From a94f2da6b2bcf3931042231dc242bead96c06e93 Mon Sep 17 00:00:00 2001
From: homeburger <pmcgeee03@gmail.com>
Date: Tue, 19 May 2026 20:52:05 -0500
Subject: [PATCH] improve device selection logic

---
 src/Device.cpp | 60 +++++++++++++++++++++++++++++++++++++++++++++-----
 src/Device.hpp |  3 +++
 2 files changed, 58 insertions(+), 5 deletions(-)

diff --git a/src/Device.cpp b/src/Device.cpp
index 92caf16..1ac37b7 100644
--- a/src/Device.cpp
+++ b/src/Device.cpp
@@ -47,10 +47,60 @@ uint32_t Device::evaluatePhysicalDevice(vk::raii::PhysicalDevice& device) {
 
     std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Physical device found: " << deviceProperties.deviceName << std::endl;
 
-    if(deviceProperties.deviceType == vk::PhysicalDeviceType::eDiscreteGpu) {
-        return 2;
-    } else {
-        return 1;
-    } // i.e. a descrete gpu is preferable to an integrated gpu
+    uint32_t score = 0;
 
+    // TODO: this is very basic and can be improved
+
+    // prefer discrete graphics to integrated graphics
+    if(deviceProperties.deviceType == vk::PhysicalDeviceType::eDiscreteGpu) {
+        score += 2;
+    } else {
+         std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Warning: physical device " << deviceProperties.deviceName << " is not a discrete device!" << std::endl;
+    }
+
+    // prefer devices that support vulkan 1.3
+    if(deviceProperties.apiVersion >= vk::ApiVersion14) {
+        score++;
+    } else {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Warning: physical device " << deviceProperties.deviceName << " does not support Vulkan 1.3! (" << std::endl;
+    }
+
+    // prefer devices that support graphics queues
+    auto queueFamilies = device.getQueueFamilyProperties();
+    if(std::ranges::any_of( queueFamilies, []( auto const & qfp ) { return !!( qfp.queueFlags & vk::QueueFlagBits::eGraphics ); } )) {
+        score++;
+    } else {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Warning: physical device " << deviceProperties.deviceName << " does not support graphics queue families!" << std::endl;
+    }
+
+    // prefer devices that support all required extensions
+    auto availableDeviceExtensions = device.enumerateDeviceExtensionProperties();
+    bool found = false;
+    uint32_t missingExtensions = 0;
+    for(auto& requiredExtension : requiredDeviceExtensions_) {
+        for(auto& availableExtension: availableDeviceExtensions) {
+            if(strcmp(availableExtension.extensionName, requiredExtension) == 0) {
+                found = true;
+                continue;
+            }
+        }
+        if(found == false) {
+            missingExtensions++;
+        }
+    }
+    if(missingExtensions == 0) {
+        score++;
+    } else {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Warning: physical device " << deviceProperties.deviceName << " is missing extensions!" << std::endl;
+    }
+
+    // prefer devices that support all required features
+    auto features = device.template getFeatures2<vk::PhysicalDeviceFeatures2, vk::PhysicalDeviceVulkan13Features, vk::PhysicalDeviceExtendedDynamicStateFeaturesEXT>();
+    if(features.template get<vk::PhysicalDeviceVulkan13Features>().dynamicRendering && features.template get<vk::PhysicalDeviceExtendedDynamicStateFeaturesEXT>().extendedDynamicState) {
+        score++;
+    } else {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Warning: physical device " << deviceProperties.deviceName << " is missing features!" << std::endl;
+    }
+
+    return score;
 }
diff --git a/src/Device.hpp b/src/Device.hpp
index a70bfd2..623980e 100644
--- a/src/Device.hpp
+++ b/src/Device.hpp
@@ -20,5 +20,8 @@ class Device {
 
     vk::raii::Instance* instance_ = nullptr;
     vk::raii::PhysicalDevice physicalDevice_ = nullptr;
+
+    // required extensions for the physical device
+    std::vector<const char*> requiredDeviceExtensions_ = { vk::KHRSwapchainExtensionName };
     
 };