imgui/backends/imgui_impl_vulkan.cpp

// dear imgui: Renderer Backend for Vulkan
// This needs to be used along with a Platform Backend (e.g. GLFW, SDL, Win32, custom..)

// Implemented features:
//  [!] Renderer: User texture binding. Use 'VkDescriptorSet' as texture identifier. Call ImGui_ImplVulkan_AddTexture() to register one. Read the FAQ about ImTextureID/ImTextureRef + https://github.com/ocornut/imgui/pull/914 for discussions.
//  [X] Renderer: Large meshes support (64k+ vertices) even with 16-bit indices (ImGuiBackendFlags_RendererHasVtxOffset).
//  [X] Renderer: Texture updates support for dynamic font atlas (ImGuiBackendFlags_RendererHasTextures).
//  [X] Renderer: Expose selected render state for draw callbacks to use. Access in '(ImGui_ImplXXXX_RenderState*)GetPlatformIO().Renderer_RenderState'.
//  [x] Renderer: Multi-viewport / platform windows. With issues (flickering when creating a new viewport).

// The aim of imgui_impl_vulkan.h/.cpp is to be usable in your engine without any modification.
// IF YOU FEEL YOU NEED TO MAKE ANY CHANGE TO THIS CODE, please share them and your feedback at https://github.com/ocornut/imgui/

// You can use unmodified imgui_impl_* files in your project. See examples/ folder for examples of using this.
// Prefer including the entire imgui/ repository into your project (either as a copy or as a submodule), and only build the backends you need.
// Learn about Dear ImGui:
// - FAQ                  https://dearimgui.com/faq
// - Getting Started      https://dearimgui.com/getting-started
// - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
// - Introduction, links and more at the top of imgui.cpp

// 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 backend in your engine/app.
// - Helper ImGui_ImplVulkanH_XXX functions and structures are only used by this example (main.cpp) and by
//   the backend itself (imgui_impl_vulkan.cpp), but should PROBABLY NOT be used by your own engine/app code.
// Read comments in imgui_impl_vulkan.h.

// CHANGELOG
// (minor and older changes stripped away, please see git history for details)
//  2025-XX-XX: Platform: Added support for multiple windows via the ImGuiPlatformIO interface.
//  2025-07-07: Vulkan: Fixed texture synchronization issue introduced on 2025-06-11. (#8772)
//  2025-06-27: Vulkan: Fixed validation errors during texture upload/update by aligning upload size to 'nonCoherentAtomSize'. (#8743, #8744)
//  2025-06-11: Vulkan: Added support for ImGuiBackendFlags_RendererHasTextures, for dynamic font atlas. Removed ImGui_ImplVulkan_CreateFontsTexture() and ImGui_ImplVulkan_DestroyFontsTexture().
//  2025-05-07: Vulkan: Fixed validation errors during window detach in multi-viewport mode. (#8600, #8176)
//  2025-05-07: Vulkan: Load dynamic rendering functions using vkGetDeviceProcAddr() + try both non-KHR and KHR versions. (#8600, #8326, #8365)
//  2025-04-07: Vulkan: Deep-copy ImGui_ImplVulkan_InitInfo::PipelineRenderingCreateInfo's pColorAttachmentFormats buffer when set, in order to reduce common user-error of specifying a pointer to data that gets out of scope. (#8282)
//  2025-02-14: *BREAKING CHANGE*: Added uint32_t api_version to ImGui_ImplVulkan_LoadFunctions().
//  2025-02-13: Vulkan: Added ApiVersion field in ImGui_ImplVulkan_InitInfo. Default to header version if unspecified. Dynamic rendering path loads "vkCmdBeginRendering/vkCmdEndRendering" (without -KHR suffix) on API 1.3. (#8326)
//  2025-01-09: Vulkan: Added IMGUI_IMPL_VULKAN_MINIMUM_IMAGE_SAMPLER_POOL_SIZE to clarify how many image sampler descriptors are expected to be available in descriptor pool. (#6642)
//  2025-01-06: Vulkan: Added more ImGui_ImplVulkanH_XXXX helper functions to simplify our examples.
//  2024-12-11: Vulkan: Fixed setting VkSwapchainCreateInfoKHR::preTransform for platforms not supporting VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR. (#8222)
//  2024-11-27: Vulkan: Make user-provided descriptor pool optional. As a convenience, when setting init_info->DescriptorPoolSize the backend will create one itself. (#8172, #4867)
//  2024-10-07: Vulkan: Changed default texture sampler to Clamp instead of Repeat/Wrap.
//  2024-10-07: Vulkan: Expose selected render state in ImGui_ImplVulkan_RenderState, which you can access in 'void* platform_io.Renderer_RenderState' during draw callbacks.
//  2024-10-07: Vulkan: Compiling with '#define ImTextureID=ImU64' is unnecessary now that dear imgui defaults ImTextureID to u64 instead of void*.
//  2024-04-19: Vulkan: Added convenience support for Volk via IMGUI_IMPL_VULKAN_USE_VOLK define (you can also use IMGUI_IMPL_VULKAN_NO_PROTOTYPES + wrap Volk via ImGui_ImplVulkan_LoadFunctions().)
//  2024-02-14: *BREAKING CHANGE*: Moved RenderPass parameter from ImGui_ImplVulkan_Init() function to ImGui_ImplVulkan_InitInfo structure. Not required when using dynamic rendering.
//  2024-02-12: *BREAKING CHANGE*: Dynamic rendering now require filling PipelineRenderingCreateInfo structure.
//  2024-01-19: Vulkan: Fixed vkAcquireNextImageKHR() validation errors in VulkanSDK 1.3.275 by allocating one extra semaphore than in-flight frames. (#7236)
//  2024-01-11: Vulkan: Fixed vkMapMemory() calls unnecessarily using full buffer size (#3957). Fixed MinAllocationSize handing (#7189).
//  2024-01-03: Vulkan: Added MinAllocationSize field in ImGui_ImplVulkan_InitInfo to workaround zealous "best practice" validation layer. (#7189, #4238)
//  2024-01-03: Vulkan: Stopped creating command pools with VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT as we don't reset them.
//  2023-11-29: Vulkan: Fixed mismatching allocator passed to vkCreateCommandPool() vs vkDestroyCommandPool(). (#7075)
//  2023-11-10: *BREAKING CHANGE*: Removed parameter from ImGui_ImplVulkan_CreateFontsTexture(): backend now creates its own command-buffer to upload fonts.
//              *BREAKING CHANGE*: Removed ImGui_ImplVulkan_DestroyFontUploadObjects() which is now unnecessary as we create and destroy those objects in the backend.
//              ImGui_ImplVulkan_CreateFontsTexture() is automatically called by NewFrame() the first time.
//              You can call ImGui_ImplVulkan_CreateFontsTexture() again to recreate the font atlas texture.
//              Added ImGui_ImplVulkan_DestroyFontsTexture() but you probably never need to call this.
//  2023-07-04: Vulkan: Added optional support for VK_KHR_dynamic_rendering. User needs to set init_info->UseDynamicRendering = true and init_info->ColorAttachmentFormat.
//  2023-01-02: Vulkan: Fixed sampler passed to ImGui_ImplVulkan_AddTexture() not being honored + removed a bunch of duplicate code.
//  2022-10-11: Using 'nullptr' instead of 'NULL' as per our switch to C++11.
//  2022-10-04: Vulkan: Added experimental ImGui_ImplVulkan_RemoveTexture() for api symmetry. (#914, #5738).
//  2022-01-20: Vulkan: Added support for ImTextureID as VkDescriptorSet. User need to call ImGui_ImplVulkan_AddTexture(). Building for 32-bit targets requires '#define ImTextureID ImU64'. (#914).
//  2021-10-15: Vulkan: Call vkCmdSetScissor() at the end of render a full-viewport to reduce likelihood of issues with people using VK_DYNAMIC_STATE_SCISSOR in their app without calling vkCmdSetScissor() explicitly every frame.
//  2021-06-29: Reorganized backend to pull data from a single structure to facilitate usage with multiple-contexts (all g_XXXX access changed to bd->XXXX).
//  2021-03-22: Vulkan: Fix mapped memory validation error when buffer sizes are not multiple of VkPhysicalDeviceLimits::nonCoherentAtomSize.
//  2021-02-18: Vulkan: Change blending equation to preserve alpha in output buffer.
//  2021-01-27: Vulkan: Added support for custom function load and IMGUI_IMPL_VULKAN_NO_PROTOTYPES by using ImGui_ImplVulkan_LoadFunctions().
//  2020-11-11: Vulkan: Added support for specifying which subpass to reference during VkPipeline creation.
//  2020-09-07: Vulkan: Added VkPipeline parameter to ImGui_ImplVulkan_RenderDrawData (default to one passed to ImGui_ImplVulkan_Init).
//  2020-05-04: Vulkan: Fixed crash if initial frame has no vertices.
//  2020-04-26: Vulkan: Fixed edge case where render callbacks wouldn't be called if the ImDrawData didn't have vertices.
//  2019-08-01: Vulkan: Added support for specifying multisample count. Set ImGui_ImplVulkan_InitInfo::MSAASamples to one of the VkSampleCountFlagBits values to use, default is non-multisampled as before.
//  2019-05-29: Vulkan: Added support for large mesh (64K+ vertices), enable ImGuiBackendFlags_RendererHasVtxOffset flag.
//  2019-04-30: Vulkan: Added support for special ImDrawCallback_ResetRenderState callback to reset render state.
//  2019-04-04: *BREAKING CHANGE*: Vulkan: Added ImageCount/MinImageCount fields in ImGui_ImplVulkan_InitInfo, required for initialization (was previously a hard #define IMGUI_VK_QUEUED_FRAMES 2). Added ImGui_ImplVulkan_SetMinImageCount().
//  2019-04-04: Vulkan: Added VkInstance argument to ImGui_ImplVulkanH_CreateWindow() optional helper.
//  2019-04-04: Vulkan: Avoid passing negative coordinates to vkCmdSetScissor, which debug validation layers do not like.
//  2019-04-01: Vulkan: Support for 32-bit index buffer (#define ImDrawIdx unsigned int).
//  2019-02-16: Vulkan: Viewport and clipping rectangles correctly using draw_data->FramebufferScale to allow retina display.
//  2018-11-30: Misc: Setting up io.BackendRendererName so it can be displayed in the About Window.
//  2018-08-25: Vulkan: Fixed mishandled VkSurfaceCapabilitiesKHR::maxImageCount=0 case.
//  2018-06-22: Inverted the parameters to ImGui_ImplVulkan_RenderDrawData() to be consistent with other backends.
//  2018-06-08: Misc: Extracted imgui_impl_vulkan.cpp/.h away from the old combined GLFW+Vulkan example.
//  2018-06-08: Vulkan: Use draw_data->DisplayPos and draw_data->DisplaySize to setup projection matrix and clipping rectangle.
//  2018-03-03: Vulkan: Various refactor, created a couple of ImGui_ImplVulkanH_XXX helper that the example can use and that viewport support will use.
//  2018-03-01: Vulkan: Renamed ImGui_ImplVulkan_Init_Info to ImGui_ImplVulkan_InitInfo and fields to match more closely Vulkan terminology.
//  2018-02-16: Misc: Obsoleted the io.RenderDrawListsFn callback, ImGui_ImplVulkan_Render() calls ImGui_ImplVulkan_RenderDrawData() itself.
//  2018-02-06: Misc: Removed call to ImGui::Shutdown() which is not available from 1.60 WIP, user needs to call CreateContext/DestroyContext themselves.
//  2017-05-15: Vulkan: Fix scissor offset being negative. Fix new Vulkan validation warnings. Set required depth member for buffer image copy.
//  2016-11-13: Vulkan: Fix validation layer warnings and errors and redeclare gl_PerVertex.
//  2016-10-18: Vulkan: Add location decorators & change to use structs as in/out in glsl, update embedded spv (produced with glslangValidator -x). Null the released resources.
//  2016-08-27: Vulkan: Fix Vulkan example for use when a depth buffer is active.

