imapp_renderer_vulkan.cpp

// imapp: Vulkan Renderer

// Important note to the reader who wish to integrate imgui_impl_vulkan.cpp/.h in their own engine/app.
// - Common ImGui_ImplVulkan_XXX functions and structures are used to interface with imgui_impl_vulkan.cpp/.h.
//   You will use those if you want to use this rendering back-end in your engine/app.
// - Helper ImGui_ImplVulkanH_XXX functions and structures are only used by this example (main.cpp) and by
//   the back-end itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
// Read comments in imgui_impl_vulkan.h.

#include "imapp.h"
#include "imapp_internal.h"

#include "imgui.h"

#ifdef IMAPP_IMPL_VULKAN_USER_TEXTURE_PATCH
#include "imapp_impl_vulkan.h"
#else
#include "imgui_impl_vulkan.h"
#endif

#include <vulkan/vulkan.h>

//#define IMGUI_UNLIMITED_FRAME_RATE
#ifdef _DEBUG
#define IMGUI_VULKAN_DEBUG_REPORT
#endif

namespace
{

bool NeedUploadFonts = true;

static VkAllocationCallbacks*   g_Allocator = NULL;
static VkInstance               g_Instance = VK_NULL_HANDLE;
static VkPhysicalDevice         g_PhysicalDevice = VK_NULL_HANDLE;
static VkDevice                 g_Device = VK_NULL_HANDLE;
static uint32_t                 g_QueueFamily = (uint32_t)-1;
static VkQueue                  g_Queue = VK_NULL_HANDLE;
static VkDebugReportCallbackEXT g_DebugReport = VK_NULL_HANDLE;
static VkPipelineCache          g_PipelineCache = VK_NULL_HANDLE;
static VkDescriptorPool         g_DescriptorPool = VK_NULL_HANDLE;

static ImGui_ImplVulkanH_Window g_MainWindowData;
static uint32_t                 g_MinImageCount = 2;
static bool                     g_SwapChainRebuild = false;
static int                      g_SwapChainResizeWidth = 0;
static int                      g_SwapChainResizeHeight = 0;

#define IMAPP_VULKAN_CHECK_RESULT(err) check_vk_result_line(err, __LINE__)

static void check_vk_result(VkResult err)
{
    if (err == 0)
        return;
    fprintf(stderr, "[vulkan] Error: VkResult = %d\n", err);
    if (err < 0)
        abort();
}

static void check_vk_result_line(VkResult err, int line = 0)
{
    if (err == 0)
        return;
    fprintf(stderr, "%d: [vulkan] Error: VkResult = %d\n", line, err);
    if (err < 0)
        abort();
}

#ifdef IMGUI_VULKAN_DEBUG_REPORT
static VKAPI_ATTR VkBool32 VKAPI_CALL debug_report(VkDebugReportFlagsEXT flags, VkDebugReportObjectTypeEXT objectType, uint64_t object, size_t location, int32_t messageCode, const char* pLayerPrefix, const char* pMessage, void* pUserData)
{
    (void)flags; (void)object; (void)location; (void)messageCode; (void)pUserData; (void)pLayerPrefix; // Unused arguments
    fprintf(stderr, "[vulkan] Debug report from ObjectType: %i\nMessage: %s\n\n", objectType, pMessage);
    return VK_FALSE;
}
#endif // IMGUI_VULKAN_DEBUG_REPORT

static void SetupVulkan(const char** extensions, uint32_t extensions_count)
{
    VkResult err;

    // Create Vulkan Instance
    {
        VkInstanceCreateInfo create_info = {};
        create_info.sType = VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO;
        create_info.enabledExtensionCount = extensions_count;
        create_info.ppEnabledExtensionNames = extensions;

#ifdef IMGUI_VULKAN_DEBUG_REPORT
        // Enabling multiple validation layers grouped as LunarG standard validation
        const char* layers[] = { "VK_LAYER_LUNARG_standard_validation" };
        create_info.enabledLayerCount = 1;
        create_info.ppEnabledLayerNames = layers;

