# Migrating to SDL 3.0

This guide provides useful information for migrating applications from SDL 2.0 to SDL 3.0.

Details on API changes are organized by SDL 2.0 header below.

Many functions and symbols have been renamed. We have provided a handy Python script [rename_symbols.py](https://github.com/libsdl-org/SDL/blob/main/build-scripts/rename_symbols.py) to rename SDL2 functions to their SDL3 counterparts:
```sh
rename_symbols.py --all-symbols source_code_path
```

It's also possible to apply a semantic patch to migrate more easily to SDL3: [SDL_migration.cocci](https://github.com/libsdl-org/SDL/blob/main/build-scripts/SDL_migration.cocci)


SDL headers should now be included as `#include <SDL3/SDL.h>`. Typically that's the only header you'll need in your application unless you are using OpenGL or Vulkan functionality. We have provided a handy Python script [rename_headers.py](https://github.com/libsdl-org/SDL/blob/main/build-scripts/rename_headers.py) to rename SDL2 headers to their SDL3 counterparts:
```sh
rename_headers.py source_code_path
```

The file with your main() function should also include <SDL3/SDL_main.h>, see below in the SDL_main.h section.

CMake users should use this snippet to include SDL support in their project:
```
find_package(SDL3 REQUIRED CONFIG REQUIRED COMPONENTS SDL3)
target_link_libraries(mygame PRIVATE SDL3::SDL3)
```

Autotools users should use this snippet to include SDL support in their project:
```
PKG_CHECK_MODULES([SDL3], [sdl3])
```
and then add $SDL3_CFLAGS to their project CFLAGS and $SDL3_LIBS to their project LDFLAGS

Makefile users can use this snippet to include SDL support in their project:
```
CFLAGS += $(shell pkg-config sdl3 --cflags)
LDFLAGS += $(shell pkg-config sdl3 --libs)
```

The SDL3test library has been renamed SDL3_test.

There is no SDLmain library anymore, it's now header-only, see below in the SDL_main.h section.


begin_code.h and close_code.h in the public headers have been renamed to SDL_begin_code.h and SDL_close_code.h. These aren't meant to be included directly by applications, but if your application did, please update your `#include` lines.

The vi format comments have been removed from source code. Vim users can use the [editorconfig plugin](https://github.com/editorconfig/editorconfig-vim) to automatically set tab spacing for the SDL coding style.

## SDL_atomic.h

The following structures have been renamed:
- SDL_atomic_t => SDL_AtomicInt

## SDL_audio.h

SDL_AudioInit() and SDL_AudioQuit() have been removed. Instead you can call SDL_InitSubSytem() and SDL_QuitSubSytem() with SDL_INIT_AUDIO, which will properly refcount the subsystems. You can choose a specific audio driver using SDL_AUDIO_DRIVER hint.

SDL_PauseAudioDevice() is only used to pause audio playback. Use SDL_PlayAudioDevice() to start playing audio.

SDL_FreeWAV has been removed and calls can be replaced with SDL_free.

SDL_AudioCVT interface is removed, SDL_AudioStream interface or SDL_ConvertAudioSamples() helper function can be used.

Code that used to look like this:
```c
    SDL_AudioCVT cvt;
    SDL_BuildAudioCVT(&cvt, src_format, src_channels, src_rate, dst_format, dst_channels, dst_rate);
    cvt.len = src_len;
    cvt.buf = (Uint8 *) SDL_malloc(src_len * cvt.len_mult);
    SDL_memcpy(cvt.buf, src_data, src_len);
    SDL_ConvertAudio(&cvt);
    do_something(cvt.buf, cvt.len_cvt);
```
should be changed to:
```c
    Uint8 *dst_data = NULL;
    int dst_len = 0;
    if (SDL_ConvertAudioSamples(src_format, src_channels, src_rate, src_data, src_len
                                dst_format, dst_channels, dst_rate, &dst_data, &dst_len) < 0) {
        /* error */
    }
    do_something(dst_data, dst_len);
    SDL_free(dst_data);
```

AUDIO_U16, AUDIO_U16LSB, AUDIO_U16MSB, and AUDIO_U16SYS have been removed. They were not heavily used, and one could not memset a buffer in this format to silence with a single byte value. Use a different audio format.

If you need to convert U16 audio data to a still-supported format at runtime, the fastest, lossless conversion is to SDL_AUDIO_S16:

```c
    /* this converts the buffer in-place. The buffer size does not change. */
    Sint16 *audio_ui16_to_si16(Uint16 *buffer, const size_t num_samples)
    {
        size_t i;
        const Uint16 *src = buffer;
        Sint16 *dst = (Sint16 *) buffer;

        for (i = 0; i < num_samples; i++) {
            dst[i] = (Sint16) (src[i] ^ 0x8000);
        }

        return dst;
    }
```

In SDL2, SDL_AudioStream would convert/resample audio data during input (via SDL_AudioStreamPut). In SDL3, it does this work when requesting audio (via SDL_GetAudioStreamData, which would have been SDL_AudioStreamPut in SDL2. The way you use an AudioStream is roughly the same, just be aware that the workload moved to a different phase.
In SDL2, SDL_AudioStreamAvailable() returns 0 if passed a NULL stream. In SDL3, the equivalent SDL_GetAudioStreamAvailable() call returns -1 and sets an error string, which matches other audiostream APIs' behavior.


The following functions have been renamed:
* SDL_AudioStreamAvailable() => SDL_GetAudioStreamAvailable()
* SDL_AudioStreamClear() => SDL_ClearAudioStream()
* SDL_AudioStreamFlush() => SDL_FlushAudioStream()
* SDL_AudioStreamGet() => SDL_GetAudioStreamData()
* SDL_AudioStreamPut() => SDL_PutAudioStreamData()
* SDL_FreeAudioStream() => SDL_DestroyAudioStream()
* SDL_NewAudioStream() => SDL_CreateAudioStream()


The following functions have been removed:
* SDL_ConvertAudio()
* SDL_BuildAudioCVT()
* SDL_OpenAudio()
* SDL_CloseAudio()
* SDL_PauseAudio()
* SDL_GetAudioStatus()
* SDL_LockAudio()
* SDL_UnlockAudio()
* SDL_MixAudio()

Use the SDL_AudioDevice functions instead.

The following symbols have been renamed:
* AUDIO_F32 => SDL_AUDIO_F32
* AUDIO_F32LSB => SDL_AUDIO_F32LSB
* AUDIO_F32MSB => SDL_AUDIO_F32MSB
* AUDIO_F32SYS => SDL_AUDIO_F32SYS
* AUDIO_S16 => SDL_AUDIO_S16
* AUDIO_S16LSB => SDL_AUDIO_S16LSB
* AUDIO_S16MSB => SDL_AUDIO_S16MSB
* AUDIO_S16SYS => SDL_AUDIO_S16SYS
* AUDIO_S32 => SDL_AUDIO_S32
* AUDIO_S32LSB => SDL_AUDIO_S32LSB
* AUDIO_S32MSB => SDL_AUDIO_S32MSB
* AUDIO_S32SYS => SDL_AUDIO_S32SYS
* AUDIO_S8 => SDL_AUDIO_S8
* AUDIO_U8 => SDL_AUDIO_U8

## SDL_cpuinfo.h

The intrinsics headers (mmintrin.h, etc.) have been moved to `<SDL3/SDL_intrin.h>` and are no longer automatically included in SDL.h.

SDL_Has3DNow() has been removed; there is no replacement.

SDL_SIMDAlloc(), SDL_SIMDRealloc(), and SDL_SIMDFree() have been removed. You can use SDL_aligned_alloc() and SDL_aligned_free() with SDL_SIMDGetAlignment() to get the same functionality.

## SDL_events.h

The timestamp member of the SDL_Event structure now represents nanoseconds, and is populated with SDL_GetTicksNS()

The timestamp_us member of the sensor events has been renamed sensor_timestamp and now represents nanoseconds. This value is filled in from the hardware, if available, and may not be synchronized with values returned from SDL_GetTicksNS().

You should set the event.common.timestamp field before passing an event to SDL_PushEvent(). If the timestamp is 0 it will be filled in with SDL_GetTicksNS().

Mouse events use floating point values for mouse coordinates and relative motion values. You can get sub-pixel motion depending on the platform and display scaling.

The SDL_DISPLAYEVENT_* events have been moved to top level events, and SDL_DISPLAYEVENT has been removed. In general, handling this change just means checking for the individual events instead of first checking for SDL_DISPLAYEVENT and then checking for display events. You can compare the event >= SDL_EVENT_DISPLAY_FIRST and <= SDL_EVENT_DISPLAY_LAST if you need to see whether it's a display event.

