Do not constantly create new surfaces with MoltenVK on macOS

Querying the VkSurfaceKHR for a window is expected to create the surface once
and then return the same value afterwards.

Task-number: QTBUG-82600
Change-Id: Ib3e99dfca4d940de1a14348eb1909d372a7dde04
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

3 files changed, 8 insertions, 7 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
index d0e69bdca5..450329f569 100644
--- a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
+++ b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
@@ -107,7 +107,7 @@ void *QCocoaNativeInterface::nativeResourceForWindow(const QByteArray &resourceS
 #if QT_CONFIG(vulkan)
     } else if (resourceString == "vkSurface") {
         if (QVulkanInstance *instance = window->vulkanInstance())
-            return static_cast<QCocoaVulkanInstance *>(instance->handle())->createSurface(window);
+            return static_cast<QCocoaVulkanInstance *>(instance->handle())->surface(window);
 #endif
     }
     return nullptr;
diff --git a/src/plugins/platforms/cocoa/qcocoavulkaninstance.h b/src/plugins/platforms/cocoa/qcocoavulkaninstance.h
index 5fe6a612af..2a8d04757e 100644
--- a/src/plugins/platforms/cocoa/qcocoavulkaninstance.h
+++ b/src/plugins/platforms/cocoa/qcocoavulkaninstance.h
@@ -61,9 +61,11 @@ public:
 
     void createOrAdoptInstance() override;
 
-    VkSurfaceKHR *createSurface(QWindow *window);
-    VkSurfaceKHR createSurface(NSView *view);
+    VkSurfaceKHR *surface(QWindow *window);
+
 private:
+    VkSurfaceKHR createSurface(NSView *view);
+
     QVulkanInstance *m_instance = nullptr;
     QLibrary m_lib;
     VkSurfaceKHR m_nullSurface = nullptr;
diff --git a/src/plugins/platforms/cocoa/qcocoavulkaninstance.mm b/src/plugins/platforms/cocoa/qcocoavulkaninstance.mm
index 94c0a11b84..9e714859f2 100644
--- a/src/plugins/platforms/cocoa/qcocoavulkaninstance.mm
+++ b/src/plugins/platforms/cocoa/qcocoavulkaninstance.mm
@@ -57,12 +57,11 @@ void QCocoaVulkanInstance::createOrAdoptInstance()
     initInstance(m_instance, QByteArrayList() << QByteArrayLiteral("VK_MVK_macos_surface"));
 }
 
-VkSurfaceKHR *QCocoaVulkanInstance::createSurface(QWindow *window)
+VkSurfaceKHR *QCocoaVulkanInstance::surface(QWindow *window)
 {
     QCocoaWindow *cocoaWindow = static_cast<QCocoaWindow *>(window->handle());
-    if (cocoaWindow->m_vulkanSurface)
-        destroySurface(cocoaWindow->m_vulkanSurface);
-    cocoaWindow->m_vulkanSurface = createSurface(cocoaWindow->m_view);
+    if (!cocoaWindow->m_vulkanSurface)
+        cocoaWindow->m_vulkanSurface = createSurface(cocoaWindow->m_view);
     return &cocoaWindow->m_vulkanSurface;
 }