VKSTRUCTURETYPE

VkStructureType, often seen as VK_STRUCTURE_TYPE in Vulkan, is an enumeration used to identify the concrete type of a Vulkan structure. Almost every Vulkan structure begins with two members: a VkStructureType named sType and a void pointer named pNext. The sType field must be set to the specific VK_STRUCTURE_TYPE_* value that corresponds to the structure being used.

The primary purpose of sType is to enable runtime validation and versioning. By inspecting sType, the Vulkan implementation can determine how to interpret the remaining fields of the structure. The pNext pointer supports a chained extension mechanism: additional extension-specific structures can be attached to the base structure by linking them through pNext, each carrying its own sType value.

Common usage involves setting sType to the appropriate value for the structure. For example, VkApplicationInfo uses sType = VK_STRUCTURE_TYPE_APPLICATION_INFO, VkInstanceCreateInfo uses sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO, and VkDeviceCreateInfo uses sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO. When enabling extensions, developers may append extra structures to the pNext chain, each with its corresponding sType.

The VK_STRUCTURE_TYPE enumeration includes many values, with well-known entries such as VK_STRUCTURE_TYPE_APPLICATION_INFO, VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO, VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO, VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO, VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO, VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO, and VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO, among others. Extensions introduce additional VK_STRUCTURE_TYPE_* values, expanding the set over time.

In summary, VkStructureType provides a standardized way to identify and validate Vulkan structures and to support a flexible extension mechanism through pNext.