The SDL_WINDOWEVENT_* events have been moved to top level events, and SDL_WINDOWEVENT has been removed. In general, handling this change just means checking for the individual events instead of first checking for SDL_WINDOWEVENT and then checking for window events. You can compare the event >= SDL_EVENT_WINDOW_FIRST and <= SDL_EVENT_WINDOW_LAST if you need to see whether it's a window event.

The SDL_EVENT_WINDOW_RESIZED event is always sent, even in response to SDL_SetWindowSize().

The SDL_EVENT_WINDOW_SIZE_CHANGED event has been removed, and you can use SDL_EVENT_WINDOW_PIXEL_SIZE_CHANGED to detect window backbuffer size changes.

The gamepad event structures caxis, cbutton, cdevice, ctouchpad, and csensor have been renamed gaxis, gbutton, gdevice, gtouchpad, and gsensor.

SDL_QUERY, SDL_IGNORE, SDL_ENABLE, and SDL_DISABLE have been removed. You can use the functions SDL_SetEventEnabled() and SDL_EventEnabled() to set and query event processing state.

The following symbols have been renamed:
* SDL_APP_DIDENTERBACKGROUND => SDL_EVENT_DID_ENTER_BACKGROUND
* SDL_APP_DIDENTERFOREGROUND => SDL_EVENT_DID_ENTER_FOREGROUND
* SDL_APP_LOWMEMORY => SDL_EVENT_LOW_MEMORY
* SDL_APP_TERMINATING => SDL_EVENT_TERMINATING
* SDL_APP_WILLENTERBACKGROUND => SDL_EVENT_WILL_ENTER_BACKGROUND
* SDL_APP_WILLENTERFOREGROUND => SDL_EVENT_WILL_ENTER_FOREGROUND
* SDL_AUDIODEVICEADDED => SDL_EVENT_AUDIO_DEVICE_ADDED
* SDL_AUDIODEVICEREMOVED => SDL_EVENT_AUDIO_DEVICE_REMOVED
* SDL_CLIPBOARDUPDATE => SDL_EVENT_CLIPBOARD_UPDATE
* SDL_CONTROLLERAXISMOTION => SDL_EVENT_GAMEPAD_AXIS_MOTION
* SDL_CONTROLLERBUTTONDOWN => SDL_EVENT_GAMEPAD_BUTTON_DOWN
* SDL_CONTROLLERBUTTONUP => SDL_EVENT_GAMEPAD_BUTTON_UP
* SDL_CONTROLLERDEVICEADDED => SDL_EVENT_GAMEPAD_ADDED
* SDL_CONTROLLERDEVICEREMAPPED => SDL_EVENT_GAMEPAD_REMAPPED
* SDL_CONTROLLERDEVICEREMOVED => SDL_EVENT_GAMEPAD_REMOVED
* SDL_CONTROLLERSENSORUPDATE => SDL_EVENT_GAMEPAD_SENSOR_UPDATE
* SDL_CONTROLLERTOUCHPADDOWN => SDL_EVENT_GAMEPAD_TOUCHPAD_DOWN
* SDL_CONTROLLERTOUCHPADMOTION => SDL_EVENT_GAMEPAD_TOUCHPAD_MOTION
* SDL_CONTROLLERTOUCHPADUP => SDL_EVENT_GAMEPAD_TOUCHPAD_UP
* SDL_DROPBEGIN => SDL_EVENT_DROP_BEGIN
* SDL_DROPCOMPLETE => SDL_EVENT_DROP_COMPLETE
* SDL_DROPFILE => SDL_EVENT_DROP_FILE
* SDL_DROPTEXT => SDL_EVENT_DROP_TEXT
* SDL_FINGERDOWN => SDL_EVENT_FINGER_DOWN
* SDL_FINGERMOTION => SDL_EVENT_FINGER_MOTION
* SDL_FINGERUP => SDL_EVENT_FINGER_UP
* SDL_FIRSTEVENT => SDL_EVENT_FIRST
* SDL_JOYAXISMOTION => SDL_EVENT_JOYSTICK_AXIS_MOTION
* SDL_JOYBATTERYUPDATED => SDL_EVENT_JOYSTICK_BATTERY_UPDATED
* SDL_JOYBUTTONDOWN => SDL_EVENT_JOYSTICK_BUTTON_DOWN
* SDL_JOYBUTTONUP => SDL_EVENT_JOYSTICK_BUTTON_UP
* SDL_JOYDEVICEADDED => SDL_EVENT_JOYSTICK_ADDED
* SDL_JOYDEVICEREMOVED => SDL_EVENT_JOYSTICK_REMOVED
* SDL_JOYHATMOTION => SDL_EVENT_JOYSTICK_HAT_MOTION
* SDL_KEYDOWN => SDL_EVENT_KEY_DOWN
* SDL_KEYMAPCHANGED => SDL_EVENT_KEYMAP_CHANGED
* SDL_KEYUP => SDL_EVENT_KEY_UP
* SDL_LASTEVENT => SDL_EVENT_LAST
* SDL_LOCALECHANGED => SDL_EVENT_LOCALE_CHANGED
* SDL_MOUSEBUTTONDOWN => SDL_EVENT_MOUSE_BUTTON_DOWN
* SDL_MOUSEBUTTONUP => SDL_EVENT_MOUSE_BUTTON_UP
* SDL_MOUSEMOTION => SDL_EVENT_MOUSE_MOTION
* SDL_MOUSEWHEEL => SDL_EVENT_MOUSE_WHEEL
* SDL_POLLSENTINEL => SDL_EVENT_POLL_SENTINEL
* SDL_QUIT => SDL_EVENT_QUIT
* SDL_RENDER_DEVICE_RESET => SDL_EVENT_RENDER_DEVICE_RESET
* SDL_RENDER_TARGETS_RESET => SDL_EVENT_RENDER_TARGETS_RESET
* SDL_SENSORUPDATE => SDL_EVENT_SENSOR_UPDATE
* SDL_SYSWMEVENT => SDL_EVENT_SYSWM
* SDL_TEXTEDITING => SDL_EVENT_TEXT_EDITING
* SDL_TEXTEDITING_EXT => SDL_EVENT_TEXT_EDITING_EXT
* SDL_TEXTINPUT => SDL_EVENT_TEXT_INPUT
* SDL_USEREVENT => SDL_EVENT_USER

The following structures have been renamed:
* SDL_ControllerAxisEvent => SDL_GamepadAxisEvent
* SDL_ControllerButtonEvent => SDL_GamepadButtonEvent
* SDL_ControllerDeviceEvent => SDL_GamepadDeviceEvent
* SDL_ControllerSensorEvent => SDL_GamepadSensorEvent
* SDL_ControllerTouchpadEvent => SDL_GamepadTouchpadEvent

The following functions have been removed:
* SDL_EventState() - replaced with SDL_SetEventEnabled()
* SDL_GetEventState() - replaced with SDL_EventEnabled()

## SDL_gamecontroller.h

SDL_gamecontroller.h has been renamed SDL_gamepad.h, and all APIs have been renamed to match.

The SDL_EVENT_GAMEPAD_ADDED event now provides the joystick instance ID in the which member of the cdevice event structure.

The functions SDL_GetGamepads(), SDL_GetGamepadInstanceName(), SDL_GetGamepadInstancePath(), SDL_GetGamepadInstancePlayerIndex(), SDL_GetGamepadInstanceGUID(), SDL_GetGamepadInstanceVendor(), SDL_GetGamepadInstanceProduct(), SDL_GetGamepadInstanceProductVersion(), and SDL_GetGamepadInstanceType() have been added to directly query the list of available gamepads.

SDL_GameControllerGetSensorDataWithTimestamp() has been removed. If you want timestamps for the sensor data, you should use the sensor_timestamp member of SDL_EVENT_GAMEPAD_SENSOR_UPDATE events.

