Tutorial02.cpp

// Copyright 2016 Intel Corporation All Rights Reserved
// 
// Intel makes no representations about the suitability of this software for any purpose.
// THIS SOFTWARE IS PROVIDED ""AS IS."" INTEL SPECIFICALLY DISCLAIMS ALL WARRANTIES,
// EXPRESS OR IMPLIED, AND ALL LIABILITY, INCLUDING CONSEQUENTIAL AND OTHER INDIRECT DAMAGES,
// FOR THE USE OF THIS SOFTWARE, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PROPRIETARY
// RIGHTS, AND INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
// Intel does not assume any responsibility for any errors which may appear in this software
// nor any responsibility to update it.

#include <cstring>
#include "Tutorial02.h"
#include "VulkanFunctions.h"

namespace Tutorial {

  Tutorial02::Tutorial02() :
    VulkanLibrary(),
    Window(),
    Vulkan() {
  }

  bool Tutorial02::PrepareVulkan( OS::WindowParameters parameters ) {
    Window = parameters;

    if( !LoadVulkanLibrary() ) {
      return false;
    }
    if( !LoadExportedEntryPoints() ) {
      return false;
    }
    if( !LoadGlobalLevelEntryPoints() ) {
      return false;
    }
    if( !CreateInstance() ) {
      return false;
    }
    if( !LoadInstanceLevelEntryPoints() ) {
      return false;
    }
    if( !CreatePresentationSurface() ) {
      return false;
    }
    if( !CreateDevice() ) {
      return false;
    }
    if( !LoadDeviceLevelEntryPoints() ) {
      return false;
    }
    if( !GetDeviceQueue() ) {
      return false;
    }
    if( !CreateSemaphores() ) {
      return false;
    }
    return true;
  }

  bool Tutorial02::LoadVulkanLibrary() {
#if defined(VK_USE_PLATFORM_WIN32_KHR)
    VulkanLibrary = LoadLibrary( "vulkan-1.dll" );
#elif defined(VK_USE_PLATFORM_XCB_KHR) || defined(VK_USE_PLATFORM_XLIB_KHR)
    VulkanLibrary = dlopen( "libvulkan.so", RTLD_NOW );
#endif

    if( VulkanLibrary == nullptr ) {
      printf( "Could not load Vulkan library!\n" );
      return false;
    }
    return true;
  }

  bool Tutorial02::LoadExportedEntryPoints() {
#if defined(VK_USE_PLATFORM_WIN32_KHR)
    #define LoadProcAddress GetProcAddress
#elif defined(VK_USE_PLATFORM_XCB_KHR) || defined(VK_USE_PLATFORM_XLIB_KHR)
    #define LoadProcAddress dlsym
#endif

#define VK_EXPORTED_FUNCTION( fun )                                     \
    if( !(fun = (PFN_##fun)LoadProcAddress( VulkanLibrary, #fun )) ) {  \
      printf( "Could not load exported function: " #fun "!\n" );        \
      return false;                                                     \
    }

#include "ListOfFunctions.inl"

    return true;
  }

  bool Tutorial02::LoadGlobalLevelEntryPoints() {
#define VK_GLOBAL_LEVEL_FUNCTION( fun )                                 \
    if( !(fun = (PFN_##fun)vkGetInstanceProcAddr( nullptr, #fun )) ) {  \
      printf( "Could not load global level function: " #fun "!\n" );    \
      return false;                                                     \
    }

#include "ListOfFunctions.inl"

      return true;
  }

  bool Tutorial02::CreateInstance() {
    uint32_t extensions_count = 0;
    if( (vkEnumerateInstanceExtensionProperties( nullptr, &extensions_count, nullptr ) != VK_SUCCESS) ||
        (extensions_count == 0) ) {
      printf( "Error occurred during instance extensions enumeration!\n" );
      return false;
    }

    std::vector<VkExtensionProperties> available_extensions( extensions_count );
    if( vkEnumerateInstanceExtensionProperties( nullptr, &extensions_count, &available_extensions[0] ) != VK_SUCCESS ) {
      printf( "Error occurred during instance extensions enumeration!\n" );
      return false;
    }

    std::vector<const char*> extensions = {
      VK_KHR_SURFACE_EXTENSION_NAME,
#if defined(VK_USE_PLATFORM_WIN32_KHR)
      VK_KHR_WIN32_SURFACE_EXTENSION_NAME
#elif defined(VK_USE_PLATFORM_XCB_KHR)
      VK_KHR_XCB_SURFACE_EXTENSION_NAME
#elif defined(VK_USE_PLATFORM_XLIB_KHR)
      VK_KHR_XLIB_SURFACE_EXTENSION_NAME
#endif
    };

    for( size_t i = 0; i < extensions.size(); ++i ) {
      if( !CheckExtensionAvailability( extensions[i], available_extensions ) ) {
        printf( "Could not find instance extension named \"%s\"!\n", extensions[i] );
        return false;
      }
    }

