with error_code={:04X}-{:04X} (raw={:08X})",
-                 static_cast<u32>(error.module.Value()), error.description.Value(), error.raw);
+                 error.module.Value(), error.description.Value(), error.raw);
     LOG_CRITICAL(Service_Fatal, "    Main Text: {}", main_text);
     LOG_CRITICAL(Service_Fatal, "    Detail Text: {}", detail_text);
 }
diff --git a/src/core/frontend/applets/general_frontend.cpp b/src/core/frontend/applets/general_frontend.cpp
index c30b36de7..7483ffb76 100644
--- a/src/core/frontend/applets/general_frontend.cpp
+++ b/src/core/frontend/applets/general_frontend.cpp
@@ -53,72 +53,4 @@ void DefaultPhotoViewerApplet::ShowAllPhotos(std::function<void()> finished) con
     finished();
 }
 
-ECommerceApplet::~ECommerceApplet() = default;
-
-DefaultECommerceApplet::~DefaultECommerceApplet() = default;
-
-void DefaultECommerceApplet::ShowApplicationInformation(
-    std::function<void()> finished, u64 title_id, std::optional<u128> user_id,
-    std::optional<bool> full_display, std::optional<std::string> extra_parameter) {
-    const auto value = user_id.value_or(u128{});
-    LOG_INFO(Service_AM,
-             "Application requested frontend show application information for EShop, "
-             "title_id={:016X}, user_id={:016X}{:016X}, full_display={}, extra_parameter={}",
-             title_id, value[1], value[0],
-             full_display.has_value() ? fmt::format("{}", *full_display) : "null",
-             extra_parameter.value_or("null"));
-    finished();
-}
-
-void DefaultECommerceApplet::ShowAddOnContentList(std::function<void()> finished, u64 title_id,
-                                                  std::optional<u128> user_id,
-                                                  std::optional<bool> full_display) {
-    const auto value = user_id.value_or(u128{});
-    LOG_INFO(Service_AM,
-             "Application requested frontend show add on content list for EShop, "
-             "title_id={:016X}, user_id={:016X}{:016X}, full_display={}",
-             title_id, value[1], value[0],
-             full_display.has_value() ? fmt::format("{}", *full_display) : "null");
-    finished();
-}
-
-void DefaultECommerceApplet::ShowSubscriptionList(std::function<void()> finished, u64 title_id,
-                                                  std::optional<u128> user_id) {
-    const auto value = user_id.value_or(u128{});
-    LOG_INFO(Service_AM,
-             "Application requested frontend show subscription list for EShop, title_id={:016X}, "
-             "user_id={:016X}{:016X}",
-             title_id, value[1], value[0]);
-    finished();
-}
-
-void DefaultECommerceApplet::ShowConsumableItemList(std::function<void()> finished, u64 title_id,
-                                                    std::optional<u128> user_id) {
-    const auto value = user_id.value_or(u128{});
-    LOG_INFO(
-        Service_AM,
-        "Application requested frontend show consumable item list for EShop, title_id={:016X}, "
-        "user_id={:016X}{:016X}",
-        title_id, value[1], value[0]);
-    finished();
-}
-
-void DefaultECommerceApplet::ShowShopHome(std::function<void()> finished, u128 user_id,
-                                          bool full_display) {
-    LOG_INFO(Service_AM,
-             "Application requested frontend show home menu for EShop, user_id={:016X}{:016X}, "
-             "full_display={}",
-             user_id[1], user_id[0], full_display);
-    finished();
-}
-
-void DefaultECommerceApplet::ShowSettings(std::function<void()> finished, u128 user_id,
-                                          bool full_display) {
-    LOG_INFO(Service_AM,
-             "Application requested frontend show settings menu for EShop, user_id={:016X}{:016X}, "
-             "full_display={}",
-             user_id[1], user_id[0], full_display);
-    finished();
-}
-
 } // namespace Core::Frontend
diff --git a/src/core/frontend/applets/general_frontend.h b/src/core/frontend/applets/general_frontend.h
index 4b63f828e..b713b14ee 100644
--- a/src/core/frontend/applets/general_frontend.h
+++ b/src/core/frontend/applets/general_frontend.h
@@ -58,55 +58,4 @@ public:
     void ShowAllPhotos(std::function<void()> finished) const override;
 };
 
