# Vulkan Headers for Rust
This library contains minimalist Rust FFI bindings for Vulkan in a way that's roughly equivalent to the Khronos Group's official [vulkan.h](https://github.com/KhronosGroup/Vulkan-Headers/blob/main/include/vulkan/vulkan.h) for C/C++. It makes no attempt at providing safe or idiomatic Rust wrappers and doesn't rename any C identifiers to match Rust's style guidelines.
The following Rust code:
```rust
use vulkan_headers::vulkan::vulkan::*;
```
is roughly equivalent to the following C code:
```c
#include <vulkan/vulkan.h>
```
## `NonNull` Types
In addition to most of what's provided by `vulkan.h`, this library adds `NonNull` type aliases for function pointer types and handle types.
`PFN_vkCreateInstance` is defined as:
```rust
pub type NonNullPFN_vkCreateInstance = unsafe extern "system" fn(pCreateInfo: *const VkInstanceCreateInfo, pAllocator: *const VkAllocationCallbacks, pInstance: *mut VkInstance) -> VkResult;
// ...
pub type PFN_vkCreateInstance = Option<NonNullPFN_vkCreateInstance>;
```
`VkInstance` is defined as:
```rust
pub type NonNullVkInstance = NonNull<VkInstance_T>;
// ...
pub type VkInstance = *mut VkInstance_T;
```
## Optional Features
External function declarations aren't provided by default, only their corresponding function pointer type aliases (e.g. `vkCreateInstance` isn't provided but `PFN_vkCreateInstance` is). This is similar to defining `VK_NO_PROTOTYPES` before including `vulkan.h`. Use the `prototypes` feature to enable these function declarations.
The `exported-prototypes` feature can be used instead to limit these declarations to exported functions only. This is similar to defining `VK_ONLY_EXPORTED_PROTOTYPES` before including `vulkan.h`. Using the `prototypes` feature implicitly enables the `exported-prototypes` feature.
Beta (a.k.a. "provisional") extensions and/or platform-specific extensions can be enabled using the `beta-extensions` and/or `<platform>-extensions` (e.g. `win32-extensions`) features. This is similar to defining `VK_ENABLE_BETA_EXTENSIONS` and/or `VK_USE_PLATFORM_<PLATFORM>` (e.g. `VK_USE_PLATFORM_WIN32_KHR`) before including `vulkan.h`.
## Requirements
This library only supports targets with 64-bit pointers. This allows pointer and `NonNull` types to be used portably for all Vulkan handle types.