I think, this code better shows the logic followed here, to determine the two queue indices.

If it looks good, I can again carry that over to all the other chapters.

Author: asuessenbach

attachments/05_window_surface.cpp

@@ -40,18 +40,14 @@ class HelloTriangleApplication {
     }
 
 private:
-    GLFWwindow* window = nullptr;
-
-    vk::raii::Context  context;
-    vk::raii::Instance instance = nullptr;
+    GLFWwindow *                     window = nullptr;
+    vk::raii::Context                context;
+    vk::raii::Instance               instance       = nullptr;
     vk::raii::DebugUtilsMessengerEXT debugMessenger = nullptr;
-    vk::raii::SurfaceKHR surface = nullptr;
-
-    vk::raii::PhysicalDevice physicalDevice = nullptr;
-    vk::raii::Device device = nullptr;
-
-    vk::raii::Queue graphicsQueue = nullptr;
-    vk::raii::Queue presentQueue = nullptr;
+    vk::raii::SurfaceKHR             surface        = nullptr;
+    vk::raii::PhysicalDevice         physicalDevice = nullptr;
+    vk::raii::Device                 device         = nullptr;
+    vk::raii::Queue                  queue          = nullptr;
 
     std::vector<const char*> requiredDeviceExtension = {
         vk::KHRSwapchainExtensionName,
@@ -201,53 +197,25 @@ class HelloTriangleApplication {
     }
 
     void createLogicalDevice() {
-        // find the index of the first queue family that supports graphics
-        std::vector<vk::QueueFamilyProperties> queueFamilyProperties = physicalDevice.getQueueFamilyProperties();
+		std::vector<vk::QueueFamilyProperties> queueFamilyProperties = physicalDevice.getQueueFamilyProperties();
 
-        // get the first index into queueFamilyProperties which supports graphics
-        auto graphicsQueueFamilyProperty = std::ranges::find_if( queueFamilyProperties, []( auto const & qfp )
-                        { return (qfp.queueFlags & vk::QueueFlagBits::eGraphics) != static_cast<vk::QueueFlags>(0); } );
-
-        auto graphicsIndex = static_cast<uint32_t>( std::distance( queueFamilyProperties.begin(), graphicsQueueFamilyProperty ) );
-
-        // determine a queueFamilyIndex that supports present
-        // first check if the graphicsIndex is good enough
-        auto presentIndex = physicalDevice.getSurfaceSupportKHR( graphicsIndex, *surface )
-                                           ? graphicsIndex
-                                           : ~0;
-        if ( presentIndex == queueFamilyProperties.size() )
+        // get the first index into queueFamilyProperties which supports both graphics and present
+        uint32_t queueIndex = ~0;
+        for (uint32_t qfpIndex = 0; qfpIndex < queueFamilyProperties.size(); qfpIndex++)
         {
-            // the graphicsIndex doesn't support present -> look for another family index that supports both
-            // graphics and present
-            for ( size_t i = 0; i < queueFamilyProperties.size(); i++ )
-            {
-                if ( ( queueFamilyProperties[i].queueFlags & vk::QueueFlagBits::eGraphics ) &&
-                     physicalDevice.getSurfaceSupportKHR( static_cast<uint32_t>( i ), *surface ) )
-                {
-                    graphicsIndex = static_cast<uint32_t>( i );
-                    presentIndex  = graphicsIndex;
-                    break;
-                }
-            }
-            if ( presentIndex == queueFamilyProperties.size() )
-            {
-                // there's nothing like a single family index that supports both graphics and present -> look for another
-                // family index that supports present
-                for ( size_t i = 0; i < queueFamilyProperties.size(); i++ )
-                {
-                    if ( physicalDevice.getSurfaceSupportKHR( static_cast<uint32_t>( i ), *surface ) )
-                    {
-                        presentIndex = static_cast<uint32_t>( i );
-                        break;
-                    }
-                }
-            }
+          if ((queueFamilyProperties[qfpIndex].queueFlags & vk::QueueFlagBits::eGraphics) &&
+              physicalDevice.getSurfaceSupportKHR(qfpIndex, *surface))
+          {
+            // found a queue family that supports both graphics and present
+            queueIndex = qfpIndex;
+            break;
+          }
         }
-        if ( ( graphicsIndex == queueFamilyProperties.size() ) || ( presentIndex == queueFamilyProperties.size() ) )
+        if (queueIndex == ~0)
         {
-            throw std::runtime_error( "Could not find a queue for graphics or present -> terminating" );
+          throw std::runtime_error("Could not find a queue for graphics and present -> terminating");
         }
-
+		
         // query for Vulkan 1.3 features
         vk::StructureChain<vk::PhysicalDeviceFeatures2, vk::PhysicalDeviceVulkan13Features, vk::PhysicalDeviceExtendedDynamicStateFeaturesEXT> featureChain = {
             {},                               // vk::PhysicalDeviceFeatures2
@@ -257,16 +225,15 @@ class HelloTriangleApplication {
 
         // create a Device
         float                     queuePriority = 0.0f;
-        vk::DeviceQueueCreateInfo deviceQueueCreateInfo{ .queueFamilyIndex = graphicsIndex, .queueCount = 1, .pQueuePriorities = &queuePriority };
+        vk::DeviceQueueCreateInfo deviceQueueCreateInfo{ .queueFamilyIndex = queueIndex, .queueCount = 1, .pQueuePriorities = &queuePriority };
         vk::DeviceCreateInfo      deviceCreateInfo{ .pNext = &featureChain.get<vk::PhysicalDeviceFeatures2>(),
                                                     .queueCreateInfoCount = 1,
                                                     .pQueueCreateInfos = &deviceQueueCreateInfo,
                                                     .enabledExtensionCount = static_cast<uint32_t>(requiredDeviceExtension.size()),
                                                     .ppEnabledExtensionNames = requiredDeviceExtension.data() };
 
         device = vk::raii::Device( physicalDevice, deviceCreateInfo );
-        graphicsQueue = vk::raii::Queue( device, graphicsIndex, 0 );
-        presentQueue = vk::raii::Queue( device, presentIndex, 0 );
+        queue  = vk::raii::Queue( device, queueIndex, 0 );
     }
 
     std::vector<const char*> getRequiredExtensions() {