VkSurfaceKHR surfaceForWindow(QWindow *window)

scott_craig

Looking through the source code it fails at
QWindowsNativeInterface::nativeResourceForWindow: 'vkSurface' requested for null window or window without handle.

void *QWindowsNativeInterface::nativeResourceForWindow(const QByteArray &resource, QWindow *window)
{
    if (!window || !window->handle()) {
        qWarning("%s: '%s' requested for null window or window without handle.", __FUNCTION__, resource.constData());
        return nullptr;
    }
    auto *bw = static_cast<QWindowsWindow *>(window->handle());
    int type = resourceType(resource);
    if (type == HandleType)
        return bw->handle();
    switch (window->surfaceType()) {
    case QWindow::RasterSurface:
    case QWindow::RasterGLSurface:
        if (type == GetDCType)
            return bw->getDC();
        if (type == ReleaseDCType) {
            bw->releaseDC();
            return nullptr;
        }
        break;
    case QWindow::VulkanSurface:
#if QT_CONFIG(vulkan)
        if (type == VkSurface)
            return bw->surface(nullptr, nullptr); // returns the address of the VkSurfaceKHR, not the value, as expected
#endif
        break;
    default:
        break;
    }
    qWarning("%s: Invalid key '%s' requested.", __FUNCTION__, resource.constData());
    return nullptr;
}

What is required for a QWindow to be properly initialized to have these values?

SGaist

Hi,

You might want to share the code you are actually using so it will help spot what is going on.

scott_craig

class Test_Window : Public QWindow{
Test_Window(){
setSurfaceType(VulkanSurface);
m_instance=std::make_shared<QVulkanInstance>();
}

void init(*vulkan_object object){
//Throws error here
  object->surface = surfaceForWindow(this);
  m_instance->setVkInstance(object->instance);
  m_instance->create();
  setVulkanInstance(&*m_instance);
}

private:
std::shared_ptr<QVulkanInstance> m_instance;
};

int main(int argc, char** argv){
QGuiApplication app(argc,argv)
vulkan_object obj{};
Test_Window test_window{};
test_window.init(vulkan_object);
test_window.show();
app.exec();
}

scott_craig

It seems the QWindow::handle() is NULL, how to fix this?

SGaist

Do you mean winId ?

In any case, shouldn't you use QVulkanWindow ?

scott_craig

The solution is to execute window->show() before you try and create a surface.

Also QVulkanWindow manages a bunch of vulkan types which is... not what you want.