        // Enable debug report extension (we need additional storage, so we duplicate the user array to add our new extension to it)
        const char** extensions_ext = (const char**)malloc(sizeof(const char*) * (extensions_count + 1));
        memcpy(extensions_ext, extensions, extensions_count * sizeof(const char*));
        extensions_ext[extensions_count] = "VK_EXT_debug_report";
        create_info.enabledExtensionCount = extensions_count + 1;
        create_info.ppEnabledExtensionNames = extensions_ext;

        // Create Vulkan Instance
        err = vkCreateInstance(&create_info, g_Allocator, &g_Instance);
        IMAPP_VULKAN_CHECK_RESULT(err);
        free(extensions_ext);

        // Get the function pointer (required for any extensions)
        auto vkCreateDebugReportCallbackEXT = (PFN_vkCreateDebugReportCallbackEXT)vkGetInstanceProcAddr(g_Instance, "vkCreateDebugReportCallbackEXT");
        IM_ASSERT(vkCreateDebugReportCallbackEXT != NULL);

        // Setup the debug report callback
        VkDebugReportCallbackCreateInfoEXT debug_report_ci = {};
        debug_report_ci.sType = VK_STRUCTURE_TYPE_DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT;
        debug_report_ci.flags = VK_DEBUG_REPORT_ERROR_BIT_EXT | VK_DEBUG_REPORT_WARNING_BIT_EXT | VK_DEBUG_REPORT_PERFORMANCE_WARNING_BIT_EXT;
        debug_report_ci.pfnCallback = debug_report;
        debug_report_ci.pUserData = NULL;
        err = vkCreateDebugReportCallbackEXT(g_Instance, &debug_report_ci, g_Allocator, &g_DebugReport);
        IMAPP_VULKAN_CHECK_RESULT(err);
#else
        // Create Vulkan Instance without any debug feature
        err = vkCreateInstance(&create_info, g_Allocator, &g_Instance);
        IMAPP_VULKAN_CHECK_RESULT(err);
        IM_UNUSED(g_DebugReport);
#endif
    }

    // Select GPU
    {
        uint32_t gpu_count;
        err = vkEnumeratePhysicalDevices(g_Instance, &gpu_count, NULL);
        IMAPP_VULKAN_CHECK_RESULT(err);
        IM_ASSERT(gpu_count > 0);

        VkPhysicalDevice* gpus = (VkPhysicalDevice*)malloc(sizeof(VkPhysicalDevice) * gpu_count);
        err = vkEnumeratePhysicalDevices(g_Instance, &gpu_count, gpus);
        IMAPP_VULKAN_CHECK_RESULT(err);

        // If a number >1 of GPUs got reported, you should find the best fit GPU for your purpose
        // e.g. VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU if available, or with the greatest memory available, etc.
        // for sake of simplicity we'll just take the first one, assuming it has a graphics queue family.
        g_PhysicalDevice = gpus[0];
        free(gpus);
    }

    // Select graphics queue family
    {
        uint32_t count;
        vkGetPhysicalDeviceQueueFamilyProperties(g_PhysicalDevice, &count, NULL);
        VkQueueFamilyProperties* queues = (VkQueueFamilyProperties*)malloc(sizeof(VkQueueFamilyProperties) * count);
        vkGetPhysicalDeviceQueueFamilyProperties(g_PhysicalDevice, &count, queues);
        for (uint32_t i = 0; i < count; i++)
            if (queues[i].queueFlags & VK_QUEUE_GRAPHICS_BIT)
            {
                g_QueueFamily = i;
                break;
            }
        free(queues);
        IM_ASSERT(g_QueueFamily != (uint32_t)-1);
    }

