C Specification

In order to support systems with multiple Vulkan implementations comprising heterogeneous collections of hardware and software, the function pointers returned by vkGetInstanceProcAddr may point to dispatch code, which calls a different real implementation for different VkDevice objects or their child objects. The overhead of this internal dispatch can be avoided for commands that dispatch from device-level objects by calling device-specific function pointers. Such function pointers can be obtained with the command:

PFN_vkVoidFunction vkGetDeviceProcAddr(
    VkDevice                                    device,
    const char*                                 pName);

Parameters

The table below defines the various use cases for vkGetDeviceProcAddr and expected return value for each case.

Description

The returned function pointer is of type PFN_vkVoidFunction, and must be cast to the type of the command being queried. The function pointer must only be called with a dispatchable object (the first parameter) that is device or a child of device.

Table 1. vkGetDeviceProcAddr behavior
device pName return value

NULL

*

undefined

invalid device

*

undefined

device

NULL

undefined

device

core device-level Vulkan command

fp

device

enabled device extension commands

fp

device

* (any pName not covered above)

NULL

Valid Usage (Implicit)
  • device must be a valid VkDevice handle

  • pName must be a null-terminated UTF-8 string

See Also

Document Notes

For more information, see the Vulkan Specification at URL

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright (c) 2014-2018 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.