Functions for creating Vulkan surfaces on SDL windows. More...

Collaboration diagram for Vulkan Support:

Functions
void	SDL::Vulkan_LoadLibrary (StringParam path)
	Dynamically load the Vulkan loader library. More...

FunctionPointer	SDL::Vulkan_GetVkGetInstanceProcAddr ()
	Get the address of the `vkGetInstanceProcAddr` function. More...

void	SDL::Vulkan_UnloadLibrary ()
	Unload the Vulkan library previously loaded by Vulkan_LoadLibrary(). More...

std::span< char const *const >	SDL::Vulkan_GetInstanceExtensions ()
	Get the Vulkan instance extensions needed for vkCreateInstance. More...

void	SDL::Vulkan_CreateSurface (WindowParam window, VkInstance instance, const struct VkAllocationCallbacks allocator, VkSurfaceKHR surface)
	Create a Vulkan rendering surface for a window. More...

void	SDL::Vulkan_DestroySurface (VkInstance instance, VkSurfaceKHR surface, const struct VkAllocationCallbacks *allocator)
	Destroy the Vulkan rendering surface of a window. More...

bool	SDL::Vulkan_GetPresentationSupport (VkInstance instance, VkPhysicalDevice physicalDevice, Uint32 queueFamilyIndex)
	Query support for presentation via a given physical device and queue family. More...

Detailed Description

For the most part, Vulkan operates independent of SDL, but it benefits from a little support during setup.

Use Vulkan_GetInstanceExtensions() to get platform-specific bits for creating a VkInstance, then Vulkan_GetVkGetInstanceProcAddr() to get the appropriate function for querying Vulkan entry points. Then Vulkan_CreateSurface() will get you the final pieces you need to prepare for rendering into an Window with Vulkan.

Unlike OpenGL, most of the details of "context" creation and window buffer swapping are handled by the Vulkan API directly, so SDL doesn't provide Vulkan equivalents of GL_SwapWindow(), etc; they aren't necessary.

Function Documentation

◆ Vulkan_CreateSurface()

void SDL::Vulkan_CreateSurface	(	WindowParam	window,
		VkInstance	instance,
		const struct VkAllocationCallbacks *	allocator,
		VkSurfaceKHR *	surface
	)

inline

The window must have been created with the WINDOW_VULKAN flag and instance must have been created with extensions returned by Vulkan_GetInstanceExtensions() enabled.

If allocator is nullptr, Vulkan will use the system default allocator. This argument is passed directly to Vulkan and isn't used by SDL itself.

Parameters

window	the window to which to attach the Vulkan surface.
instance	the Vulkan instance handle.
allocator	a VkAllocationCallbacks struct, which lets the app set the allocator that creates the surface. Can be nullptr.
surface	a pointer to a VkSurfaceKHR handle to output the newly created surface.

Exceptions

Error on failure.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_GetInstanceExtensions; Vulkan_DestroySurface

◆ Vulkan_DestroySurface()

void SDL::Vulkan_DestroySurface	(	VkInstance	instance,
		VkSurfaceKHR	surface,
		const struct VkAllocationCallbacks *	allocator
	)

inline

This should be called before Window.Destroy, if Vulkan_CreateSurface was called after Window.Window.

The instance must have been created with extensions returned by Vulkan_GetInstanceExtensions() enabled and surface must have been created successfully by an Vulkan_CreateSurface() call.

If allocator is nullptr, Vulkan will use the system default allocator. This argument is passed directly to Vulkan and isn't used by SDL itself.

Parameters

instance	the Vulkan instance handle.
surface	vkSurfaceKHR handle to destroy.
allocator	a VkAllocationCallbacks struct, which lets the app set the allocator that destroys the surface. Can be nullptr.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_GetInstanceExtensions; Vulkan_CreateSurface

◆ Vulkan_GetInstanceExtensions()

std::span< char const *const > SDL::Vulkan_GetInstanceExtensions ( )

inline

This should be called after either calling Vulkan_LoadLibrary() or creating an Window with the WINDOW_VULKAN flag.

On return, the variable pointed to by count will be set to the number of elements returned, suitable for using with VkInstanceCreateInfo::enabledExtensionCount, and the returned array can be used with VkInstanceCreateInfo::ppEnabledExtensionNames, for calling Vulkan's vkCreateInstance API.

