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).
You can rename APIs using rename.py and all the code and documentation will be updated, and entries will be added to WhatsNew.txt and docs/README-migration.md.
e.g.
rename.py SDL_foo.h function SDL_CreateFoo SDL_FooCreate
SDL_oldnames.h is included in the SDL header, and if you define SDL_ENABLE_OLD_NAMES, will redefine the old API functions to call the new ones, and if not, will define them as a symbol letting you what the new API function is.
SDL.h now exists solely as a header that includes everything else, instead
of one that forces you to include everything else when you just want the
declaration for SDL_Init().
Fixes#6840.
(remaining platforms will follow)
SDL_main.h is *not* included by SDL.h anymore, users are supposed to
include it directly now, usually only in the file they implement main() in.
If they need the header elsewhere or don't want SDL_main to implement
main() (but only call SDL_SetMainReady() or whatever), they
can #define SDL_MAIN_HANDLED first, same as before.
For SDL-internal usage, I added _SDL_MAIN_NOIMPL, which *also* skips the
implementation and `#define main SDL_main`, but still defines
SDL_MAIN_AVAILABLE and SDL_MAIN_NEEDED in SDL_main.h, as before.
To make the implementaion in the header shorter and avoid including windows.h,
I moved most of the Win32 SDL_main code into SDL3.dll via SDL_Win32RunApp(),
so the header-only part is just the different main functions calling
SDL_Win32RunApp(SDL_main, NULL)
Note that I changed changed the return value and type of OutOfMemory()
to return -1 instead of FALSE, so main() (or WinMain() or whatever)
returns -1 instead of 0 in case of an out-of-memory error
Compared to original Win32 SDL_main, I tweaked the part of the
implementation in SDL_main_impl.h a bit to avoid linker warnings
and conflicts with stuff from windows.h:
- replaced windows.h with own define of WINAPI
and typedef-ing HINSTANCE and LPSTR.
This prevents conflicts between all the generically-named #defines and
types in windows.h and user code (like DrawState in some SDL tests)
- only using one of main() or wmain() gets rid of a MSVC linker error
("warning LNK4067: ambiguous entry point")
If this still causes problems, we might try getting rid of wmain(),
seemed to me like MSVC can use regular main() in UNICODE mode as well
- simplified the UNICODE logic for that - while this is not exactly
equivalent to the old, it should make sense and Works For Me
I ran this script in the include directory:
```sh
sed -i '' -e 's,#include "\(SDL.*\)",#include <SDL3/\1>,' *.h
```
I ran this script in the src directory:
```sh
for i in ../include/SDL3/SDL*.h
do hdr=$(basename $i)
if [ x"$(echo $hdr | egrep 'SDL_main|SDL_name|SDL_test|SDL_syswm|SDL_opengl|SDL_egl|SDL_vulkan')" != x ]; then
find . -type f -exec sed -i '' -e 's,#include "\('$hdr'\)",#include <SDL3/\1>,' {} \;
else
find . -type f -exec sed -i '' -e '/#include "'$hdr'"/d' {} \;
fi
done
```
Fixes https://github.com/libsdl-org/SDL/issues/6575