    // Create Logical Device (with 1 queue)
    {
        int device_extension_count = 1;
        const char* device_extensions[] = { "VK_KHR_swapchain" };
        const float queue_priority[] = { 1.0f };
        VkDeviceQueueCreateInfo queue_info[1] = {};
        queue_info[0].sType = VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO;
        queue_info[0].queueFamilyIndex = g_QueueFamily;
        queue_info[0].queueCount = 1;
        queue_info[0].pQueuePriorities = queue_priority;
        VkDeviceCreateInfo create_info = {};
        create_info.sType = VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO;
        create_info.queueCreateInfoCount = sizeof(queue_info) / sizeof(queue_info[0]);
        create_info.pQueueCreateInfos = queue_info;
        create_info.enabledExtensionCount = device_extension_count;
        create_info.ppEnabledExtensionNames = device_extensions;
        err = vkCreateDevice(g_PhysicalDevice, &create_info, g_Allocator, &g_Device);
        IMAPP_VULKAN_CHECK_RESULT(err);
        vkGetDeviceQueue(g_Device, g_QueueFamily, 0, &g_Queue);
    }

    // Create Descriptor Pool
    {
        VkDescriptorPoolSize pool_sizes[] =
        {
            { VK_DESCRIPTOR_TYPE_SAMPLER, 1000 },
            { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, 1000 },
            { VK_DESCRIPTOR_TYPE_SAMPLED_IMAGE, 1000 },
            { VK_DESCRIPTOR_TYPE_STORAGE_IMAGE, 1000 },
            { VK_DESCRIPTOR_TYPE_UNIFORM_TEXEL_BUFFER, 1000 },
            { VK_DESCRIPTOR_TYPE_STORAGE_TEXEL_BUFFER, 1000 },
            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER, 1000 },
            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER, 1000 },
            { VK_DESCRIPTOR_TYPE_UNIFORM_BUFFER_DYNAMIC, 1000 },
            { VK_DESCRIPTOR_TYPE_STORAGE_BUFFER_DYNAMIC, 1000 },
            { VK_DESCRIPTOR_TYPE_INPUT_ATTACHMENT, 1000 }
        };
        VkDescriptorPoolCreateInfo pool_info = {};
        pool_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO;
        pool_info.flags = VK_DESCRIPTOR_POOL_CREATE_FREE_DESCRIPTOR_SET_BIT;
        pool_info.maxSets = 1000 * IM_ARRAYSIZE(pool_sizes);
        pool_info.poolSizeCount = (uint32_t)IM_ARRAYSIZE(pool_sizes);
        pool_info.pPoolSizes = pool_sizes;
        err = vkCreateDescriptorPool(g_Device, &pool_info, g_Allocator, &g_DescriptorPool);
        IMAPP_VULKAN_CHECK_RESULT(err);
    }
}

// All the ImGui_ImplVulkanH_XXX structures/functions are optional helpers used by the demo.
// Your real engine/app may not use them.
static void SetupVulkanWindow(ImGui_ImplVulkanH_Window* wd, VkSurfaceKHR surface, int width, int height)
{
    wd->Surface = surface;

    // Check for WSI support
    VkBool32 res;
    vkGetPhysicalDeviceSurfaceSupportKHR(g_PhysicalDevice, g_QueueFamily, wd->Surface, &res);
    if (res != VK_TRUE)
    {
        fprintf(stderr, "Error no WSI support on physical device 0\n");
        exit(-1);
    }

    // Select Surface Format
    const VkFormat requestSurfaceImageFormat[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(g_PhysicalDevice, wd->Surface, requestSurfaceImageFormat, (size_t)IM_ARRAYSIZE(requestSurfaceImageFormat), requestSurfaceColorSpace);

    // Select Present Mode
#ifdef IMGUI_UNLIMITED_FRAME_RATE
    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
#else
    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_FIFO_KHR };
#endif
    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(g_PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
    //printf("[vulkan] Selected PresentMode = %d\n", wd->PresentMode);

    // Create SwapChain, RenderPass, Framebuffer, etc.
    IM_ASSERT(g_MinImageCount >= 2);
    ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, wd, g_QueueFamily, g_Allocator, width, height, g_MinImageCount);
}

static void CleanupVulkan()
{
    vkDestroyDescriptorPool(g_Device, g_DescriptorPool, g_Allocator);