#include "imgui.h"
#ifndef IMGUI_DISABLE
#include "imgui_impl_vulkan.h"
#include <stdio.h>
#ifndef IM_MAX
#define IM_MAX(A, B)    (((A) >= (B)) ? (A) : (B))
#endif
#undef Status // X11 headers are leaking this.

// Visual Studio warnings
#ifdef _MSC_VER
#pragma warning (disable: 4127) // condition expression is constant
#endif

// Forward Declarations
struct ImGui_ImplVulkan_FrameRenderBuffers;
struct ImGui_ImplVulkan_WindowRenderBuffers;
bool ImGui_ImplVulkan_CreateDeviceObjects();
void ImGui_ImplVulkan_DestroyDeviceObjects();
void ImGui_ImplVulkan_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulkan_FrameRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkan_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator);
void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd, const VkAllocationCallbacks* allocator);
void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator);
void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator);
void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
void ImGui_ImplVulkanH_CreateWindowCommandBuffers(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator);

// Vulkan prototypes for use with custom loaders
// (see description of IMGUI_IMPL_VULKAN_NO_PROTOTYPES in imgui_impl_vulkan.h
#if defined(VK_NO_PROTOTYPES) && !defined(VOLK_H_)
#define IMGUI_IMPL_VULKAN_USE_LOADER
static bool g_FunctionsLoaded = false;
#else
static bool g_FunctionsLoaded = true;
#endif
#ifdef IMGUI_IMPL_VULKAN_USE_LOADER
#define IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_MAP_MACRO) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateCommandBuffers) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateDescriptorSets) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAllocateMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkAcquireNextImageKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkBeginCommandBuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindBufferMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkBindImageMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBeginRenderPass) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindDescriptorSets) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindIndexBuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindPipeline) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdBindVertexBuffers) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdCopyBufferToImage) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdDrawIndexed) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdEndRenderPass) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPipelineBarrier) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdPushConstants) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdSetScissor) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCmdSetViewport) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateBuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateCommandPool) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateDescriptorPool) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateDescriptorSetLayout) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateFence) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateFramebuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateGraphicsPipelines) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateImage) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateImageView) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreatePipelineLayout) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateRenderPass) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateSampler) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateSemaphore) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateShaderModule) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkCreateSwapchainKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyBuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyCommandPool) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyDescriptorPool) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyDescriptorSetLayout) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyFence) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyFramebuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyImage) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyImageView) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyPipeline) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyPipelineLayout) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyRenderPass) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySampler) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySemaphore) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroyShaderModule) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySurfaceKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDestroySwapchainKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkDeviceWaitIdle) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkEnumeratePhysicalDevices) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkEndCommandBuffer) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkFlushMappedMemoryRanges) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeCommandBuffers) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeDescriptorSets) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkFreeMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetBufferMemoryRequirements) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetDeviceQueue) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetImageMemoryRequirements) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceProperties) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceMemoryProperties) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceQueueFamilyProperties) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceCapabilitiesKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceFormatsKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfacePresentModesKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetPhysicalDeviceSurfaceSupportKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkGetSwapchainImagesKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkMapMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueuePresentKHR) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueSubmit) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkQueueWaitIdle) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetCommandPool) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkResetFences) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUnmapMemory) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkUpdateDescriptorSets) \
    IMGUI_VULKAN_FUNC_MAP_MACRO(vkWaitForFences)

// Define function pointers
#define IMGUI_VULKAN_FUNC_DEF(func) static PFN_##func func;
IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_DEF)
#undef IMGUI_VULKAN_FUNC_DEF
#endif // IMGUI_IMPL_VULKAN_USE_LOADER

#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
static PFN_vkCmdBeginRenderingKHR   ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR;
static PFN_vkCmdEndRenderingKHR     ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR;
#endif

// Reusable buffers used for rendering 1 current in-flight frame, for ImGui_ImplVulkan_RenderDrawData()
// [Please zero-clear before use!]
struct ImGui_ImplVulkan_FrameRenderBuffers
{
    VkDeviceMemory      VertexBufferMemory;
    VkDeviceMemory      IndexBufferMemory;
    VkDeviceSize        VertexBufferSize;
    VkDeviceSize        IndexBufferSize;
    VkBuffer            VertexBuffer;
    VkBuffer            IndexBuffer;
};

// Each viewport will hold 1 ImGui_ImplVulkanH_WindowRenderBuffers
// [Please zero-clear before use!]
struct ImGui_ImplVulkan_WindowRenderBuffers
{
    uint32_t            Index;
    uint32_t            Count;
    ImVector<ImGui_ImplVulkan_FrameRenderBuffers> FrameRenderBuffers;
};

struct ImGui_ImplVulkan_Texture
{
    VkDeviceMemory              Memory;
    VkImage                     Image;
    VkImageView                 ImageView;
    VkDescriptorSet             DescriptorSet;

    ImGui_ImplVulkan_Texture() { memset((void*)this, 0, sizeof(*this)); }
};

// For multi-viewport support:
// Helper structure we store in the void* RendererUserData field of each ImGuiViewport to easily retrieve our backend data.
struct ImGui_ImplVulkan_ViewportData
{
    ImGui_ImplVulkanH_Window                Window;                 // Used by secondary viewports only
    ImGui_ImplVulkan_WindowRenderBuffers    RenderBuffers;          // Used by all viewports
    bool                                    WindowOwned;
    bool                                    SwapChainNeedRebuild;   // Flag when viewport swapchain resized in the middle of processing a frame
    bool                                    SwapChainSuboptimal;    // Flag when VK_SUBOPTIMAL_KHR was returned.

    ImGui_ImplVulkan_ViewportData() { WindowOwned = SwapChainNeedRebuild = SwapChainSuboptimal = false; memset((void*)&RenderBuffers, 0, sizeof(RenderBuffers)); }
    ~ImGui_ImplVulkan_ViewportData() { }
};

// Vulkan data
struct ImGui_ImplVulkan_Data
{
    ImGui_ImplVulkan_InitInfo   VulkanInitInfo;
    VkDeviceSize                BufferMemoryAlignment;
    VkDeviceSize                NonCoherentAtomSize;
    VkPipelineCreateFlags       PipelineCreateFlags;
    VkDescriptorSetLayout       DescriptorSetLayout;
    VkPipelineLayout            PipelineLayout;
    VkPipeline                  Pipeline;               // pipeline for main render pass (created by app)
    VkPipeline                  PipelineForViewports;   // pipeline for secondary viewports (created by backend)
    VkShaderModule              ShaderModuleVert;
    VkShaderModule              ShaderModuleFrag;
    VkDescriptorPool            DescriptorPool;

    // Texture management
    VkSampler                   TexSampler;
    VkCommandPool               TexCommandPool;
    VkCommandBuffer             TexCommandBuffer;

    // Render buffers for main window
    ImGui_ImplVulkan_WindowRenderBuffers MainWindowRenderBuffers;

    ImGui_ImplVulkan_Data()
    {
        memset((void*)this, 0, sizeof(*this));
        BufferMemoryAlignment = 256;
        NonCoherentAtomSize = 64;
    }
};

//-----------------------------------------------------------------------------
// SHADERS
//-----------------------------------------------------------------------------

// Forward Declarations
static void ImGui_ImplVulkan_InitMultiViewportSupport();
static void ImGui_ImplVulkan_ShutdownMultiViewportSupport();

// backends/vulkan/glsl_shader.vert, compiled with:
// # glslangValidator -V -x -o glsl_shader.vert.u32 glsl_shader.vert
/*
#version 450 core
layout(location = 0) in vec2 aPos;
layout(location = 1) in vec2 aUV;
layout(location = 2) in vec4 aColor;
layout(push_constant) uniform uPushConstant { vec2 uScale; vec2 uTranslate; } pc;

out gl_PerVertex { vec4 gl_Position; };
layout(location = 0) out struct { vec4 Color; vec2 UV; } Out;

