Added a new hint SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION.

When set to "1", the orientation of the Apple TV remote affects the axes of the corresponding SDL joystick. It is "0" (disabled) by default.

Author: slime73

include/SDL_hints.h

@@ -295,6 +295,16 @@ extern "C" {
  */
 #define SDL_HINT_APPLE_TV_CONTROLLER_UI_EVENTS "SDL_APPLE_TV_CONTROLLER_UI_EVENTS"
 
+/**
+ * \brief A variable controlling whether the Apple TV remote's joystick axes
+ * will automatically match the rotation of the remote.
+ *
+ * This variable can be set to the following values:
+ * "0" - Remote orientation does not affect joystick axes (the default).
+ * "1" - Joystick axes are based on the orientation of the remote.
+ */
+#define SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION "SDL_APPLE_TV_REMOTE_ALLOW_ROTATION"
+
 /**
  * \brief A variable controlling whether the Android / iOS built-in
  * accelerometer should be listed as a joystick device, rather than listing

src/joystick/iphoneos/SDL_sysjoystick.m

@@ -127,9 +127,13 @@
  }
 #if TARGET_OS_TV
  else if (controller.microGamepad) {
+ const char *hint = SDL_GetHint(SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION);
+
  device->naxes = 2; /* treat the touch surface as two axes */
  device->nhats = 0; /* apparently the touch surface-as-dpad is buggy */
  device->nbuttons = 3; /* AX, pause button */
+
+ controller.microGamepad.allowsRotation = (hint != NULL && *hint != '0');
  }
 #endif /* TARGET_OS_TV */
 
@@ -248,6 +252,22 @@
  return next;
 }
 
+#if TARGET_OS_TV
+static void
+SDL_AppleTVRemoteRotationHintChanged(void *udata, const char *name, const char *oldValue, const char *newValue)
+{
+ BOOL allowRotation = newValue != NULL && *newValue != '0';
+
+ @autoreleasepool {
+ for (GCController *controller in [GCController controllers]) {
+ if (controller.microGamepad) {
+ controller.microGamepad.allowsRotation = allowRotation;
+ }
+ }
+ }
+}
+#endif /* TARGET_OS_TV */
+
 /* Function to scan the system for joysticks.
  * Joystick 0 should be the system default joystick.
  * It should return 0, or -1 on an unrecoverable fatal error.
@@ -276,6 +296,11 @@
  SDL_SYS_AddJoystickDevice(controller, SDL_FALSE);
  }
 
+#if TARGET_OS_TV
+ SDL_AddHintCallback(SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION,
+ SDL_AppleTVRemoteRotationHintChanged, NULL);
+#endif /* TARGET_OS_TV */
+
  connectObserver = [center addObserverForName:GCControllerDidConnectNotification
  object:nil
  queue:nil
@@ -656,6 +681,11 @@ SDL_JoystickID SDL_SYS_GetInstanceIdOfDeviceIndex(int device_index)
  [center removeObserver:disconnectObserver name:GCControllerDidDisconnectNotification object:nil];
  disconnectObserver = nil;
  }
+
+#if TARGET_OS_TV
+ SDL_DelHintCallback(SDL_HINT_APPLE_TV_REMOTE_ALLOW_ROTATION,
+ SDL_AppleTVRemoteRotationHintChanged, NULL);
+#endif /* TARGET_OS_TV */
 #endif /* SDL_JOYSTICK_MFI */
 
  while (deviceList != NULL) {