#ifdef IMGUI_VULKAN_DEBUG_REPORT
    // Remove the debug report callback
    auto vkDestroyDebugReportCallbackEXT = (PFN_vkDestroyDebugReportCallbackEXT)vkGetInstanceProcAddr(g_Instance, "vkDestroyDebugReportCallbackEXT");
    vkDestroyDebugReportCallbackEXT(g_Instance, g_DebugReport, g_Allocator);
#endif // IMGUI_VULKAN_DEBUG_REPORT

    vkDestroyDevice(g_Device, g_Allocator);
    vkDestroyInstance(g_Instance, g_Allocator);
}

static void CleanupVulkanWindow()
{
    ImGui_ImplVulkanH_DestroyWindow(g_Instance, g_Device, &g_MainWindowData, g_Allocator);
}

static void FrameRender(ImGui_ImplVulkanH_Window* wd, ImDrawData* draw_data)
{
    VkResult err;

    VkSemaphore image_acquired_semaphore  = wd->FrameSemaphores[wd->SemaphoreIndex].ImageAcquiredSemaphore;
    VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
    err = vkAcquireNextImageKHR(g_Device, wd->Swapchain, UINT64_MAX, image_acquired_semaphore, VK_NULL_HANDLE, &wd->FrameIndex);
    IMAPP_VULKAN_CHECK_RESULT(err);

    ImGui_ImplVulkanH_Frame* fd = &wd->Frames[wd->FrameIndex];
    {
        err = vkWaitForFences(g_Device, 1, &fd->Fence, VK_TRUE, UINT64_MAX);    // wait indefinitely instead of periodically checking
        IMAPP_VULKAN_CHECK_RESULT(err);

        err = vkResetFences(g_Device, 1, &fd->Fence);
        IMAPP_VULKAN_CHECK_RESULT(err);
    }
    {
        err = vkResetCommandPool(g_Device, fd->CommandPool, 0);
        IMAPP_VULKAN_CHECK_RESULT(err);
        VkCommandBufferBeginInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
        info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
        err = vkBeginCommandBuffer(fd->CommandBuffer, &info);
        IMAPP_VULKAN_CHECK_RESULT(err);
    }
    {
        VkRenderPassBeginInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO;
        info.renderPass = wd->RenderPass;
        info.framebuffer = fd->Framebuffer;
        info.renderArea.extent.width = wd->Width;
        info.renderArea.extent.height = wd->Height;
        info.clearValueCount = 1;
        info.pClearValues = &wd->ClearValue;
        vkCmdBeginRenderPass(fd->CommandBuffer, &info, VK_SUBPASS_CONTENTS_INLINE);
    }

    // Record dear imgui primitives into command buffer
    ImGui_ImplVulkan_RenderDrawData(draw_data, fd->CommandBuffer);

    // Submit command buffer
    vkCmdEndRenderPass(fd->CommandBuffer);
    {
        VkPipelineStageFlags wait_stage = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
        VkSubmitInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
        info.waitSemaphoreCount = 1;
        info.pWaitSemaphores = &image_acquired_semaphore;
        info.pWaitDstStageMask = &wait_stage;
        info.commandBufferCount = 1;
        info.pCommandBuffers = &fd->CommandBuffer;
        info.signalSemaphoreCount = 1;
        info.pSignalSemaphores = &render_complete_semaphore;

        err = vkEndCommandBuffer(fd->CommandBuffer);
        IMAPP_VULKAN_CHECK_RESULT(err);
        err = vkQueueSubmit(g_Queue, 1, &info, fd->Fence);
        IMAPP_VULKAN_CHECK_RESULT(err);
    }
}