void main()
{
    Out.Color = aColor;
    Out.UV = aUV;
    gl_Position = vec4(aPos * pc.uScale + pc.uTranslate, 0, 1);
}
*/
static uint32_t __glsl_shader_vert_spv[] =
{
    0x07230203,0x00010000,0x00080001,0x0000002e,0x00000000,0x00020011,0x00000001,0x0006000b,
    0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
    0x000a000f,0x00000000,0x00000004,0x6e69616d,0x00000000,0x0000000b,0x0000000f,0x00000015,
    0x0000001b,0x0000001c,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
    0x00000000,0x00030005,0x00000009,0x00000000,0x00050006,0x00000009,0x00000000,0x6f6c6f43,
    0x00000072,0x00040006,0x00000009,0x00000001,0x00005655,0x00030005,0x0000000b,0x0074754f,
    0x00040005,0x0000000f,0x6c6f4361,0x0000726f,0x00030005,0x00000015,0x00565561,0x00060005,
    0x00000019,0x505f6c67,0x65567265,0x78657472,0x00000000,0x00060006,0x00000019,0x00000000,
    0x505f6c67,0x7469736f,0x006e6f69,0x00030005,0x0000001b,0x00000000,0x00040005,0x0000001c,
    0x736f5061,0x00000000,0x00060005,0x0000001e,0x73755075,0x6e6f4368,0x6e617473,0x00000074,
    0x00050006,0x0000001e,0x00000000,0x61635375,0x0000656c,0x00060006,0x0000001e,0x00000001,
    0x61725475,0x616c736e,0x00006574,0x00030005,0x00000020,0x00006370,0x00040047,0x0000000b,
    0x0000001e,0x00000000,0x00040047,0x0000000f,0x0000001e,0x00000002,0x00040047,0x00000015,
    0x0000001e,0x00000001,0x00050048,0x00000019,0x00000000,0x0000000b,0x00000000,0x00030047,
    0x00000019,0x00000002,0x00040047,0x0000001c,0x0000001e,0x00000000,0x00050048,0x0000001e,
    0x00000000,0x00000023,0x00000000,0x00050048,0x0000001e,0x00000001,0x00000023,0x00000008,
    0x00030047,0x0000001e,0x00000002,0x00020013,0x00000002,0x00030021,0x00000003,0x00000002,
    0x00030016,0x00000006,0x00000020,0x00040017,0x00000007,0x00000006,0x00000004,0x00040017,
    0x00000008,0x00000006,0x00000002,0x0004001e,0x00000009,0x00000007,0x00000008,0x00040020,
    0x0000000a,0x00000003,0x00000009,0x0004003b,0x0000000a,0x0000000b,0x00000003,0x00040015,
    0x0000000c,0x00000020,0x00000001,0x0004002b,0x0000000c,0x0000000d,0x00000000,0x00040020,
    0x0000000e,0x00000001,0x00000007,0x0004003b,0x0000000e,0x0000000f,0x00000001,0x00040020,
    0x00000011,0x00000003,0x00000007,0x0004002b,0x0000000c,0x00000013,0x00000001,0x00040020,
    0x00000014,0x00000001,0x00000008,0x0004003b,0x00000014,0x00000015,0x00000001,0x00040020,
    0x00000017,0x00000003,0x00000008,0x0003001e,0x00000019,0x00000007,0x00040020,0x0000001a,
    0x00000003,0x00000019,0x0004003b,0x0000001a,0x0000001b,0x00000003,0x0004003b,0x00000014,
    0x0000001c,0x00000001,0x0004001e,0x0000001e,0x00000008,0x00000008,0x00040020,0x0000001f,
    0x00000009,0x0000001e,0x0004003b,0x0000001f,0x00000020,0x00000009,0x00040020,0x00000021,
    0x00000009,0x00000008,0x0004002b,0x00000006,0x00000028,0x00000000,0x0004002b,0x00000006,
    0x00000029,0x3f800000,0x00050036,0x00000002,0x00000004,0x00000000,0x00000003,0x000200f8,
    0x00000005,0x0004003d,0x00000007,0x00000010,0x0000000f,0x00050041,0x00000011,0x00000012,
    0x0000000b,0x0000000d,0x0003003e,0x00000012,0x00000010,0x0004003d,0x00000008,0x00000016,
    0x00000015,0x00050041,0x00000017,0x00000018,0x0000000b,0x00000013,0x0003003e,0x00000018,
    0x00000016,0x0004003d,0x00000008,0x0000001d,0x0000001c,0x00050041,0x00000021,0x00000022,
    0x00000020,0x0000000d,0x0004003d,0x00000008,0x00000023,0x00000022,0x00050085,0x00000008,
    0x00000024,0x0000001d,0x00000023,0x00050041,0x00000021,0x00000025,0x00000020,0x00000013,
    0x0004003d,0x00000008,0x00000026,0x00000025,0x00050081,0x00000008,0x00000027,0x00000024,
    0x00000026,0x00050051,0x00000006,0x0000002a,0x00000027,0x00000000,0x00050051,0x00000006,
    0x0000002b,0x00000027,0x00000001,0x00070050,0x00000007,0x0000002c,0x0000002a,0x0000002b,
    0x00000028,0x00000029,0x00050041,0x00000011,0x0000002d,0x0000001b,0x0000000d,0x0003003e,
    0x0000002d,0x0000002c,0x000100fd,0x00010038
};

// backends/vulkan/glsl_shader.frag, compiled with:
// # glslangValidator -V -x -o glsl_shader.frag.u32 glsl_shader.frag
/*
#version 450 core
layout(location = 0) out vec4 fColor;
layout(set=0, binding=0) uniform sampler2D sTexture;
layout(location = 0) in struct { vec4 Color; vec2 UV; } In;
void main()
{
    fColor = In.Color * texture(sTexture, In.UV.st);
}
*/
static uint32_t __glsl_shader_frag_spv[] =
{
    0x07230203,0x00010000,0x00080001,0x0000001e,0x00000000,0x00020011,0x00000001,0x0006000b,
    0x00000001,0x4c534c47,0x6474732e,0x3035342e,0x00000000,0x0003000e,0x00000000,0x00000001,
    0x0007000f,0x00000004,0x00000004,0x6e69616d,0x00000000,0x00000009,0x0000000d,0x00030010,
    0x00000004,0x00000007,0x00030003,0x00000002,0x000001c2,0x00040005,0x00000004,0x6e69616d,
    0x00000000,0x00040005,0x00000009,0x6c6f4366,0x0000726f,0x00030005,0x0000000b,0x00000000,
    0x00050006,0x0000000b,0x00000000,0x6f6c6f43,0x00000072,0x00040006,0x0000000b,0x00000001,
    0x00005655,0x00030005,0x0000000d,0x00006e49,0x00050005,0x00000016,0x78655473,0x65727574,
    0x00000000,0x00040047,0x00000009,0x0000001e,0x00000000,0x00040047,0x0000000d,0x0000001e,
    0x00000000,0x00040047,0x00000016,0x00000022,0x00000000,0x00040047,0x00000016,0x00000021,
    0x00000000,0x00020013,0x00000002,0x00030021,0x00000003,0x00000002,0x00030016,0x00000006,
    0x00000020,0x00040017,0x00000007,0x00000006,0x00000004,0x00040020,0x00000008,0x00000003,
    0x00000007,0x0004003b,0x00000008,0x00000009,0x00000003,0x00040017,0x0000000a,0x00000006,
    0x00000002,0x0004001e,0x0000000b,0x00000007,0x0000000a,0x00040020,0x0000000c,0x00000001,
    0x0000000b,0x0004003b,0x0000000c,0x0000000d,0x00000001,0x00040015,0x0000000e,0x00000020,
    0x00000001,0x0004002b,0x0000000e,0x0000000f,0x00000000,0x00040020,0x00000010,0x00000001,
    0x00000007,0x00090019,0x00000013,0x00000006,0x00000001,0x00000000,0x00000000,0x00000000,
    0x00000001,0x00000000,0x0003001b,0x00000014,0x00000013,0x00040020,0x00000015,0x00000000,
    0x00000014,0x0004003b,0x00000015,0x00000016,0x00000000,0x0004002b,0x0000000e,0x00000018,
    0x00000001,0x00040020,0x00000019,0x00000001,0x0000000a,0x00050036,0x00000002,0x00000004,
    0x00000000,0x00000003,0x000200f8,0x00000005,0x00050041,0x00000010,0x00000011,0x0000000d,
    0x0000000f,0x0004003d,0x00000007,0x00000012,0x00000011,0x0004003d,0x00000014,0x00000017,
    0x00000016,0x00050041,0x00000019,0x0000001a,0x0000000d,0x00000018,0x0004003d,0x0000000a,
    0x0000001b,0x0000001a,0x00050057,0x00000007,0x0000001c,0x00000017,0x0000001b,0x00050085,
    0x00000007,0x0000001d,0x00000012,0x0000001c,0x0003003e,0x00000009,0x0000001d,0x000100fd,
    0x00010038
};

//-----------------------------------------------------------------------------
// FUNCTIONS
//-----------------------------------------------------------------------------

// Backend data stored in io.BackendRendererUserData to allow support for multiple Dear ImGui contexts
// It is STRONGLY preferred that you use docking branch with multi-viewports (== single Dear ImGui context + multiple windows) instead of multiple Dear ImGui contexts.
// FIXME: multi-context support is not tested and probably dysfunctional in this backend.
static ImGui_ImplVulkan_Data* ImGui_ImplVulkan_GetBackendData()
{
    return ImGui::GetCurrentContext() ? (ImGui_ImplVulkan_Data*)ImGui::GetIO().BackendRendererUserData : nullptr;
}

static uint32_t ImGui_ImplVulkan_MemoryType(VkMemoryPropertyFlags properties, uint32_t type_bits)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkPhysicalDeviceMemoryProperties prop;
    vkGetPhysicalDeviceMemoryProperties(v->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
}

static void check_vk_result(VkResult err)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    if (!bd)
        return;
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    if (v->CheckVkResultFn)
        v->CheckVkResultFn(err);
}

// Same as IM_MEMALIGN(). 'alignment' must be a power of two.
static inline VkDeviceSize AlignBufferSize(VkDeviceSize size, VkDeviceSize alignment)
{
    return (size + alignment - 1) & ~(alignment - 1);
}

static void CreateOrResizeBuffer(VkBuffer& buffer, VkDeviceMemory& buffer_memory, VkDeviceSize& buffer_size, VkDeviceSize new_size, VkBufferUsageFlagBits usage)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkResult err;
    if (buffer != VK_NULL_HANDLE)
        vkDestroyBuffer(v->Device, buffer, v->Allocator);
    if (buffer_memory != VK_NULL_HANDLE)
        vkFreeMemory(v->Device, buffer_memory, v->Allocator);

    VkDeviceSize buffer_size_aligned = AlignBufferSize(IM_MAX(v->MinAllocationSize, new_size), bd->BufferMemoryAlignment);
    VkBufferCreateInfo buffer_info = {};
    buffer_info.sType = VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO;
    buffer_info.size = buffer_size_aligned;
    buffer_info.usage = usage;
    buffer_info.sharingMode = VK_SHARING_MODE_EXCLUSIVE;
    err = vkCreateBuffer(v->Device, &buffer_info, v->Allocator, &buffer);
    check_vk_result(err);

    VkMemoryRequirements req;
    vkGetBufferMemoryRequirements(v->Device, buffer, &req);
    bd->BufferMemoryAlignment = (bd->BufferMemoryAlignment > req.alignment) ? bd->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(v->Device, &alloc_info, v->Allocator, &buffer_memory);
    check_vk_result(err);

    err = vkBindBufferMemory(v->Device, buffer, buffer_memory, 0);
    check_vk_result(err);
    buffer_size = buffer_size_aligned;
}

static void ImGui_ImplVulkan_SetupRenderState(ImDrawData* draw_data, VkPipeline pipeline, VkCommandBuffer command_buffer, ImGui_ImplVulkan_FrameRenderBuffers* rb, int fb_width, int fb_height)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();

    // Bind pipeline:
    {
        vkCmdBindPipeline(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, pipeline);
    }

