vkGetInstanceProcAddr

Function pointers for all Vulkan commands can be obtained by calling:

PFN_vkVoidFunction vkGetInstanceProcAddr(
    VkInstance instance,
    const char* pName);

instance is the instance that the function pointer will be compatible with, or NULL for commands not dependent on any instance.
pName is the name of the command to obtain.

vkGetInstanceProcAddr itself is obtained in a platform- and loader- specific manner. Typically, the loader library will export this command as a function symbol, so applications can link against the loader library, or load it dynamically and look up the symbol using platform-specific APIs.

The table below defines the various use cases for vkGetInstanceProcAddr and expected return value (fp is function pointer) for each case. A valid returned function pointer (fp) must not be NULL.

The returned function pointer is of type PFN_vkVoidFunction, and must be cast to the type of the command being queried before use.

Table 1. vkGetInstanceProcAddr behavior
instance	pName	return value
*1	NULL	undefined:
invalid non-NULL instance	*1	undefined:
NULL	global command2	fp
instance	vkGetInstanceProcAddr	fp
instance	core dispatchable command	fp3
instance	enabled instance extension dispatchable command for instance	fp3
instance	available device extension4 dispatchable command for instance	fp3
any other case, not covered above		NULL

Valid Usage (Implicit)

VUID-vkGetInstanceProcAddr-instance-parameter

If instance is not NULL, instance must be a valid VkInstance handle

VUID-vkGetInstanceProcAddr-pName-parameter

pName must be a null-terminated UTF-8 string