static void FramePresent(ImGui_ImplVulkanH_Window* wd)
{
    VkSemaphore render_complete_semaphore = wd->FrameSemaphores[wd->SemaphoreIndex].RenderCompleteSemaphore;
    VkPresentInfoKHR info = {};
    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    info.waitSemaphoreCount = 1;
    info.pWaitSemaphores = &render_complete_semaphore;
    info.swapchainCount = 1;
    info.pSwapchains = &wd->Swapchain;
    info.pImageIndices = &wd->FrameIndex;
    VkResult err = vkQueuePresentKHR(g_Queue, &info);
    IMAPP_VULKAN_CHECK_RESULT(err);
    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->ImageCount; // Now we can use the next set of semaphores
}

static void resize_callback(void*, int w, int h)
{
    g_SwapChainRebuild = true;
    g_SwapChainResizeWidth = w;
    g_SwapChainResizeHeight = h;
}

static uint32_t ImGui_ImplVulkan_MemoryType(VkMemoryPropertyFlags properties, uint32_t type_bits)
{
    //ImGui_ImplVulkan_InitInfo* v = &g_VulkanInitInfo;
    VkPhysicalDeviceMemoryProperties prop;
    vkGetPhysicalDeviceMemoryProperties(g_PhysicalDevice, &prop);
    for (uint32_t i = 0; i < prop.memoryTypeCount; i++)
        if ((prop.memoryTypes[i].propertyFlags & properties) == properties && type_bits & (1<<i))
            return i;
    return 0xFFFFFFFF; // Unable to find memoryType
}

struct TextureData
{
    VkDescriptorSet          DescriptorSet = VK_NULL_HANDLE;

    VkSampler                Sampler = VK_NULL_HANDLE;
    VkDeviceMemory           Memory = VK_NULL_HANDLE;
    VkImage                  Image = VK_NULL_HANDLE;
    VkImageView              View = VK_NULL_HANDLE;
};

ImVector<TextureData*> Textures;

TextureData* CreateTextureData()
{
    TextureData *tex_data = IM_NEW(TextureData);
    Textures.push_back(tex_data);
    return tex_data;
}

void DestroyTextureData(TextureData* TextureData)
{
    if (TextureData)
    {
        if (TextureData->View)    { vkDestroyImageView(g_Device, TextureData->View, g_Allocator); TextureData->View = VK_NULL_HANDLE; }
        if (TextureData->Image)   { vkDestroyImage(g_Device, TextureData->Image, g_Allocator); TextureData->Image = VK_NULL_HANDLE; }
        if (TextureData->Memory)  { vkFreeMemory(g_Device, TextureData->Memory, g_Allocator); TextureData->Memory = VK_NULL_HANDLE; }
        if (TextureData->Sampler) { vkDestroySampler(g_Device, TextureData->Sampler, g_Allocator); TextureData->Sampler = VK_NULL_HANDLE; }
        TextureData->DescriptorSet = VK_NULL_HANDLE;
    }

    IM_DELETE(TextureData);
}

void DestroyTextureDataAll()
{
    for (auto *Data : Textures)
    {
        DestroyTextureData(Data);
    }

    Textures.clear();
}

} // namespace

namespace ImApp
{

bool SetupRenderer() {

    // Setup Vulkan
    uint32_t extensions_count = 0;
    const char** extensions = GetInstanceExtensions(&extensions_count);
    SetupVulkan(extensions, extensions_count);
    ReleaseInstanceExtensions(extensions);

    // Create Window Surface
    VkSurfaceKHR surface;
    VkResult err = static_cast<VkResult>(CreateWindowSurface(g_Instance, g_Allocator, &surface));
    IMAPP_VULKAN_CHECK_RESULT(err);

    // Create Framebuffers
    int w, h;
    GetFramebufferSize(w, h);
    SetFramebufferSizeCallback((void*)resize_callback);
    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
    SetupVulkanWindow(wd, surface, w, h);

    return true;
}

void ShutdownRenderer() {
    CleanupVulkanWindow();
    CleanupVulkan();
}

bool InitRenderer()
{
    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;