    // Bind Vertex And Index Buffer:
    if (draw_data->TotalVtxCount > 0)
    {
        VkBuffer vertex_buffers[1] = { rb->VertexBuffer };
        VkDeviceSize vertex_offset[1] = { 0 };
        vkCmdBindVertexBuffers(command_buffer, 0, 1, vertex_buffers, vertex_offset);
        vkCmdBindIndexBuffer(command_buffer, rb->IndexBuffer, 0, sizeof(ImDrawIdx) == 2 ? VK_INDEX_TYPE_UINT16 : VK_INDEX_TYPE_UINT32);
    }

    // Setup viewport:
    {
        VkViewport viewport;
        viewport.x = 0;
        viewport.y = 0;
        viewport.width = (float)fb_width;
        viewport.height = (float)fb_height;
        viewport.minDepth = 0.0f;
        viewport.maxDepth = 1.0f;
        vkCmdSetViewport(command_buffer, 0, 1, &viewport);
    }

    // Setup scale and translation:
    // Our visible imgui space lies from draw_data->DisplayPps (top left) to draw_data->DisplayPos+data_data->DisplaySize (bottom right). DisplayPos is (0,0) for single viewport apps.
    {
        float scale[2];
        scale[0] = 2.0f / draw_data->DisplaySize.x;
        scale[1] = 2.0f / draw_data->DisplaySize.y;
        float translate[2];
        translate[0] = -1.0f - draw_data->DisplayPos.x * scale[0];
        translate[1] = -1.0f - draw_data->DisplayPos.y * scale[1];
        vkCmdPushConstants(command_buffer, bd->PipelineLayout, VK_SHADER_STAGE_VERTEX_BIT, sizeof(float) * 0, sizeof(float) * 2, scale);
        vkCmdPushConstants(command_buffer, bd->PipelineLayout, VK_SHADER_STAGE_VERTEX_BIT, sizeof(float) * 2, sizeof(float) * 2, translate);
    }
}

// Render function
void ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer command_buffer, VkPipeline pipeline)
{
    // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates)
    int fb_width = (int)(draw_data->DisplaySize.x * draw_data->FramebufferScale.x);
    int fb_height = (int)(draw_data->DisplaySize.y * draw_data->FramebufferScale.y);
    if (fb_width <= 0 || fb_height <= 0)
        return;

    // Catch up with texture updates. Most of the times, the list will have 1 element with an OK status, aka nothing to do.
    // (This almost always points to ImGui::GetPlatformIO().Textures[] but is part of ImDrawData to allow overriding or disabling texture updates).
    if (draw_data->Textures != nullptr)
        for (ImTextureData* tex : *draw_data->Textures)
            if (tex->Status != ImTextureStatus_OK)
                ImGui_ImplVulkan_UpdateTexture(tex);

    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    if (pipeline == VK_NULL_HANDLE)
        pipeline = bd->Pipeline;

    // Allocate array to store enough vertex/index buffers. Each unique viewport gets its own storage.
    ImGui_ImplVulkan_ViewportData* viewport_renderer_data = (ImGui_ImplVulkan_ViewportData*)draw_data->OwnerViewport->RendererUserData;
    IM_ASSERT(viewport_renderer_data != nullptr);
    ImGui_ImplVulkan_WindowRenderBuffers* wrb = &viewport_renderer_data->RenderBuffers;
    if (wrb->FrameRenderBuffers.Size == 0)
    {
        wrb->Index = 0;
        wrb->Count = v->ImageCount;
        wrb->FrameRenderBuffers.resize(wrb->Count);
        memset((void*)wrb->FrameRenderBuffers.Data, 0, wrb->FrameRenderBuffers.size_in_bytes());
    }
    IM_ASSERT(wrb->Count == v->ImageCount);
    wrb->Index = (wrb->Index + 1) % wrb->Count;
    ImGui_ImplVulkan_FrameRenderBuffers* rb = &wrb->FrameRenderBuffers[wrb->Index];

    if (draw_data->TotalVtxCount > 0)
    {
        // Create or resize the vertex/index buffers
        VkDeviceSize vertex_size = AlignBufferSize(draw_data->TotalVtxCount * sizeof(ImDrawVert), bd->BufferMemoryAlignment);
        VkDeviceSize index_size = AlignBufferSize(draw_data->TotalIdxCount * sizeof(ImDrawIdx), bd->BufferMemoryAlignment);
        if (rb->VertexBuffer == VK_NULL_HANDLE || rb->VertexBufferSize < vertex_size)
            CreateOrResizeBuffer(rb->VertexBuffer, rb->VertexBufferMemory, rb->VertexBufferSize, vertex_size, VK_BUFFER_USAGE_VERTEX_BUFFER_BIT);
        if (rb->IndexBuffer == VK_NULL_HANDLE || rb->IndexBufferSize < index_size)
            CreateOrResizeBuffer(rb->IndexBuffer, rb->IndexBufferMemory, rb->IndexBufferSize, index_size, VK_BUFFER_USAGE_INDEX_BUFFER_BIT);

        // Upload vertex/index data into a single contiguous GPU buffer
        ImDrawVert* vtx_dst = nullptr;
        ImDrawIdx* idx_dst = nullptr;
        VkResult err = vkMapMemory(v->Device, rb->VertexBufferMemory, 0, vertex_size, 0, (void**)&vtx_dst);
        check_vk_result(err);
        err = vkMapMemory(v->Device, rb->IndexBufferMemory, 0, index_size, 0, (void**)&idx_dst);
        check_vk_result(err);
        for (int n = 0; n < draw_data->CmdListsCount; n++)
        {
            const ImDrawList* draw_list = draw_data->CmdLists[n];
            memcpy(vtx_dst, draw_list->VtxBuffer.Data, draw_list->VtxBuffer.Size * sizeof(ImDrawVert));
            memcpy(idx_dst, draw_list->IdxBuffer.Data, draw_list->IdxBuffer.Size * sizeof(ImDrawIdx));
            vtx_dst += draw_list->VtxBuffer.Size;
            idx_dst += draw_list->IdxBuffer.Size;
        }
        VkMappedMemoryRange range[2] = {};
        range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
        range[0].memory = rb->VertexBufferMemory;
        range[0].size = VK_WHOLE_SIZE;
        range[1].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
        range[1].memory = rb->IndexBufferMemory;
        range[1].size = VK_WHOLE_SIZE;
        err = vkFlushMappedMemoryRanges(v->Device, 2, range);
        check_vk_result(err);
        vkUnmapMemory(v->Device, rb->VertexBufferMemory);
        vkUnmapMemory(v->Device, rb->IndexBufferMemory);
    }

    // Setup desired Vulkan state
    ImGui_ImplVulkan_SetupRenderState(draw_data, pipeline, command_buffer, rb, fb_width, fb_height);

    // Setup render state structure (for callbacks and custom texture bindings)
    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
    ImGui_ImplVulkan_RenderState render_state;
    render_state.CommandBuffer = command_buffer;
    render_state.Pipeline = pipeline;
    render_state.PipelineLayout = bd->PipelineLayout;
    platform_io.Renderer_RenderState = &render_state;

    // Will project scissor/clipping rectangles into framebuffer space
    ImVec2 clip_off = draw_data->DisplayPos;         // (0,0) unless using multi-viewports
    ImVec2 clip_scale = draw_data->FramebufferScale; // (1,1) unless using retina display which are often (2,2)

    // Render command lists
    // (Because we merged all buffers into a single one, we maintain our own offset into them)
    int global_vtx_offset = 0;
    int global_idx_offset = 0;
    for (int n = 0; n < draw_data->CmdListsCount; n++)
    {
        const ImDrawList* draw_list = draw_data->CmdLists[n];
        for (int cmd_i = 0; cmd_i < draw_list->CmdBuffer.Size; cmd_i++)
        {
            const ImDrawCmd* pcmd = &draw_list->CmdBuffer[cmd_i];
            if (pcmd->UserCallback != nullptr)
            {
                // User callback, registered via ImDrawList::AddCallback()
                // (ImDrawCallback_ResetRenderState is a special callback value used by the user to request the renderer to reset render state.)
                if (pcmd->UserCallback == ImDrawCallback_ResetRenderState)
                    ImGui_ImplVulkan_SetupRenderState(draw_data, pipeline, command_buffer, rb, fb_width, fb_height);
                else
                    pcmd->UserCallback(draw_list, pcmd);
            }
            else
            {
                // Project scissor/clipping rectangles into framebuffer space
                ImVec2 clip_min((pcmd->ClipRect.x - clip_off.x) * clip_scale.x, (pcmd->ClipRect.y - clip_off.y) * clip_scale.y);
                ImVec2 clip_max((pcmd->ClipRect.z - clip_off.x) * clip_scale.x, (pcmd->ClipRect.w - clip_off.y) * clip_scale.y);

                // Clamp to viewport as vkCmdSetScissor() won't accept values that are off bounds
                if (clip_min.x < 0.0f) { clip_min.x = 0.0f; }
                if (clip_min.y < 0.0f) { clip_min.y = 0.0f; }
                if (clip_max.x > fb_width) { clip_max.x = (float)fb_width; }
                if (clip_max.y > fb_height) { clip_max.y = (float)fb_height; }
                if (clip_max.x <= clip_min.x || clip_max.y <= clip_min.y)
                    continue;

                // Apply scissor/clipping rectangle
                VkRect2D scissor;
                scissor.offset.x = (int32_t)(clip_min.x);
                scissor.offset.y = (int32_t)(clip_min.y);
                scissor.extent.width = (uint32_t)(clip_max.x - clip_min.x);
                scissor.extent.height = (uint32_t)(clip_max.y - clip_min.y);
                vkCmdSetScissor(command_buffer, 0, 1, &scissor);

                // Bind DescriptorSet with font or user texture
                VkDescriptorSet desc_set = (VkDescriptorSet)pcmd->GetTexID();
                vkCmdBindDescriptorSets(command_buffer, VK_PIPELINE_BIND_POINT_GRAPHICS, bd->PipelineLayout, 0, 1, &desc_set, 0, nullptr);

                // Draw
                vkCmdDrawIndexed(command_buffer, pcmd->ElemCount, 1, pcmd->IdxOffset + global_idx_offset, pcmd->VtxOffset + global_vtx_offset, 0);
            }
        }
        global_idx_offset += draw_list->IdxBuffer.Size;
        global_vtx_offset += draw_list->VtxBuffer.Size;
    }
    platform_io.Renderer_RenderState = nullptr;

