Change Cocoa SDL_VideoData and SDL_WindowData implementations from C structs to Objective-C objects, since bridging between C and ObjC is easier that way.
This isn't obvious, but makes sense when thinking about how games actually use it. This is also in line with how Windows mouse relative mode is implemented.
Fixes https://github.com/libsdl-org/SDL/issues/5340
Rounding the scroll deltas from trackpads causes jerky scrolling behavior
by artificially amplifying the effects of very small scroll movements.
We should only round events from devices with discrete scroll wheels,
because we know the smallest unit of movement there is a single tick.
It doesn't appear to work anymore, and was disabled by default anyhow, since
the needed APIs are forbidden on the Mac App Store.
A better solution to lock the mouse to the window on macOS would still be
welcome. CGAssociateMouseAndMouseCursorPosition() works fine for relative
mouse mode, this was just a question of SDL_SetWindowGrab(). As it stands
now, a grabbed mouse can briefly break out of the window, causing varying
degrees of chaos.
This time, we make anything we think is a MacBook trackpad report its touches
as SDL_MOUSE_TOUCHID, even though they're not _actually_ synthesized events,
and let all mouse input--even if the OS synthesized it from a multitouch
trackpad on our behalf--look like physical input. This is backwards from
reality, but produces the results most apps will expect.
Note that if you have a real touch device that doesn't appear to be the
trackpad, it'll produce real touch events with unique device ids, so it's
not a total loss here, but also note that the way we decide if it was the
trackpad is an imperfect heuristic; it happens to work out right now, but
it's not impossible that a real touchscreen could come to the Mac at some
point and (incorrectly?) call it a "mouse" input, etc.
But for now, good enough.
Fixes Bugzilla #4690.
Eric Wasylishen
This bug was reintroduced by https://hg.libsdl.org/SDL/rev/fcf24b38a28a
The steps to reproduce are the same: run the "testrelative" SDL demo with "--info all",
connect a USB mouse with a scroll wheel, and roll the scroll wheel one "notch". You'll get log output like:
testdraw2[1644:67222] INFO: SDL EVENT: Mouse: wheel scrolled 0 in x and 0 in y (reversed: 1) in window 1
As far as I can tell macOS doesn't have an API for getting the number of "wheel notches"; I get a deltaY of 0.100006 for one "notch", and it's heavily accelerated (if you roll the wheel quickly you'll get large deltas). So NSEvent's deltaY is only meant to be used for scrolling a scroll view, with the given distance in points, not something like selecting an item in a game.
Here's a temporary patch that at restores the foor/ceil in Cocoa_HandleMouseWheel.
Not ideal, but at least it restores the ability to scroll one notch of a mousewheel.
Martijn Courteaux
I implemented precise scrolling events. I have been through all the folders in /src/video/[platform] to implement where possible. This works on OS X, but I can't speak for others. Build farm will figure that out, I guess. I think this patch should introduce precise scrolling on OS X, Wayland, Mir, Windows, Android, Nacl, Windows RT.
The way I provide precise scrolling events is by adding two float fields to the SDL_MouseWheelScrollEvent datastructure, called "preciseX" and "preciseY". The old integer fields "x" and "y" are still present. The idea is that every platform specific code normalises the scroll amounts and forwards them to the SDL_SendMouseWheel function. It is this function that will now accumulate these (using a static variable, as I have seen how it was implemented in the Windows specific code) and once we hit a unit size, set the traditional integer "x" and "y" fields.
I believe this is pretty solid way of doing it, although I'm not the expert here.
There is also a fix in the patch for a typo recently introduced, that might need to be taken away by the time anybody merges this in. There is also a file in Nacl which I have stripped a horrible amount of trailing whitespaces. (Leave that part out if you want).
There are platforms it isn't implemented on (and currently can't be
implemented on!), and there's currently no way for an app to know this.
This shouldn't break ABI on apps that moved to a revision between 2.0.3 and
2.0.4.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().