Returns: an array of extension name strings on success.

Exceptions

Error on failure.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_CreateSurface

◆ Vulkan_GetPresentationSupport()

bool SDL::Vulkan_GetPresentationSupport	(	VkInstance	instance,
		VkPhysicalDevice	physicalDevice,
		Uint32	queueFamilyIndex
	)

inline

The instance must have been created with extensions returned by Vulkan_GetInstanceExtensions() enabled.

Parameters

instance	the Vulkan instance handle.
physicalDevice	a valid Vulkan physical device handle.
queueFamilyIndex	a valid queue family index for the given physical device.

Returns: true if supported, false if unsupported or an error occurred.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_GetInstanceExtensions

◆ Vulkan_GetVkGetInstanceProcAddr()

FunctionPointer SDL::Vulkan_GetVkGetInstanceProcAddr ( )

inline

This should be called after either calling Vulkan_LoadLibrary() or creating an Window with the WINDOW_VULKAN flag.

The actual type of the returned function pointer is PFN_vkGetInstanceProcAddr, but that isn't available because the Vulkan headers are not included here. You should cast the return value of this function to that type, e.g.

vkGetInstanceProcAddr = (PFN_vkGetInstanceProcAddr)Vulkan_GetVkGetInstanceProcAddr();

Returns: the function pointer for vkGetInstanceProcAddr or nullptr on failure; call GetError() for more information.

Since: This function is available since SDL 3.2.0.

◆ Vulkan_LoadLibrary()

void SDL::Vulkan_LoadLibrary ( StringParam path )

inline

This should be called after initializing the video driver, but before creating any Vulkan windows. If no Vulkan loader library is loaded, the default library will be loaded upon creation of the first Vulkan window.

SDL keeps a counter of how many times this function has been successfully called, so it is safe to call this function multiple times, so long as it is eventually paired with an equivalent number of calls to Vulkan_UnloadLibrary. The path argument is ignored unless there is no library currently loaded, and and the library isn't actually unloaded until there have been an equivalent number of calls to Vulkan_UnloadLibrary.

It is fairly common for Vulkan applications to link with libvulkan instead of explicitly loading it at run time. This will work with SDL provided the application links to a dynamic library and both it and SDL use the same search path.

If you specify a non-nullptr path, an application should retrieve all of the Vulkan functions it uses from the dynamic library using Vulkan_GetVkGetInstanceProcAddr unless you can guarantee path points to the same vulkan loader library the application linked to.

On Apple devices, if path is nullptr, SDL will attempt to find the vkGetInstanceProcAddr address within all the Mach-O images of the current process. This is because it is fairly common for Vulkan applications to link with libvulkan (and historically MoltenVK was provided as a static library). If it is not found, on macOS, SDL will attempt to load vulkan.framework/vulkan, libvulkan.1.dylib, MoltenVK.framework/MoltenVK, and libMoltenVK.dylib, in that order. On iOS, SDL will attempt to load libMoltenVK.dylib. Applications using a dynamic framework or .dylib must ensure it is included in its application bundle.

On non-Apple devices, application linking with a static libvulkan is not supported. Either do not link to the Vulkan loader or link to a dynamic library version.

Parameters

path	the platform dependent Vulkan loader library name or nullptr.

Exceptions

Error on failure.

Thread safety:: This function is not thread safe.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_GetVkGetInstanceProcAddr; Vulkan_UnloadLibrary

◆ Vulkan_UnloadLibrary()

void SDL::Vulkan_UnloadLibrary ( )

inline

SDL keeps a counter of how many times this function has been called, so it is safe to call this function multiple times, so long as it is paired with an equivalent number of calls to Vulkan_LoadLibrary. The library isn't actually unloaded until there have been an equivalent number of calls to Vulkan_UnloadLibrary.

Once the library has actually been unloaded, if any Vulkan instances remain, they will likely crash the program. Clean up any existing Vulkan resources, and destroy appropriate windows, renderers and GPU devices before calling this function.

Thread safety:: This function is not thread safe.

Since: This function is available since SDL 3.2.0.

See also: Vulkan_LoadLibrary