Add LR triggers as axes, half press to initiate a press, add GC axis id in config, clarify some code blocks for better readability

src/input_common/gcadapter/gc_adapter.cpp

@@ -144,6 +144,18 @@ void Adapter::Read() {
                     pads[port].axis_value = pads[port].substick_y;
                     pad_queue[port].Push(pads[port]);
                 }
+                if (pads[port].trigger_left > pads[port].TRIGGER_CENTER + pads[port].THRESHOLD ||
+                    pads[port].trigger_left < pads[port].TRIGGER_CENTER - pads[port].THRESHOLD) {
+                    pads[port].axis = GCAdapter::PadAxes::TriggerLeft;
+                    pads[port].axis_value = pads[port].trigger_left;
+                    pad_queue[port].Push(pads[port]);
+                }
+                if (pads[port].trigger_right > pads[port].TRIGGER_CENTER + pads[port].THRESHOLD ||
+                    pads[port].trigger_right < pads[port].TRIGGER_CENTER - pads[port].THRESHOLD) {
+                    pads[port].axis = GCAdapter::PadAxes::TriggerRight;
+                    pads[port].axis_value = pads[port].trigger_right;
+                    pad_queue[port].Push(pads[port]);
+                }
             }
             PadToState(pads[port], state[port]);
         }

src/input_common/gcadapter/gc_poller.cpp

@@ -34,7 +34,13 @@ public:
     explicit GCAxisButton(int port_, int axis_, float threshold_, bool trigger_if_greater_,
                           GCAdapter::Adapter* adapter)
         : port(port_), axis(axis_), threshold(threshold_), trigger_if_greater(trigger_if_greater_),
-          gcadapter(adapter) {}
+          gcadapter(adapter) {
+        // L/R triggers range is only in positive direction beginning near 0
+        // 0.0 threshold equates to near half trigger press, but threshold accounts for variability.
+        if (axis > 3) {
+            threshold *= -0.5;
+        }
+    }
 
     bool GetStatus() const override {
         const float axis_value = (gcadapter->GetPadState()[port].axes.at(axis) - 128.0f) / 128.0f;
@@ -60,10 +66,20 @@ GCButton::~GCButton() = default;
 std::unique_ptr<Input::ButtonDevice> GCButtonFactory::Create(const Common::ParamPackage& params) {
     const int button_id = params.Get("button", 0);
     const int port = params.Get("port", 0);
+
+    constexpr int PAD_STICK_ID = static_cast<u16>(GCAdapter::PadButton::PAD_STICK);
+
+    // button is not an axis/stick button
+    if (button_id != PAD_STICK_ID) {
+        std::unique_ptr<GCButton> button =
+            std::make_unique<GCButton>(port, button_id, params.Get("axis", 0), adapter.get());
+        return std::move(button);
+    }
+
     // For Axis buttons, used by the binary sticks.
-    if (params.Has("axis")) {
+    if (button_id == PAD_STICK_ID) {
         const int axis = params.Get("axis", 0);
-        const float threshold = params.Get("threshold", 0.5f);
+        const float threshold = params.Get("threshold", 0.25f);
         const std::string direction_name = params.Get("direction", "");
         bool trigger_if_greater;
         if (direction_name == "+") {
@@ -77,10 +93,6 @@ std::unique_ptr<Input::ButtonDevice> GCButtonFactory::Create(const Common::Param
         return std::make_unique<GCAxisButton>(port, axis, threshold, trigger_if_greater,
                                               adapter.get());
     }
-
-    std::unique_ptr<GCButton> button =
-        std::make_unique<GCButton>(port, button_id, params.Get("axis", 0), adapter.get());
-    return std::move(button);
 }
 
 Common::ParamPackage GCButtonFactory::GetNextInput() {
@@ -106,10 +118,10 @@ Common::ParamPackage GCButtonFactory::GetNextInput() {
                 params.Set("button", static_cast<u16>(GCAdapter::PadButton::PAD_STICK));
                 if (pad.axis_value > 128) {
                     params.Set("direction", "+");
-                    params.Set("threshold", "0.5");
+                    params.Set("threshold", "0.25");
                 } else {
                     params.Set("direction", "-");
-                    params.Set("threshold", "-0.5");
+                    params.Set("threshold", "-0.25");
                 }
                 break;
             }
@@ -232,7 +244,7 @@ Common::ParamPackage GCAnalogFactory::GetNextInput() {
                 continue;
             }
             // An analog device needs two axes, so we need to store the axis for later and wait for
-            // a second SDL event. The axes also must be from the same joystick.
+            // a second input event. The axes also must be from the same joystick.
             const u8 axis = static_cast<u8>(pad.axis);
             if (analog_x_axis == -1) {
                 analog_x_axis = axis;

src/yuzu/configuration/configure_input_player.cpp

@@ -120,7 +120,7 @@ static QString AnalogToText(const Common::ParamPackage& param, const std::string
         return ButtonToText(Common::ParamPackage{param.Get(dir, "")});
     }
 