-class ECommerceApplet {
-public:
-    virtual ~ECommerceApplet();
-
-    // Shows a page with application icons, description, name, and price.
-    virtual void ShowApplicationInformation(std::function<void()> finished, u64 title_id,
-                                            std::optional<u128> user_id = {},
-                                            std::optional<bool> full_display = {},
-                                            std::optional<std::string> extra_parameter = {}) = 0;
-
-    // Shows a page with all of the add on content available for a game, with name, description, and
-    // price.
-    virtual void ShowAddOnContentList(std::function<void()> finished, u64 title_id,
-                                      std::optional<u128> user_id = {},
-                                      std::optional<bool> full_display = {}) = 0;
-
-    // Shows a page with all of the subscriptions (recurring payments) for a game, with name,
-    // description, price, and renewal period.
-    virtual void ShowSubscriptionList(std::function<void()> finished, u64 title_id,
-                                      std::optional<u128> user_id = {}) = 0;
-
-    // Shows a page with a list of any additional game related purchasable items (DLC,
-    // subscriptions, etc) for a particular game, with name, description, type, and price.
-    virtual void ShowConsumableItemList(std::function<void()> finished, u64 title_id,
-                                        std::optional<u128> user_id = {}) = 0;
-
-    // Shows the home page of the shop.
-    virtual void ShowShopHome(std::function<void()> finished, u128 user_id, bool full_display) = 0;
-
-    // Shows the user settings page of the shop.
-    virtual void ShowSettings(std::function<void()> finished, u128 user_id, bool full_display) = 0;
-};
-
-class DefaultECommerceApplet : public ECommerceApplet {
-public:
-    ~DefaultECommerceApplet() override;
-
-    void ShowApplicationInformation(std::function<void()> finished, u64 title_id,
-                                    std::optional<u128> user_id, std::optional<bool> full_display,
-                                    std::optional<std::string> extra_parameter) override;
-    void ShowAddOnContentList(std::function<void()> finished, u64 title_id,
-                              std::optional<u128> user_id,
-                              std::optional<bool> full_display) override;
-    void ShowSubscriptionList(std::function<void()> finished, u64 title_id,
-                              std::optional<u128> user_id) override;
-    void ShowConsumableItemList(std::function<void()> finished, u64 title_id,
-                                std::optional<u128> user_id) override;
-    void ShowShopHome(std::function<void()> finished, u128 user_id, bool full_display) override;
-    void ShowSettings(std::function<void()> finished, u128 user_id, bool full_display) override;
-};
-
 } // namespace Core::Frontend
diff --git a/src/core/frontend/applets/web_browser.cpp b/src/core/frontend/applets/web_browser.cpp
index 528295ffc..50db6a654 100644
--- a/src/core/frontend/applets/web_browser.cpp
+++ b/src/core/frontend/applets/web_browser.cpp
@@ -11,14 +11,22 @@ WebBrowserApplet::~WebBrowserApplet() = default;
 
 DefaultWebBrowserApplet::~DefaultWebBrowserApplet() = default;
 
-void DefaultWebBrowserApplet::OpenPageLocal(std::string_view filename,
-                                            std::function<void()> unpack_romfs_callback,
-                                            std::function<void()> finished_callback) {
-    LOG_INFO(Service_AM,
-             "(STUBBED) called - No suitable web browser implementation found to open website page "
-             "at '{}'!",
-             filename);
-    finished_callback();
+void DefaultWebBrowserApplet::OpenLocalWebPage(
+    std::string_view local_url, std::function<void()> extract_romfs_callback,
+    std::function<void(Service::AM::Applets::WebExitReason, std::string)> callback) const {
+    LOG_WARNING(Service_AM, "(STUBBED) called, backend requested to open local web page at {}",
+                local_url);
+
+    callback(Service::AM::Applets::WebExitReason::WindowClosed, "http://localhost/");
+}
+
+void DefaultWebBrowserApplet::OpenExternalWebPage(
+    std::string_view external_url,
+    std::function<void(Service::AM::Applets::WebExitReason, std::string)> callback) const {
+    LOG_WARNING(Service_AM, "(STUBBED) called, backend requested to open external web page at {}",
+                external_url);
+
+    callback(Service::AM::Applets::WebExitReason::WindowClosed, "http://localhost/");
 }
 
