From 49c451d17f494cd39f12dc8a9241d5986e56b9bb Mon Sep 17 00:00:00 2001
From: Eugene Golushkov <e.golushkov@nospam-gmail.com>
Date: Wed, 27 Nov 2024 18:20:38 +0100
Subject: [PATCH] [Vk] Unfortunately deviceUUID is not random enough to xor
 parts together into 64bit value

---
 RenderSystems/Vulkan/include/OgreVulkanRenderSystem.h | 2 +-
 RenderSystems/Vulkan/src/OgreVulkanDevice.cpp         | 5 ++---
 RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp   | 8 ++++----
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/RenderSystems/Vulkan/include/OgreVulkanRenderSystem.h b/RenderSystems/Vulkan/include/OgreVulkanRenderSystem.h
index 6a6dbf777a..1509e70f84 100644
--- a/RenderSystems/Vulkan/include/OgreVulkanRenderSystem.h
+++ b/RenderSystems/Vulkan/include/OgreVulkanRenderSystem.h
@@ -56,7 +56,7 @@ namespace Ogre
     struct VulkanPhysicalDevice
     {
         VkPhysicalDevice physicalDevice;
-        uint64 physicalDeviceID;  // deviceLUID on Windows
+        uint64 physicalDeviceID[2];  // { deviceLUID, 0 } on Windows, deviceUUID or name hash otherwise
         String title;
     };
 
diff --git a/RenderSystems/Vulkan/src/OgreVulkanDevice.cpp b/RenderSystems/Vulkan/src/OgreVulkanDevice.cpp
index 79968cd266..d6872c4b60 100644
--- a/RenderSystems/Vulkan/src/OgreVulkanDevice.cpp
+++ b/RenderSystems/Vulkan/src/OgreVulkanDevice.cpp
@@ -468,7 +468,7 @@ namespace Ogre
             if( sameNameIndex != 0 )
                 name += " (" + Ogre::StringConverter::toString( sameNameIndex + 1 ) + ")";
 
-            // use deviceLUID or deviceUUID if available
+            // { deviceLUID, 0 } on Windows, deviceUUID or name hash otherwise
             uint64 uid[2] = {};
             if( hasVulkan11 && deviceVulkan11Props.deviceLUIDValid )
                 memcpy( uid, deviceVulkan11Props.deviceLUID, VK_LUID_SIZE );
@@ -480,10 +480,9 @@ namespace Ogre
                 memcpy( uid, deviceIDProps.deviceUUID, VK_UUID_SIZE );
             else
                 OGRE_HASH128_FUNC( name.c_str(), (int)name.size(), IdString::Seed, uid );
-            uint64 deviceLUID = uid[0] ^ uid[1];
 
             LogManager::getSingleton().logMessage( "Vulkan: \"" + name + "\"" );
-            mVulkanPhysicalDevices.push_back( { device, deviceLUID, name } );
+            mVulkanPhysicalDevices.push_back( { device, { uid[0], uid[1] }, name } );
         }
 
         LogManager::getSingleton().logMessage( "Vulkan: Device detection ends" );
diff --git a/RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp b/RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp
index 3dbf26fa1d..cc3092b6af 100644
--- a/RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp
+++ b/RenderSystems/Vulkan/src/OgreVulkanRenderSystem.cpp
@@ -173,7 +173,7 @@ namespace Ogre
         mVulkanProgramFactory1( 0 ),
         mVulkanProgramFactory2( 0 ),
         mVulkanProgramFactory3( 0 ),
-        mActiveDevice( { 0, 0, String() } ),
+        mActiveDevice( { 0, {}, String() } ),
         mFirstUnflushedAutoParamsBuffer( 0 ),
         mAutoParamsBufferIdx( 0 ),
         mCurrentAutoParamsBufferPtr( 0 ),
@@ -1091,9 +1091,9 @@ namespace Ogre
                                                               dbgFunc, this );
             }
 
-            mActiveDevice = externalDevice
-                                ? VulkanPhysicalDevice( { externalDevice->physicalDevice, 0, String() } )
-                                : *mInstance->findByName( mVulkanSupport->getSelectedDeviceName() );
+            mActiveDevice =
+                externalDevice ? VulkanPhysicalDevice( { externalDevice->physicalDevice, {}, String() } )
+                               : *mInstance->findByName( mVulkanSupport->getSelectedDeviceName() );
 
             mDevice = new VulkanDevice( this );
             mDevice->setPhysicalDevice( mInstance, mActiveDevice, externalDevice );