Feature: VkDevice Creation (#5)

* update contributing with goals

* add required extensions to vulkan instance

* add validation layers + debug callback

* add device class which enumerates availble gpu devices

* improve device selection logic

* add logical device creation

src/Device.cpp

@@ -0,0 +1,155 @@
+
+#include "Device.hpp"
+
+#include <iostream>
+
+Device::Device(vk::raii::Instance* instance): instance_(instance) {
+
+}
+
+Device::~Device() {
+
+}
+
+bool Device::selectPhysicalDevice() {
+
+    std::vector<vk::raii::PhysicalDevice> physicalDevices = instance_->enumeratePhysicalDevices();
+
+    if(physicalDevices.empty()) {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Error: no physical devices with Vulkan support found." << std::endl;
+        return false;
+    }
+
+    // validate found devices
+    uint32_t maxScore = 0;
+    for(vk::raii::PhysicalDevice& physicalDevice : physicalDevices) {
+        uint32_t capabilityScore = evaluatePhysicalDevice(physicalDevice);
+        if(capabilityScore > maxScore) {
+            maxScore = capabilityScore;
+            physicalDevice_ = physicalDevice;
+        }
+    }
+    if(maxScore = 0) {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Error: physical devices found, but none capable for this engine." << std::endl;
+        return false;
+    } else {
+        vk::PhysicalDeviceProperties deviceProperties = physicalDevice_.getProperties();
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Physical device selected: " << deviceProperties.deviceName << std::endl;
+        return true;
+    }
+
+}
+
+uint32_t Device::evaluatePhysicalDevice(vk::raii::PhysicalDevice& device) {
+
+    vk::PhysicalDeviceProperties deviceProperties = device.getProperties();
+    vk::PhysicalDeviceFeatures deviceFeatures = device.getFeatures();
+
+    std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Physical device found: " << deviceProperties.deviceName << std::endl;
+
+    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;
+}
+
+bool Device::createLogicalDevice() {
+
+    if(physicalDevice_ == nullptr) {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Error: cannot create logical device without a valid physical device." << std::endl;
+        return false;
+    }
+
+    // specify queue family requirements
+    std::vector<vk::QueueFamilyProperties> queueFamilyProperties = physicalDevice_.getQueueFamilyProperties();
+    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));
+    float queuePriority = 1.0f;
+    vk::DeviceQueueCreateInfo deviceQueueCreateInfo {
+        .queueFamilyIndex = graphicsIndex,
+        .queueCount = 1,
+        .pQueuePriorities = &queuePriority
+    };
+
+    // specify device feature requirements
+    vk::PhysicalDeviceVulkan13Features deviceFeatures = { .dynamicRendering = true };
+    vk::PhysicalDeviceExtendedDynamicStateFeaturesEXT deviceStateFeatures = { . extendedDynamicState = true };
+    vk::StructureChain<vk::PhysicalDeviceFeatures2, vk::PhysicalDeviceVulkan13Features, vk::PhysicalDeviceExtendedDynamicStateFeaturesEXT> featureChain = {
+        {}, // empty for now
+        deviceFeatures,
+        deviceStateFeatures
+    };
+
+    // create logical device
+    vk::DeviceCreateInfo deviceCreateInfo {
+        .pNext = &featureChain.get<vk::PhysicalDeviceFeatures2>(),
+        .queueCreateInfoCount = 1,
+        .pQueueCreateInfos = &deviceQueueCreateInfo,
+        .enabledExtensionCount = static_cast<uint32_t>(requiredDeviceExtensions_.size()),
+        .ppEnabledExtensionNames = requiredDeviceExtensions_.data()
+    };
+    logicalDevice_ = vk::raii::Device(physicalDevice_, deviceCreateInfo);
+
+    // initialize the graphics queue
+    graphicsQueue_ = vk::raii::Queue(logicalDevice_, graphicsIndex, 0);
+
+    if(logicalDevice_ != nullptr) {
+        return true;
+    } else {
+        std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Error: could not create a valid logical device." << std::endl;
+        return false;
+    }
+
+}

src/Device.hpp

@@ -0,0 +1,32 @@
+
+#pragma once
+
+#include <vulkan/vulkan_raii.hpp>
+
+class Device {
+
+    public:
+
+    Device(vk::raii::Instance* instance);
+    ~Device();
+
+    // assigns a capable gpu vkdevice to physicalDevice 
+    bool selectPhysicalDevice();
+
+    // initializes the logical device
+    bool createLogicalDevice();
+
+    private:
+
+    // gives a device a score to attempt to select the most capable device
+    uint32_t evaluatePhysicalDevice(vk::raii::PhysicalDevice& device);
+
+    vk::raii::Instance* instance_ = nullptr;
+    vk::raii::PhysicalDevice physicalDevice_ = nullptr;
+    vk::raii::Device logicalDevice_ = nullptr;
+    vk::raii::Queue graphicsQueue_ = nullptr;
+
+    // required extensions for the physical device
+    std::vector<const char*> requiredDeviceExtensions_ = { vk::KHRSwapchainExtensionName };
+    
+};

src/Engine.cpp

@@ -3,6 +3,8 @@
 
 #include <iostream>
 
+#include "Device.hpp"
+
 Engine::Engine(Window* window): window_(window) {
 
     // cleans up this constructor 
@@ -19,8 +21,12 @@ void Engine::init() {
         std::cout << "[" << __FUNCTION__ << ": " << __LINE__ << "] Error creating Vulkan instance." << std::endl;
     }
 
-    // next steps:
     // device selection and setup
+    Device device(&instance_);
+    (void)device.selectPhysicalDevice();
+    (void)device.createLogicalDevice();
+
+    // next steps:
     // queue creation
     // vulkan memory allocator
     // create vulkan surface