 } // namespace Core::Frontend
diff --git a/src/core/frontend/applets/web_browser.h b/src/core/frontend/applets/web_browser.h
index 110e33bc4..1c5ef19a9 100644
--- a/src/core/frontend/applets/web_browser.h
+++ b/src/core/frontend/applets/web_browser.h
@@ -7,22 +7,34 @@
 #include <functional>
 #include <string_view>
 
+#include "core/hle/service/am/applets/web_types.h"
+
 namespace Core::Frontend {
 
 class WebBrowserApplet {
 public:
     virtual ~WebBrowserApplet();
 
-    virtual void OpenPageLocal(std::string_view url, std::function<void()> unpack_romfs_callback,
-                               std::function<void()> finished_callback) = 0;
+    virtual void OpenLocalWebPage(
+        std::string_view local_url, std::function<void()> extract_romfs_callback,
+        std::function<void(Service::AM::Applets::WebExitReason, std::string)> callback) const = 0;
+
+    virtual void OpenExternalWebPage(
+        std::string_view external_url,
+        std::function<void(Service::AM::Applets::WebExitReason, std::string)> callback) const = 0;
 };
 
 class DefaultWebBrowserApplet final : public WebBrowserApplet {
 public:
     ~DefaultWebBrowserApplet() override;
 
-    void OpenPageLocal(std::string_view url, std::function<void()> unpack_romfs_callback,
-                       std::function<void()> finished_callback) override;
+    void OpenLocalWebPage(std::string_view local_url, std::function<void()> extract_romfs_callback,
+                          std::function<void(Service::AM::Applets::WebExitReason, std::string)>
+                              callback) const override;
+
+    void OpenExternalWebPage(std::string_view external_url,
+                             std::function<void(Service::AM::Applets::WebExitReason, std::string)>
+                                 callback) const override;
 };
 
 } // namespace Core::Frontend
diff --git a/src/core/frontend/emu_window.cpp b/src/core/frontend/emu_window.cpp
index 9a081fbd4..8c1193894 100644
--- a/src/core/frontend/emu_window.cpp
+++ b/src/core/frontend/emu_window.cpp
@@ -84,10 +84,12 @@ void EmuWindow::TouchPressed(unsigned framebuffer_x, unsigned framebuffer_y) {
         return;
 
     std::lock_guard guard{touch_state->mutex};
-    touch_state->touch_x = static_cast<float>(framebuffer_x - framebuffer_layout.screen.left) /
-                           (framebuffer_layout.screen.right - framebuffer_layout.screen.left);
-    touch_state->touch_y = static_cast<float>(framebuffer_y - framebuffer_layout.screen.top) /
-                           (framebuffer_layout.screen.bottom - framebuffer_layout.screen.top);
+    touch_state->touch_x =
+        static_cast<float>(framebuffer_x - framebuffer_layout.screen.left) /
+        static_cast<float>(framebuffer_layout.screen.right - framebuffer_layout.screen.left);
+    touch_state->touch_y =
+        static_cast<float>(framebuffer_y - framebuffer_layout.screen.top) /
+        static_cast<float>(framebuffer_layout.screen.bottom - framebuffer_layout.screen.top);
 
     touch_state->touch_pressed = true;
 }
diff --git a/src/core/frontend/emu_window.h b/src/core/frontend/emu_window.h
index 3e8780243..276d2b906 100644
--- a/src/core/frontend/emu_window.h
+++ b/src/core/frontend/emu_window.h
@@ -102,8 +102,8 @@ public:
         float render_surface_scale = 1.0f;
     };
 
-    /// Polls window events
-    virtual void PollEvents() = 0;
+    /// Called from GPU thread when a frame is displayed.
+    virtual void OnFrameDisplayed() {}
 
     /**
      * Returns a GraphicsContext that the frontend provides to be used for rendering.
diff --git a/src/core/frontend/framebuffer_layout.cpp b/src/core/frontend/framebuffer_layout.cpp
index c1fbc235b..b9a270a55 100644
--- a/src/core/frontend/framebuffer_layout.cpp
+++ b/src/core/frontend/framebuffer_layout.cpp
@@ -14,8 +14,8 @@ namespace Layout {
 template <class T>
 static Common::Rectangle<T> MaxRectangle(Common::Rectangle<T> window_area,
                                          float screen_aspect_ratio) {
-    float scale = std::min(static_cast<float>(window_area.GetWidth()),
-                           window_area.GetHeight() / screen_aspect_ratio);
+    const float scale = std::min(static_cast<float>(window_area.GetWidth()),
+                                 static_cast<float>(window_area.GetHeight()) / screen_aspect_ratio);
     return Common::Rectangle<T>{0, 0, static_cast<T>(std::round(scale)),
                                 static_cast<T>(std::round(scale * screen_aspect_ratio))};
 }
@@ -27,7 +27,7 @@ FramebufferLayout DefaultFrameLayout(u32 width, u32 height) {
     // so just calculate them both even if the other isn't showing.
     FramebufferLayout res{width, height, false, {}};
 
