Add special SDL2 joystick event system for input config

The SDL1.2 system cannot cope with Dualshock and similar controllers. After
pressing the config button, an random axis will be configured. This happens
because the state of the device (with 27 or more axis) changes all the time.

This problem can be avoided for these devices under Linux when SDL2 is used
together with its event system. These random movements doesn't anymore with
these joysticks and the hid_sony driver in SDL2+SDL_PollEvent.

This seem to be fixable with SDL1.2 because it just cannot handle newer
devices. Also the SDL_PollEvent doesn't work with the ctypes version of PySDL
for unknown reasons. Thus the implementation cannot be shared between SDL1.2
and SDL2.

To use the new input detection, m64py must be started with the sdl2 option and
a version of mupen64plus compiled against SDL2.

 $ m64py --sdl2

Author: Fayvel Victor

src/m64py/frontend/joystick.py

@@ -21,12 +21,15 @@
 
 from m64py.opts import SDL2
 from m64py.frontend.log import log
+import ctypes
 
 if SDL2:
     from m64py.SDL2 import SDL_WasInit, SDL_InitSubSystem, SDL_INIT_JOYSTICK
     from m64py.SDL2 import SDL_JoystickOpen, SDL_JoystickClose, SDL_NumJoysticks, SDL_JoystickNameForIndex
     from m64py.SDL2 import SDL_JoystickNumAxes, SDL_JoystickNumButtons, SDL_JoystickNumHats, SDL_JoystickNumBalls
-    from m64py.SDL2 import SDL_JoystickGetAxis, SDL_JoystickGetButton, SDL_JoystickGetHat, SDL_JoystickUpdate
+    from m64py.SDL2 import SDL_JoystickGetAxis, SDL_JoystickGetButton, SDL_JoystickGetHat, SDL_JoystickUpdate, SDL_JoystickInstanceID
+    from m64py.SDL2 import SDL_Event, SDL_PollEvent
+    from m64py.SDL2 import SDL_JOYAXISMOTION, SDL_JOYHATMOTION, SDL_JOYBALLMOTION, SDL_JOYBUTTONDOWN, SDL_JOYBUTTONUP
 else:
     from m64py.SDL import SDL_WasInit, SDL_InitSubSystem, SDL_INIT_JOYSTICK
     from m64py.SDL import SDL_JoystickOpen, SDL_JoystickClose, SDL_NumJoysticks, SDL_JoystickName
@@ -81,10 +84,20 @@ def init(self):
                         self.joystick_names.append(SDL_JoystickNameForIndex(i))
                     else:
                         self.joystick_names.append(SDL_JoystickName(i))
-                self.joystick_timer.timeout.connect(self.process_events)
+
+                if SDL2:
+                    self.joystick_timer.timeout.connect(self.process_events_sdl2)
+                else:
+                    self.joystick_timer.timeout.connect(self.process_events)
             else:
                 log.info("couldn't initialize SDL joystick support")
 
+    def clear_events(self):
+	if SDL2:
+            event = SDL_Event()
+            while SDL_PollEvent(ctypes.byref(event)) != 0:
+                pass
+
     def open(self, stick=0):
         if self.joystick:
             self.close()
@@ -114,6 +127,7 @@ def open(self, stick=0):
                 self.hats[i] = SDL_JoystickGetHat(self.joystick, i)
                 self.hat_repeat_timers[i] = QTime()
 
+            self.clear_events()
             self.joystick_timer.start(self.event_timeout)
             return True
         else:
@@ -181,3 +195,72 @@ def process_events(self):
             dx, dy = self.joystick.get_ball(i)
             if dx != 0 or dy != 0:
                 self.trackball_value_changed.emit(i, dx, dy)
+
+    def process_events_sdl2(self):
+        if not self.joystick:
+            return
+
+        stickid = SDL_JoystickInstanceID(self.joystick)
+        event = SDL_Event()
+        while SDL_PollEvent(ctypes.byref(event)) != 0:
+            if event.type == SDL_JOYAXISMOTION:
+                if stickid != event.jaxis.which:
+                    continue
+                moved = event.jaxis.value
+                i = event.jaxis.axis
+                if abs(moved) >= self.deadzones[i]:
+                    if moved != self.axes[i]:
+                        delta_moved = abs(self.axes[i] - moved)
+                        if delta_moved >= self.sensitivities[i]:
+                            self.axis_value_changed.emit(i, moved)
+                        self.axes[i] = moved
+                        self.axis_repeat_timers[i].restart()
+                    elif self.auto_repeat and moved != 0:
+                        if self.axis_repeat_timers[i].elapsed() >= self.auto_repeat_delay:
+                            self.axis_value_changed.emit(i, moved)
+                            self.axes[i] = moved
+                    else:
+                        self.axis_repeat_timers[i].restart()
+                else:
+                    self.axis_value_changed.emit(i, 0)
+
+            elif event.type == SDL_JOYHATMOTION:
+                if stickid != event.jhat.which:
+                    continue
+                changed = event.jhat.value
+                i = event.jhat.hat
+                if changed != self.hats[i]:
+                    self.hat_value_changed.emit(i, changed)
+                    self.hats[i] = changed
+                    self.hat_repeat_timers[i].restart()
+                elif self.auto_repeat and changed != 0:
+                    if self.hat_repeat_timers[i].elapsed() >= self.auto_repeat_delay:
+                        self.hat_value_changed.emit(i, changed)
+                        self.hats[i] = changed
+                else:
+                    self.hat_repeat_timers[i].restart()
+
+            elif event.type == SDL_JOYBALLMOTION:
+                if stickid != event.jball.which:
+                    continue
+                dx = event.jball.xrel
+                dy = event.jball.yrel
+                i = event.jball.ball
+                if dx != 0 or dy != 0:
+                    self.trackball_value_changed.emit(i, dx, dy)
+
+            elif event.type == SDL_JOYBUTTONDOWN or event.type == SDL_JOYBUTTONUP:
+                if stickid != event.jbutton.which:
+                    continue
+                changed = event.jbutton.state
+                i = event.jbutton.button
+                if changed != self.buttons[i]:
+                    self.button_value_changed.emit(i, changed)
+                    self.buttons[i] = changed
+                    self.button_repeat_timers[i].restart()
+                elif self.auto_repeat and changed != 0:
+                    if self.button_repeat_timers[i].elapsed() >= self.auto_repeat_delay:
+                        self.button_value_changed.emit(i, changed)
+                        self.button[si] = changed
+                else:
+                    self.button_repeat_timers[i].restart()