    VkApplicationInfo application_info = {
      VK_STRUCTURE_TYPE_APPLICATION_INFO,             // VkStructureType            sType
      nullptr,                                        // const void                *pNext
      "API without Secrets: Introduction to Vulkan",  // const char                *pApplicationName
      VK_MAKE_VERSION( 1, 0, 0 ),                     // uint32_t                   applicationVersion
      "Vulkan Tutorial by Intel",                     // const char                *pEngineName
      VK_MAKE_VERSION( 1, 0, 0 ),                     // uint32_t                   engineVersion
      VK_API_VERSION                                  // uint32_t                   apiVersion
    };

    VkInstanceCreateInfo instance_create_info = {
      VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO,         // VkStructureType            sType
      nullptr,                                        // const void                *pNext
      0,                                              // VkInstanceCreateFlags      flags
      &application_info,                              // const VkApplicationInfo   *pApplicationInfo
      0,                                              // uint32_t                   enabledLayerCount
      nullptr,                                        // const char * const        *ppEnabledLayerNames
      static_cast<uint32_t>(extensions.size()),       // uint32_t                   enabledExtensionCount
      &extensions[0]                                  // const char * const        *ppEnabledExtensionNames
    };

    if( vkCreateInstance( &instance_create_info, nullptr, &Vulkan.Instance ) != VK_SUCCESS ) {
      printf( "Could not create Vulkan instance!\n" );
      return false;
    }
    return true;
  }

  bool Tutorial02::CheckExtensionAvailability( const char *extension_name, const std::vector<VkExtensionProperties> &available_extensions ) {
    for( size_t i = 0; i < available_extensions.size(); ++i ) {
      if( strcmp( available_extensions[i].extensionName, extension_name ) == 0 ) {
        return true;
      }
    }
    return false;
  }

  bool Tutorial02::LoadInstanceLevelEntryPoints() {
#define VK_INSTANCE_LEVEL_FUNCTION( fun )                                       \
    if( !(fun = (PFN_##fun)vkGetInstanceProcAddr( Vulkan.Instance, #fun )) ) {  \
      printf( "Could not load instance level function: " #fun "\n" );           \
      return false;                                                             \
    }

#include "ListOfFunctions.inl"

      return true;
  }

  bool Tutorial02::CreatePresentationSurface() {
#if defined(VK_USE_PLATFORM_WIN32_KHR)
    VkWin32SurfaceCreateInfoKHR surface_create_info = {
      VK_STRUCTURE_TYPE_WIN32_SURFACE_CREATE_INFO_KHR,  // VkStructureType                  sType
      nullptr,                                          // const void                      *pNext
      0,                                                // VkWin32SurfaceCreateFlagsKHR     flags
      Window.Instance,                                  // HINSTANCE                        hinstance
      Window.Handle                                     // HWND                             hwnd
    };

    if( vkCreateWin32SurfaceKHR( Vulkan.Instance, &surface_create_info, nullptr, &Vulkan.PresentationSurface ) == VK_SUCCESS ) {
      return true;
    }

#elif defined(VK_USE_PLATFORM_XCB_KHR)
    VkXcbSurfaceCreateInfoKHR surface_create_info = {
      VK_STRUCTURE_TYPE_XCB_SURFACE_CREATE_INFO_KHR,    // VkStructureType                  sType
      nullptr,                                          // const void                      *pNext
      0,                                                // VkXcbSurfaceCreateFlagsKHR       flags
      Window.Connection,                                // xcb_connection_t*                connection
      Window.Handle                                     // xcb_window_t                     window
    };

    if( vkCreateXcbSurfaceKHR( Vulkan.Instance, &surface_create_info, nullptr, &Vulkan.PresentationSurface ) == VK_SUCCESS ) {
      return true;
    }

#elif defined(VK_USE_PLATFORM_XLIB_KHR)
    VkXlibSurfaceCreateInfoKHR surface_create_info = {
      VK_STRUCTURE_TYPE_XLIB_SURFACE_CREATE_INFO_KHR,   // VkStructureType                sType
      nullptr,                                          // const void                    *pNext
      0,                                                // VkXlibSurfaceCreateFlagsKHR    flags
      Window.DisplayPtr,                                // Display                       *dpy
      Window.Handle                                     // Window                         window
    };
    if( vkCreateXlibSurfaceKHR( Vulkan.Instance, &surface_create_info, nullptr, &Vulkan.PresentationSurface ) == VK_SUCCESS ) {
      return true;
    }