    // Note: at this point both vkCmdSetViewport() and vkCmdSetScissor() have been called.
    // Our last values will leak into user/application rendering IF:
    // - Your app uses a pipeline with VK_DYNAMIC_STATE_VIEWPORT or VK_DYNAMIC_STATE_SCISSOR dynamic state
    // - And you forgot to call vkCmdSetViewport() and vkCmdSetScissor() yourself to explicitly set that state.
    // If you use VK_DYNAMIC_STATE_VIEWPORT or VK_DYNAMIC_STATE_SCISSOR you are responsible for setting the values before rendering.
    // In theory we should aim to backup/restore those values but I am not sure this is possible.
    // We perform a call to vkCmdSetScissor() to set back a full viewport which is likely to fix things for 99% users but technically this is not perfect. (See github #4644)
    VkRect2D scissor = { { 0, 0 }, { (uint32_t)fb_width, (uint32_t)fb_height } };
    vkCmdSetScissor(command_buffer, 0, 1, &scissor);
}

static void ImGui_ImplVulkan_DestroyTexture(ImTextureData* tex)
{
    ImGui_ImplVulkan_Texture* backend_tex = (ImGui_ImplVulkan_Texture*)tex->BackendUserData;
    if (backend_tex == nullptr)
        return;
    IM_ASSERT(backend_tex->DescriptorSet == (VkDescriptorSet)tex->TexID);
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    ImGui_ImplVulkan_RemoveTexture(backend_tex->DescriptorSet);
    vkDestroyImageView(v->Device, backend_tex->ImageView, v->Allocator);
    vkDestroyImage(v->Device, backend_tex->Image, v->Allocator);
    vkFreeMemory(v->Device, backend_tex->Memory, v->Allocator);
    IM_DELETE(backend_tex);

    // Clear identifiers and mark as destroyed (in order to allow e.g. calling InvalidateDeviceObjects while running)
    tex->SetTexID(ImTextureID_Invalid);
    tex->SetStatus(ImTextureStatus_Destroyed);
    tex->BackendUserData = nullptr;
}

void ImGui_ImplVulkan_UpdateTexture(ImTextureData* tex)
{
    if (tex->Status == ImTextureStatus_OK)
        return;
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkResult err;

    if (tex->Status == ImTextureStatus_WantCreate)
    {
        // Create and upload new texture to graphics system
        //IMGUI_DEBUG_LOG("UpdateTexture #%03d: WantCreate %dx%d\n", tex->UniqueID, tex->Width, tex->Height);
        IM_ASSERT(tex->TexID == ImTextureID_Invalid && tex->BackendUserData == nullptr);
        IM_ASSERT(tex->Format == ImTextureFormat_RGBA32);
        ImGui_ImplVulkan_Texture* backend_tex = IM_NEW(ImGui_ImplVulkan_Texture)();

        // 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 = tex->Width;
            info.extent.height = tex->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(v->Device, &info, v->Allocator, &backend_tex->Image);
            check_vk_result(err);
            VkMemoryRequirements req;
            vkGetImageMemoryRequirements(v->Device, backend_tex->Image, &req);
            VkMemoryAllocateInfo alloc_info = {};
            alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
            alloc_info.allocationSize = IM_MAX(v->MinAllocationSize, req.size);
            alloc_info.memoryTypeIndex = ImGui_ImplVulkan_MemoryType(VK_MEMORY_PROPERTY_DEVICE_LOCAL_BIT, req.memoryTypeBits);
            err = vkAllocateMemory(v->Device, &alloc_info, v->Allocator, &backend_tex->Memory);
            check_vk_result(err);
            err = vkBindImageMemory(v->Device, backend_tex->Image, backend_tex->Memory, 0);
            check_vk_result(err);
        }

        // Create the Image View:
        {
            VkImageViewCreateInfo info = {};
            info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
            info.image = backend_tex->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(v->Device, &info, v->Allocator, &backend_tex->ImageView);
            check_vk_result(err);
        }

        // Create the Descriptor Set
        backend_tex->DescriptorSet = ImGui_ImplVulkan_AddTexture(bd->TexSampler, backend_tex->ImageView, VK_IMAGE_LAYOUT_SHADER_READ_ONLY_OPTIMAL);

        // Store identifiers
        tex->SetTexID((ImTextureID)backend_tex->DescriptorSet);
        tex->BackendUserData = backend_tex;
    }

    if (tex->Status == ImTextureStatus_WantCreate || tex->Status == ImTextureStatus_WantUpdates)
    {
        ImGui_ImplVulkan_Texture* backend_tex = (ImGui_ImplVulkan_Texture*)tex->BackendUserData;

        // Update full texture or selected blocks. We only ever write to textures regions which have never been used before!
        // This backend choose to use tex->UpdateRect but you can use tex->Updates[] to upload individual regions.
        // We could use the smaller rect on _WantCreate but using the full rect allows us to clear the texture.
        const int upload_x = (tex->Status == ImTextureStatus_WantCreate) ? 0 : tex->UpdateRect.x;
        const int upload_y = (tex->Status == ImTextureStatus_WantCreate) ? 0 : tex->UpdateRect.y;
        const int upload_w = (tex->Status == ImTextureStatus_WantCreate) ? tex->Width : tex->UpdateRect.w;
        const int upload_h = (tex->Status == ImTextureStatus_WantCreate) ? tex->Height : tex->UpdateRect.h;

        // Create the Upload Buffer:
        VkDeviceMemory upload_buffer_memory;

        VkBuffer upload_buffer;
        VkDeviceSize upload_pitch = upload_w * tex->BytesPerPixel;
        VkDeviceSize upload_size = AlignBufferSize(upload_h * upload_pitch, bd->NonCoherentAtomSize);
        {
            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(v->Device, &buffer_info, v->Allocator, &upload_buffer);
            check_vk_result(err);
            VkMemoryRequirements req;
            vkGetBufferMemoryRequirements(v->Device, upload_buffer, &req);
            bd->BufferMemoryAlignment = (bd->BufferMemoryAlignment > req.alignment) ? bd->BufferMemoryAlignment : req.alignment;
            VkMemoryAllocateInfo alloc_info = {};
            alloc_info.sType = VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO;
            alloc_info.allocationSize = IM_MAX(v->MinAllocationSize, req.size);
            alloc_info.memoryTypeIndex = ImGui_ImplVulkan_MemoryType(VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT, req.memoryTypeBits);
            err = vkAllocateMemory(v->Device, &alloc_info, v->Allocator, &upload_buffer_memory);
            check_vk_result(err);
            err = vkBindBufferMemory(v->Device, upload_buffer, upload_buffer_memory, 0);
            check_vk_result(err);
        }

        // Upload to Buffer:
        {
            char* map = nullptr;
            err = vkMapMemory(v->Device, upload_buffer_memory, 0, upload_size, 0, (void**)(&map));
            check_vk_result(err);
            for (int y = 0; y < upload_h; y++)
                memcpy(map + upload_pitch * y, tex->GetPixelsAt(upload_x, upload_y + y), (size_t)upload_pitch);
            VkMappedMemoryRange range[1] = {};
            range[0].sType = VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE;
            range[0].memory = upload_buffer_memory;
            range[0].size = upload_size;
            err = vkFlushMappedMemoryRanges(v->Device, 1, range);
            check_vk_result(err);
            vkUnmapMemory(v->Device, upload_buffer_memory);
        }

        // Start command buffer
        {
            err = vkResetCommandPool(v->Device, bd->TexCommandPool, 0);
            check_vk_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(bd->TexCommandBuffer, &begin_info);
            check_vk_result(err);
        }

        // Copy to Image:
        {
            VkBufferMemoryBarrier upload_barrier[1] = {};
            upload_barrier[0].sType = VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER;
            upload_barrier[0].srcAccessMask = VK_ACCESS_HOST_WRITE_BIT;
            upload_barrier[0].dstAccessMask = VK_ACCESS_TRANSFER_READ_BIT;
            upload_barrier[0].srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
            upload_barrier[0].dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
            upload_barrier[0].buffer = upload_buffer;
            upload_barrier[0].offset = 0;
            upload_barrier[0].size = upload_size;

            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 = backend_tex->Image;
            copy_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            copy_barrier[0].subresourceRange.levelCount = 1;
            copy_barrier[0].subresourceRange.layerCount = 1;
            vkCmdPipelineBarrier(bd->TexCommandBuffer, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT | VK_PIPELINE_STAGE_HOST_BIT, VK_PIPELINE_STAGE_TRANSFER_BIT, 0, 0, nullptr, 1, upload_barrier, 1, copy_barrier);

            VkBufferImageCopy region = {};
            region.imageSubresource.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            region.imageSubresource.layerCount = 1;
            region.imageExtent.width = upload_w;
            region.imageExtent.height = upload_h;
            region.imageExtent.depth = 1;
            region.imageOffset.x = upload_x;
            region.imageOffset.y = upload_y;
            vkCmdCopyBufferToImage(bd->TexCommandBuffer, upload_buffer, backend_tex->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 = backend_tex->Image;
            use_barrier[0].subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            use_barrier[0].subresourceRange.levelCount = 1;
            use_barrier[0].subresourceRange.layerCount = 1;
            vkCmdPipelineBarrier(bd->TexCommandBuffer, VK_PIPELINE_STAGE_TRANSFER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, 0, 0, nullptr, 0, nullptr, 1, use_barrier);
        }

        // End command buffer
        {
            VkSubmitInfo end_info = {};
            end_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
            end_info.commandBufferCount = 1;
            end_info.pCommandBuffers = &bd->TexCommandBuffer;
            err = vkEndCommandBuffer(bd->TexCommandBuffer);
            check_vk_result(err);
            err = vkQueueSubmit(v->Queue, 1, &end_info, VK_NULL_HANDLE);
            check_vk_result(err);
        }

        err = vkQueueWaitIdle(v->Queue); // FIXME-OPT: Suboptimal!
        check_vk_result(err);
        vkDestroyBuffer(v->Device, upload_buffer, v->Allocator);
        vkFreeMemory(v->Device, upload_buffer_memory, v->Allocator);

        tex->SetStatus(ImTextureStatus_OK);
    }

    if (tex->Status == ImTextureStatus_WantDestroy && tex->UnusedFrames >= (int)bd->VulkanInitInfo.ImageCount)
        ImGui_ImplVulkan_DestroyTexture(tex);
}

static void ImGui_ImplVulkan_CreateShaderModules(VkDevice device, const VkAllocationCallbacks* allocator)
{
    // Create the shader modules
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    if (bd->ShaderModuleVert == VK_NULL_HANDLE)
    {
        VkShaderModuleCreateInfo vert_info = {};
        vert_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
        vert_info.codeSize = sizeof(__glsl_shader_vert_spv);
        vert_info.pCode = (uint32_t*)__glsl_shader_vert_spv;
        VkResult err = vkCreateShaderModule(device, &vert_info, allocator, &bd->ShaderModuleVert);
        check_vk_result(err);
    }
    if (bd->ShaderModuleFrag == VK_NULL_HANDLE)
    {
        VkShaderModuleCreateInfo frag_info = {};
        frag_info.sType = VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO;
        frag_info.codeSize = sizeof(__glsl_shader_frag_spv);
        frag_info.pCode = (uint32_t*)__glsl_shader_frag_spv;
        VkResult err = vkCreateShaderModule(device, &frag_info, allocator, &bd->ShaderModuleFrag);
        check_vk_result(err);
    }
}

static void ImGui_ImplVulkan_CreatePipeline(VkDevice device, const VkAllocationCallbacks* allocator, VkPipelineCache pipelineCache, VkRenderPass renderPass, VkSampleCountFlagBits MSAASamples, VkPipeline* pipeline, uint32_t subpass)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_CreateShaderModules(device, allocator);