The following enums have been renamed:
* SDL_GameControllerAxis => SDL_GamepadAxis
* SDL_GameControllerBindType => SDL_GamepadBindingType
* SDL_GameControllerButton => SDL_GamepadButton
* SDL_GameControllerType => SDL_GamepadType

The following structures have been renamed:
* SDL_GameController => SDL_Gamepad
* SDL_GameControllerButtonBind => SDL_GamepadBinding

The following functions have been renamed:
* SDL_GameControllerAddMapping() => SDL_AddGamepadMapping()
* SDL_GameControllerAddMappingsFromFile() => SDL_AddGamepadMappingsFromFile()
* SDL_GameControllerAddMappingsFromRW() => SDL_AddGamepadMappingsFromRW()
* SDL_GameControllerClose() => SDL_CloseGamepad()
* SDL_GameControllerFromInstanceID() => SDL_GetGamepadFromInstanceID()
* SDL_GameControllerFromPlayerIndex() => SDL_GetGamepadFromPlayerIndex()
* SDL_GameControllerGetAppleSFSymbolsNameForAxis() => SDL_GetGamepadAppleSFSymbolsNameForAxis()
* SDL_GameControllerGetAppleSFSymbolsNameForButton() => SDL_GetGamepadAppleSFSymbolsNameForButton()
* SDL_GameControllerGetAttached() => SDL_GamepadConnected()
* SDL_GameControllerGetAxis() => SDL_GetGamepadAxis()
* SDL_GameControllerGetAxisFromString() => SDL_GetGamepadAxisFromString()
* SDL_GameControllerGetBindForAxis() => SDL_GetGamepadBindForAxis()
* SDL_GameControllerGetBindForButton() => SDL_GetGamepadBindForButton()
* SDL_GameControllerGetButton() => SDL_GetGamepadButton()
* SDL_GameControllerGetButtonFromString() => SDL_GetGamepadButtonFromString()
* SDL_GameControllerGetFirmwareVersion() => SDL_GetGamepadFirmwareVersion()
* SDL_GameControllerGetJoystick() => SDL_GetGamepadJoystick()
* SDL_GameControllerGetNumTouchpadFingers() => SDL_GetNumGamepadTouchpadFingers()
* SDL_GameControllerGetNumTouchpads() => SDL_GetNumGamepadTouchpads()
* SDL_GameControllerGetPlayerIndex() => SDL_GetGamepadPlayerIndex()
* SDL_GameControllerGetProduct() => SDL_GetGamepadProduct()
* SDL_GameControllerGetProductVersion() => SDL_GetGamepadProductVersion()
* SDL_GameControllerGetSensorData() => SDL_GetGamepadSensorData()
* SDL_GameControllerGetSensorDataRate() => SDL_GetGamepadSensorDataRate()
* SDL_GameControllerGetSerial() => SDL_GetGamepadSerial()
* SDL_GameControllerGetStringForAxis() => SDL_GetGamepadStringForAxis()
* SDL_GameControllerGetStringForButton() => SDL_GetGamepadStringForButton()
* SDL_GameControllerGetTouchpadFinger() => SDL_GetGamepadTouchpadFinger()
* SDL_GameControllerGetType() => SDL_GetGamepadType()
* SDL_GameControllerGetVendor() => SDL_GetGamepadVendor()
* SDL_GameControllerHasAxis() => SDL_GamepadHasAxis()
* SDL_GameControllerHasButton() => SDL_GamepadHasButton()
* SDL_GameControllerHasLED() => SDL_GamepadHasLED()
* SDL_GameControllerHasRumble() => SDL_GamepadHasRumble()
* SDL_GameControllerHasRumbleTriggers() => SDL_GamepadHasRumbleTriggers()
* SDL_GameControllerHasSensor() => SDL_GamepadHasSensor()
* SDL_GameControllerIsSensorEnabled() => SDL_GamepadSensorEnabled()
* SDL_GameControllerMapping() => SDL_GetGamepadMapping()
* SDL_GameControllerMappingForGUID() => SDL_GetGamepadMappingForGUID()
* SDL_GameControllerMappingForIndex() => SDL_GetGamepadMappingForIndex()
* SDL_GameControllerName() => SDL_GetGamepadName()
* SDL_GameControllerNumMappings() => SDL_GetNumGamepadMappings()
* SDL_GameControllerOpen() => SDL_OpenGamepad()
* SDL_GameControllerPath() => SDL_GetGamepadPath()
* SDL_GameControllerRumble() => SDL_RumbleGamepad()
* SDL_GameControllerRumbleTriggers() => SDL_RumbleGamepadTriggers()
* SDL_GameControllerSendEffect() => SDL_SendGamepadEffect()
* SDL_GameControllerSetLED() => SDL_SetGamepadLED()
* SDL_GameControllerSetPlayerIndex() => SDL_SetGamepadPlayerIndex()
* SDL_GameControllerSetSensorEnabled() => SDL_SetGamepadSensorEnabled()
* SDL_GameControllerUpdate() => SDL_UpdateGamepads()
* SDL_IsGameController() => SDL_IsGamepad()

The following functions have been removed:
* SDL_GameControllerEventState() - replaced with SDL_SetGamepadEventsEnabled() and SDL_GamepadEventsEnabled()
* SDL_GameControllerMappingForDeviceIndex() - replaced with SDL_GetGamepadInstanceMapping()
* SDL_GameControllerNameForIndex() - replaced with SDL_GetGamepadInstanceName()
* SDL_GameControllerPathForIndex() - replaced with SDL_GetGamepadInstancePath()
* SDL_GameControllerTypeForIndex() - replaced with SDL_GetGamepadInstanceType()

The following symbols have been renamed:
* SDL_CONTROLLER_AXIS_INVALID => SDL_GAMEPAD_AXIS_INVALID
* SDL_CONTROLLER_AXIS_LEFTX => SDL_GAMEPAD_AXIS_LEFTX
* SDL_CONTROLLER_AXIS_LEFTY => SDL_GAMEPAD_AXIS_LEFTY
* SDL_CONTROLLER_AXIS_MAX => SDL_GAMEPAD_AXIS_MAX
* SDL_CONTROLLER_AXIS_RIGHTX => SDL_GAMEPAD_AXIS_RIGHTX
* SDL_CONTROLLER_AXIS_RIGHTY => SDL_GAMEPAD_AXIS_RIGHTY
* SDL_CONTROLLER_AXIS_TRIGGERLEFT => SDL_GAMEPAD_AXIS_LEFT_TRIGGER
* SDL_CONTROLLER_AXIS_TRIGGERRIGHT => SDL_GAMEPAD_AXIS_RIGHT_TRIGGER
* SDL_CONTROLLER_BINDTYPE_AXIS => SDL_GAMEPAD_BINDTYPE_AXIS
* SDL_CONTROLLER_BINDTYPE_BUTTON => SDL_GAMEPAD_BINDTYPE_BUTTON
* SDL_CONTROLLER_BINDTYPE_HAT => SDL_GAMEPAD_BINDTYPE_HAT
* SDL_CONTROLLER_BINDTYPE_NONE => SDL_GAMEPAD_BINDTYPE_NONE
* SDL_CONTROLLER_BUTTON_A => SDL_GAMEPAD_BUTTON_A
* SDL_CONTROLLER_BUTTON_B => SDL_GAMEPAD_BUTTON_B
* SDL_CONTROLLER_BUTTON_BACK => SDL_GAMEPAD_BUTTON_BACK
* SDL_CONTROLLER_BUTTON_DPAD_DOWN => SDL_GAMEPAD_BUTTON_DPAD_DOWN
* SDL_CONTROLLER_BUTTON_DPAD_LEFT => SDL_GAMEPAD_BUTTON_DPAD_LEFT
* SDL_CONTROLLER_BUTTON_DPAD_RIGHT => SDL_GAMEPAD_BUTTON_DPAD_RIGHT
* SDL_CONTROLLER_BUTTON_DPAD_UP => SDL_GAMEPAD_BUTTON_DPAD_UP
* SDL_CONTROLLER_BUTTON_GUIDE => SDL_GAMEPAD_BUTTON_GUIDE
* SDL_CONTROLLER_BUTTON_INVALID => SDL_GAMEPAD_BUTTON_INVALID
* SDL_CONTROLLER_BUTTON_LEFTSHOULDER => SDL_GAMEPAD_BUTTON_LEFT_SHOULDER
* SDL_CONTROLLER_BUTTON_LEFTSTICK => SDL_GAMEPAD_BUTTON_LEFT_STICK
* SDL_CONTROLLER_BUTTON_MAX => SDL_GAMEPAD_BUTTON_MAX
* SDL_CONTROLLER_BUTTON_MISC1 => SDL_GAMEPAD_BUTTON_MISC1
* SDL_CONTROLLER_BUTTON_PADDLE1 => SDL_GAMEPAD_BUTTON_PADDLE1
* SDL_CONTROLLER_BUTTON_PADDLE2 => SDL_GAMEPAD_BUTTON_PADDLE2
* SDL_CONTROLLER_BUTTON_PADDLE3 => SDL_GAMEPAD_BUTTON_PADDLE3
* SDL_CONTROLLER_BUTTON_PADDLE4 => SDL_GAMEPAD_BUTTON_PADDLE4
* SDL_CONTROLLER_BUTTON_RIGHTSHOULDER => SDL_GAMEPAD_BUTTON_RIGHT_SHOULDER
* SDL_CONTROLLER_BUTTON_RIGHTSTICK => SDL_GAMEPAD_BUTTON_RIGHT_STICK
* SDL_CONTROLLER_BUTTON_START => SDL_GAMEPAD_BUTTON_START
* SDL_CONTROLLER_BUTTON_TOUCHPAD => SDL_GAMEPAD_BUTTON_TOUCHPAD
* SDL_CONTROLLER_BUTTON_X => SDL_GAMEPAD_BUTTON_X
* SDL_CONTROLLER_BUTTON_Y => SDL_GAMEPAD_BUTTON_Y
* SDL_CONTROLLER_TYPE_AMAZON_LUNA => SDL_GAMEPAD_TYPE_AMAZON_LUNA
* SDL_CONTROLLER_TYPE_GOOGLE_STADIA => SDL_GAMEPAD_TYPE_GOOGLE_STADIA
* SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_JOYCON_LEFT => SDL_GAMEPAD_TYPE_NINTENDO_SWITCH_JOYCON_LEFT
* SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_JOYCON_PAIR => SDL_GAMEPAD_TYPE_NINTENDO_SWITCH_JOYCON_PAIR
* SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_JOYCON_RIGHT => SDL_GAMEPAD_TYPE_NINTENDO_SWITCH_JOYCON_RIGHT
* SDL_CONTROLLER_TYPE_NINTENDO_SWITCH_PRO => SDL_GAMEPAD_TYPE_NINTENDO_SWITCH_PRO
* SDL_CONTROLLER_TYPE_NVIDIA_SHIELD => SDL_GAMEPAD_TYPE_NVIDIA_SHIELD
* SDL_CONTROLLER_TYPE_PS3 => SDL_GAMEPAD_TYPE_PS3
* SDL_CONTROLLER_TYPE_PS4 => SDL_GAMEPAD_TYPE_PS4
* SDL_CONTROLLER_TYPE_PS5 => SDL_GAMEPAD_TYPE_PS5
* SDL_CONTROLLER_TYPE_UNKNOWN => SDL_GAMEPAD_TYPE_UNKNOWN
* SDL_CONTROLLER_TYPE_VIRTUAL => SDL_GAMEPAD_TYPE_VIRTUAL
* SDL_CONTROLLER_TYPE_XBOX360 => SDL_GAMEPAD_TYPE_XBOX360
* SDL_CONTROLLER_TYPE_XBOXONE => SDL_GAMEPAD_TYPE_XBOXONE