#endif

    printf( "Could not create presentation surface!\n" );
    return false;
  }

  bool Tutorial02::CreateDevice() {
    uint32_t num_devices = 0;
    if( (vkEnumeratePhysicalDevices( Vulkan.Instance, &num_devices, nullptr ) != VK_SUCCESS) ||
        (num_devices == 0) ) {
      printf( "Error occurred during physical devices enumeration!\n" );
      return false;
    }

    std::vector<VkPhysicalDevice> physical_devices( num_devices );
    if( vkEnumeratePhysicalDevices( Vulkan.Instance, &num_devices, &physical_devices[0] ) != VK_SUCCESS ) {
      printf( "Error occurred during physical devices enumeration!\n" );
      return false;
    }

    uint32_t selected_graphics_queue_family_index = UINT32_MAX;
    uint32_t selected_present_queue_family_index = UINT32_MAX;

    for( uint32_t i = 0; i < num_devices; ++i ) {
      if( CheckPhysicalDeviceProperties( physical_devices[i], selected_graphics_queue_family_index, selected_present_queue_family_index ) ) {
        Vulkan.PhysicalDevice = physical_devices[i];
      }
    }
    if( Vulkan.PhysicalDevice == VK_NULL_HANDLE ) {
      printf( "Could not select physical device based on the chosen properties!\n" );
      return false;
    }

    std::vector<VkDeviceQueueCreateInfo> queue_create_infos;
    std::vector<float> queue_priorities = { 1.0f };

    queue_create_infos.push_back( {
        VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,     // VkStructureType              sType
        nullptr,                                        // const void                  *pNext
        0,                                              // VkDeviceQueueCreateFlags     flags
        selected_graphics_queue_family_index,           // uint32_t                     queueFamilyIndex
        static_cast<uint32_t>(queue_priorities.size()), // uint32_t                     queueCount
        &queue_priorities[0]                            // const float                 *pQueuePriorities
    } );

    if( selected_graphics_queue_family_index != selected_present_queue_family_index ) {
      queue_create_infos.push_back( {
        VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO,     // VkStructureType              sType
        nullptr,                                        // const void                  *pNext
        0,                                              // VkDeviceQueueCreateFlags     flags
        selected_present_queue_family_index,            // uint32_t                     queueFamilyIndex
        static_cast<uint32_t>(queue_priorities.size()), // uint32_t                     queueCount
        &queue_priorities[0]                            // const float                 *pQueuePriorities
      } );
    }

    std::vector<const char*> extensions = {
      VK_KHR_SWAPCHAIN_EXTENSION_NAME
    };

    VkDeviceCreateInfo device_create_info = {
      VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO,             // VkStructureType                    sType
      nullptr,                                          // const void                        *pNext
      0,                                                // VkDeviceCreateFlags                flags
      1,                                                // uint32_t                           queueCreateInfoCount
      &queue_create_infos[0],                           // const VkDeviceQueueCreateInfo     *pQueueCreateInfos
      0,                                                // uint32_t                           enabledLayerCount
      nullptr,                                          // const char * const                *ppEnabledLayerNames
      static_cast<uint32_t>(extensions.size()),         // uint32_t                           enabledExtensionCount
      &extensions[0],                                   // const char * const                *ppEnabledExtensionNames
      nullptr                                           // const VkPhysicalDeviceFeatures    *pEnabledFeatures
    };

    if( vkCreateDevice( Vulkan.PhysicalDevice, &device_create_info, nullptr, &Vulkan.Device ) != VK_SUCCESS ) {
      printf( "Could not create Vulkan device!\n" );
      return false;
    }

    Vulkan.GraphicsQueueFamilyIndex = selected_graphics_queue_family_index;
    Vulkan.PresentQueueFamilyIndex = selected_present_queue_family_index;
    return true;
  }

  bool Tutorial02::CheckPhysicalDeviceProperties( VkPhysicalDevice physical_device, uint32_t &selected_graphics_queue_family_index, uint32_t &selected_present_queue_family_index ) {
    uint32_t extensions_count = 0;
    if( (vkEnumerateDeviceExtensionProperties( physical_device, nullptr, &extensions_count, nullptr ) != VK_SUCCESS) ||
        (extensions_count == 0) ) {
      printf( "Error occurred during physical device %p extensions enumeration!\n", physical_device );
      return false;
    }

    std::vector<VkExtensionProperties> available_extensions( extensions_count );
    if( vkEnumerateDeviceExtensionProperties( physical_device, nullptr, &extensions_count, &available_extensions[0] ) != VK_SUCCESS ) {
      printf( "Error occurred during physical device %p extensions enumeration!\n", physical_device );
      return false;
    }

    std::vector<const char*> device_extensions = {
      VK_KHR_SWAPCHAIN_EXTENSION_NAME
    };

    for( size_t i = 0; i < device_extensions.size(); ++i ) {
      if( !CheckExtensionAvailability( device_extensions[i], available_extensions ) ) {
        printf( "Physical device %p doesn't support extension named \"%s\"!\n", physical_device, device_extensions[i] );
        return false;
      }
    }

