QVulkanWindow: Add a way to control post-1.0 Vulkan features

So now instead of filling out a VkPhysicalDeviceFeatures and
sending it in via VkDeviceCreateInfo::pEnabledFeatures,
we rather create a VkPhysicalDeviceFeatures2, which contains
a VkPhysicalDeviceFeatures (for 1.0 stuff) and a pNext
chain, and chain it via pNext to the VkDeviceCreateInfo.

QVulkanWindow will not do anything with post-1.0 features
by default. (in this regard it deviates from the QRhi
Vulkan backend which already tackles 1.1, 1.2, and 1.3
features as well, but this is not going to change)

However, applications may want to enable some of those still.
To enable this, add a new callback. When set, the callback is
invoked and the alternative behavior described above is
activated.

Fixes: QTBUG-117966
Change-Id: I8560a6b23421f545ee760e714cbe2ec2f6078406
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 63 insertions, 18 deletions

diff --git a/src/gui/vulkan/qvulkanwindow.cpp b/src/gui/vulkan/qvulkanwindow.cpp
index baaa5a8d55..e383bebb74 100644
--- a/src/gui/vulkan/qvulkanwindow.cpp
+++ b/src/gui/vulkan/qvulkanwindow.cpp
@@ -178,12 +178,12 @@ Q_DECLARE_LOGGING_CATEGORY(lcGuiVk)
   As an exception to this rule, \c robustBufferAccess is never enabled. Use the
   callback mechanism described below, if enabling that feature is desired.
 
-  Just enabling the 1.0 core features is not always sufficient, and therefore
-  full control over the VkPhysicalDeviceFeatures used for device creation is
-  possible too by registering a callback function with
+  This is not always desirable, and may be insufficient with Vulkan 1.1 and
+  higher. Therefore, full control over the VkPhysicalDeviceFeatures used for
+  device creation is possible too by registering a callback function with
   setEnabledFeaturesModifier(). When set, the callback function is invoked,
-  letting it alter the VkPhysicalDeviceFeatures, instead of enabling only the
-  1.0 core features.
+  letting it alter the VkPhysicalDeviceFeatures. To instead provide a chainable
+  VkPhysicalDeviceFeatures2, call setEnabledFeatures2Modifier().
 
   \sa QVulkanInstance, QWindow
  */
@@ -702,17 +702,22 @@ void QVulkanWindowPrivate::init()
     devInfo.enabledExtensionCount = devExts.size();
     devInfo.ppEnabledExtensionNames = devExts.constData();
 
-    VkPhysicalDeviceFeatures features;
-    memset(&features, 0, sizeof(features));
-    if (enabledFeaturesModifier) {
+    VkPhysicalDeviceFeatures features = {};
+    VkPhysicalDeviceFeatures2 features2 = {};
+    if (enabledFeatures2Modifier) {
+        features2.sType = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2;
+        enabledFeatures2Modifier(features2);
+        devInfo.pNext = &features2;
+    } else if (enabledFeaturesModifier) {
         enabledFeaturesModifier(features);
+        devInfo.pEnabledFeatures = &features;
     } else {
         // Enable all supported 1.0 core features, except ones that likely
         // involve a performance penalty.
         f->vkGetPhysicalDeviceFeatures(physDev, &features);
         features.robustBufferAccess = VK_FALSE;
+        devInfo.pEnabledFeatures = &features;
     }
-    devInfo.pEnabledFeatures = &features;
 
     // Device layers are not supported by QVulkanWindow since that's an already deprecated
     // API. However, have a workaround for systems with older API and layers (f.ex. L4T
@@ -1625,16 +1630,12 @@ void QVulkanWindow::setQueueCreateInfoModifier(const QueueCreateInfoModifier &mo
     praticular, \c robustBufferAccess is always disabled in order to avoid
     unexpected performance hits.
 
-    This however is not always sufficient when working with Vulkan 1.1 or 1.2
-    features and extensions. Hence this callback mechanism.
-
     The VkPhysicalDeviceFeatures reference passed in is all zeroed out at the
     point when the function is invoked. It is up to the function to change
-    members to true, or set up \c pNext chains as it sees fit.
+    members as it sees fit.
 
-    \note When setting up \c pNext chains, make sure the referenced objects
-    have a long enough lifetime, for example by storing them as member
-    variables in the QVulkanWindow subclass.
+    \note To control Vulkan 1.1, 1.2, or 1.3 features, use
+    setEnabledFeatures2Modifier() and the corresponding callback type instead.
 
     \sa setEnabledFeaturesModifier()
  */
@@ -1642,9 +1643,14 @@ void QVulkanWindow::setQueueCreateInfoModifier(const QueueCreateInfoModifier &mo
 /*!
     Sets the enabled device features modification function \a modifier.
 
-    \sa EnabledFeaturesModifier
+    \note To control Vulkan 1.1, 1.2, or 1.3 features, use
+    setEnabledFeatures2Modifier() instead.
+
+    \note \a modifier is passed to the callback function with all members set
+    to false. It is up to the function to change members as it sees fit.
 
-    \since 6.4
+    \since 6.7
+    \sa EnabledFeaturesModifier
  */
 void QVulkanWindow::setEnabledFeaturesModifier(const EnabledFeaturesModifier &modifier)
 {
@@ -1653,6 +1659,45 @@ void QVulkanWindow::setEnabledFeaturesModifier(const EnabledFeaturesModifier &mo
 }
 
 /*!
+    \typedef QVulkanWindow::EnabledFeatures2Modifier
+
+    A function that is called during graphics initialization to alter the
+    VkPhysicalDeviceFeatures2 that is changed to the VkDeviceCreateInfo.
+
+    By default QVulkanWindow enables all Vulkan 1.0 core features that the
+    physical device reports as supported, with certain exceptions. In
+    praticular, \c robustBufferAccess is always disabled in order to avoid
+    unexpected performance hits.
+
+    This however is not always sufficient when working with Vulkan 1.1, 1.2, or
+    1.3 features and extensions. Hence this callback mechanism. If only Vulkan
+    1.0 is relevant at run time, use setEnabledFeaturesModifier() instead.
+
+    The VkPhysicalDeviceFeatures2 reference passed to the callback function
+    with \c sType set, but the rest zeroed out. It is up to the function to
+    change members to true, or set up \c pNext chains as it sees fit.
+
+    \note When setting up \c pNext chains, make sure the referenced objects
+    have a long enough lifetime, for example by storing them as member
+    variables in the QVulkanWindow subclass.
+
+    \since 6.7
+    \sa setEnabledFeatures2Modifier()
+ */
+
+/*!
+    Sets the enabled device features modification function \a modifier.
+
+    \since 6.7
+    \sa EnabledFeatures2Modifier
+*/
+void QVulkanWindow::setEnabledFeatures2Modifier(const EnabledFeatures2Modifier &modifier)
+{
+    Q_D(QVulkanWindow);
+    d->enabledFeatures2Modifier = modifier;
+}
+
+/*!
     Returns true if this window has successfully initialized all Vulkan
     resources, including the swapchain.