VkSurfaceKHR does not to update when resizing xcb window

Question

I have followed the tutorial at https://vulkan-tutorial.com... I created it without using the GLFW etension. So far I'm up to "Swap chain Recreation", and all is setup and rendering correctly.

However, I can't seem to get resizing working correctly!

I've hooked into the XCB_RESIZE_REQUEST and am setting my info struct w/h like so:

if (resize->width > 0) { info.width = resize->width; }
if (resize->height > 0) { info.height = resize->height; }
info.framebufferResized = true;

Which causes (in the next drawFrame() call) recreateSwapchain() to be called:

if (res == VK_ERROR_OUT_OF_DATE_KHR || res == VK_SUBOPTIMAL_KHR || info.framebufferResized) {
    info.framebufferResized = false;
    recreateSwapchain();
} else  if (res != VK_SUCCESS) {
    throw runtime_error("failed to present swap chain image!");
}

recreateSwapchain() {
    vkDeviceWaitIdle(info.device);

    cleanupSwapchain();

    querySwapchainSupport(info.physicalDevice);
    createSwapchain();
    createImageViews();
    createRenderPass();
    createGraphicsPipeline();
    createFramebuffers();
    createCommandBuffers();
}

I've done some debugging, and have found that the swapchainSupport.capabilities.minImageExtent.width (and height) do not change from the initial values!.. That is, this call

querySwapchainSupport(VkPhysicalDevice physicalDevice) {
    VkResult res = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(
        physicalDevice, info.surface, &info.swapchainSupport.capabilities);
    assert(res == VK_SUCCESS);

Does not update the info.swapchainSupport.capabilities with new window size.

Any help, or comments would be greatly appreciated.

Example Screenshot:

Armorer

I'd rather not resort to using a library such as GLFW.. as I'll most likely want to target mobile at some point; – Armorer

Why are you looking at minImageExtent instead of currentExtent? – Monterrey

current, min, and max all stay the same: 800x600 – Armorer

Answer 1

I'm not sure if XCB_RESIZE_REQUEST is the right event to wait for. In my examples I use XCB_CONFIGURE_NOTIFY to check for window resize events, and querying the surface capabilities after that event gives me the new window size as the surface capabilities extents as expected:

case XCB_CONFIGURE_NOTIFY:
{
    const xcb_configure_notify_event_t *cfgEvent = (const xcb_configure_notify_event_t *)event;
    if (((cfgEvent->width != width) || (cfgEvent->height != height)))
    {
            destWidth = cfgEvent->width;
            destHeight = cfgEvent->height;
            if ((destWidth > 0) && (destHeight > 0))
            {
                // Swap chain recreation ins done in this function              
                windowResize();                 
            }
    }
}

You also need to add the accompanying flag at XCB window creation time:

uint32_t value_list[32];
value_list[1] = ... | XCB_EVENT_MASK_STRUCTURE_NOTIFY...

xcb_create_window(connection,
    ...     
    value_list);

This has been tested to work on many different Linux implementations and platforms.

If you need some help getting XCB up and running you may want to take a look at my Vulkan samples. The interesting parts are in the example base class and the swapchain header.

Wycliffite

Yup, the same is performed in the "API without Secrets" series of Intel's Vulkan tutorials. Have a look here. – Hundredfold

That Worked! Very Good! Does this have something to do with adding to XCB_EVENT_MASK_STRUCTURE_NOTIFY to the value_list? – Armorer