## SDL_gesture.h

The gesture API has been removed. There is no replacement planned in SDL3.
However, the SDL2 code has been moved to a single-header library that can
be dropped into an SDL3 or SDL2 program, to continue to provide this
functionality to your app and aid migration. That is located in the
[SDL_gesture GitHub repository](https://github.com/libsdl-org/SDL_gesture).

## SDL_hints.h

SDL_AddHintCallback() now returns a standard int result instead of void, returning 0 if the function succeeds or a negative error code if there was an error.

The following hints have been removed:
* SDL_HINT_VIDEO_HIGHDPI_DISABLED - high DPI support is always enabled
* SDL_HINT_IDLE_TIMER_DISABLED - use SDL_DisableScreenSaver instead
* SDL_HINT_MOUSE_RELATIVE_SCALING - mouse coordinates are no longer automatically scaled by the SDL renderer
* SDL_HINT_RENDER_LOGICAL_SIZE_MODE - the logical size mode is explicitly set with SDL_SetRenderLogicalPresentation()
* SDL_HINT_VIDEO_X11_FORCE_EGL - use SDL_HINT_VIDEO_FORCE_EGL instead
* SDL_HINT_VIDEO_X11_XINERAMA - Xinerama no longer supported by the X11 backend
* SDL_HINT_VIDEO_X11_XVIDMODE - Xvidmode no longer supported by the X11 backend

* Renamed hints SDL_HINT_VIDEODRIVER and SDL_HINT_AUDIODRIVER to SDL_HINT_VIDEO_DRIVER and SDL_HINT_AUDIO_DRIVER
* Renamed environment variables SDL_VIDEODRIVER and SDL_AUDIODRIVER to SDL_VIDEO_DRIVER and SDL_AUDIO_DRIVER

## SDL_init.h

The following symbols have been renamed:
* SDL_INIT_GAMECONTROLLER => SDL_INIT_GAMEPAD

The following symbols have been removed:
* SDL_INIT_NOPARACHUTE

## SDL_joystick.h

SDL_JoystickID has changed from Sint32 to Uint32, with an invalid ID being 0.

Rather than iterating over joysticks using device index, there is a new function SDL_GetJoysticks() to get the current list of joysticks, and new functions to get information about joysticks from their instance ID:
```c
{
    if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) == 0) {
        int i, num_joysticks;
        SDL_JoystickID *joysticks = SDL_GetJoysticks(&num_joysticks);
        if (joysticks) {
            for (i = 0; i < num_joysticks; ++i) {
                SDL_JoystickID instance_id = joysticks[i];
                const char *name = SDL_GetJoystickInstanceName(instance_id);
                const char *path = SDL_GetJoystickInstancePath(instance_id);

                SDL_Log("Joystick %" SDL_PRIu32 ": %s%s%s VID 0x%.4x, PID 0x%.4x\n",
                        instance_id, name ? name : "Unknown", path ? ", " : "", path ? path : "", SDL_GetJoystickInstanceVendor(instance_id), SDL_GetJoystickInstanceProduct(instance_id));
            }
            SDL_free(joysticks);
        }
        SDL_QuitSubSystem(SDL_INIT_JOYSTICK);
    }
}
```

The SDL_EVENT_JOYSTICK_ADDED event now provides the joystick instance ID in the `which` member of the jdevice event structure.

The functions SDL_GetJoysticks(), SDL_GetJoystickInstanceName(), SDL_GetJoystickInstancePath(), SDL_GetJoystickInstancePlayerIndex(), SDL_GetJoystickInstanceGUID(), SDL_GetJoystickInstanceVendor(), SDL_GetJoystickInstanceProduct(), SDL_GetJoystickInstanceProductVersion(), and SDL_GetJoystickInstanceType() have been added to directly query the list of available joysticks.

SDL_AttachVirtualJoystick() and SDL_AttachVirtualJoystickEx() now return the joystick instance ID instead of a device index, and return 0 if there was an error.

The following functions have been renamed:
* SDL_JoystickAttachVirtual() => SDL_AttachVirtualJoystick()
* SDL_JoystickAttachVirtualEx() => SDL_AttachVirtualJoystickEx()
* SDL_JoystickClose() => SDL_CloseJoystick()
* SDL_JoystickCurrentPowerLevel() => SDL_GetJoystickPowerLevel()
* SDL_JoystickDetachVirtual() => SDL_DetachVirtualJoystick()
* SDL_JoystickFromInstanceID() => SDL_GetJoystickFromInstanceID()
* SDL_JoystickFromPlayerIndex() => SDL_GetJoystickFromPlayerIndex()
* SDL_JoystickGetAttached() => SDL_JoystickConnected()
* SDL_JoystickGetAxis() => SDL_GetJoystickAxis()
* SDL_JoystickGetAxisInitialState() => SDL_GetJoystickAxisInitialState()
* SDL_JoystickGetButton() => SDL_GetJoystickButton()
* SDL_JoystickGetFirmwareVersion() => SDL_GetJoystickFirmwareVersion()
* SDL_JoystickGetGUID() => SDL_GetJoystickGUID()
* SDL_JoystickGetGUIDFromString() => SDL_GetJoystickGUIDFromString()
* SDL_JoystickGetGUIDString() => SDL_GetJoystickGUIDString()
* SDL_JoystickGetHat() => SDL_GetJoystickHat()
* SDL_JoystickGetPlayerIndex() => SDL_GetJoystickPlayerIndex()
* SDL_JoystickGetProduct() => SDL_GetJoystickProduct()
* SDL_JoystickGetProductVersion() => SDL_GetJoystickProductVersion()
* SDL_JoystickGetSerial() => SDL_GetJoystickSerial()
* SDL_JoystickGetType() => SDL_GetJoystickType()
* SDL_JoystickGetVendor() => SDL_GetJoystickVendor()
* SDL_JoystickInstanceID() => SDL_GetJoystickInstanceID()
* SDL_JoystickIsVirtual() => SDL_IsJoystickVirtual()
* SDL_JoystickName() => SDL_GetJoystickName()
* SDL_JoystickNumAxes() => SDL_GetNumJoystickAxes()
* SDL_JoystickNumButtons() => SDL_GetNumJoystickButtons()
* SDL_JoystickNumHats() => SDL_GetNumJoystickHats()
* SDL_JoystickOpen() => SDL_OpenJoystick()
* SDL_JoystickPath() => SDL_GetJoystickPath()
* SDL_JoystickRumble() => SDL_RumbleJoystick()
* SDL_JoystickRumbleTriggers() => SDL_RumbleJoystickTriggers()
* SDL_JoystickSendEffect() => SDL_SendJoystickEffect()
* SDL_JoystickSetLED() => SDL_SetJoystickLED()
* SDL_JoystickSetPlayerIndex() => SDL_SetJoystickPlayerIndex()
* SDL_JoystickSetVirtualAxis() => SDL_SetJoystickVirtualAxis()
* SDL_JoystickSetVirtualButton() => SDL_SetJoystickVirtualButton()
* SDL_JoystickSetVirtualHat() => SDL_SetJoystickVirtualHat()
* SDL_JoystickUpdate() => SDL_UpdateJoysticks()

