Send keyboard and mouse added/removed events when seat capabilities change. Note that Wayland only supports one global keyboard and mouse object per seat, so events coming from different keyboards and mice on the same seat can't be distinguished.
```
[1/1] Building C object test/CMakeFiles/testffmpeg.dir/testffmpeg_vulkan.c.o
/src/SDL/test/testffmpeg_vulkan.c: In function ‘BeginVulkanFrameRendering’:
/src/SDL/test/testffmpeg_vulkan.c:787:20: warning: passing argument 1 of ‘vk->lock_frame’ from incompatible pointer type [-Wincompatible-pointer-types]
787 | vk->lock_frame(frames, pVkFrame);
| ^~~~~~
| |
| AVHWFramesContext *
/src/SDL/test/testffmpeg_vulkan.c:787:20: note: expected ‘struct AVHWFramesContext *’ but argument is of type ‘AVHWFramesContext *’
/src/SDL/test/testffmpeg_vulkan.c: In function ‘FinishVulkanFrameRendering’:
/src/SDL/test/testffmpeg_vulkan.c:885:22: warning: passing argument 1 of ‘vk->unlock_frame’ from incompatible pointer type [-Wincompatible-pointer-types]
885 | vk->unlock_frame(frames, pVkFrame);
| ^~~~~~
| |
| AVHWFramesContext *
/src/SDL/test/testffmpeg_vulkan.c:885:22: note: expected ‘struct AVHWFramesContext *’ but argument is of type ‘AVHWFramesContext *’
```
If we get ENOENT we call that success. If the parent directory doesn't exist, that's fine, other operations on it will fail if it matters to the application.
Some POSIX platforms don't define macros to note the presence of the POSIX.1-2008 st_*tim timespec members of the stat struct, so check if this member exists during CMake configuration and conditionally enable it.
Apple platforms use st_*timespec naming, which is supported as of OSX 10.6. SDL3 requires 10.9+, so no fallback is needed.
Android only supports the POSIX.1-2008 semantics as of API version 26 or higher, so this has to be conditionally enabled in the makefile build via an API version definition check.
In other cases, file times fall back to the legacy path with second precision.
Adds functions to query the system's realtime clock, convert time intervals to/from a calendar date and time in either UTC or the local time, and perform time related calculations.
An SDL_Time type (a time interval represented in nanoseconds), and SDL_DateTime struct (broken down calendar date and time) were added to facilitate this functionality.
Querying the system time results in a value expressed in nanoseconds since the Unix epoch (Jan 1, 1970) in UTC +0000. Conversions to and from the various platform epochs and units are performed when required.
Any direct handling of timezones and DST were intentionally avoided. The offset from UTC is provided when converting from UTC to a local time by calculating the difference between the original UTC and the resulting local time, but no other timezone or DST information is used.
The preferred date formatting and 12/24 hour time for the system locale can be retrieved via global preferences.
Helper functions for obtaining the day of week or day or year for calendar date, and getting the number of days in a month in a given year are provided for convenience. These are simple, but useful for performing various time related calculations.
An automated test for time conversion is included, as is a simple standalone test to display the current system date and time onscreen along with a calendar, the rendering of which demonstrates the use of the utility functions (press up/down to increment or decrement the current month, and keys 1-5 to change the date and time formats).
By using the SDL_WaitEventTimeout_Device() path even when polling is required,
we can still achieve sub-millisecond latency for non-gamepad/sensor events when
a gamepad or sensor is in use by the application.
