This lets apps optionally have a handful of callbacks for their entry points instead of a single main function. If used, the actual main/SDL_main/whatever entry point will be implemented in the single-header library SDL_main.h and the app will implement four separate functions:
First:
int SDL_AppInit(int argc, char **argv);
This will be called once before anything else. argc/argv work like they always do. If this returns 0, the app runs. If it returns < 0, the app calls SDL_AppQuit and terminates with an exit code that reports an error to the platform. If it returns > 0, the app calls SDL_AppQuit and terminates with an exit code that reports success to the platform. This function should not go into an infinite mainloop; it should do any one-time startup it requires and then return.
Then:
int SDL_AppIterate(void);
This is called over and over, possibly at the refresh rate of the display or some other metric that the platform dictates. This is where the heart of your app runs. It should return as quickly as reasonably possible, but it's not a "run one memcpy and that's all the time you have" sort of thing. The app should do any game updates, and render a frame of video. If it returns < 0, SDL will call SDL_AppQuit and terminate the process with an exit code that reports an error to the platform. If it returns > 0, the app calls SDL_AppQuit and terminates with an exit code that reports success to the platform. If it returns 0, then SDL_AppIterate will be called again at some regular frequency. The platform may choose to run this more or less (perhaps less in the background, etc), or it might just call this function in a loop as fast as possible. You do not check the event queue in this function (SDL_AppEvent exists for that).
Next:
int SDL_AppEvent(const SDL_Event *event);
This will be called once for each event pushed into the SDL queue. This may be called from any thread, and possibly in parallel to SDL_AppIterate. The fields in event do not need to be free'd (as you would normally need to do for SDL_EVENT_DROP_FILE, etc), and your app should not call SDL_PollEvent, SDL_PumpEvent, etc, as SDL will manage this for you. Return values are the same as from SDL_AppIterate(), so you can terminate in response to SDL_EVENT_QUIT, etc.
Finally:
void SDL_AppQuit(void);
This is called once before terminating the app--assuming the app isn't being forcibly killed or crashed--as a last chance to clean up. After this returns, SDL will call SDL_Quit so the app doesn't have to (but it's safe for the app to call it, too). Process termination proceeds as if the app returned normally from main(), so atexit handles will run, if your platform supports that.
The app does not implement SDL_main if using this. To turn this on, define SDL_MAIN_USE_CALLBACKS before including SDL_main.h. Defines like SDL_MAIN_HANDLED and SDL_MAIN_NOIMPL are also respected for callbacks, if the app wants to do some sort of magic main implementation thing.
In theory, on most platforms these can be implemented in the app itself, but this saves some #ifdefs in the app and lets everyone struggle less against some platforms, and might be more efficient in the long run, too.
On some platforms, it's possible this is the only reasonable way to go, but we haven't actually hit one that 100% requires it yet (but we will, if we want to write a RetroArch backend, for example).
Using the callback entry points works on every platform, because on platforms that don't require them, we can fake them with a simple loop in an internal implementation of the usual SDL_main.
The primary way we expect people to write SDL apps is with SDL_main, and this is not intended to replace it. If the app chooses to use this, it just removes some platform-specific details they might have to otherwise manage, and maybe removes a barrier to entry on some future platform.
Fixes#6785.
Reference PR #8247.
Not destroying the windows, caused a leak in checkkeys when
exiting by clicking somewhere in the window:
Allocation 0: 8 bytes
0x7f46f56d2fe8: SDL_realloc_REAL+0x3d
0x7f46f565deb7: GetMouseInputSource+0x88
0x7f46f565e07b: SDL_PrivateSendMouseButton+0x56
0x7f46f565e5aa: SDL_SendMouseButton+0x44
0x7f46f57fb0a4: pointer_handle_button_common+0x1bb
0x7f46f57fb0f3: pointer_handle_button+0x41
0x7f46f5123be6: ffi_prep_go_closure+0x2c6
0x7f46f51204bf: SDL_InitSubSystem+0x19
0x7f46f512318e: ffi_call+0x12e
This will simplify the X11 and Wayland implementations, which were doing that under the hood, and makes application interaction between the two APIs consistent.