-    const float window_aspect_ratio = static_cast<float>(height) / width;
+    const float window_aspect_ratio = static_cast<float>(height) / static_cast<float>(width);
     const float emulation_aspect_ratio = EmulationAspectRatio(
         static_cast<AspectRatio>(Settings::values.aspect_ratio.GetValue()), window_aspect_ratio);
 
@@ -47,7 +47,7 @@ FramebufferLayout DefaultFrameLayout(u32 width, u32 height) {
 FramebufferLayout FrameLayoutFromResolutionScale(u32 res_scale) {
     u32 width, height;
 
-    if (Settings::values.use_docked_mode) {
+    if (Settings::values.use_docked_mode.GetValue()) {
         width = ScreenDocked::Width * res_scale;
         height = ScreenDocked::Height * res_scale;
     } else {
diff --git a/src/core/frontend/input.h b/src/core/frontend/input.h
index 9da0d2829..de51a754e 100644
--- a/src/core/frontend/input.h
+++ b/src/core/frontend/input.h
@@ -30,7 +30,12 @@ public:
     virtual StatusType GetStatus() const {
         return {};
     }
-    virtual bool GetAnalogDirectionStatus(AnalogDirection direction) const {
+    virtual bool GetAnalogDirectionStatus([[maybe_unused]] AnalogDirection direction) const {
+        return {};
+    }
+    virtual bool SetRumblePlay([[maybe_unused]] f32 amp_low, [[maybe_unused]] f32 freq_low,
+                               [[maybe_unused]] f32 amp_high,
+                               [[maybe_unused]] f32 freq_high) const {
         return {};
     }
 };
@@ -119,6 +124,13 @@ using ButtonDevice = InputDevice<bool>;
 using AnalogDevice = InputDevice<std::tuple<float, float>>;
 
 /**
+ * A vibration device is an input device that returns an unsigned byte as status.
+ * It represents whether the vibration device supports vibration or not.
+ * If the status returns 1, it supports vibration. Otherwise, it does not support vibration.
+ */
+using VibrationDevice = InputDevice<u8>;
+
+/**
  * A motion status is an object that returns a tuple of accelerometer state vector,
  * gyroscope state vector, rotation state vector and orientation state matrix.
  *
@@ -151,10 +163,15 @@ using MotionStatus = std::tuple<Common::Vec3<float>, Common::Vec3<float>, Common
 using MotionDevice = InputDevice<MotionStatus>;
 
 /**
- * A touch device is an input device that returns a tuple of two floats and a bool. The floats are
+ * A touch status is an object that returns a tuple of two floats and a bool. The floats are
  * x and y coordinates in the range 0.0 - 1.0, and the bool indicates whether it is pressed.
  */
-using TouchDevice = InputDevice<std::tuple<float, float, bool>>;
+using TouchStatus = std::tuple<float, float, bool>;
+
+/**
+ * A touch device is an input device that returns a touch status object
+ */
+using TouchDevice = InputDevice<TouchStatus>;
 
