vulkan: Add instance-level version getter

...as described in the Vulkan >= 1.1 spec. One can now call
supportedApiVersion() (before create(), similarly to the other
supported* functions) to determine the available Vulkan
(instance-level) version.

Fixes: QTBUG-90333
Change-Id: Ibe8482402b7f07e4abc48c88252ff0365e4e2faa
Reviewed-by: Andy Nichols <andy.nichols@qt.io>

1 files changed, 24 insertions, 0 deletions

diff --git a/src/gui/vulkan/qbasicvulkanplatforminstance.cpp b/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
index 01d6179166..abb17e9d6d 100644
--- a/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
+++ b/src/gui/vulkan/qbasicvulkanplatforminstance.cpp
@@ -135,6 +135,25 @@ void QBasicPlatformVulkanInstance::init(QLibrary *lib)
         return;
     }
 
+    // Do not rely on non-1.0 header typedefs here.
+    typedef VkResult (VKAPI_PTR *T_enumerateInstanceVersion)(uint32_t* pApiVersion);
+    // Determine instance-level version as described in the Vulkan 1.2 spec.
+    T_enumerateInstanceVersion enumerateInstanceVersion = reinterpret_cast<T_enumerateInstanceVersion>(
+        m_vkGetInstanceProcAddr(VK_NULL_HANDLE, "vkEnumerateInstanceVersion"));
+    if (enumerateInstanceVersion) {
+        uint32_t ver = 0;
+        if (enumerateInstanceVersion(&ver) == VK_SUCCESS) {
+            m_supportedApiVersion = QVersionNumber(VK_VERSION_MAJOR(ver),
+                                                   VK_VERSION_MINOR(ver),
+                                                   VK_VERSION_PATCH(ver));
+        } else {
+            m_supportedApiVersion = QVersionNumber(1, 0, 0);
+        }
+    } else {
+        // Vulkan 1.0
+        m_supportedApiVersion = QVersionNumber(1, 0, 0);
+    }
+
     uint32_t layerCount = 0;
     m_vkEnumerateInstanceLayerProperties(&layerCount, nullptr);
     if (layerCount) {
@@ -180,6 +199,11 @@ QVulkanInfoVector<QVulkanExtension> QBasicPlatformVulkanInstance::supportedExten
     return m_supportedExtensions;
 }
 
+QVersionNumber QBasicPlatformVulkanInstance::supportedApiVersion() const
+{
+    return m_supportedApiVersion;
+}
+
 void QBasicPlatformVulkanInstance::initInstance(QVulkanInstance *instance, const QByteArrayList &extraExts)
 {
     if (!m_vkGetInstanceProcAddr) {