Also renamed SDL_GetDisplayOrientation() SDL_GetDisplayCurrentOrientation()
The natural orientation of the primary display is the frame of reference for accelerometer and gyro sensor readings.
Alt-Enter will go from the current state to fullscreen desktop, or if already there, will leave fullscreen mode.
Ctrl-Enter will go from the current state to exclusive fullscreen mode, or if already there, will leave fullscreen mode.
We have gotten feedback that abstracting the coordinate system based on the display scale is unexpected and it is difficult to adapt existing applications to the proposed API.
The new approach is to provide the coordinate systems that people expect, but provide additional information that will help applications properly handle high DPI situations.
The concepts needed for high DPI support are documented in README-highdpi.md. An example of automatically adapting the content to display scale changes can be found in SDL_test_common.c, where auto_scale_content is checked.
Also, the SDL_WINDOW_ALLOW_HIGHDPI window flag has been replaced by the SDL_HINT_VIDEO_ENABLE_HIGH_PIXEL_DENSITY hint.
Fixes https://github.com/libsdl-org/SDL/issues/7709
It turns out there's a race condition on X11 where the window could be placed by the window manager while being placed by the application, so we need to have the initial position available at window creation.
* Fix -Wundef warnings due to use of unguarded SDL_LOADSO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_LOADSO_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_COCOA
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_UIKIT
* Fix -Wundef warnings due to use of unguarded SDL_TIMERS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_EVENTS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_TIMER_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_SENSOR_DISABLED
* Fix -Wundef warnings due to use of unguarded __ANDROID__
* Fix -Wundef warnings due to use of unguarded __IOS__
* Fix -Wundef warnings due to use of unguarded EMULATE_CAS
* Fix -Wundef warnings due to use of unguarded SDL_ATOMIC_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_THREADS_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_SNDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_NETBSD
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_WASAPI
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DSOUND
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_COREAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_AAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_OPENSLES
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_NEON_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_ALTIVEC_BLITTERS
* Fix -Wundef warnings due to use of unguarded __VITA__
* Fix -Wundef warnings due to use of unguarded __3DS__
* Fix -Wundef warnings due to use of unguarded SDL_DYNAPI_PROC_NO_VARARGS
* Fix -Wundef warnings due to use of unguarded __APPLE__
* Fix -Wundef warnings due to use of unguarded __WINRT__
* Fix -Wundef warnings due to use of unguarded SDL_HIDAPI_DISABLED
* Fix -Wundef warnings due to use of unguarded __TVOS__
* Fix -Wundef warnings due to use of unguarded HAVE_DRIVER_BACKEND
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_XINPUT
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_WGI
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_DINPUT
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_MFI
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_PS2
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_PSP
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_VITA
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_N3DS
* Fix -Wundef warnings due to use of unguarded __MACOS__
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WINRT
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RPI
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PVR_OGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VIVANTE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D11
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_D3D12
* Fix -Wundef warnings due to use of unguarded SDL_RENDER_DISABLED
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_METAL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_VITA_GXM
* Fix -Wundef warnings due to use of unguarded SDL_ARM_SIMD_BLITTERS
* Fix -Wundef warnings due to use of unguarded SDL_ARM_NEON_BLITTERS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_PS2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_KMSDRM
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RISCOS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_NGAGE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_METAL
