VKAPIPTR

VKAPIPTR is a term used in discussions of Vulkan API design to denote a pointer-based mechanism for accessing Vulkan commands. It is not a formal standard and may refer to various implementations that store Vulkan function pointers in a structured dispatch table and expose a typed API to the programmer.

The goal of this approach is to enable runtime loading, extension negotiation, and layered functionality without requiring direct, hand-written Vulkan function calls. By centralizing pointers in a dispatch structure, VKAPIPTR-based solutions can swap implementations, defer binding until runtime, and better isolate platform-specific concerns.

Typical characteristics include a dispatch table of PFN_vk* pointers, a loader component that resolves symbols from the Vulkan driver, and wrapper constructs (such as templated wrappers or small shim layers) that provide a safer or more convenient calling convention. Some designs also embed version checks and extension discovery within the dispatch layer to ensure compatibility across environments.

In practice, VKAPIPTR-style techniques are used to simplify integration with multiple Vulkan loaders or layers and to facilitate portable code across platforms. Because VKAPIPTR is not standardized, specific APIs and naming conventions vary between implementations.

Related concepts include Vulkan's own VKAPI_PTR macro and other runtime loaders such as Volk; VKAPIPTR is one of several patterns for managing Vulkan function pointers.