    VkPipelineShaderStageCreateInfo stage[2] = {};
    stage[0].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    stage[0].stage = VK_SHADER_STAGE_VERTEX_BIT;
    stage[0].module = bd->ShaderModuleVert;
    stage[0].pName = "main";
    stage[1].sType = VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO;
    stage[1].stage = VK_SHADER_STAGE_FRAGMENT_BIT;
    stage[1].module = bd->ShaderModuleFrag;
    stage[1].pName = "main";

    VkVertexInputBindingDescription binding_desc[1] = {};
    binding_desc[0].stride = sizeof(ImDrawVert);
    binding_desc[0].inputRate = VK_VERTEX_INPUT_RATE_VERTEX;

    VkVertexInputAttributeDescription attribute_desc[3] = {};
    attribute_desc[0].location = 0;
    attribute_desc[0].binding = binding_desc[0].binding;
    attribute_desc[0].format = VK_FORMAT_R32G32_SFLOAT;
    attribute_desc[0].offset = offsetof(ImDrawVert, pos);
    attribute_desc[1].location = 1;
    attribute_desc[1].binding = binding_desc[0].binding;
    attribute_desc[1].format = VK_FORMAT_R32G32_SFLOAT;
    attribute_desc[1].offset = offsetof(ImDrawVert, uv);
    attribute_desc[2].location = 2;
    attribute_desc[2].binding = binding_desc[0].binding;
    attribute_desc[2].format = VK_FORMAT_R8G8B8A8_UNORM;
    attribute_desc[2].offset = offsetof(ImDrawVert, col);

    VkPipelineVertexInputStateCreateInfo vertex_info = {};
    vertex_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO;
    vertex_info.vertexBindingDescriptionCount = 1;
    vertex_info.pVertexBindingDescriptions = binding_desc;
    vertex_info.vertexAttributeDescriptionCount = 3;
    vertex_info.pVertexAttributeDescriptions = attribute_desc;

    VkPipelineInputAssemblyStateCreateInfo ia_info = {};
    ia_info.sType = VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO;
    ia_info.topology = VK_PRIMITIVE_TOPOLOGY_TRIANGLE_LIST;

    VkPipelineViewportStateCreateInfo viewport_info = {};
    viewport_info.sType = VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO;
    viewport_info.viewportCount = 1;
    viewport_info.scissorCount = 1;

    VkPipelineRasterizationStateCreateInfo raster_info = {};
    raster_info.sType = VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO;
    raster_info.polygonMode = VK_POLYGON_MODE_FILL;
    raster_info.cullMode = VK_CULL_MODE_NONE;
    raster_info.frontFace = VK_FRONT_FACE_COUNTER_CLOCKWISE;
    raster_info.lineWidth = 1.0f;

    VkPipelineMultisampleStateCreateInfo ms_info = {};
    ms_info.sType = VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO;
    ms_info.rasterizationSamples = (MSAASamples != 0) ? MSAASamples : VK_SAMPLE_COUNT_1_BIT;

    VkPipelineColorBlendAttachmentState color_attachment[1] = {};
    color_attachment[0].blendEnable = VK_TRUE;
    color_attachment[0].srcColorBlendFactor = VK_BLEND_FACTOR_SRC_ALPHA;
    color_attachment[0].dstColorBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
    color_attachment[0].colorBlendOp = VK_BLEND_OP_ADD;
    color_attachment[0].srcAlphaBlendFactor = VK_BLEND_FACTOR_ONE;
    color_attachment[0].dstAlphaBlendFactor = VK_BLEND_FACTOR_ONE_MINUS_SRC_ALPHA;
    color_attachment[0].alphaBlendOp = VK_BLEND_OP_ADD;
    color_attachment[0].colorWriteMask = VK_COLOR_COMPONENT_R_BIT | VK_COLOR_COMPONENT_G_BIT | VK_COLOR_COMPONENT_B_BIT | VK_COLOR_COMPONENT_A_BIT;

    VkPipelineDepthStencilStateCreateInfo depth_info = {};
    depth_info.sType = VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO;

    VkPipelineColorBlendStateCreateInfo blend_info = {};
    blend_info.sType = VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO;
    blend_info.attachmentCount = 1;
    blend_info.pAttachments = color_attachment;

    VkDynamicState dynamic_states[2] = { VK_DYNAMIC_STATE_VIEWPORT, VK_DYNAMIC_STATE_SCISSOR };
    VkPipelineDynamicStateCreateInfo dynamic_state = {};
    dynamic_state.sType = VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO;
    dynamic_state.dynamicStateCount = (uint32_t)IM_ARRAYSIZE(dynamic_states);
    dynamic_state.pDynamicStates = dynamic_states;

    VkGraphicsPipelineCreateInfo info = {};
    info.sType = VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO;
    info.flags = bd->PipelineCreateFlags;
    info.stageCount = 2;
    info.pStages = stage;
    info.pVertexInputState = &vertex_info;
    info.pInputAssemblyState = &ia_info;
    info.pViewportState = &viewport_info;
    info.pRasterizationState = &raster_info;
    info.pMultisampleState = &ms_info;
    info.pDepthStencilState = &depth_info;
    info.pColorBlendState = &blend_info;
    info.pDynamicState = &dynamic_state;
    info.layout = bd->PipelineLayout;
    info.renderPass = renderPass;
    info.subpass = subpass;

#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
    if (bd->VulkanInitInfo.UseDynamicRendering)
    {
        IM_ASSERT(bd->VulkanInitInfo.PipelineRenderingCreateInfo.sType == VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR && "PipelineRenderingCreateInfo sType must be VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO_KHR");
        IM_ASSERT(bd->VulkanInitInfo.PipelineRenderingCreateInfo.pNext == nullptr && "PipelineRenderingCreateInfo pNext must be nullptr");
        info.pNext = &bd->VulkanInitInfo.PipelineRenderingCreateInfo;
        info.renderPass = VK_NULL_HANDLE; // Just make sure it's actually nullptr.
    }
#endif

    VkResult err = vkCreateGraphicsPipelines(device, pipelineCache, 1, &info, allocator, pipeline);
    check_vk_result(err);
}

bool ImGui_ImplVulkan_CreateDeviceObjects()
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkResult err;

    if (!bd->TexSampler)
    {
        // Bilinear sampling is required by default. Set 'io.Fonts->Flags |= ImFontAtlasFlags_NoBakedLines' or 'style.AntiAliasedLinesUseTex = false' to allow point/nearest sampling.
        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_CLAMP_TO_EDGE;
        info.addressModeV = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
        info.addressModeW = VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;
        info.minLod = -1000;
        info.maxLod = 1000;
        info.maxAnisotropy = 1.0f;
        err = vkCreateSampler(v->Device, &info, v->Allocator, &bd->TexSampler);
        check_vk_result(err);
    }

    if (!bd->DescriptorSetLayout)
    {
        VkDescriptorSetLayoutBinding binding[1] = {};
        binding[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
        binding[0].descriptorCount = 1;
        binding[0].stageFlags = VK_SHADER_STAGE_FRAGMENT_BIT;
        VkDescriptorSetLayoutCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO;
        info.bindingCount = 1;
        info.pBindings = binding;
        err = vkCreateDescriptorSetLayout(v->Device, &info, v->Allocator, &bd->DescriptorSetLayout);
        check_vk_result(err);
    }

    if (v->DescriptorPoolSize != 0)
    {
        IM_ASSERT(v->DescriptorPoolSize >= IMGUI_IMPL_VULKAN_MINIMUM_IMAGE_SAMPLER_POOL_SIZE);
        VkDescriptorPoolSize pool_size = { VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER, v->DescriptorPoolSize };
        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 = v->DescriptorPoolSize;
        pool_info.poolSizeCount = 1;
        pool_info.pPoolSizes = &pool_size;

        err = vkCreateDescriptorPool(v->Device, &pool_info, v->Allocator, &bd->DescriptorPool);
        check_vk_result(err);
    }

    if (!bd->PipelineLayout)
    {
        // Constants: we are using 'vec2 offset' and 'vec2 scale' instead of a full 3d projection matrix
        VkPushConstantRange push_constants[1] = {};
        push_constants[0].stageFlags = VK_SHADER_STAGE_VERTEX_BIT;
        push_constants[0].offset = sizeof(float) * 0;
        push_constants[0].size = sizeof(float) * 4;
        VkDescriptorSetLayout set_layout[1] = { bd->DescriptorSetLayout };
        VkPipelineLayoutCreateInfo layout_info = {};
        layout_info.sType = VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO;
        layout_info.setLayoutCount = 1;
        layout_info.pSetLayouts = set_layout;
        layout_info.pushConstantRangeCount = 1;
        layout_info.pPushConstantRanges = push_constants;
        err = vkCreatePipelineLayout(v->Device, &layout_info, v->Allocator, &bd->PipelineLayout);
        check_vk_result(err);
    }

    ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, v->PipelineCache, v->RenderPass, v->MSAASamples, &bd->Pipeline, v->Subpass);

    // Create command pool/buffer for texture upload
    if (!bd->TexCommandPool)
    {
        VkCommandPoolCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
        info.flags = 0;
        info.queueFamilyIndex = v->QueueFamily;
        err = vkCreateCommandPool(v->Device, &info, v->Allocator, &bd->TexCommandPool);
        check_vk_result(err);
    }
    if (!bd->TexCommandBuffer)
    {
        VkCommandBufferAllocateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
        info.commandPool = bd->TexCommandPool;
        info.commandBufferCount = 1;
        err = vkAllocateCommandBuffers(v->Device, &info, &bd->TexCommandBuffer);
        check_vk_result(err);
    }

    return true;
}

void    ImGui_ImplVulkan_DestroyDeviceObjects()
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);