    VkPhysicalDeviceProperties device_properties;
    VkPhysicalDeviceFeatures   device_features;

    vkGetPhysicalDeviceProperties( physical_device, &device_properties );
    vkGetPhysicalDeviceFeatures( physical_device, &device_features );

    uint32_t major_version = VK_VERSION_MAJOR( device_properties.apiVersion );

    if( (major_version < 1) &&
        (device_properties.limits.maxImageDimension2D < 4096) ) {
      printf( "Physical device %p doesn't support required parameters!\n", physical_device );
      return false;
    }

    uint32_t queue_families_count = 0;
    vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, nullptr );
    if( queue_families_count == 0 ) {
      printf( "Physical device %p doesn't have any queue families!\n", physical_device );
      return false;
    }

    std::vector<VkQueueFamilyProperties>  queue_family_properties( queue_families_count );
    std::vector<VkBool32>                 queue_present_support( queue_families_count );

    vkGetPhysicalDeviceQueueFamilyProperties( physical_device, &queue_families_count, &queue_family_properties[0] );

    uint32_t graphics_queue_family_index = UINT32_MAX;
    uint32_t present_queue_family_index = UINT32_MAX;

    for( uint32_t i = 0; i < queue_families_count; ++i ) {
      vkGetPhysicalDeviceSurfaceSupportKHR( physical_device, i, Vulkan.PresentationSurface, &queue_present_support[i] );

      if( (queue_family_properties[i].queueCount > 0) &&
          (queue_family_properties[i].queueFlags & VK_QUEUE_GRAPHICS_BIT) ) {
        // Select first queue that supports graphics
        if( graphics_queue_family_index == UINT32_MAX ) {
          graphics_queue_family_index = i;
        }

        // If there is queue that supports both graphics and present - prefer it
        if( queue_present_support[i] ) {
          selected_graphics_queue_family_index = i;
          selected_present_queue_family_index = i;
          return true;
        }
      }
    }

    // We don't have queue that supports both graphics and present so we have to use separate queues
    for( uint32_t i = 0; i < queue_families_count; ++i ) {
      if( queue_present_support[i] ) {
        present_queue_family_index = i;
        break;
      }
    }

    // If this device doesn't support queues with graphics and present capabilities don't use it
    if( (graphics_queue_family_index == UINT32_MAX) ||
        (present_queue_family_index == UINT32_MAX) ) {
      printf( "Could not find queue families with required properties on physical device %p!\n", physical_device );
      return false;
    }

    selected_graphics_queue_family_index = graphics_queue_family_index;
    selected_present_queue_family_index = present_queue_family_index;
    return true;
  }

  bool Tutorial02::LoadDeviceLevelEntryPoints() {
#define VK_DEVICE_LEVEL_FUNCTION( fun )                                     \
    if( !(fun = (PFN_##fun)vkGetDeviceProcAddr( Vulkan.Device, #fun )) ) {  \
      printf( "Could not load device level function: " #fun "!\n" );        \
      return false;                                                         \
    }

#include "ListOfFunctions.inl"

      return true;
  }

  bool Tutorial02::GetDeviceQueue() {
    vkGetDeviceQueue( Vulkan.Device, Vulkan.GraphicsQueueFamilyIndex, 0, &Vulkan.GraphicsQueue );
    vkGetDeviceQueue( Vulkan.Device, Vulkan.PresentQueueFamilyIndex, 0, &Vulkan.PresentQueue );
    return true;
  }

  bool Tutorial02::CreateSemaphores() {
    VkSemaphoreCreateInfo semaphore_create_info = {
      VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO,      // VkStructureType          sType
      nullptr,                                      // const void*              pNext
      0                                             // VkSemaphoreCreateFlags   flags
    };

    if( (vkCreateSemaphore( Vulkan.Device, &semaphore_create_info, nullptr, &Vulkan.ImageAvailableSemaphore ) != VK_SUCCESS) ||
        (vkCreateSemaphore( Vulkan.Device, &semaphore_create_info, nullptr, &Vulkan.RenderingFinishedSemaphore ) != VK_SUCCESS) ) {
      printf( "Could not create semaphores!\n" );
      return false;
    }

    return true;
  }

  bool Tutorial02::CreateSwapChain() {
    if( Vulkan.Device != VK_NULL_HANDLE ) {
      vkDeviceWaitIdle( Vulkan.Device );
    }