The following symbols have been renamed:
* SDL_JOYSTICK_TYPE_GAMECONTROLLER => SDL_JOYSTICK_TYPE_GAMEPAD

The following functions have been removed:
* SDL_JoystickEventState() - replaced with SDL_SetJoystickEventsEnabled() and SDL_JoystickEventsEnabled()
* SDL_JoystickGetDeviceGUID() - replaced with SDL_GetJoystickInstanceGUID()
* SDL_JoystickGetDeviceInstanceID()
* SDL_JoystickGetDevicePlayerIndex() - replaced with SDL_GetJoystickInstancePlayerIndex()
* SDL_JoystickGetDeviceProduct() - replaced with SDL_GetJoystickInstanceProduct()
* SDL_JoystickGetDeviceProductVersion() - replaced with SDL_GetJoystickInstanceProductVersion()
* SDL_JoystickGetDeviceType() - replaced with SDL_GetJoystickInstanceType()
* SDL_JoystickGetDeviceVendor() - replaced with SDL_GetJoystickInstanceVendor()
* SDL_JoystickNameForIndex() - replaced with SDL_GetJoystickInstanceName()
* SDL_JoystickNumBalls() - API has been removed, see https://github.com/libsdl-org/SDL/issues/6766
* SDL_JoystickPathForIndex() - replaced with SDL_GetJoystickInstancePath()
* SDL_NumJoysticks() - replaced with SDL_GetJoysticks()

The following symbols have been removed:
* SDL_JOYBALLMOTION

## SDL_keyboard.h

The following functions have been renamed:
* SDL_IsScreenKeyboardShown() => SDL_ScreenKeyboardShown()
* SDL_IsTextInputActive() => SDL_TextInputActive()
* SDL_IsTextInputShown() => SDL_TextInputShown()

## SDL_keycode.h

The following symbols have been renamed:
* KMOD_ALT => SDL_KMOD_ALT
* KMOD_CAPS => SDL_KMOD_CAPS
* KMOD_CTRL => SDL_KMOD_CTRL
* KMOD_GUI => SDL_KMOD_GUI
* KMOD_LALT => SDL_KMOD_LALT
* KMOD_LCTRL => SDL_KMOD_LCTRL
* KMOD_LGUI => SDL_KMOD_LGUI
* KMOD_LSHIFT => SDL_KMOD_LSHIFT
* KMOD_MODE => SDL_KMOD_MODE
* KMOD_NONE => SDL_KMOD_NONE
* KMOD_NUM => SDL_KMOD_NUM
* KMOD_RALT => SDL_KMOD_RALT
* KMOD_RCTRL => SDL_KMOD_RCTRL
* KMOD_RESERVED => SDL_KMOD_RESERVED
* KMOD_RGUI => SDL_KMOD_RGUI
* KMOD_RSHIFT => SDL_KMOD_RSHIFT
* KMOD_SCROLL => SDL_KMOD_SCROLL
* KMOD_SHIFT => SDL_KMOD_SHIFT

## SDL_loadso.h

SDL_LoadFunction() now returns `SDL_FunctionPointer` instead of `void *`, and should be cast to the appropriate function type. You can define SDL_FUNCTION_POINTER_IS_VOID_POINTER in your project to restore the previous behavior.

## SDL_main.h

SDL3 doesn't have a static libSDLmain to link against anymore.
Instead SDL_main.h is now a header-only library **and not included by SDL.h anymore**.

Using it is really simple: Just `#include <SDL3/SDL_main.h>` in the source file with your standard
`int main(int argc, char* argv[])` function.

The rest happens automatically: If your target platform needs the SDL_main functionality,
your main function will be renamed to SDL_main (with a macro, just like in SDL2),
and the real main-function will be implemented by inline code from SDL_main.h - and if your target
platform doesn't need it, nothing happens.
Like in SDL2, if you want to handle the platform-specific main yourself instead of using the SDL_main magic,
you can `#define SDL_MAIN_HANDLED` before `#include <SDL3/SDL_main.h>` - don't forget to call SDL_SetMainReady()

If you need SDL_main.h in another source file (that doesn't implement main()), you also need to
`#define SDL_MAIN_HANDLED` there, to avoid that multiple main functions are generated by SDL_main.h

There is currently one platform where this approach doesn't always work: WinRT.
It requires WinMain to be implemented in a C++ source file that's compiled with `/ZW`. If your main
is implemented in plain C, or you can't use `/ZW` on that file, you can add another .cpp
source file that just contains `#include <SDL3/SDL_main.h>` and compile that with `/ZW` - but keep
in mind that the source file with your standard main also needs that include!
See [README-winrt.md](./README-winrt.md) for more details.

Furthermore, the different SDL_*RunApp() functions (SDL_WinRtRunApp, SDL_GDKRunApp, SDL_UIKitRunApp)
have been unified into just `int SDL_RunApp(int argc, char* argv[], void * reserved)` (which is also
used by additional platforms that didn't have a SDL_RunApp-like function before).

## SDL_metal.h

SDL_Metal_GetDrawableSize() has been removed. SDL_GetWindowSizeInPixels() can be used in its place.

## SDL_mouse.h

SDL_ShowCursor() has been split into three functions: SDL_ShowCursor(), SDL_HideCursor(), and SDL_CursorVisible()

SDL_GetMouseState(), SDL_GetGlobalMouseState(), SDL_GetRelativeMouseState(), SDL_WarpMouseInWindow(), and SDL_WarpMouseGlobal() all use floating point mouse positions, to provide sub-pixel precision on platforms that support it.

The following functions have been renamed:
* SDL_FreeCursor() => SDL_DestroyCursor()

## SDL_mutex.h

The following functions have been renamed:
* SDL_CondBroadcast() => SDL_BroadcastCondition()
* SDL_CondSignal() => SDL_SignalCondition()
* SDL_CondWait() => SDL_WaitCondition()
* SDL_CondWaitTimeout() => SDL_WaitConditionTimeout()
* SDL_CreateCond() => SDL_CreateCondition()
* SDL_DestroyCond() => SDL_DestroyCondition()
* SDL_SemPost() => SDL_PostSemaphore()
* SDL_SemTryWait() => SDL_TryWaitSemaphore()
* SDL_SemValue() => SDL_GetSemaphoreValue()
* SDL_SemWait() => SDL_WaitSemaphore()
* SDL_SemWaitTimeout() => SDL_WaitSemaphoreTimeout()

The following symbols have been renamed:
* SDL_cond => SDL_Condition
* SDL_mutex => SDL_Mutex
* SDL_sem => SDL_Semaphore

## SDL_pixels.h

SDL_CalculateGammaRamp has been removed, because SDL_SetWindowGammaRamp has been removed as well due to poor support in modern operating systems (see [SDL_video.h](#sdl_videoh)).

The following functions have been renamed:
* SDL_AllocFormat() => SDL_CreatePixelFormat()
* SDL_AllocPalette() => SDL_CreatePalette()
* SDL_FreeFormat() => SDL_DestroyPixelFormat()
* SDL_FreePalette() => SDL_DestroyPalette()
* SDL_MasksToPixelFormatEnum() => SDL_GetPixelFormatEnumForMasks()
* SDL_PixelFormatEnumToMasks() => SDL_GetMasksForPixelFormatEnum()

The following symbols have been renamed:
* SDL_DISPLAYEVENT_DISCONNECTED => SDL_EVENT_DISPLAY_DISCONNECTED
* SDL_DISPLAYEVENT_MOVED => SDL_EVENT_DISPLAY_MOVED
* SDL_DISPLAYEVENT_ORIENTATION => SDL_EVENT_DISPLAY_ORIENTATION
* SDL_WINDOWEVENT_CLOSE => SDL_EVENT_WINDOW_CLOSE_REQUESTED
* SDL_WINDOWEVENT_DISPLAY_CHANGED => SDL_EVENT_WINDOW_DISPLAY_CHANGED
* SDL_WINDOWEVENT_ENTER => SDL_EVENT_WINDOW_ENTER
* SDL_WINDOWEVENT_EXPOSED => SDL_EVENT_WINDOW_EXPOSED
* SDL_WINDOWEVENT_FOCUS_GAINED => SDL_EVENT_WINDOW_FOCUS_GAINED
* SDL_WINDOWEVENT_FOCUS_LOST => SDL_EVENT_WINDOW_FOCUS_LOST
* SDL_WINDOWEVENT_HIDDEN => SDL_EVENT_WINDOW_HIDDEN
* SDL_WINDOWEVENT_HIT_TEST => SDL_EVENT_WINDOW_HIT_TEST
* SDL_WINDOWEVENT_ICCPROF_CHANGED => SDL_EVENT_WINDOW_ICCPROF_CHANGED
* SDL_WINDOWEVENT_LEAVE => SDL_EVENT_WINDOW_LEAVE
* SDL_WINDOWEVENT_MAXIMIZED => SDL_EVENT_WINDOW_MAXIMIZED
* SDL_WINDOWEVENT_MINIMIZED => SDL_EVENT_WINDOW_MINIMIZED
* SDL_WINDOWEVENT_MOVED => SDL_EVENT_WINDOW_MOVED
* SDL_WINDOWEVENT_RESIZED => SDL_EVENT_WINDOW_RESIZED
* SDL_WINDOWEVENT_RESTORED => SDL_EVENT_WINDOW_RESTORED
* SDL_WINDOWEVENT_SHOWN => SDL_EVENT_WINDOW_SHOWN
* SDL_WINDOWEVENT_SIZE_CHANGED => SDL_EVENT_WINDOW_SIZE_CHANGED
* SDL_WINDOWEVENT_TAKE_FOCUS => SDL_EVENT_WINDOW_TAKE_FOCUS