    // Destroy all textures
    for (ImTextureData* tex : ImGui::GetPlatformIO().Textures)
        if (tex->RefCount == 1)
            ImGui_ImplVulkan_DestroyTexture(tex);

    if (bd->TexCommandBuffer)     { vkFreeCommandBuffers(v->Device, bd->TexCommandPool, 1, &bd->TexCommandBuffer); bd->TexCommandBuffer = VK_NULL_HANDLE; }
    if (bd->TexCommandPool)       { vkDestroyCommandPool(v->Device, bd->TexCommandPool, v->Allocator); bd->TexCommandPool = VK_NULL_HANDLE; }
    if (bd->TexSampler)           { vkDestroySampler(v->Device, bd->TexSampler, v->Allocator); bd->TexSampler = VK_NULL_HANDLE; }
    if (bd->ShaderModuleVert)     { vkDestroyShaderModule(v->Device, bd->ShaderModuleVert, v->Allocator); bd->ShaderModuleVert = VK_NULL_HANDLE; }
    if (bd->ShaderModuleFrag)     { vkDestroyShaderModule(v->Device, bd->ShaderModuleFrag, v->Allocator); bd->ShaderModuleFrag = VK_NULL_HANDLE; }
    if (bd->DescriptorSetLayout)  { vkDestroyDescriptorSetLayout(v->Device, bd->DescriptorSetLayout, v->Allocator); bd->DescriptorSetLayout = VK_NULL_HANDLE; }
    if (bd->PipelineLayout)       { vkDestroyPipelineLayout(v->Device, bd->PipelineLayout, v->Allocator); bd->PipelineLayout = VK_NULL_HANDLE; }
    if (bd->Pipeline)             { vkDestroyPipeline(v->Device, bd->Pipeline, v->Allocator); bd->Pipeline = VK_NULL_HANDLE; }
    if (bd->PipelineForViewports) { vkDestroyPipeline(v->Device, bd->PipelineForViewports, v->Allocator); bd->PipelineForViewports = VK_NULL_HANDLE; }
    if (bd->DescriptorPool)       { vkDestroyDescriptorPool(v->Device, bd->DescriptorPool, v->Allocator); bd->DescriptorPool = VK_NULL_HANDLE; }
}

#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
static void ImGui_ImplVulkan_LoadDynamicRenderingFunctions(uint32_t api_version, PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data)
{
    IM_UNUSED(api_version);

    // Manually load those two (see #5446, #8326, #8365, #8600)
    // - Try loading core (non-KHR) versions first (this will work for Vulkan 1.3+ and the device supports dynamic rendering)
    ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(loader_func("vkCmdBeginRendering", user_data));
    ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(loader_func("vkCmdEndRendering", user_data));

    // - Fallback to KHR versions if core not available (this will work if KHR extension is available and enabled and also the device supports dynamic rendering)
    if (ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR == nullptr || ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR == nullptr)
    {
        ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR = reinterpret_cast<PFN_vkCmdBeginRenderingKHR>(loader_func("vkCmdBeginRenderingKHR", user_data));
        ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR = reinterpret_cast<PFN_vkCmdEndRenderingKHR>(loader_func("vkCmdEndRenderingKHR", user_data));
    }
}
#endif

// If unspecified by user, assume that ApiVersion == HeaderVersion
 // We don't care about other versions than 1.3 for our checks, so don't need to make this exhaustive (e.g. with all #ifdef VK_VERSION_1_X checks)
static uint32_t ImGui_ImplVulkan_GetDefaultApiVersion()
{
#ifdef VK_HEADER_VERSION_COMPLETE
    return VK_HEADER_VERSION_COMPLETE;
#else
    return VK_API_VERSION_1_0;
#endif
}

bool    ImGui_ImplVulkan_LoadFunctions(uint32_t api_version, PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data)
{
    // Load function pointers
    // You can use the default Vulkan loader using:
    //      ImGui_ImplVulkan_LoadFunctions(VK_API_VERSION_1_3, [](const char* function_name, void*) { return vkGetInstanceProcAddr(your_vk_isntance, function_name); });
    // But this would be roughly equivalent to not setting VK_NO_PROTOTYPES.
    if (api_version == 0)
        api_version = ImGui_ImplVulkan_GetDefaultApiVersion();

#ifdef IMGUI_IMPL_VULKAN_USE_LOADER
#define IMGUI_VULKAN_FUNC_LOAD(func) \
    func = reinterpret_cast<decltype(func)>(loader_func(#func, user_data)); \
    if (func == nullptr)   \
        return false;
    IMGUI_VULKAN_FUNC_MAP(IMGUI_VULKAN_FUNC_LOAD)
#undef IMGUI_VULKAN_FUNC_LOAD

#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
    ImGui_ImplVulkan_LoadDynamicRenderingFunctions(api_version, loader_func, user_data);
#endif
#else
    IM_UNUSED(loader_func);
    IM_UNUSED(user_data);
#endif

    g_FunctionsLoaded = true;
    return true;
}

bool    ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info)
{
    IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");

    if (info->ApiVersion == 0)
        info->ApiVersion = ImGui_ImplVulkan_GetDefaultApiVersion();

    if (info->UseDynamicRendering)
    {
#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
#ifndef IMGUI_IMPL_VULKAN_USE_LOADER
        ImGui_ImplVulkan_LoadDynamicRenderingFunctions(info->ApiVersion, [](const char* function_name, void* user_data) { return vkGetDeviceProcAddr((VkDevice)user_data, function_name); }, (void*)info->Device);
#endif
        IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR != nullptr);
        IM_ASSERT(ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR != nullptr);
#else
        IM_ASSERT(0 && "Can't use dynamic rendering when neither VK_VERSION_1_3 or VK_KHR_dynamic_rendering is defined.");
#endif
    }

    ImGuiIO& io = ImGui::GetIO();
    IMGUI_CHECKVERSION();
    IM_ASSERT(io.BackendRendererUserData == nullptr && "Already initialized a renderer backend!");

    // Setup backend capabilities flags
    ImGui_ImplVulkan_Data* bd = IM_NEW(ImGui_ImplVulkan_Data)();
    io.BackendRendererUserData = (void*)bd;
    io.BackendRendererName = "imgui_impl_vulkan";
    io.BackendFlags |= ImGuiBackendFlags_RendererHasVtxOffset;  // We can honor the ImDrawCmd::VtxOffset field, allowing for large meshes.
    io.BackendFlags |= ImGuiBackendFlags_RendererHasTextures;   // We can honor ImGuiPlatformIO::Textures[] requests during render.
    io.BackendFlags |= ImGuiBackendFlags_RendererHasViewports;  // We can create multi-viewports on the Renderer side (optional)

    IM_ASSERT(info->Instance != VK_NULL_HANDLE);
    IM_ASSERT(info->PhysicalDevice != VK_NULL_HANDLE);
    IM_ASSERT(info->Device != VK_NULL_HANDLE);
    IM_ASSERT(info->Queue != VK_NULL_HANDLE);
    if (info->DescriptorPool != VK_NULL_HANDLE) // Either DescriptorPool or DescriptorPoolSize must be set, not both!
        IM_ASSERT(info->DescriptorPoolSize == 0);
    else
        IM_ASSERT(info->DescriptorPoolSize > 0);
    IM_ASSERT(info->MinImageCount >= 2);
    IM_ASSERT(info->ImageCount >= info->MinImageCount);
    if (info->UseDynamicRendering == false)
        IM_ASSERT(info->RenderPass != VK_NULL_HANDLE);

    bd->VulkanInitInfo = *info;

    VkPhysicalDeviceProperties properties;
    vkGetPhysicalDeviceProperties(info->PhysicalDevice, &properties);
    bd->NonCoherentAtomSize = properties.limits.nonCoherentAtomSize;

#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    if (v->PipelineRenderingCreateInfo.pColorAttachmentFormats != NULL)
    {
        // Deep copy buffer to reduce error-rate for end user (#8282)
        VkFormat* formats_copy = (VkFormat*)IM_ALLOC(sizeof(VkFormat) * v->PipelineRenderingCreateInfo.colorAttachmentCount);
        memcpy(formats_copy, v->PipelineRenderingCreateInfo.pColorAttachmentFormats, sizeof(VkFormat) * v->PipelineRenderingCreateInfo.colorAttachmentCount);
        v->PipelineRenderingCreateInfo.pColorAttachmentFormats = formats_copy;
    }
#endif

    if (!ImGui_ImplVulkan_CreateDeviceObjects())
        IM_ASSERT(0 && "ImGui_ImplVulkan_CreateDeviceObjects() failed!"); // <- Can't be hit yet.

    // Our render function expect RendererUserData to be storing the window render buffer we need (for the main viewport we won't use ->Window)
    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
    main_viewport->RendererUserData = IM_NEW(ImGui_ImplVulkan_ViewportData)();

    ImGui_ImplVulkan_InitMultiViewportSupport();

    return true;
}

void ImGui_ImplVulkan_Shutdown()
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    IM_ASSERT(bd != nullptr && "No renderer backend to shutdown, or already shutdown?");
    ImGuiIO& io = ImGui::GetIO();

    // First destroy objects in all viewports
    ImGui_ImplVulkan_DestroyDeviceObjects();
#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
    IM_FREE((void*)const_cast<VkFormat*>(bd->VulkanInitInfo.PipelineRenderingCreateInfo.pColorAttachmentFormats));
#endif

    // Manually delete main viewport render data in-case we haven't initialized for viewports
    ImGuiViewport* main_viewport = ImGui::GetMainViewport();
    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)main_viewport->RendererUserData)
        IM_DELETE(vd);
    main_viewport->RendererUserData = nullptr;

    // Clean up windows
    ImGui_ImplVulkan_ShutdownMultiViewportSupport();

    io.BackendRendererName = nullptr;
    io.BackendRendererUserData = nullptr;
    io.BackendFlags &= ~(ImGuiBackendFlags_RendererHasVtxOffset | ImGuiBackendFlags_RendererHasTextures | ImGuiBackendFlags_RendererHasViewports);
    IM_DELETE(bd);
}

void ImGui_ImplVulkan_NewFrame()
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    IM_ASSERT(bd != nullptr && "Context or backend not initialized! Did you call ImGui_ImplVulkan_Init()?");
    IM_UNUSED(bd);
}

void ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    IM_ASSERT(min_image_count >= 2);
    if (bd->VulkanInitInfo.MinImageCount == min_image_count)
        return;

    IM_ASSERT(0); // FIXME-VIEWPORT: Unsupported. Need to recreate all swap chains!
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkResult err = vkDeviceWaitIdle(v->Device);
    check_vk_result(err);
    ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(v->Device, v->Allocator);

    bd->VulkanInitInfo.MinImageCount = min_image_count;
}

// Register a texture by creating a descriptor
// FIXME: This is experimental in the sense that we are unsure how to best design/tackle this problem, please post to https://github.com/ocornut/imgui/pull/914 if you have suggestions.
VkDescriptorSet ImGui_ImplVulkan_AddTexture(VkSampler sampler, VkImageView image_view, VkImageLayout image_layout)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkDescriptorPool pool = bd->DescriptorPool ? bd->DescriptorPool : v->DescriptorPool;

