Please check "CONFIGURATION SECTION" in the code to find macros that you can define before each include of this file or change directly in this file to provide your own implementation of basic facilities like assert, min() and max() functions, mutex etc. C++ STL is used by default, but changing these allows you to get rid of any STL usage if you want, as many game developers tend to do.

Pointers to Vulkan functions

The library uses Vulkan functions straight from the vulkan.h header by default. If you want to provide your own pointers to these functions, e.g. fetched using vkGetInstanceProcAddr() and vkGetDeviceProcAddr():

Define VMA_STATIC_VULKAN_FUNCTIONS 0.
Provide valid pointers through VmaAllocatorCreateInfo::pVulkanFunctions.

Custom host memory allocator

If you use custom allocator for CPU memory rather than default operator new and delete from C++, you can make this library using your allocator as well by filling optional member VmaAllocatorCreateInfo::pAllocationCallbacks. These functions will be passed to Vulkan, as well as used by the library itself to make any CPU-side allocations.

Device memory allocation callbacks

The library makes calls to vkAllocateMemory() and vkFreeMemory() internally. You can setup callbacks to be informed about these calls, e.g. for the purpose of gathering some statistics. To do it, fill optional member VmaAllocatorCreateInfo::pDeviceMemoryCallbacks.

Device heap memory limit

If you want to test how your program behaves with limited amount of Vulkan device memory available without switching your graphics card to one that really has smaller VRAM, you can use a feature of this library intended for this purpose. To do it, fill optional member VmaAllocatorCreateInfo::pHeapSizeLimit.