QVulkanFunctions Class

Detailed Description

Qt and Qt applications do not link to any Vulkan libraries by default. Instead, all functions are resolved dynamically at run time. Each QVulkanInstance provides a QVulkanFunctions object retrievable via QVulkanInstance::functions(). This does not contain device level functions in order to avoid the potential overhead of an internal dispatching. Instead, functions that rely on a device, or a dispatchable child object of a device, are exposed via QVulkanDeviceFunctions and QVulkanInstance::deviceFunctions(). QVulkanFunctions and QVulkanDeviceFunctions together provides access to the full core Vulkan API, excluding any extensions.

The typical usage is the following:

 void Window::init()
 {
     QVulkanInstance *inst = vulkanInstance();
     QVulkanFunctions *f = inst->functions();
     // ...
     uint32_t count = 0;
     VkResult err = f->vkEnumeratePhysicalDevices(inst->vkInstance(), &count, nullptr);
     // ...
 }

To access additional functions, applications can use QVulkanInstance::getInstanceProcAddr() and vkGetDeviceProcAddr(). Applications can also decide to link to a Vulkan library directly, as platforms with an appropriate loader will typically export function symbols for the core commands. See the man page for vkGetInstanceProcAddr for more information.