Qt: Rough deadzone estimation

CHANGES

@@ -8,6 +8,7 @@ Features:
  - Rewind now shows the frame after rewinding
  - Import/Export of GameShark/Action Replay snapshots
  - Add "Step backwards" item for single increment rewind
+ - Deadzone estimation for game controllers
 Bugfixes:
  - GBA: Fix timers not updating timing when writing to only the reload register
  - All: Fix sanitize-deb script not cleaning up after itself

src/platform/qt/GBAKeyEditor.cpp

@@ -47,9 +47,10 @@ GBAKeyEditor::GBAKeyEditor(InputController* controller, int type, const QString&
 	refresh();
 
 #ifdef BUILD_SDL
-	lookupAxes(map);
-
 	if (type == SDL_BINDING_BUTTON) {
+		controller->recalibrateAxes();
+		lookupAxes(map);
+
 		m_profileSelect = new QComboBox(this);
 		m_profileSelect->addItems(controller->connectedGamepads(type));
 		int activeGamepad = controller->gamepad(type);
@@ -61,6 +62,7 @@ GBAKeyEditor::GBAKeyEditor(InputController* controller, int type, const QString&
 			m_controller->setGamepad(m_type, i);
 			m_profile = m_profileSelect->currentText();
 			m_controller->loadProfile(m_type, m_profile);
+			m_controller->recalibrateAxes();
 			refresh();
 		});
 	}

src/platform/qt/InputController.cpp

@@ -226,14 +226,27 @@ QSet<int> InputController::activeGamepadButtons() {
 	return activeButtons;
 }
 
+void InputController::recalibrateAxes() {
+	SDL_Joystick* joystick = m_sdlPlayer.joystick;
+	SDL_JoystickUpdate();
+	int numAxes = SDL_JoystickNumAxes(joystick);
+	m_deadzones.resize(numAxes);
+	int i;
+	for (i = 0; i < numAxes; ++i) {
+		m_deadzones[i] = SDL_JoystickGetAxis(joystick, i);
+	}
+}
+
 QSet<QPair<int, GamepadAxisEvent::Direction>> InputController::activeGamepadAxes() {
 	SDL_Joystick* joystick = m_sdlPlayer.joystick;
 	SDL_JoystickUpdate();
-	int numButtons = SDL_JoystickNumAxes(joystick);
+	int numAxes = SDL_JoystickNumAxes(joystick);
+	m_deadzones.resize(numAxes);
 	QSet<QPair<int, GamepadAxisEvent::Direction>> activeAxes;
 	int i;
-	for (i = 0; i < numButtons; ++i) {
+	for (i = 0; i < numAxes; ++i) {
 		int32_t axis = SDL_JoystickGetAxis(joystick, i);
+		axis -= m_deadzones[i];
 		if (axis >= AXIS_THRESHOLD || axis <= -AXIS_THRESHOLD) {
 			activeAxes.insert(qMakePair(i, axis > 0 ? GamepadAxisEvent::POSITIVE : GamepadAxisEvent::NEGATIVE));
 		}
@@ -250,11 +263,11 @@ void InputController::bindAxis(uint32_t type, int axis, GamepadAxisEvent::Direct
 	switch (direction) {
 	case GamepadAxisEvent::NEGATIVE:
 		description.lowDirection = key;
-		description.deadLow = -AXIS_THRESHOLD;
+		description.deadLow = m_deadzones[axis] - AXIS_THRESHOLD;
 		break;
 	case GamepadAxisEvent::POSITIVE:
 		description.highDirection = key;
-		description.deadHigh = AXIS_THRESHOLD;
+		description.deadHigh = m_deadzones[axis] + AXIS_THRESHOLD;
 		break;
 	default:
 		return;

src/platform/qt/InputController.h

@@ -10,6 +10,7 @@
 
 #include <QObject>
 #include <QSet>
+#include <QVector>
 
 class QTimer;
 
@@ -56,6 +57,7 @@ public:
 	int testSDLEvents();
 	QSet<int> activeGamepadButtons();
 	QSet<QPair<int, GamepadAxisEvent::Direction>> activeGamepadAxes();
+	void recalibrateAxes();
 
 	void bindAxis(uint32_t type, int axis, GamepadAxisEvent::Direction, GBAKey);
 
@@ -84,6 +86,7 @@ private:
 	static GBASDLEvents s_sdlEvents;
 	GBASDLPlayer m_sdlPlayer;
 	bool m_playerAttached;
+	QVector<int> m_deadzones;
 #endif
 
 	QSet<int> m_activeButtons;