    // Setup Renderer bindings
    ImGui_ImplVulkan_InitInfo init_info = {};
    init_info.Instance = g_Instance;
    init_info.PhysicalDevice = g_PhysicalDevice;
    init_info.Device = g_Device;
    init_info.QueueFamily = g_QueueFamily;
    init_info.Queue = g_Queue;
    init_info.PipelineCache = g_PipelineCache;
    init_info.DescriptorPool = g_DescriptorPool;
    init_info.Allocator = g_Allocator;
    init_info.MinImageCount = g_MinImageCount;
    init_info.ImageCount = wd->ImageCount;
    init_info.CheckVkResultFn = check_vk_result;
    return ImGui_ImplVulkan_Init(&init_info, wd->RenderPass);
}

void CleanupRenderer()
{
    VkResult err = vkDeviceWaitIdle(g_Device);
    IMAPP_VULKAN_CHECK_RESULT(err);
    ImGui_ImplVulkan_Shutdown();

    DestroyTextureDataAll();
}

void BeginFrameRenderer()
{
    if (NeedUploadFonts)
    {
        NeedUploadFonts = false;
        UploadFonts();
    }
    
    // Resize swap chain?
    if (g_SwapChainRebuild && g_SwapChainResizeWidth > 0 && g_SwapChainResizeHeight > 0)
    {
        g_SwapChainRebuild = false;
        ImGui_ImplVulkan_SetMinImageCount(g_MinImageCount);
        ImGui_ImplVulkanH_CreateOrResizeWindow(g_Instance, g_PhysicalDevice, g_Device, &g_MainWindowData, g_QueueFamily, g_Allocator, g_SwapChainResizeWidth, g_SwapChainResizeHeight, g_MinImageCount);
        g_MainWindowData.FrameIndex = 0;
    }

    ImGui_ImplVulkan_NewFrame();
}

void EndFrameRenderer(const ImVec4 &clear_col)
{
    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;

    ImDrawData* draw_data = ImGui::GetDrawData();
    const bool is_minimized = (draw_data->DisplaySize.x <= 0.0f || draw_data->DisplaySize.y <= 0.0f);
    if (!is_minimized)
    {
        FrameRender(wd, draw_data);
    }

#ifdef IMGUI_HAS_VIEWPORT
    UpdateViewportPlatform();
#endif

    if (!is_minimized)
    {
        FramePresent(wd);
    }
}

bool CreateTexture(unsigned char* pixels, int width, int height, ImTextureID* out_texture_id)
{
#ifdef IMAPP_IMPL_VULKAN_USER_TEXTURE_PATCH

    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
    VkResult err;

    // Use any command queue
    VkCommandPool command_pool = wd->Frames[wd->FrameIndex].CommandPool;
    VkCommandBuffer command_buffer = wd->Frames[wd->FrameIndex].CommandBuffer;

    err = vkResetCommandPool(g_Device, command_pool, 0);
    IMAPP_VULKAN_CHECK_RESULT(err);
    VkCommandBufferBeginInfo begin_info = {};
    begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
    err = vkBeginCommandBuffer(command_buffer, &begin_info);
    IMAPP_VULKAN_CHECK_RESULT(err);

    //ImGui_ImplVulkan_CreateFontsTexture(command_buffer);

    TextureData *texture_data = CreateTextureData();
    static VkDeviceMemory           g_UploadBufferMemory = VK_NULL_HANDLE;
    static VkBuffer                 g_UploadBuffer = VK_NULL_HANDLE;
    static VkDeviceSize             g_BufferMemoryAlignment = 256;
    
    size_t upload_size = width*height*4*sizeof(char);