-    if (param.Get("engine", "") == "sdl" || param.Get("engine", "") == "gcpad") {
+    if (param.Get("engine", "") == "sdl") {
         if (dir == "modifier") {
             return QObject::tr("[unused]");
         }
@@ -140,6 +140,25 @@ static QString AnalogToText(const Common::ParamPackage& param, const std::string
         return {};
     }
 
+    if (param.Get("engine", "") == "gcpad") {
+        if (dir == "modifier") {
+            return QObject::tr("[unused]");
+        }
+
+        if (dir == "left" || dir == "right") {
+            const QString axis_x_str = QString::fromStdString(param.Get("axis_x", ""));
+
+            return QObject::tr("GC Axis %1").arg(axis_x_str);
+        }
+
+        if (dir == "up" || dir == "down") {
+            const QString axis_y_str = QString::fromStdString(param.Get("axis_y", ""));
+
+            return QObject::tr("GC Axis %1").arg(axis_y_str);
+        }
+
+        return {};
+    }
     return QObject::tr("[unknown]");
 }
 
@@ -262,24 +281,25 @@ ConfigureInputPlayer::ConfigureInputPlayer(QWidget* parent, std::size_t player_i
 
         button->setContextMenuPolicy(Qt::CustomContextMenu);
         connect(button, &QPushButton::clicked, [=] {
-            HandleClick(button_map[button_id],
-                        [=](Common::ParamPackage params) {
-                            // Workaround for ZL & ZR for analog triggers like on XBOX controllors.
-                            // Analog triggers (from controllers like the XBOX controller) would not
-                            // work due to a different range of their signals (from 0 to 255 on
-                            // analog triggers instead of -32768 to 32768 on analog joysticks). The
-                            // SDL driver misinterprets analog triggers as analog joysticks.
-                            // TODO: reinterpret the signal range for analog triggers to map the
-                            // values correctly. This is required for the correct emulation of the
-                            // analog triggers of the GameCube controller.
-                            if (button_id == Settings::NativeButton::ZL ||
-                                button_id == Settings::NativeButton::ZR) {
-                                params.Set("direction", "+");
-                                params.Set("threshold", "0.5");
-                            }
-                            buttons_param[button_id] = std::move(params);
-                        },
-                        InputCommon::Polling::DeviceType::Button);
+            HandleClick(
+                button_map[button_id],
+                [=](Common::ParamPackage params) {
+                    // Workaround for ZL & ZR for analog triggers like on XBOX controllors.
+                    // Analog triggers (from controllers like the XBOX controller) would not
+                    // work due to a different range of their signals (from 0 to 255 on
+                    // analog triggers instead of -32768 to 32768 on analog joysticks). The
+                    // SDL driver misinterprets analog triggers as analog joysticks.
+                    // TODO: reinterpret the signal range for analog triggers to map the
+                    // values correctly. This is required for the correct emulation of the
+                    // analog triggers of the GameCube controller.
+                    if (button_id == Settings::NativeButton::ZL ||
+                        button_id == Settings::NativeButton::ZR) {
+                        params.Set("direction", "+");
+                        params.Set("threshold", "0.5");
+                    }
+                    buttons_param[button_id] = std::move(params);
+                },
+                InputCommon::Polling::DeviceType::Button);
         });
         connect(button, &QPushButton::customContextMenuRequested, [=](const QPoint& menu_location) {
             QMenu context_menu;
@@ -305,12 +325,13 @@ ConfigureInputPlayer::ConfigureInputPlayer(QWidget* parent, std::size_t player_i
 
             analog_button->setContextMenuPolicy(Qt::CustomContextMenu);
             connect(analog_button, &QPushButton::clicked, [=]() {
-                HandleClick(analog_map_buttons[analog_id][sub_button_id],
-                            [=](const Common::ParamPackage& params) {
-                                SetAnalogButton(params, analogs_param[analog_id],
-                                                analog_sub_buttons[sub_button_id]);
-                            },
-                            InputCommon::Polling::DeviceType::Button);
+                HandleClick(
+                    analog_map_buttons[analog_id][sub_button_id],
+                    [=](const Common::ParamPackage& params) {
+                        SetAnalogButton(params, analogs_param[analog_id],
+                                        analog_sub_buttons[sub_button_id]);
+                    },
+                    InputCommon::Polling::DeviceType::Button);
             });
             connect(analog_button, &QPushButton::customContextMenuRequested,
                     [=](const QPoint& menu_location) {