    VkSurfaceCapabilitiesKHR surface_capabilities;
    if( vkGetPhysicalDeviceSurfaceCapabilitiesKHR( Vulkan.PhysicalDevice, Vulkan.PresentationSurface, &surface_capabilities ) != VK_SUCCESS ) {
      printf( "Could not check presentation surface capabilities!\n" );
      return false;
    }

    uint32_t formats_count;
    if( (vkGetPhysicalDeviceSurfaceFormatsKHR( Vulkan.PhysicalDevice, Vulkan.PresentationSurface, &formats_count, nullptr ) != VK_SUCCESS) ||
        (formats_count == 0) ) {
      printf( "Error occurred during presentation surface formats enumeration!\n" );
      return false;
    }

    std::vector<VkSurfaceFormatKHR> surface_formats( formats_count );
    if( vkGetPhysicalDeviceSurfaceFormatsKHR( Vulkan.PhysicalDevice, Vulkan.PresentationSurface, &formats_count, &surface_formats[0] ) != VK_SUCCESS ) {
      printf( "Error occurred during presentation surface formats enumeration!\n" );
      return false;
    }

    uint32_t present_modes_count;
    if( (vkGetPhysicalDeviceSurfacePresentModesKHR( Vulkan.PhysicalDevice, Vulkan.PresentationSurface, &present_modes_count, nullptr ) != VK_SUCCESS) ||
        (present_modes_count == 0) ) {
      printf( "Error occurred during presentation surface present modes enumeration!\n" );
      return false;
    }

    std::vector<VkPresentModeKHR> present_modes( present_modes_count );
    if( vkGetPhysicalDeviceSurfacePresentModesKHR( Vulkan.PhysicalDevice, Vulkan.PresentationSurface, &present_modes_count, &present_modes[0] ) != VK_SUCCESS ) {
      printf( "Error occurred during presentation surface present modes enumeration!\n" );
      return false;
    }

    uint32_t                      desired_number_of_images = GetSwapChainNumImages( surface_capabilities );
    VkSurfaceFormatKHR            desired_format = GetSwapChainFormat( surface_formats );
    VkExtent2D                    desired_extent = GetSwapChainExtent( surface_capabilities );
    VkImageUsageFlags             desired_usage = GetSwapChainUsageFlags( surface_capabilities );
    VkSurfaceTransformFlagBitsKHR desired_transform = GetSwapChainTransform( surface_capabilities );
    VkPresentModeKHR              desired_present_mode = GetSwapChainPresentMode( present_modes );
    VkSwapchainKHR                old_swap_chain = Vulkan.SwapChain;

    if( static_cast<int>(desired_usage) == 0 ) {
      printf( "TRANSFER_DST image usage is not supported by the swap chain!" );
      return false;
    }

    VkSwapchainCreateInfoKHR swap_chain_create_info = {
      VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR,  // VkStructureType                sType
      nullptr,                                      // const void                    *pNext
      0,                                            // VkSwapchainCreateFlagsKHR      flags
      Vulkan.PresentationSurface,                   // VkSurfaceKHR                   surface
      desired_number_of_images,                     // uint32_t                       minImageCount
      desired_format.format,                        // VkFormat                       imageFormat
      desired_format.colorSpace,                    // VkColorSpaceKHR                imageColorSpace
      desired_extent,                               // VkExtent2D                     imageExtent
      1,                                            // uint32_t                       imageArrayLayers
      desired_usage,                                // VkImageUsageFlags              imageUsage
      VK_SHARING_MODE_EXCLUSIVE,                    // VkSharingMode                  imageSharingMode
      0,                                            // uint32_t                       queueFamilyIndexCount
      nullptr,                                      // const uint32_t                *pQueueFamilyIndices
      desired_transform,                            // VkSurfaceTransformFlagBitsKHR  preTransform
      VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR,            // VkCompositeAlphaFlagBitsKHR    compositeAlpha
      desired_present_mode,                         // VkPresentModeKHR               presentMode
      VK_TRUE,                                      // VkBool32                       clipped
      old_swap_chain                                // VkSwapchainKHR                 oldSwapchain
    };

    if( vkCreateSwapchainKHR( Vulkan.Device, &swap_chain_create_info, nullptr, &Vulkan.SwapChain ) != VK_SUCCESS ) {
      printf( "Could not create swap chain!\n" );
      return false;
    }
    if( old_swap_chain != VK_NULL_HANDLE ) {
      vkDestroySwapchainKHR( Vulkan.Device, old_swap_chain, nullptr );
    }

    return true;
  }

  uint32_t Tutorial02::GetSwapChainNumImages( VkSurfaceCapabilitiesKHR &surface_capabilities ) {
    // Set of images defined in a swap chain may not always be available for application to render to:
    // One may be displayed and one may wait in a queue to be presented
    // If application wants to use more images at the same time it must ask for more images
    uint32_t image_count = surface_capabilities.minImageCount + 1;
    if( (surface_capabilities.maxImageCount > 0) &&
        (image_count > surface_capabilities.maxImageCount) ) {
      image_count = surface_capabilities.maxImageCount;
    }
    return image_count;
  }

  VkSurfaceFormatKHR Tutorial02::GetSwapChainFormat( std::vector<VkSurfaceFormatKHR> &surface_formats ) {
    // If the list contains only one entry with undefined format
    // it mean that there are no preferred surface formats and any can be choosen
    if( (surface_formats.size() == 1) &&
        (surface_formats[0].format == VK_FORMAT_UNDEFINED) ) {
      return{ VK_FORMAT_R8G8B8A8_UNORM, VK_COLORSPACE_SRGB_NONLINEAR_KHR };
    }

