Context and device

VulkanContext owns the Vulkan instance, physical device, logical device, queue families, queues, and optional debug messenger. Other Vulkan wrappers receive a pointer to this context and must not outlive it.

Queue modes

CORE exposes two queue modes through QueueFamilyType:

• Compute selects a compute queue for headless workloads.

• Graphics selects graphics and presentation queues for windowed rendering.

Compute initialization

core::vulkan::VulkanContext context(
    true, core::vulkan::QueueFamilyType::Compute, VK_NULL_HANDLE);
context.Init();

The first argument enables validation layers. They are useful during development and should be selected deliberately by applications.

Graphics initialization

For rendering, create the platform surface after the context has created its instance, then finish initialization with that surface:

#define GLFW_INCLUDE_VULKAN
#include <GLFW/glfw3.h>

glfwInit();
glfwWindowHint(GLFW_CLIENT_API, GLFW_NO_API);
GLFWwindow* window =
    glfwCreateWindow(800, 600, "CORE Vulkan", nullptr, nullptr);

core::vulkan::VulkanContext context(
    true, core::vulkan::QueueFamilyType::Graphics, VK_NULL_HANDLE);

VkSurfaceKHR surface = VK_NULL_HANDLE;
VK_CHECK(glfwCreateWindowSurface(
    context.instance, window, nullptr, &surface));
context.Init(surface);

The constructor creates the Vulkan instance immediately. Init() then selects a physical device, finds the required queue families, creates the logical device, and retrieves the queues.

Access queues and device properties

const core::vulkan::QueueFamilyIndices indices =
    context.GetQueueFamilyIndices();

VkQueue graphics_queue = context.graphics_queue();
VkQueue present_queue = context.present_queue();
const float timestamp_period_ns = context.timestamp_period;

Note

The current implementation requests Vulkan 1.3 and selects only devices that support dynamic rendering, either in Vulkan 1.3 or through VK_KHR_dynamic_rendering. A machine with Vulkan support can still be rejected if that feature is unavailable.

Warning

For QueueFamilyType::Graphics, pass the real surface to Init(surface). Presentation support is checked against that surface while the physical device is selected.

Lifetime rule

Declare the context before buffers, images, pipelines, command buffers, and sync objects. C++ then destroys the dependent wrappers before destroying the logical device and instance.

For a windowed application, VulkanSwapChain currently owns and destroys the surface. Destroy the swapchain before the context, and destroy the GLFW window after the device has become idle.