* Fix -Wundef warnings due to use of unguarded SDL_LSX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_NP_H
* Fix -Wundef warnings due to use of unguarded __RISCOS__
* Fix -Wundef warnings due to use of unguarded FAKE_RECURSIVE_MUTEX
* Fix -Wundef warnings due to use of unguarded USE_POSIX_SPAWN
* textureData is only needed when SDL is built with YUV support
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_ALSA
* Fix -Wundef warnings due to use of unguarded SDL_SSE3_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE4_2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE4_1_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX512F_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_AVX2_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_SSE_INTRINSICS
* Fix -Wundef warnings due to use of unguarded SDL_MMX_INTRINSICS
* Fix -Wundef warnings due to use of unguarded HAVE_CLOCK_GETTIME
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DISK
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DUMMY
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_DUMMY
* Fix -Wundef warnings due to use of unguarded HAVE_GCC_ATOMICS
* Fix -Wundef warnings due to use of unguarded HAVE_GCC_SYNC_LOCK_TEST_AND_SET
* Fix -Wundef warnings due to use of unguarded SDL_USE_LIBDBUS
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_JACK
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_VIRTUAL
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_LINUX
* Fix -Wundef warnings due to use of unguarded HAVE_LIBC
* Fix -Wundef warnings due to disabling SDL_LIBC
* Fix -Wundef warnings due to use of unguarded HAVE_PLATFORM_BACKEND
* Fix -Wundef warnings due to use of unguarded DEBUG
* Fix -Wundef warnings due to use of unguarded HAVE_LINUX_INPUT_H
* Fix -Werror=unused-variable when building with SDL_LIBC=OFF
* Fix -Wundef warnings due to use of unguqrded SDL_USE_LIBUDEV
* Use SDL alloc functions in libusb/hid.c
* Fix -Wundef warnings due to use of unguarded HAVE_LIBUDEV_H
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VULKAN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_OFFSCREEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_OGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_GLX
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES2
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_RENDER_OGL_ES2
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_OSS
* Remove SDL_AUDIO_DRIVER_SUNAUDIO reference since it is never set
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PIPEWIRE
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_PULSEAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XCURSOR
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XDBE
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XFIXES
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XINPUT2
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XINPUT2_SUPPORTS_MULTITOUCH
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XRANDR
* Fix -Wundef warnings due to use of unguarded #if SDL_VIDEO_DRIVER_X11_XSCRNSAVER
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_XSHAPE
* Don't call XShape functions when XShape is diabled
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WAYLAND
* Fix -Wundef warnings due to use of unuarded SDL_VIDEO_DRIVER_X11
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_RISCOS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_EGL
* Disable array when compiled with SDL_EVENTS=OFF
* Fix -Wundef warnings due to use of unguarded SDL_INPUT_LINUXEV
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PS2
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PSP
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_VITA
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_N3DS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_STDCPP
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_NGAGE
* Fix -Wundef warnings due to use of unguarded __WINDOWS__
* Fix -Wundef warnings due to use of unguarded __WINGDK__
* Fix -Wundef warnings due to use of unguarded __ANDROID__
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_GENERIC_COND_SUFFIX
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PIB
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_VITA_PVR
* Fix -Wundef warnings due to use of unguarded SDL_FILE_DISABLED
* Fix -Wundef warnings due to use of unguarded __XBOXONE__
* Fix -Wundef warnings due to use of unguarded __XBOXSERIES__
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_WGL
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_QNX
* Fix -Wundef warnings due to use of unguarded SDL_AUDIO_DRIVER_DISK