    // Check if list contains most widely used R8 G8 B8 A8 format
    // with nonlinear color space
    for( VkSurfaceFormatKHR &surface_format : surface_formats ) {
      if( surface_format.format == VK_FORMAT_R8G8B8A8_UNORM ) {
        return surface_format;
      }
    }

    // Return the first format from the list
    return surface_formats[0];
  }

  VkExtent2D Tutorial02::GetSwapChainExtent( VkSurfaceCapabilitiesKHR &surface_capabilities ) {
    // Special value of surface extent is width == height == -1
    // If this is so we define the size by ourselves but it must fit within defined confines
    if( surface_capabilities.currentExtent.width == -1 ) {
      VkExtent2D swap_chain_extent = { 640, 480 };
      if( swap_chain_extent.width < surface_capabilities.minImageExtent.width ) {
        swap_chain_extent.width = surface_capabilities.minImageExtent.width;
      }
      if( swap_chain_extent.height < surface_capabilities.minImageExtent.height ) {
        swap_chain_extent.height = surface_capabilities.minImageExtent.height;
      }
      if( swap_chain_extent.width > surface_capabilities.maxImageExtent.width ) {
        swap_chain_extent.width = surface_capabilities.maxImageExtent.width;
      }
      if( swap_chain_extent.height > surface_capabilities.maxImageExtent.height ) {
        swap_chain_extent.height = surface_capabilities.maxImageExtent.height;
      }
      return swap_chain_extent;
    }

    // Most of the cases we define size of the swap_chain images equal to current window's size
    return surface_capabilities.currentExtent;
  }

  VkImageUsageFlags Tutorial02::GetSwapChainUsageFlags( VkSurfaceCapabilitiesKHR &surface_capabilities ) {
    // Color attachment flag must always be supported
    // We can define other usage flags but we always need to check if they are supported
    if( surface_capabilities.supportedUsageFlags & VK_IMAGE_USAGE_TRANSFER_DST_BIT ) {
      return VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
    }
    return 0;
  }

  VkSurfaceTransformFlagBitsKHR Tutorial02::GetSwapChainTransform( VkSurfaceCapabilitiesKHR &surface_capabilities ) {
    // Sometimes images must be transformed before they are presented (i.e. due to device's orienation
    // being other than default orientation)
    // If the specified transform is other than current transform, presentation engine will transform image
    // during presentation operation; this operation may hit performance on some platforms
    // Here we don't want any transformations to occur so if the identity transform is supported use it
    // otherwise just use the same transform as current transform
    if( surface_capabilities.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR ) {
      return VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR;
    } else {
      return surface_capabilities.currentTransform;
    }
  }

  VkPresentModeKHR Tutorial02::GetSwapChainPresentMode( std::vector<VkPresentModeKHR> &present_modes ) {
    // FIFO present mode is always available
    // MAILBOX is the lowest latency V-Sync enabled mode (something like triple-buffering) so use it if available
    for( VkPresentModeKHR &present_mode : present_modes ) {
      if( present_mode == VK_PRESENT_MODE_MAILBOX_KHR ) {
        return present_mode;
      }
    }
    return VK_PRESENT_MODE_FIFO_KHR;
  }

  bool Tutorial02::OnWindowSizeChanged() {
    Clear();

    if( !CreateSwapChain() ) {
      return false;
    }
    if( !CreateCommandBuffers() ) {
      return false;
    }
    return true;
  }

  bool Tutorial02::CreateCommandBuffers() {
    VkCommandPoolCreateInfo cmd_pool_create_info = {
      VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO,     // VkStructureType              sType
      nullptr,                                        // const void*                  pNext
      0,                                              // VkCommandPoolCreateFlags     flags
      Vulkan.PresentQueueFamilyIndex                  // uint32_t                     queueFamilyIndex
    };

    if( vkCreateCommandPool( Vulkan.Device, &cmd_pool_create_info, nullptr, &Vulkan.PresentQueueCmdPool ) != VK_SUCCESS ) {
      printf( "Could not create a command pool!\n" );
      return false;
    }

    uint32_t image_count = 0;
    if( (vkGetSwapchainImagesKHR( Vulkan.Device, Vulkan.SwapChain, &image_count, nullptr ) != VK_SUCCESS) ||
        (image_count == 0) ) {
      printf( "Could not get the number of swap chain images!\n" );
      return false;
    }

    Vulkan.PresentQueueCmdBuffers.resize( image_count );