 /**
  * A mouse device is an input device that returns a tuple of two floats and four ints.
diff --git a/src/core/frontend/input_interpreter.cpp b/src/core/frontend/input_interpreter.cpp
new file mode 100644
index 000000000..66ae506cd
--- /dev/null
+++ b/src/core/frontend/input_interpreter.cpp
@@ -0,0 +1,45 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/core.h"
+#include "core/frontend/input_interpreter.h"
+#include "core/hle/service/hid/controllers/npad.h"
+#include "core/hle/service/hid/hid.h"
+#include "core/hle/service/sm/sm.h"
+
+InputInterpreter::InputInterpreter(Core::System& system)
+    : npad{system.ServiceManager()
+               .GetService<Service::HID::Hid>("hid")
+               ->GetAppletResource()
+               ->GetController<Service::HID::Controller_NPad>(Service::HID::HidController::NPad)} {}
+
+InputInterpreter::~InputInterpreter() = default;
+
+void InputInterpreter::PollInput() {
+    const u32 button_state = npad.GetAndResetPressState();
+
+    previous_index = current_index;
+    current_index = (current_index + 1) % button_states.size();
+
+    button_states[current_index] = button_state;
+}
+
+bool InputInterpreter::IsButtonPressedOnce(HIDButton button) const {
+    const bool current_press =
+        (button_states[current_index] & (1U << static_cast<u8>(button))) != 0;
+    const bool previous_press =
+        (button_states[previous_index] & (1U << static_cast<u8>(button))) != 0;
+
+    return current_press && !previous_press;
+}
+
+bool InputInterpreter::IsButtonHeld(HIDButton button) const {
+    u32 held_buttons{button_states[0]};
+
+    for (std::size_t i = 1; i < button_states.size(); ++i) {
+        held_buttons &= button_states[i];
+    }
+
+    return (held_buttons & (1U << static_cast<u8>(button))) != 0;
+}
diff --git a/src/core/frontend/input_interpreter.h b/src/core/frontend/input_interpreter.h
new file mode 100644
index 000000000..fea9aebe6
--- /dev/null
+++ b/src/core/frontend/input_interpreter.h
@@ -0,0 +1,120 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <array>
+
+#include "common/common_types.h"
+
+namespace Core {
+class System;
+}
+
+namespace Service::HID {
+class Controller_NPad;
+}
+
+enum class HIDButton : u8 {
+    A,
+    B,
+    X,
+    Y,
+    LStick,
+    RStick,
+    L,
+    R,
+    ZL,
+    ZR,
+    Plus,
+    Minus,
+
+    DLeft,
+    DUp,
+    DRight,
+    DDown,
+
+    LStickLeft,
+    LStickUp,
+    LStickRight,
+    LStickDown,
+
+    RStickLeft,
+    RStickUp,
+    RStickRight,
+    RStickDown,
+
+    LeftSL,
+    LeftSR,
+
+    RightSL,
+    RightSR,
+};
+
+/**
+ * The InputInterpreter class interfaces with HID to retrieve button press states.
+ * Input is intended to be polled every 50ms so that a button is considered to be
+ * held down after 400ms has elapsed since the initial button press and subsequent
+ * repeated presses occur every 50ms.
+ */
+class InputInterpreter {
+public:
+    explicit InputInterpreter(Core::System& system);
+    virtual ~InputInterpreter();
+
+    /// Gets a button state from HID and inserts it into the array of button states.
+    void PollInput();
+
+    /**
+     * The specified button is considered to be pressed once
+     * if it is currently pressed and not pressed previously.
+     *
+     * @param button The button to check.
+     *
+     * @returns True when the button is pressed once.
+     */
+    [[nodiscard]] bool IsButtonPressedOnce(HIDButton button) const;
+
+    /**
+     * Checks whether any of the buttons in the parameter list is pressed once.
+     *
+     * @tparam HIDButton The buttons to check.
+     *
+     * @returns True when at least one of the buttons is pressed once.
+     */
+    template <HIDButton... T>
+    [[nodiscard]] bool IsAnyButtonPressedOnce() {
+        return (IsButtonPressedOnce(T) || ...);
+    }
+
+    /**
+     * The specified button is considered to be held down if it is pressed in all 9 button states.
+     *
+     * @param button The button to check.
+     *
+     * @returns True when the button is held down.
+     */
+    [[nodiscard]] bool IsButtonHeld(HIDButton button) const;
+
+    /**
+     * Checks whether any of the buttons in the parameter list is held down.
+     *
+     * @tparam HIDButton The buttons to check.
+     *
+     * @returns True when at least one of the buttons is held down.
+     */
+    template <HIDButton... T>
+    [[nodiscard]] bool IsAnyButtonHeld() {
+        return (IsButtonHeld(T) || ...);
+    }
+
+private:
+    Service::HID::Controller_NPad& npad;
+
+    /// Stores 9 consecutive button states polled from HID.
+    std::array<u32, 9> button_states{};
+
+    std::size_t previous_index{};
+    std::size_t current_index{};
+};