## SDL_platform.h

The preprocessor symbol `__MACOSX__` has been renamed `__MACOS__`, and `__IPHONEOS__` has been renamed `__IOS__`

## SDL_rect.h

The following functions have been renamed:
* SDL_EncloseFPoints() => SDL_GetRectEnclosingPointsFloat()
* SDL_EnclosePoints() => SDL_GetRectEnclosingPoints()
* SDL_FRectEmpty() => SDL_RectEmptyFloat()
* SDL_FRectEquals() => SDL_RectsEqualFloat()
* SDL_FRectEqualsEpsilon() => SDL_RectsEqualEpsilon()
* SDL_HasIntersection() => SDL_HasRectIntersection()
* SDL_HasIntersectionF() => SDL_HasRectIntersectionFloat()
* SDL_IntersectFRect() => SDL_GetRectIntersectionFloat()
* SDL_IntersectFRectAndLine() => SDL_GetRectAndLineIntersectionFloat()
* SDL_IntersectRect() => SDL_GetRectIntersection()
* SDL_IntersectRectAndLine() => SDL_GetRectAndLineIntersection()
* SDL_PointInFRect() => SDL_PointInRectFloat()
* SDL_RectEquals() => SDL_RectsEqual()
* SDL_UnionFRect() => SDL_GetRectUnionFloat()
* SDL_UnionRect() => SDL_GetRectUnion()

## SDL_render.h

SDL_GetRenderDriverInfo() has been removed, since most of the information it reported were
estimates and could not be accurate before creating a renderer. Often times this function
was used to figure out the index of a driver, so one would call it in a for-loop, looking
for the driver named "opengl" or whatnot. SDL_GetRenderDriver() has been added for this
functionality, which returns only the name of the driver.

Additionally, SDL_CreateRenderer()'s second argument is no longer an integer index, but a
`const char *` representing a renderer's name; if you were just using a for-loop to find
which index is the "opengl" or whatnot driver, you can just pass that string directly
here, now. Passing NULL is the same as passing -1 here in SDL2, to signify you want SDL
to decide for you.

When a renderer is created, it will automatically set the logical size to the size of
the window in screen coordinates. For high DPI displays, this will set up scaling from
window coordinates to pixels. You can disable this scaling with:
```c
    SDL_SetRenderLogicalPresentation(renderer, 0, 0, SDL_LOGICAL_PRESENTATION_DISABLED, SDL_SCALEMODE_NEAREST);
```

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.

The following functions have been renamed:
* SDL_GetRendererOutputSize() => SDL_GetCurrentRenderOutputSize()
* SDL_RenderCopy() => SDL_RenderTexture()
* SDL_RenderCopyEx() => SDL_RenderTextureRotated()
* SDL_RenderCopyExF() => SDL_RenderTextureRotated()
* SDL_RenderCopyF() => SDL_RenderTexture()
* SDL_RenderDrawLine() => SDL_RenderLine()
* SDL_RenderDrawLineF() => SDL_RenderLine()
* SDL_RenderDrawLines() => SDL_RenderLines()
* SDL_RenderDrawLinesF() => SDL_RenderLines()
* SDL_RenderDrawPoint() => SDL_RenderPoint()
* SDL_RenderDrawPointF() => SDL_RenderPoint()
* SDL_RenderDrawPoints() => SDL_RenderPoints()
* SDL_RenderDrawPointsF() => SDL_RenderPoints()
* SDL_RenderDrawRect() => SDL_RenderRect()
* SDL_RenderDrawRectF() => SDL_RenderRect()
* SDL_RenderDrawRects() => SDL_RenderRects()
* SDL_RenderDrawRectsF() => SDL_RenderRects()
* SDL_RenderFillRectF() => SDL_RenderFillRect()
* SDL_RenderFillRectsF() => SDL_RenderFillRects()
* SDL_RenderGetClipRect() => SDL_GetRenderClipRect()
* SDL_RenderGetIntegerScale() => SDL_GetRenderIntegerScale()
* SDL_RenderGetLogicalSize() => SDL_GetRenderLogicalPresentation()
* SDL_RenderGetMetalCommandEncoder() => SDL_GetRenderMetalCommandEncoder()
* SDL_RenderGetMetalLayer() => SDL_GetRenderMetalLayer()
* SDL_RenderGetScale() => SDL_GetRenderScale()
* SDL_RenderGetViewport() => SDL_GetRenderViewport()
* SDL_RenderGetWindow() => SDL_GetRenderWindow()
* SDL_RenderIsClipEnabled() => SDL_RenderClipEnabled()
* SDL_RenderLogicalToWindow() => SDL_RenderCoordinatesToWindow()
* SDL_RenderSetClipRect() => SDL_SetRenderClipRect()
* SDL_RenderSetIntegerScale() => SDL_SetRenderIntegerScale()
* SDL_RenderSetLogicalSize() => SDL_SetRenderLogicalPresentation()
* SDL_RenderSetScale() => SDL_SetRenderScale()
* SDL_RenderSetVSync() => SDL_SetRenderVSync()
* SDL_RenderSetViewport() => SDL_SetRenderViewport()
* SDL_RenderWindowToLogical() => SDL_RenderCoordinatesFromWindow()

The following functions have been removed:
* SDL_RenderGetIntegerScale()
* SDL_RenderSetIntegerScale() - this is now explicit with SDL_LOGICAL_PRESENTATION_INTEGER_SCALE
* SDL_RenderTargetSupported() - render targets are always supported

The following symbols have been renamed:
* SDL_ScaleModeBest => SDL_SCALEMODE_BEST
* SDL_ScaleModeLinear => SDL_SCALEMODE_LINEAR
* SDL_ScaleModeNearest => SDL_SCALEMODE_NEAREST

## SDL_rwops.h

The following symbols have been renamed:
* RW_SEEK_CUR => SDL_RW_SEEK_CUR
* RW_SEEK_END => SDL_RW_SEEK_END
* RW_SEEK_SET => SDL_RW_SEEK_SET

SDL_RWread and SDL_RWwrite (and SDL_RWops::read, SDL_RWops::write) have a different function signature in SDL3.

Previously they looked more like stdio:

```c
size_t SDL_RWread(SDL_RWops *context, void *ptr, size_t size, size_t maxnum);
size_t SDL_RWwrite(SDL_RWops *context, const void *ptr, size_t size, size_t maxnum);
```

But now they look more like POSIX:

```c
Sint64 SDL_RWread(SDL_RWops *context, void *ptr, Sint64 size);
Sint64 SDL_RWwrite(SDL_RWops *context, const void *ptr, Sint64 size);
```

SDL_RWread() previously returned 0 at end of file or other error. Now it returns the number of bytes read, 0 for end of file, -1 for another error, or -2 for data not ready (in the case of a non-blocking context).

Code that used to look like this:
```
size_t custom_read(void *ptr, size_t size, size_t nitems, SDL_RWops *stream)
{
    return (size_t)SDL_RWread(stream, ptr, size, nitems);
}
```
should be changed to:
```
size_t custom_read(void *ptr, size_t size, size_t nitems, SDL_RWops *stream)
{
    Sint64 amount = SDL_RWread(stream, ptr, size * nitems);
    if (amount <= 0) {
        return 0;
    }
    return (size_t)(amount / size);
}
```

Similarly, SDL_RWwrite() can return -2 for data not ready in the case of a non-blocking context. There is currently no way to create a non-blocking context, we have simply defined the semantic for your own custom SDL_RWops object.

SDL_RWFromFP has been removed from the API, due to issues when the SDL library uses a different C runtime from the application.