    VkCommandBufferAllocateInfo cmd_buffer_allocate_info = {
      VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO, // VkStructureType              sType
      nullptr,                                        // const void*                  pNext
      Vulkan.PresentQueueCmdPool,                     // VkCommandPool                commandPool
      VK_COMMAND_BUFFER_LEVEL_PRIMARY,                // VkCommandBufferLevel         level
      image_count                                     // uint32_t                     bufferCount
    };
    if( vkAllocateCommandBuffers( Vulkan.Device, &cmd_buffer_allocate_info, &Vulkan.PresentQueueCmdBuffers[0] ) != VK_SUCCESS ) {
      printf( "Could not allocate command buffers!\n" );
      return false;
    }

    if( !RecordCommandBuffers() ) {
      printf( "Could not record command buffers!\n" );
      return false;
    }
    return true;
  }

  bool Tutorial02::RecordCommandBuffers() {
    uint32_t image_count = static_cast<uint32_t>(Vulkan.PresentQueueCmdBuffers.size());

    std::vector<VkImage> swap_chain_images( image_count );
    if( vkGetSwapchainImagesKHR( Vulkan.Device, Vulkan.SwapChain, &image_count, &swap_chain_images[0] ) != VK_SUCCESS ) {
      printf( "Could not get swap chain images!\n" );
      return false;
    }

    VkCommandBufferBeginInfo cmd_buffer_begin_info = {
      VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO,  // VkStructureType                        sType
      nullptr,                                      // const void                            *pNext
      VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, // VkCommandBufferUsageFlags              flags
      nullptr                                       // const VkCommandBufferInheritanceInfo  *pInheritanceInfo
    };

    VkClearColorValue clear_color = {
      { 1.0f, 0.8f, 0.4f, 0.0f }
    };

    VkImageSubresourceRange image_subresource_range = {
      VK_IMAGE_ASPECT_COLOR_BIT,                    // VkImageAspectFlags                     aspectMask
      0,                                            // uint32_t                               baseMipLevel
      1,                                            // uint32_t                               levelCount
      0,                                            // uint32_t                               baseArrayLayer
      1                                             // uint32_t                               layerCount
    };

    for( uint32_t i = 0; i < image_count; ++i ) {
      VkImageMemoryBarrier barrier_from_present_to_clear = {
        VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,     // VkStructureType                        sType
        nullptr,                                    // const void                            *pNext
        VK_ACCESS_MEMORY_READ_BIT,                  // VkAccessFlags                          srcAccessMask
        VK_ACCESS_TRANSFER_WRITE_BIT,               // VkAccessFlags                          dstAccessMask
        VK_IMAGE_LAYOUT_UNDEFINED,                  // VkImageLayout                          oldLayout
        VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,       // VkImageLayout                          newLayout
        Vulkan.PresentQueueFamilyIndex,             // uint32_t                               srcQueueFamilyIndex
        Vulkan.PresentQueueFamilyIndex,             // uint32_t                               dstQueueFamilyIndex
        swap_chain_images[i],                       // VkImage                                image
        image_subresource_range                     // VkImageSubresourceRange                subresourceRange
      };

      VkImageMemoryBarrier barrier_from_clear_to_present = {
        VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER,     // VkStructureType                        sType
        nullptr,                                    // const void                            *pNext
        VK_ACCESS_TRANSFER_WRITE_BIT,               // VkAccessFlags                          srcAccessMask
        VK_ACCESS_MEMORY_READ_BIT,                  // VkAccessFlags                          dstAccessMask
        VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL,       // VkImageLayout                          oldLayout
        VK_IMAGE_LAYOUT_PRESENT_SRC_KHR,            // VkImageLayout                          newLayout
        Vulkan.PresentQueueFamilyIndex,             // uint32_t                               srcQueueFamilyIndex
        Vulkan.PresentQueueFamilyIndex,             // uint32_t                               dstQueueFamilyIndex
        swap_chain_images[i],                       // VkImage                                image
        image_subresource_range                     // VkImageSubresourceRange                subresourceRange
      };

      vkBeginCommandBuffer( Vulkan.PresentQueueCmdBuffers[i], &cmd_buffer_begin_info );
      vkCmdPipelineBarrier( Vulkan.PresentQueueCmdBuffers[i], VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier_from_present_to_clear );

      vkCmdClearColorImage( Vulkan.PresentQueueCmdBuffers[i], swap_chain_images[i], VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, &clear_color, 1, &image_subresource_range );

      vkCmdPipelineBarrier( Vulkan.PresentQueueCmdBuffers[i], VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier_from_clear_to_present );
      if( vkEndCommandBuffer( Vulkan.PresentQueueCmdBuffers[i] ) != VK_SUCCESS ) {
        printf( "Could not record command buffers!\n" );
        return false;
      }
    }

    return true;
  }

  void Tutorial02::Clear() {
    if( Vulkan.Device != VK_NULL_HANDLE ) {
      vkDeviceWaitIdle( Vulkan.Device );

      if( (Vulkan.PresentQueueCmdBuffers.size() > 0) && (Vulkan.PresentQueueCmdBuffers[0] != VK_NULL_HANDLE) ) {
        vkFreeCommandBuffers( Vulkan.Device, Vulkan.PresentQueueCmdPool, static_cast<uint32_t>(Vulkan.PresentQueueCmdBuffers.size()), &Vulkan.PresentQueueCmdBuffers[0] );
        Vulkan.PresentQueueCmdBuffers.clear();
      }

