SDL2: Load game controller mappings and utilize game controller if available

qgcresources.qrc

@@ -247,6 +247,9 @@
         <file alias="joystickThrottleUp.png">resources/calibration/joystick/joystickThrottleUp.png</file>
         <file alias="joystickThrottleDown.png">resources/calibration/joystick/joystickThrottleDown.png</file>
     </qresource>
+    <qresource prefix="/db/mapping/joystick">
+        <file alias="gamecontrollerdb.txt">resources/SDL_GameControllerDB/gamecontrollerdb.txt</file>
+    </qresource>
     <qresource prefix="/res/styles">
         <file alias="style-dark.css">resources/styles/style-dark.css</file>
         <file alias="style-light.css">resources/styles/style-light.css</file>

src/Joystick/JoystickSDL.cc

@@ -3,9 +3,11 @@
 #include "QGCApplication.h"
 
 #include <QQmlEngine>
+#include <QTextStream>
 
-JoystickSDL::JoystickSDL(const QString& name, int axisCount, int buttonCount, int hatCount, int index, MultiVehicleManager* multiVehicleManager)
+JoystickSDL::JoystickSDL(const QString& name, int axisCount, int buttonCount, int hatCount, int index, bool isGameController, MultiVehicleManager* multiVehicleManager)
     : Joystick(name,axisCount,buttonCount,hatCount,multiVehicleManager)
+    , _isGameController(isGameController)
     , _index(index)
 {
 }
@@ -13,11 +15,13 @@ JoystickSDL::JoystickSDL(const QString& name, int axisCount, int buttonCount, in
 QMap<QString, Joystick*> JoystickSDL::discover(MultiVehicleManager* _multiVehicleManager) {
     static QMap<QString, Joystick*> ret;
 
-    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK | SDL_INIT_NOPARACHUTE) < 0) {
+    if (SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER | SDL_INIT_NOPARACHUTE) < 0) {
         qWarning() << "Couldn't initialize SimpleDirectMediaLayer:" << SDL_GetError();
         return ret;
     }
 
+    _loadGameControllerMappings();
+
     // Load available joysticks
 
     qCDebug(JoystickLog) << "Available joysticks";
@@ -25,26 +29,27 @@ QMap<QString, Joystick*> JoystickSDL::discover(MultiVehicleManager* _multiVehicl
     for (int i=0; i<SDL_NumJoysticks(); i++) {
         QString name = SDL_JoystickNameForIndex(i);
 
-        if (SDL_IsGameController(i)) {
-            qDebug() << name << "supports SDL GameController!";
-        } else {
-            qDebug() << name << "DOES NOT support SDL GameController!";
-        }
-
-        SDL_GameController* sdlController = SDL_GameControllerOpen(i);
-        qDebug() << SDL_GetError();
-
         if (!ret.contains(name)) {
             int axisCount, buttonCount, hatCount;
+            bool isGameController;
 
             SDL_Joystick* sdlJoystick = SDL_JoystickOpen(i);
+            if (SDL_IsGameController(i)) {
+                isGameController = true;
+                axisCount = SDL_CONTROLLER_AXIS_MAX;
+                buttonCount = SDL_CONTROLLER_BUTTON_MAX;
+                hatCount = 0;
+            } else {
+                isGameController = false;
                 axisCount = SDL_JoystickNumAxes(sdlJoystick);
                 buttonCount = SDL_JoystickNumButtons(sdlJoystick);
                 hatCount = SDL_JoystickNumHats(sdlJoystick);
+            }
+
             SDL_JoystickClose(sdlJoystick);
 
             qCDebug(JoystickLog) << "\t" << name << "axes:" << axisCount << "buttons:" << buttonCount << "hats:" << hatCount;
-            ret[name] = new JoystickSDL(name, axisCount, buttonCount, hatCount, i, _multiVehicleManager);
+            ret[name] = new JoystickSDL(name, axisCount, buttonCount, hatCount, i, isGameController, _multiVehicleManager);
         } else {
             qCDebug(JoystickLog) << "\tSkipping duplicate" << name;
         }
@@ -52,8 +57,28 @@ QMap<QString, Joystick*> JoystickSDL::discover(MultiVehicleManager* _multiVehicl
     return ret;
 }
 
+void JoystickSDL::_loadGameControllerMappings(void) {
+    QFile file(":/db/mapping/joystick/gamecontrollerdb.txt");
+    if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
+    {
+        qWarning() << "Couldn't load GameController mapping database.";
+        return;
+    }
+
+    QTextStream s(&file);
+
+    while (!s.atEnd()) {
+        SDL_GameControllerAddMapping(s.readLine().toStdString().c_str());
+    }
+}
+
 bool JoystickSDL::_open(void) {
+    if ( _isGameController ) {
+        sdlController = SDL_GameControllerOpen(_index);
+        sdlJoystick = SDL_GameControllerGetJoystick(sdlController);
+    } else {
         sdlJoystick = SDL_JoystickOpen(_index);
+    }
 
     if (!sdlJoystick) {
         qCWarning(JoystickLog) << "SDL_JoystickOpen failed:" << SDL_GetError();
@@ -70,15 +95,24 @@ void JoystickSDL::_close(void) {
 bool JoystickSDL::_update(void)
 {
     SDL_JoystickUpdate();
+    SDL_GameControllerUpdate();
     return true;
 }
 
 bool JoystickSDL::_getButton(int i) {
+    if ( _isGameController ) {
+        return !!SDL_GameControllerGetButton(sdlController, SDL_GameControllerButton(i));
+    } else {
         return !!SDL_JoystickGetButton(sdlJoystick, i);
+    }
 }
 
 int JoystickSDL::_getAxis(int i) {
+    if ( _isGameController ) {
+        return SDL_GameControllerGetAxis(sdlController, SDL_GameControllerAxis(i));
+    } else {
         return SDL_JoystickGetAxis(sdlJoystick, i);
+    }
 }
 
 uint8_t JoystickSDL::_getHat(int hat,int i) {

src/Joystick/JoystickSDL.h

@@ -15,11 +15,13 @@
 class JoystickSDL : public Joystick
 {
 public:
-    JoystickSDL(const QString& name, int axisCount, int buttonCount, int hatCount, int index, MultiVehicleManager* multiVehicleManager);
+    JoystickSDL(const QString& name, int axisCount, int buttonCount, int hatCount, int index, bool isGameController, MultiVehicleManager* multiVehicleManager);
 
     static QMap<QString, Joystick*> discover(MultiVehicleManager* _multiVehicleManager); 
 
 private:
+    static void _loadGameControllerMappings();
+
     bool _open() final;
     void _close() final;
     bool _update() final;
@@ -29,6 +31,8 @@ private:
     uint8_t _getHat(int hat,int i) final;
 
     SDL_Joystick *sdlJoystick;
+    SDL_GameController *sdlController;
+    bool    _isGameController;
     int     _index;      ///< Index for SDL_JoystickOpen
 };