It turns out that when you enable raw input and then process Windows messages, you'll get the currently pending input in GetRawInputBuffer(), and you'll get any new input that occurs while processing messages as WM_INPUT.
The fix for this is to create a dedicated thread to handle raw input and only use GetRawInputBuffer() in that thread. A nice side effect of this is that we'll get mouse input at the lowest latency possible, but raw mouse events will now occur on a separate thread, outside of the normal event loop processing.
Improved fix for https://github.com/libsdl-org/SDL/issues/8756
Matches the one in `GetMouseMessageSource()`.
From my testing on Windows 11, the lower 8 bits in touch events cycle
trough the values 0x8c-0x95 in order.
SDL window size, state, and position functions have been considered immediate, with their effects assuming to have taken effect upon successful return of the function. However, several windowing systems handle these requests asynchronously, resulting in the functions blocking until the changes have taken effect, potentially for long periods of time. Additionally, some windowing systems treat these as requests, and can potentially deny or fulfill the request in a manner differently than the application expects, such as not allowing a window to be positioned or sized beyond desktop borders, prohibiting fullscreen, and so on.
With these changes, applications can make requests of the window manager that do not block, with the understanding that an associated event will be sent if the request is fulfilled. Currently, size, position, maximize, minimize, and fullscreen calls are handled as asynchronous requests, with events being returned if the request is honored. If the application requires that the change take effect immediately, it can call the new SDL_SyncWindow function, which will attempt to block until the request is fulfilled, or some arbitrary timeout period elapses, the duration of which depends not only on the windowing system, but on the operation requested as well (e.g. a 100ms timeout is fine for most X11 events, but maximizing a window can take considerably longer for some reason). There is also a new hint 'SDL_VIDEO_SYNC_ALL_WINDOW_OPS' that will mimic the old behavior by synchronizing after every window operation with, again, the understanding that using this may result in the associated calls blocking for a relatively long period.
The deferred model also results in the window size and position getters not reporting false coordinates anymore, as they only forward what the window manager reports vs allowing applications to set arbitrary values, and fullscreen enter/leave events that were initiated via the window manager update the window state appropriately, where they didn't before.
Care was taken to ensure that order of operations is maintained, and that requests are not ignored or dropped. This does require some implicit internal synchronization in the various backends if many requests are made in a short period, as some state and behavior depends on other bits of state that need to be known at that particular point in time, but this isn't something that typical applications will hit, unless they are sending a lot of window state in a short time as the tests do.
The automated tests developed to test the previous behavior also resulted in previously undefined behavior being defined and normalized across platforms, particularly when it comes to the sizing and positioning of windows when they are in a fixed-size state, such as maximized or fullscreen. Size and position requests made when the window is not in a movable or resizable state will be deferred until it can be applied, so no requests are lost. These changes fix another long-standing issue with renderers recreating maximized windows, where the original non-maximized size was lost, resulting in the window being restored to the wrong size. All automated video tests pass across all platforms.
Overall, the "make a request/get an event" model better reflects how most windowing systems work, and some backends avoid spending significant time blocking while waiting for operations to complete.
This means the allocator's caller doesn't need to use SDL_OutOfMemory directly
if the allocation fails.
This applies to the usual allocators: SDL_malloc, SDL_calloc, SDL_realloc
(all of these regardless of if the app supplied a custom allocator or we're
using system malloc() or an internal copy of dlmalloc under the hood),
SDL_aligned_alloc, SDL_small_alloc, SDL_strdup, SDL_asprintf, SDL_wcsdup...
probably others. If it returns something you can pass to SDL_free, it should
work.
The caller might still need to use SDL_OutOfMemory if something that wasn't
SDL allocated the memory: operator new in C++ code, Objective-C's alloc
message, win32 GlobalAlloc, etc.
Fixes#8642.
Now it returns an array and optional count, to match other SDL3 APIs.
SDL_GetTouchName() was replaced with a function that takes an instance ID
instead of an index, too.
Old implementation with `MapVirtualKey(..., MAPVK_VK_TO_CHAR) & 0x7FFFF` simply returned `A`..`Z` for VK_A..VK_Z and
completely useless <U+0002 START OF TEXT> (`WCH_LGTR 0xF002` without high-order bit) in case of ligature.
See https://kbdlayout.info/features/ligatures for a list of affected keyboard layouts.
More info on `MAPVK_VK_TO_CHAR`: https://stackoverflow.com/a/72464584/1795050
If you're using the application main callbacks, your SDL_AppIterate() function will be called while Windows is moving and resizing your window. If not, then SDL will send an SDL_EVENT_WINDOW_EXPOSED event for your window and you can use an event watcher to redraw your window directly from the callback.
Fixes https://github.com/libsdl-org/SDL/issues/1059
Closes https://github.com/libsdl-org/SDL/pull/4836
