context.cpp

#include <common.hpp>
#include <vulkan/vulkan.hpp>
#include <vks/version.hpp>
#include <vector>
#include <iostream>

namespace vkx {
// A trimmed down version of our context class.
// The full version creates additional objects required for rendering:
//
//  vk::Device
//  vk::Queue
//  vk::PipelineCache
//  vk::CommandPool
//
// The full version also sets up validation layers for debugging if requested
// See vulkanContext.hpp
class Context {
public:
    // Vulkan instance, stores all per-application states
    vk::Instance instance;
    std::vector<vk::PhysicalDevice> physicalDevices;
    // Physical device (GPU) that Vulkan will ise
    vk::PhysicalDevice physicalDevice;
    // Stores physical device properties (for e.g. checking device limits)
    vk::PhysicalDeviceProperties deviceProperties;
    // Stores phyiscal device features (for e.g. checking if a feature is available)
    vk::PhysicalDeviceFeatures deviceFeatures;
    // Stores all available memory (type) properties for the physical device
    vk::PhysicalDeviceMemoryProperties deviceMemoryProperties;

    vks::Version version;
    vks::Version driverVersion;

    void createContext() {
        {
            // Vulkan instance
            vk::ApplicationInfo appInfo;
            appInfo.pApplicationName = "VulkanExamples";
            appInfo.pEngineName = "VulkanExamples";
            appInfo.apiVersion = VK_API_VERSION_1_0;

            vk::InstanceCreateInfo instanceCreateInfo;
            instanceCreateInfo.pApplicationInfo = &appInfo;
            instance = vk::createInstance(instanceCreateInfo);
        }

        // Physical device
        physicalDevices = instance.enumeratePhysicalDevices();
        // Note :
        // This example will always use the first physical device reported,
        // change the vector index if you have multiple Vulkan devices installed
        // and want to use another one
        physicalDevice = physicalDevices[0];

        // Version information for Vulkan is stored in a single 32 bit integer
        // with individual bits representing the major, minor and patch versions.
        // The maximum possible major and minor version is 512 (look out nVidia)
        // while the maximum possible patch version is 2048

        // Store properties (including limits) and features of the phyiscal device
        // So examples can check against them and see if a feature is actually supported
        deviceProperties = physicalDevice.getProperties();
        version = deviceProperties.apiVersion;
        driverVersion = deviceProperties.driverVersion;
        deviceFeatures = physicalDevice.getFeatures();
        // Gather physical device memory properties
        deviceMemoryProperties = physicalDevice.getMemoryProperties();
    }

    void destroyContext() { instance.destroy(); }
};
}  // namespace vkx

std::string toHumanSize(size_t size) {
    static const std::vector<std::string> SUFFIXES{ { "B", "KB", "MB", "GB", "TB", "PB" } };
    size_t suffixIndex = 0;
    while (suffixIndex < SUFFIXES.size() - 1 && size > 1024) {
        size >>= 10;
        ++suffixIndex;
    }

    std::stringstream buffer;
    buffer << size << " " << SUFFIXES[suffixIndex];
    return buffer.str();
}

class InitContextExample {
    vkx::Context context;

public:
    InitContextExample() { context.createContext(); }

    ~InitContextExample() { context.destroyContext(); }

    void run() {
        std::cout << "Vulkan Context Created" << std::endl;
        std::cout << "API Version:    " << context.version.toString() << std::endl;
        std::cout << "Driver Version: " << context.driverVersion.toString() << std::endl;
        std::cout << "Device Name:    " << context.deviceProperties.deviceName << std::endl;
        std::cout << "Device Type:    " << vk::to_string(context.deviceProperties.deviceType) << std::endl;
        std::cout << "Memory Heaps:  " << context.deviceMemoryProperties.memoryHeapCount << std::endl;
        for (size_t i = 0; i < context.deviceMemoryProperties.memoryHeapCount; ++i) {
            const auto& heap = context.deviceMemoryProperties.memoryHeaps[i];
            std::cout << "\tHeap " << i << " flags " << vk::to_string(heap.flags) << " size " << toHumanSize(heap.size) << std::endl;
        }
        std::cout << std::endl;
        std::cout << "Memory Types:  " << context.deviceMemoryProperties.memoryTypeCount << std::endl;
        for (size_t i = 0; i < context.deviceMemoryProperties.memoryTypeCount; ++i) {
            const auto type = context.deviceMemoryProperties.memoryTypes[i];
            std::cout << "\tType " << i << " flags " << vk::to_string(type.propertyFlags) << " heap " << type.heapIndex << std::endl;
        }
        std::cout << std::endl;
        std::cout << "Queues:" << std::endl;
        std::vector<vk::QueueFamilyProperties> queueProps = context.physicalDevice.getQueueFamilyProperties();

        for (size_t i = 0; i < queueProps.size(); ++i) {
            const auto& queueFamilyProperties = queueProps[i];
            std::cout << std::endl;
            std::cout << "Queue Family: " << i << std::endl;
            std::cout << "\tQueue Family Flags: " << vk::to_string(queueFamilyProperties.queueFlags) << std::endl;
            std::cout << "\tQueue Count: " << queueFamilyProperties.queueCount << std::endl;
        }
        std::cout << "Press enter to exit";
        std::cin.get();
    }
};

RUN_EXAMPLE(InitContextExample)