      if( Vulkan.PresentQueueCmdPool != VK_NULL_HANDLE ) {
        vkDestroyCommandPool( Vulkan.Device, Vulkan.PresentQueueCmdPool, nullptr );
        Vulkan.PresentQueueCmdPool = VK_NULL_HANDLE;
      }
    }
  }

  bool Tutorial02::Draw() {
    uint32_t image_index;
    VkResult result = vkAcquireNextImageKHR( Vulkan.Device, Vulkan.SwapChain, UINT64_MAX, Vulkan.ImageAvailableSemaphore, VK_NULL_HANDLE, &image_index );
    switch( result ) {
      case VK_SUCCESS:
      case VK_SUBOPTIMAL_KHR:
        break;
      case VK_ERROR_OUT_OF_DATE_KHR:
        return OnWindowSizeChanged();
      default:
        printf( "Problem occurred during swap chain image acquisition!\n" );
        return false;
    }

    VkPipelineStageFlags wait_dst_stage_mask = VK_PIPELINE_STAGE_TRANSFER_BIT;
    VkSubmitInfo submit_info = {
      VK_STRUCTURE_TYPE_SUBMIT_INFO,                // VkStructureType              sType
      nullptr,                                      // const void                  *pNext
      1,                                            // uint32_t                     waitSemaphoreCount
      &Vulkan.ImageAvailableSemaphore,              // const VkSemaphore           *pWaitSemaphores
      &wait_dst_stage_mask,                         // const VkPipelineStageFlags  *pWaitDstStageMask;
      1,                                            // uint32_t                     commandBufferCount
      &Vulkan.PresentQueueCmdBuffers[image_index],  // const VkCommandBuffer       *pCommandBuffers
      1,                                            // uint32_t                     signalSemaphoreCount
      &Vulkan.RenderingFinishedSemaphore            // const VkSemaphore           *pSignalSemaphores
    };

    if( vkQueueSubmit( Vulkan.PresentQueue, 1, &submit_info, VK_NULL_HANDLE ) != VK_SUCCESS ) {
      return false;
    }

    VkPresentInfoKHR present_info = {
      VK_STRUCTURE_TYPE_PRESENT_INFO_KHR,           // VkStructureType              sType
      nullptr,                                      // const void                  *pNext
      1,                                            // uint32_t                     waitSemaphoreCount
      &Vulkan.RenderingFinishedSemaphore,           // const VkSemaphore           *pWaitSemaphores
      1,                                            // uint32_t                     swapchainCount
      &Vulkan.SwapChain,                            // const VkSwapchainKHR        *pSwapchains
      &image_index,                                 // const uint32_t              *pImageIndices
      nullptr                                       // VkResult                    *pResults
    };
    result = vkQueuePresentKHR( Vulkan.PresentQueue, &present_info );

    switch( result ) {
      case VK_SUCCESS:
        break;
      case VK_ERROR_OUT_OF_DATE_KHR:
      case VK_SUBOPTIMAL_KHR:
        return OnWindowSizeChanged();
      default:
        printf( "Problem occurred during image presentation!\n" );
        return false;
    }

    return true;
  }

  Tutorial02::~Tutorial02() {
    Clear();

    if( Vulkan.Device != VK_NULL_HANDLE ) {
      vkDeviceWaitIdle( Vulkan.Device );

      if( Vulkan.ImageAvailableSemaphore != VK_NULL_HANDLE ) {
        vkDestroySemaphore( Vulkan.Device, Vulkan.ImageAvailableSemaphore, nullptr );
      }
      if( Vulkan.RenderingFinishedSemaphore != VK_NULL_HANDLE ) {
        vkDestroySemaphore( Vulkan.Device, Vulkan.RenderingFinishedSemaphore, nullptr );
      }
      if( Vulkan.SwapChain != VK_NULL_HANDLE ) {
        vkDestroySwapchainKHR( Vulkan.Device, Vulkan.SwapChain, nullptr );
      }
      vkDestroyDevice( Vulkan.Device, nullptr );
    }

    if( Vulkan.PresentationSurface != VK_NULL_HANDLE ) {
      vkDestroySurfaceKHR( Vulkan.Instance, Vulkan.PresentationSurface, nullptr );
    }

    if( Vulkan.Instance != VK_NULL_HANDLE ) {
      vkDestroyInstance( Vulkan.Instance, nullptr );
    }

    if( VulkanLibrary ) {
#if defined(VK_USE_PLATFORM_WIN32_KHR)
      FreeLibrary( VulkanLibrary );
#elif defined(VK_USE_PLATFORM_XCB_KHR) || defined(VK_USE_PLATFORM_XLIB_KHR)
      dlclose( VulkanLibrary );
#endif
    }
  }

} // namespace Tutorial