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_QNX
* Fix -Wundef warnings due to use of unguarded DEBUG_RAZOR
* Fix -Wundef warnings due to use of unguarded WINAPI_FAMILY_PHONE_APP
* Fix -Wundef warnings due to use of unguarded SDL_MAC_NO_SANDBOX
* Fix -Wundef warnings due to use of unguarded __(IPHONE|APPLETV|MAC)_OS_VERSION_MAX_ALLOWED
* Fix C4090 warning ('function': different 'const' qualifiers)
* ci: use -isystem for include dirs of pspdev toolchain
* cmake: add -Wundef option
* Fix remaining -Wundef warnings due to use of unguarded SDL_VIDEO_VULKAN and SDL_VIDEO_METAL
* Fix -Wundef warnings due to use of unguarded __MACOS__
* DEBUG_CONVERT is guaranteed to be defined in src/audio/SDL_audiocvt.c
* Fix -Wundef warnings due to use of unguarded HAVE_NANOSLEEP
* Fix -Wundef warnings due to use of unguarded HAVE_DXGI_H
* Fix -Wundef warnings due to use of unguarded HAVE_LINUX_INPUT_H
* fix SDL_VIDEO_DRIVER_WAYLAND
* fix SDL_VIDEO_DRIVER_X11
* Fix -Wundef warnings due to use of unguarded HAVE_MMDEVICEAPI_H
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_SETNAME_NP
* Fix -Wundef warnings due to use of unguarded HAVE_PTHREAD_SET_NAME_NP
* Fix -Wundef warnings due to use of unguarded HAVE_SETJMP
* Fix -Wundef warnings due to use of unguarded HAVE_SIGNAL_H
* Fix -Wundef warnings due to use of unguarded HAVE_TPCSHRD_H
* Fix -Wundef warnings due to use of unguarded MACOSX_COREAUDIO
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_DINPUT
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_IOKIT
* Fix -Wundef warnings due to use of unguarded SDL_HAPTIC_XINPUT
* Fix -Wundef warnings due to use of unguarded SDL_IPHONE_KEYBOARD
* Fix -Wundef warnings due to use of unguarded SDL_JOYSTICK_RAWINPUT
* Fix -Wundef warnings due to use of unguarded SDL_POWER_ANDROID
* Fix -Wundef warnings due to use of unguarded SDL_POWER_EMSCRIPTEN
* Fix -Wundef warnings due to use of unguarded SDL_POWER_HAIKU
* Fix -Wundef warnings due to use of unguarded SDL_POWER_LINUX
* Fix -Wundef warnings due to use of unguarded SDL_POWER_MACOSX
* Fix -Wundef warnings due to use of unguarded SDL_POWER_PSP
* Fix -Wundef warnings due to use of unguarded SDL_POWER_UIKIT
* Fix -Wundef warnings due to use of unguarded SDL_POWER_VITA
* Fix -Wundef warnings due to use of unguarded SDL_POWER_WINDOWS
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD_RECURSIVE_MUTEX
* Fix -Wundef warnings due to use of unguarded SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_VIVANTE_VDK
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_WAYLAND
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_HAS_XKBKEYCODETOKEYSYM
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_DRIVER_X11_SUPPORTS_GENERIC_EVENTS
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_CGL
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_EGL
* Fix -Wundef warnings due to use of unguarded __MACOS__
* Fix -Wundef warnings due to use of unguarded __OpenBSD__
* Fix -Wundef warnings due to use of unguarded __FreeBSD__
* Fix -Wundef warnings due to use of unguarded __MWERKS__
* Fix -Wundef warnings due to use of unguarded __WIN32__
* Fix -Wundef warnings due to use of unguarded SDL_IPHONE_LAUNCHSCREEN
* Fix -Wundef warnings due to use of unguarded SDL_VIDEO_OPENGL_ES2
* Remove unused HAVE_CONST, HAVE_INLINE and HAVE_VOLATILE
* Revert "Use SDL alloc functions in libusb/hid.c"
This reverts commit 847c64b00d.
* Handle FAKE_RECURSIVE_MUTEX in similar way as SDL2
* Don't use defined in macro
This function wasn't consistently correct across platforms and devices.
If you want the UI scale factor, you can use display_scale in the structure returned by SDL_GetDesktopDisplayMode(). If you need an approximate DPI, you can multiply this value times 160 on iPhone and Android, and 96 on other platforms.
This fixes rounding errors with coordinate scaling and gives more flexibility in the presentation, as well as making it easy to maintain device independent resolution as windows move between different pixel density displays.
By default when a renderer is created, it will match the window size so window coordinates and render coordinates are 1-1.
Mouse and touch events are no longer filtered to change their coordinates, instead you can call SDL_ConvertEventToRenderCoordinates() to explicitly map event coordinates into the rendering viewport.
SDL_RenderWindowToLogical() and SDL_RenderLogicalToWindow() have been renamed SDL_RenderCoordinatesFromWindow() and SDL_RenderCoordinatesToWindow() and take floating point coordinates in both directions.
The viewport, clipping state, and scale for render targets are now persistent and will remain set whenever they are active.