    // Create the Image:
    {
        VkImageCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO;
        info.imageType = VK_IMAGE_TYPE_2D;
        info.format = VK_FORMAT_R8G8B8A8_UNORM;
        info.extent.width = width;
        info.extent.height = height;
        info.extent.depth = 1;
        info.mipLevels = 1;
        info.arrayLayers = 1;
        info.samples = VK_SAMPLE_COUNT_1_BIT;
        info.tiling = VK_IMAGE_TILING_OPTIMAL;
        info.usage = VK_IMAGE_USAGE_SAMPLED_BIT | VK_IMAGE_USAGE_TRANSFER_DST_BIT;
        info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
        info.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        err = vkCreateImage(g_Device, &info, g_Allocator, &texture_data->Image);
        check_vk_result(err);
        VkMemoryRequirements req;
        vkGetImageMemoryRequirements(g_Device, texture_data->Image, &req);
        VkMemoryAllocateInfo alloc_info = {};
        alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
        alloc_info.allocationSize = req.size;
        alloc_info.memoryTypeIndex = ImGui_ImplVulkan_MemoryType(VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, req.memoryTypeBits);
        err = vkAllocateMemory(g_Device, &alloc_info, g_Allocator, &texture_data->Memory);
        check_vk_result(err);
        err = vkBindImageMemory(g_Device, texture_data->Image, texture_data->Memory, 0);
        check_vk_result(err);
    }

    // Create the Image View:
    {
        VkImageViewCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
        info.image = texture_data->Image;
        info.viewType = VK_IMAGE_VIEW_TYPE_2D;
        info.format = VK_FORMAT_R8G8B8A8_UNORM;
        info.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        info.subresourceRange.levelCount = 1;
        info.subresourceRange.layerCount = 1;
        err = vkCreateImageView(g_Device, &info, g_Allocator, &texture_data->View);
        check_vk_result(err);
    }

    // Create the Image Sampler:
    {
        VkSamplerCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO;
        info.magFilter = VK_FILTER_LINEAR;
        info.minFilter = VK_FILTER_LINEAR;
        info.mipmapMode = VK_SAMPLER_MIPMAP_MODE_LINEAR;
        info.addressModeU = VK_SAMPLER_ADDRESS_MODE_REPEAT;
        info.addressModeV = VK_SAMPLER_ADDRESS_MODE_REPEAT;
        info.addressModeW = VK_SAMPLER_ADDRESS_MODE_REPEAT;
        info.minLod = -1000;
        info.maxLod = 1000;
        info.maxAnisotropy = 1.0f;
        err = vkCreateSampler(g_Device, &info, g_Allocator, &texture_data->Sampler);
        check_vk_result(err);
    }

    VkDescriptorSet descriptor_set = (VkDescriptorSet)ImGui_ImplVulkan_AddTexture(texture_data->Sampler, texture_data->View, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);

    // Create the Upload Buffer:
    {
        VkBufferCreateInfo buffer_info = {};
        buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
        buffer_info.size = upload_size;
        buffer_info.usage = VK_BUFFER_USAGE_TRANSFER_SRC_BIT;
        buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
        err = vkCreateBuffer(g_Device, &buffer_info, g_Allocator, &g_UploadBuffer);
        check_vk_result(err);
        VkMemoryRequirements req;
        vkGetBufferMemoryRequirements(g_Device, g_UploadBuffer, &req);
        g_BufferMemoryAlignment = (g_BufferMemoryAlignment > req.alignment) ? g_BufferMemoryAlignment : req.alignment;
        VkMemoryAllocateInfo alloc_info = {};
        alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
        alloc_info.allocationSize = req.size;
        alloc_info.memoryTypeIndex = ImGui_ImplVulkan_MemoryType(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, req.memoryTypeBits);
        err = vkAllocateMemory(g_Device, &alloc_info, g_Allocator, &g_UploadBufferMemory);
        check_vk_result(err);
        err = vkBindBufferMemory(g_Device, g_UploadBuffer, g_UploadBufferMemory, 0);
        check_vk_result(err);
    }

    // Upload to Buffer:
    {
        char* map = NULL;
        err = vkMapMemory(g_Device, g_UploadBufferMemory, 0, upload_size, 0, (void**)(&map));
        check_vk_result(err);
        memcpy(map, pixels, upload_size);
        VkMappedMemoryRange range[1] = {};
        range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
        range[0].memory = g_UploadBufferMemory;
        range[0].size = upload_size;
        err = vkFlushMappedMemoryRanges(g_Device, 1, range);
        check_vk_result(err);
        vkUnmapMemory(g_Device, g_UploadBufferMemory);
    }