You can implement this in your own code easily:
```c
#include <stdio.h>


static Sint64 SDLCALL
stdio_size(SDL_RWops * context)
{
    Sint64 pos, size;

    pos = SDL_RWseek(context, 0, SDL_RW_SEEK_CUR);
    if (pos < 0) {
        return -1;
    }
    size = SDL_RWseek(context, 0, SDL_RW_SEEK_END);

    SDL_RWseek(context, pos, SDL_RW_SEEK_SET);
    return size;
}

static Sint64 SDLCALL
stdio_seek(SDL_RWops * context, Sint64 offset, int whence)
{
    int stdiowhence;

    switch (whence) {
    case SDL_RW_SEEK_SET:
        stdiowhence = SEEK_SET;
        break;
    case SDL_RW_SEEK_CUR:
        stdiowhence = SEEK_CUR;
        break;
    case SDL_RW_SEEK_END:
        stdiowhence = SEEK_END;
        break;
    default:
        return SDL_SetError("Unknown value for 'whence'");
    }

    if (fseek((FILE *)context->hidden.stdio.fp, (fseek_off_t)offset, stdiowhence) == 0) {
        Sint64 pos = ftell((FILE *)context->hidden.stdio.fp);
        if (pos < 0) {
            return SDL_SetError("Couldn't get stream offset");
        }
        return pos;
    }
    return SDL_Error(SDL_EFSEEK);
}

static Sint64 SDLCALL
stdio_read(SDL_RWops * context, void *ptr, Sint64 size)
{
    size_t nread;

    nread = fread(ptr, 1, (size_t) size, (FILE *)context->hidden.stdio.fp);
    if (nread == 0 && ferror((FILE *)context->hidden.stdio.fp)) {
        return SDL_Error(SDL_EFREAD);
    }
    return (Sint64) nread;
}

static Sint64 SDLCALL
stdio_write(SDL_RWops * context, const void *ptr, Sint64 size)
{
    size_t nwrote;

    nwrote = fwrite(ptr, 1, (size_t) size, (FILE *)context->hidden.stdio.fp);
    if (nwrote == 0 && ferror((FILE *)context->hidden.stdio.fp)) {
        return SDL_Error(SDL_EFWRITE);
    }
    return (Sint64) nwrote;
}

static int SDLCALL
stdio_close(SDL_RWops * context)
{
    int status = 0;
    if (context) {
        if (context->hidden.stdio.autoclose) {
            /* WARNING:  Check the return value here! */
            if (fclose((FILE *)context->hidden.stdio.fp) != 0) {
                status = SDL_Error(SDL_EFWRITE);
            }
        }
        SDL_DestroyRW(context);
    }
    return status;
}

SDL_RWops *
SDL_RWFromFP(void *fp, SDL_bool autoclose)
{
    SDL_RWops *rwops = NULL;

    rwops = SDL_CreateRW();
    if (rwops != NULL) {
        rwops->size = stdio_size;
        rwops->seek = stdio_seek;
        rwops->read = stdio_read;
        rwops->write = stdio_write;
        rwops->close = stdio_close;
        rwops->hidden.stdio.fp = fp;
        rwops->hidden.stdio.autoclose = autoclose;
        rwops->type = SDL_RWOPS_STDFILE;
    }
    return rwops;
}
```


The following functions have been renamed:
* SDL_AllocRW() => SDL_CreateRW()
* SDL_FreeRW() => SDL_DestroyRW()

## SDL_sensor.h

SDL_SensorID has changed from Sint32 to Uint32, with an invalid ID being 0.

Rather than iterating over sensors using device index, there is a new function SDL_GetSensors() to get the current list of sensors, and new functions to get information about sensors from their instance ID:
```c
{
    if (SDL_InitSubSystem(SDL_INIT_SENSOR) == 0) {
        int i, num_sensors;
        SDL_SensorID *sensors = SDL_GetSensors(&num_sensors);
        if (sensors) {
            for (i = 0; i < num_sensors; ++i) {
                SDL_Log("Sensor %" SDL_PRIu32 ": %s, type %d, platform type %d\n",
                        sensors[i],
                        SDL_GetSensorInstanceName(sensors[i]),
                        SDL_GetSensorInstanceType(sensors[i]),
                        SDL_GetSensorInstanceNonPortableType(sensors[i]));
            }
            SDL_free(sensors);
        }
        SDL_QuitSubSystem(SDL_INIT_SENSOR);
    }
}
```

Removed SDL_SensorGetDataWithTimestamp(), if you want timestamps for the sensor data, you should use the sensor_timestamp member of SDL_EVENT_SENSOR_UPDATE events.


The following functions have been renamed:
* SDL_SensorClose() => SDL_CloseSensor()
* SDL_SensorFromInstanceID() => SDL_GetSensorFromInstanceID()
* SDL_SensorGetData() => SDL_GetSensorData()
* SDL_SensorGetInstanceID() => SDL_GetSensorInstanceID()
* SDL_SensorGetName() => SDL_GetSensorName()
* SDL_SensorGetNonPortableType() => SDL_GetSensorNonPortableType()
* SDL_SensorGetType() => SDL_GetSensorType()
* SDL_SensorOpen() => SDL_OpenSensor()
* SDL_SensorUpdate() => SDL_UpdateSensors()

The following functions have been removed:
* SDL_LockSensors()
* SDL_NumSensors() - replaced with SDL_GetSensors()
* SDL_SensorGetDeviceInstanceID()
* SDL_SensorGetDeviceName() - replaced with SDL_GetSensorInstanceName()
* SDL_SensorGetDeviceNonPortableType() - replaced with SDL_GetSensorInstanceNonPortableType()
* SDL_SensorGetDeviceType() - replaced with SDL_GetSensorInstanceType()
* SDL_UnlockSensors()

## SDL_stdinc.h

The standard C headers like stdio.h and stdlib.h are no longer included, you should include them directly in your project if you use non-SDL C runtime functions.
M_PI is no longer defined in SDL_stdinc.h, you can use the new symbols SDL_PI_D (double) and SDL_PI_F (float) instead.


## SDL_surface.h

Removed unused 'flags' parameter from SDL_ConvertSurface and SDL_ConvertSurfaceFormat.

SDL_CreateRGBSurface() and SDL_CreateRGBSurfaceWithFormat() have been combined into a new function SDL_CreateSurface().
SDL_CreateRGBSurfaceFrom() and SDL_CreateRGBSurfaceWithFormatFrom() have been combined into a new function SDL_CreateSurfaceFrom().

You can implement the old functions in your own code easily:
```c
SDL_Surface *SDL_CreateRGBSurface(Uint32 flags, int width, int height, int depth, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
{
    return SDL_CreateSurface(width, height,
            SDL_GetPixelFormatEnumForMasks(depth, Rmask, Gmask, Bmask, Amask));
}

SDL_Surface *SDL_CreateRGBSurfaceWithFormat(Uint32 flags, int width, int height, int depth, Uint32 format)
{
    return SDL_CreateSurface(width, height, format);
}

SDL_Surface *SDL_CreateRGBSurfaceFrom(void *pixels, int width, int height, int depth, int pitch, Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask)
{
    return SDL_CreateSurfaceFrom(pixels, width, height, pitch,
            SDL_GetPixelFormatEnumForMasks(depth, Rmask, Gmask, Bmask, Amask));
}

SDL_Surface *SDL_CreateRGBSurfaceWithFormatFrom(void *pixels, int width, int height, int depth, int pitch, Uint32 format)
{
    return SDL_CreateSurfaceFrom(pixels, width, height, pitch, format);
}

```

But if you're migrating your code which uses masks, you probably have a format in mind, possibly one of these:
```c
// Various mask (R, G, B, A) and their corresponding format:
0xFF000000 0x00FF0000 0x0000FF00 0x000000FF => SDL_PIXELFORMAT_RGBA8888
0x00FF0000 0x0000FF00 0x000000FF 0xFF000000 => SDL_PIXELFORMAT_ARGB8888
0x0000FF00 0x00FF0000 0xFF000000 0x000000FF => SDL_PIXELFORMAT_BGRA8888
0x000000FF 0x0000FF00 0x00FF0000 0xFF000000 => SDL_PIXELFORMAT_ABGR8888
0x0000F800 0x000007E0 0x0000001F 0x00000000 => SDL_PIXELFORMAT_RGB565
```


The following functions have been renamed:
* SDL_FillRect() => SDL_FillSurfaceRect()
* SDL_FillRects() => SDL_FillSurfaceRects()
* SDL_FreeSurface() => SDL_DestroySurface()
* SDL_GetClipRect() => SDL_GetSurfaceClipRect()
* SDL_GetColorKey() => SDL_GetSurfaceColorKey()
* SDL_HasColorKey() => SDL_SurfaceHasColorKey()
* SDL_HasSurfaceRLE() => SDL_SurfaceHasRLE()
* SDL_LowerBlit() => SDL_BlitSurfaceUnchecked()
* SDL_LowerBlitScaled() => SDL_BlitSurfaceUncheckedScaled()
* SDL_SetClipRect() => SDL_SetSurfaceClipRect()
* SDL_SetColorKey() => SDL_SetSurfaceColorKey()
* SDL_UpperBlit() => SDL_BlitSurface()
* SDL_UpperBlitScaled() => SDL_BlitSurfaceScaled()

## SDL_system.h

SDL_AndroidGetExternalStorageState() takes the state as an output parameter and returns 0 if the function succeeds or a negative error code if there was an error.

