Bug in AccelerometerDelegateWrapper.mm

cocos2d-x C++
#1

Hi.

You have a bug in ios-specific file ‘AccelerometerDelegateWrapper.mm’.

The bug is in lines 97-100:

    case UIInterfaceOrientationPortraitUpsideDown:
        acceleration_->x = -acceleration_->y;
        acceleration_->y = -tmp;
        break;

Note, that this case handles UpsideDown orientation.
Proper way to manage x and y accelerometer values in this orientation is to change them to negative, but do not exchange x and y.

So, valid code should look like this:

    case UIInterfaceOrientationPortraitUpsideDown:
        acceleration_->x = -acceleration_->x;
        acceleration_->y = -acceleration_->y;
        break;