    // Copy to Image:
    {
        VkImageMemoryBarrier copy_barrier[1] = {};
        copy_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
        copy_barrier[0].dstAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
        copy_barrier[0].oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        copy_barrier[0].newLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
        copy_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        copy_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        copy_barrier[0].image = texture_data->Image;
        copy_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        copy_barrier[0].subresourceRange.levelCount = 1;
        copy_barrier[0].subresourceRange.layerCount = 1;
        vkCmdPipelineBarrier(command_buffer, VK_PIPELINE_STAGE_HOST_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, NULL, 0, NULL, 1, copy_barrier);

        VkBufferImageCopy region = {};
        region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        region.imageSubresource.layerCount = 1;
        region.imageExtent.width = width;
        region.imageExtent.height = height;
        region.imageExtent.depth = 1;
        vkCmdCopyBufferToImage(command_buffer, g_UploadBuffer, texture_data->Image, VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL, 1, &region);

        VkImageMemoryBarrier use_barrier[1] = {};
        use_barrier[0].sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
        use_barrier[0].srcAccessMask = VK_ACCESS_TRANSFER_WRITE_BIT;
        use_barrier[0].dstAccessMask = VK_ACCESS_SHADER_READ_BIT;
        use_barrier[0].oldLayout = VK_IMAGE_LAYOUT_TRANSFER_DST_OPTIMAL;
        use_barrier[0].newLayout = VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL;
        use_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        use_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        use_barrier[0].image = texture_data->Image;
        use_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        use_barrier[0].subresourceRange.levelCount = 1;
        use_barrier[0].subresourceRange.layerCount = 1;
        vkCmdPipelineBarrier(command_buffer, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0, 0, NULL, 0, NULL, 1, use_barrier);
    }

    // Store our identifier
    if (out_texture_id) *out_texture_id = (ImTextureID)descriptor_set;

    VkSubmitInfo end_info = {};
    end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    end_info.commandBufferCount = 1;
    end_info.pCommandBuffers = &command_buffer;
    err = vkEndCommandBuffer(command_buffer);
    IMAPP_VULKAN_CHECK_RESULT(err);
    err = vkQueueSubmit(g_Queue, 1, &end_info, VK_NULL_HANDLE);
    IMAPP_VULKAN_CHECK_RESULT(err);

    err = vkDeviceWaitIdle(g_Device);
    IMAPP_VULKAN_CHECK_RESULT(err);
    //ImGui_ImplVulkan_DestroyFontUploadObjects();

    return true;
#else
    return false;
#endif
}

bool UploadFonts()
{
    ImGui_ImplVulkanH_Window* wd = &g_MainWindowData;
    VkResult err;

    // Use any command queue
    VkCommandPool command_pool = wd->Frames[wd->FrameIndex].CommandPool;
    VkCommandBuffer command_buffer = wd->Frames[wd->FrameIndex].CommandBuffer;

    err = vkResetCommandPool(g_Device, command_pool, 0);
    IMAPP_VULKAN_CHECK_RESULT(err);
    VkCommandBufferBeginInfo begin_info = {};
    begin_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO;
    begin_info.flags |= VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT;
    err = vkBeginCommandBuffer(command_buffer, &begin_info);
    IMAPP_VULKAN_CHECK_RESULT(err);

    ImGui_ImplVulkan_CreateFontsTexture(command_buffer);

    VkSubmitInfo end_info = {};
    end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    end_info.commandBufferCount = 1;
    end_info.pCommandBuffers = &command_buffer;
    err = vkEndCommandBuffer(command_buffer);
    IMAPP_VULKAN_CHECK_RESULT(err);
    err = vkQueueSubmit(g_Queue, 1, &end_info, VK_NULL_HANDLE);
    IMAPP_VULKAN_CHECK_RESULT(err);

    err = vkDeviceWaitIdle(g_Device);
    IMAPP_VULKAN_CHECK_RESULT(err);
    ImGui_ImplVulkan_DestroyFontUploadObjects();

    return true;
}

}