The following functions have been renamed:
* SDL_RenderGetD3D11Device() => SDL_GetRenderD3D11Device()
* SDL_RenderGetD3D9Device() => SDL_GetRenderD3D9Device()

## SDL_syswm.h

The structures in this file are versioned separately from the rest of SDL, allowing better backwards compatibility and limited forwards compatibility with your application. Instead of calling `SDL_VERSION(&info.version)` before calling SDL_GetWindowWMInfo(), you pass the version in explicitly as SDL_SYSWM_CURRENT_VERSION so SDL knows what fields you expect to be filled out.

### SDL_GetWindowWMInfo

This function now returns a standard int result instead of SDL_bool, returning 0 if the function succeeds or a negative error code if there was an error. You should also pass SDL_SYSWM_CURRENT_VERSION as the new third version parameter. The version member of the info structure will be filled in with the version of data that is returned, the minimum of the version you requested and the version supported by the runtime SDL library.


## SDL_timer.h

SDL_GetTicks() now returns a 64-bit value. Instead of using the SDL_TICKS_PASSED macro, you can directly compare tick values, e.g.
```c
Uint32 deadline = SDL_GetTicks() + 1000;
...
if (SDL_TICKS_PASSED(SDL_GetTicks(), deadline)) {
    ...
}
```
becomes:
```c
Uint64 deadline = SDL_GetTicks() + 1000
...
if (SDL_GetTicks() >= deadline) {
    ...
}
```

If you were using this macro for other things besides SDL ticks values, you can define it in your own code as:
```c
#define SDL_TICKS_PASSED(A, B)  ((Sint32)((B) - (A)) <= 0)
```

## SDL_touch.h

SDL_GetNumTouchFingers() returns a negative error code if there was an error.

## SDL_version.h

SDL_GetRevisionNumber() has been removed from the API, it always returned 0 in SDL 2.0.


## SDL_video.h

SDL_VideoInit() and SDL_VideoQuit() have been removed. Instead you can call SDL_InitSubSytem() and SDL_QuitSubSytem() with SDL_INIT_VIDEO, which will properly refcount the subsystems. You can choose a specific video driver using SDL_VIDEO_DRIVER hint.

Rather than iterating over displays using display index, there is a new function SDL_GetDisplays() to get the current list of displays, and functions which used to take a display index now take SDL_DisplayID, with an invalid ID being 0.
```c
{
    if (SDL_InitSubSystem(SDL_INIT_VIDEO) == 0) {
        int i, num_displays = 0;
        SDL_DisplayID *displays = SDL_GetDisplays(&num_displays);
        if (displays) {
            for (i = 0; i < num_displays; ++i) {
                SDL_DisplayID instance_id = displays[i];
                const char *name = SDL_GetDisplayName(instance_id);

                SDL_Log("Display %" SDL_PRIu32 ": %s\n", instance_id, name ? name : "Unknown");
            }
            SDL_free(displays);
        }
        SDL_QuitSubSystem(SDL_INIT_VIDEO);
    }
}
```

SDL_CreateWindow() has been simplified and no longer takes a window position. You can use SDL_CreateWindowWithPosition() if you need to set the window position when creating it.

The SDL_WINDOWPOS_UNDEFINED_DISPLAY() and SDL_WINDOWPOS_CENTERED_DISPLAY() macros take a display ID instead of display index. The display ID 0 has a special meaning in this case, and is used to indicate the primary display.

The SDL_WINDOW_SHOWN flag has been removed. Windows are shown by default and can be created hidden by using the SDL_WINDOW_HIDDEN flag.

The SDL_WINDOW_ALLOW_HIGHDPI flag has been removed. Windows are automatically high DPI aware and their coordinates are in screen space, which may differ from physical pixels on displays using display scaling.

SDL_DisplayMode now includes the pixel size, the screen size and the relationship between the two. For example, a 4K display at 200% scale could have a pixel size of 3840x2160, a screen size of 1920x1080, and a display scale of 2.0.

The refresh rate in SDL_DisplayMode is now a float.

Rather than iterating over display modes using an index, there is a new function SDL_GetFullscreenDisplayModes() to get the list of available fullscreen modes on a display.
```c
{
    SDL_DisplayID display = SDL_GetPrimaryDisplay();
    int num_modes = 0;
    SDL_DisplayMode **modes = SDL_GetFullscreenDisplayModes(display, &num_modes);
    if (modes) {
        for (i = 0; i < num_modes; ++i) {
            SDL_DisplayMode *mode = modes[i];
            SDL_Log("Display %" SDL_PRIu32 " mode %d:  %dx%d@%gHz, %d%% scale\n",
                    display, i, mode->pixel_w, mode->pixel_h, mode->refresh_rate, (int)(mode->display_scale * 100.0f));
        }
        SDL_free(modes);
    }
}
```

SDL_GetDesktopDisplayMode() and SDL_GetCurrentDisplayMode() return pointers to display modes rather than filling in application memory.

Windows now have an explicit fullscreen mode that is set, using SDL_SetWindowFullscreenMode(). The fullscreen mode for a window can be queried with SDL_GetWindowFullscreenMode(), which returns a pointer to the mode, or NULL if the window will be fullscreen desktop. SDL_SetWindowFullscreen() just takes a boolean value, setting the correct fullscreen state based on the selected mode.

SDL_WINDOW_FULLSCREEN_DESKTOP has been removed, and you can call SDL_GetWindowFullscreenMode() to see whether an exclusive fullscreen mode will be used or the fullscreen desktop mode will be used when the window is fullscreen.

SDL_SetWindowBrightness and SDL_SetWindowGammaRamp have been removed from the API, because they interact poorly with modern operating systems and aren't able to limit their effects to the SDL window.

Programs which have access to shaders can implement more robust versions of those functions using custom shader code rendered as a post-process effect.

Removed SDL_GL_CONTEXT_EGL from OpenGL configuration attributes. You can instead use `SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_ES);`

SDL_GL_GetProcAddress() and SDL_EGL_GetProcAddress() now return `SDL_FunctionPointer` instead of `void *`, and should be cast to the appropriate function type. You can define SDL_FUNCTION_POINTER_IS_VOID_POINTER in your project to restore the previous behavior.

SDL_GL_SwapWindow() returns 0 if the function succeeds or a negative error code if there was an error.

SDL_GL_GetSwapInterval() takes the interval as an output parameter and returns 0 if the function succeeds or a negative error code if there was an error.

SDL_GL_GetDrawableSize() has been removed. SDL_GetWindowSizeInPixels() can be used in its place.

The SDL_WINDOW_TOOLTIP and SDL_WINDOW_POPUP_MENU window flags are now supported on Windows, Mac (Cocoa), X11, and Wayland. Creating windows with these flags must happen via the `SDL_CreatePopupWindow()` function. This function requires passing in the handle to a valid parent window for the popup, and the popup window is positioned relative to the parent.

The following functions have been renamed:
* SDL_GetClosestDisplayMode() => SDL_GetClosestFullscreenDisplayMode()
* SDL_GetPointDisplayIndex() => SDL_GetDisplayForPoint()
* SDL_GetRectDisplayIndex() => SDL_GetDisplayForRect()
* SDL_GetWindowDisplayIndex() => SDL_GetDisplayForWindow()
* SDL_GetWindowDisplayMode() => SDL_GetWindowFullscreenMode()
* SDL_IsScreenSaverEnabled() => SDL_ScreenSaverEnabled()
* SDL_SetWindowDisplayMode() => SDL_SetWindowFullscreenMode()

The following functions have been removed:
* SDL_GetClosestFullscreenDisplayMode()
* SDL_GetDisplayDPI() - not reliable across platforms, approximately replaced by multiplying `display_scale` in the structure returned by SDL_GetDesktopDisplayMode() times 160 on iPhone and Android, and 96 on other platforms.
* SDL_GetDisplayMode()
* SDL_GetNumDisplayModes() - replaced with SDL_GetFullscreenDisplayModes()
* SDL_GetNumVideoDisplays() - replaced with SDL_GetDisplays()

SDL_Window id type is named SDL_WindowID

The following symbols have been renamed:
* SDL_WINDOW_INPUT_GRABBED => SDL_WINDOW_MOUSE_GRABBED

## SDL_vulkan.h

SDL_Vulkan_GetInstanceExtensions() no longer takes a window parameter.

SDL_Vulkan_GetVkGetInstanceProcAddr() now returns `SDL_FunctionPointer` instead of `void *`, and should be cast to PFN_vkGetInstanceProcAddr.

SDL_Vulkan_GetDrawableSize() has been removed. SDL_GetWindowSizeInPixels() can be used in its place.