    // Create Descriptor Set:
    VkDescriptorSet descriptor_set;
    {
        VkDescriptorSetAllocateInfo alloc_info = {};
        alloc_info.sType = VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO;
        alloc_info.descriptorPool = pool;
        alloc_info.descriptorSetCount = 1;
        alloc_info.pSetLayouts = &bd->DescriptorSetLayout;
        VkResult err = vkAllocateDescriptorSets(v->Device, &alloc_info, &descriptor_set);
        check_vk_result(err);
    }

    // Update the Descriptor Set:
    {
        VkDescriptorImageInfo desc_image[1] = {};
        desc_image[0].sampler = sampler;
        desc_image[0].imageView = image_view;
        desc_image[0].imageLayout = image_layout;
        VkWriteDescriptorSet write_desc[1] = {};
        write_desc[0].sType = VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET;
        write_desc[0].dstSet = descriptor_set;
        write_desc[0].descriptorCount = 1;
        write_desc[0].descriptorType = VK_DESCRIPTOR_TYPE_COMBINED_IMAGE_SAMPLER;
        write_desc[0].pImageInfo = desc_image;
        vkUpdateDescriptorSets(v->Device, 1, write_desc, 0, nullptr);
    }
    return descriptor_set;
}

void ImGui_ImplVulkan_RemoveTexture(VkDescriptorSet descriptor_set)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkDescriptorPool pool = bd->DescriptorPool ? bd->DescriptorPool : v->DescriptorPool;
    vkFreeDescriptorSets(v->Device, pool, 1, &descriptor_set);
}

void ImGui_ImplVulkan_DestroyFrameRenderBuffers(VkDevice device, ImGui_ImplVulkan_FrameRenderBuffers* buffers, const VkAllocationCallbacks* allocator)
{
    if (buffers->VertexBuffer) { vkDestroyBuffer(device, buffers->VertexBuffer, allocator); buffers->VertexBuffer = VK_NULL_HANDLE; }
    if (buffers->VertexBufferMemory) { vkFreeMemory(device, buffers->VertexBufferMemory, allocator); buffers->VertexBufferMemory = VK_NULL_HANDLE; }
    if (buffers->IndexBuffer) { vkDestroyBuffer(device, buffers->IndexBuffer, allocator); buffers->IndexBuffer = VK_NULL_HANDLE; }
    if (buffers->IndexBufferMemory) { vkFreeMemory(device, buffers->IndexBufferMemory, allocator); buffers->IndexBufferMemory = VK_NULL_HANDLE; }
    buffers->VertexBufferSize = 0;
    buffers->IndexBufferSize = 0;
}

void ImGui_ImplVulkan_DestroyWindowRenderBuffers(VkDevice device, ImGui_ImplVulkan_WindowRenderBuffers* buffers, const VkAllocationCallbacks* allocator)
{
    for (uint32_t n = 0; n < buffers->Count; n++)
        ImGui_ImplVulkan_DestroyFrameRenderBuffers(device, &buffers->FrameRenderBuffers[n], allocator);
    buffers->FrameRenderBuffers.clear();
    buffers->Index = 0;
    buffers->Count = 0;
}

//-------------------------------------------------------------------------
// Internal / Miscellaneous Vulkan Helpers
// (Used by example's main.cpp. Used by multi-viewport features. PROBABLY NOT used by your own app.)
//-------------------------------------------------------------------------
// You probably do NOT need to use or care about those functions.
// Those functions only exist because:
//   1) they facilitate the readability and maintenance of the multiple main.cpp examples files.
//   2) the upcoming multi-viewport feature will need them internally.
// Generally we avoid exposing any kind of superfluous high-level helpers in the backends,
// but it is too much code to duplicate everywhere so we exceptionally expose them.
//
// Your engine/app will likely _already_ have code to setup all that stuff (swap chain, render pass, frame buffers, etc.).
// You may read this code to learn about Vulkan, but it is recommended you use you own custom tailored code to do equivalent work.
// (The ImGui_ImplVulkanH_XXX functions do not interact with any of the state used by the regular ImGui_ImplVulkan_XXX functions)
//-------------------------------------------------------------------------

VkSurfaceFormatKHR ImGui_ImplVulkanH_SelectSurfaceFormat(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkFormat* request_formats, int request_formats_count, VkColorSpaceKHR request_color_space)
{
    IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
    IM_ASSERT(request_formats != nullptr);
    IM_ASSERT(request_formats_count > 0);

    // Per Spec Format and View Format are expected to be the same unless VK_IMAGE_CREATE_MUTABLE_BIT was set at image creation
    // Assuming that the default behavior is without setting this bit, there is no need for separate Swapchain image and image view format
    // Additionally several new color spaces were introduced with Vulkan Spec v1.0.40,
    // hence we must make sure that a format with the mostly available color space, VK_COLOR_SPACE_SRGB_NONLINEAR_KHR, is found and used.
    uint32_t avail_count;
    vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device, surface, &avail_count, nullptr);
    ImVector<VkSurfaceFormatKHR> avail_format;
    avail_format.resize((int)avail_count);
    vkGetPhysicalDeviceSurfaceFormatsKHR(physical_device, surface, &avail_count, avail_format.Data);

    // First check if only one format, VK_FORMAT_UNDEFINED, is available, which would imply that any format is available
    if (avail_count == 1)
    {
        if (avail_format[0].format == VK_FORMAT_UNDEFINED)
        {
            VkSurfaceFormatKHR ret;
            ret.format = request_formats[0];
            ret.colorSpace = request_color_space;
            return ret;
        }
        else
        {
            // No point in searching another format
            return avail_format[0];
        }
    }
    else
    {
        // Request several formats, the first found will be used
        for (int request_i = 0; request_i < request_formats_count; request_i++)
            for (uint32_t avail_i = 0; avail_i < avail_count; avail_i++)
                if (avail_format[avail_i].format == request_formats[request_i] && avail_format[avail_i].colorSpace == request_color_space)
                    return avail_format[avail_i];

        // If none of the requested image formats could be found, use the first available
        return avail_format[0];
    }
}

VkPresentModeKHR ImGui_ImplVulkanH_SelectPresentMode(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkPresentModeKHR* request_modes, int request_modes_count)
{
    IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
    IM_ASSERT(request_modes != nullptr);
    IM_ASSERT(request_modes_count > 0);

    // Request a certain mode and confirm that it is available. If not use VK_PRESENT_MODE_FIFO_KHR which is mandatory
    uint32_t avail_count = 0;
    vkGetPhysicalDeviceSurfacePresentModesKHR(physical_device, surface, &avail_count, nullptr);
    ImVector<VkPresentModeKHR> avail_modes;
    avail_modes.resize((int)avail_count);
    vkGetPhysicalDeviceSurfacePresentModesKHR(physical_device, surface, &avail_count, avail_modes.Data);
    //for (uint32_t avail_i = 0; avail_i < avail_count; avail_i++)
    //    printf("[vulkan] avail_modes[%d] = %d\n", avail_i, avail_modes[avail_i]);

    for (int request_i = 0; request_i < request_modes_count; request_i++)
        for (uint32_t avail_i = 0; avail_i < avail_count; avail_i++)
            if (request_modes[request_i] == avail_modes[avail_i])
                return request_modes[request_i];

    return VK_PRESENT_MODE_FIFO_KHR; // Always available
}

VkPhysicalDevice ImGui_ImplVulkanH_SelectPhysicalDevice(VkInstance instance)
{
    uint32_t gpu_count;
    VkResult err = vkEnumeratePhysicalDevices(instance, &gpu_count, nullptr);
    check_vk_result(err);
    IM_ASSERT(gpu_count > 0);

    ImVector<VkPhysicalDevice> gpus;
    gpus.resize(gpu_count);
    err = vkEnumeratePhysicalDevices(instance, &gpu_count, gpus.Data);
    check_vk_result(err);

    // If a number >1 of GPUs got reported, find discrete GPU if present, or use first one available. This covers
    // most common cases (multi-gpu/integrated+dedicated graphics). Handling more complicated setups (multiple
    // dedicated GPUs) is out of scope of this sample.
    for (VkPhysicalDevice& device : gpus)
    {
        VkPhysicalDeviceProperties properties;
        vkGetPhysicalDeviceProperties(device, &properties);
        if (properties.deviceType == VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU)
            return device;
    }

    // Use first GPU (Integrated) is a Discrete one is not available.
    if (gpu_count > 0)
        return gpus[0];
    return VK_NULL_HANDLE;
}


uint32_t ImGui_ImplVulkanH_SelectQueueFamilyIndex(VkPhysicalDevice physical_device)
{
    uint32_t count;
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &count, nullptr);
    ImVector<VkQueueFamilyProperties> queues_properties;
    queues_properties.resize((int)count);
    vkGetPhysicalDeviceQueueFamilyProperties(physical_device, &count, queues_properties.Data);
    for (uint32_t i = 0; i < count; i++)
        if (queues_properties[i].queueFlags & VK_QUEUE_GRAPHICS_BIT)
            return i;
    return (uint32_t)-1;
}

void ImGui_ImplVulkanH_CreateWindowCommandBuffers(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator)
{
    IM_ASSERT(physical_device != VK_NULL_HANDLE && device != VK_NULL_HANDLE);
    IM_UNUSED(physical_device);

    // Create Command Buffers
    VkResult err;
    for (uint32_t i = 0; i < wd->ImageCount; i++)
    {
        ImGui_ImplVulkanH_Frame* fd = &wd->Frames[i];
        {
            VkCommandPoolCreateInfo info = {};
            info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
            info.flags = 0;
            info.queueFamilyIndex = queue_family;
            err = vkCreateCommandPool(device, &info, allocator, &fd->CommandPool);
            check_vk_result(err);
        }
        {
            VkCommandBufferAllocateInfo info = {};
            info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
            info.commandPool = fd->CommandPool;
            info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
            info.commandBufferCount = 1;
            err = vkAllocateCommandBuffers(device, &info, &fd->CommandBuffer);
            check_vk_result(err);
        }
        {
            VkFenceCreateInfo info = {};
            info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
            info.flags = VK_FENCE_CREATE_SIGNALED_BIT;
            err = vkCreateFence(device, &info, allocator, &fd->Fence);
            check_vk_result(err);
        }
    }

    for (uint32_t i = 0; i < wd->SemaphoreCount; i++)
    {
        ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[i];
        {
            VkSemaphoreCreateInfo info = {};
            info.sType = VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO;
            err = vkCreateSemaphore(device, &info, allocator, &fsd->ImageAcquiredSemaphore);
            check_vk_result(err);
            err = vkCreateSemaphore(device, &info, allocator, &fsd->RenderCompleteSemaphore);
            check_vk_result(err);
        }
    }
}

int ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(VkPresentModeKHR present_mode)
{
    if (present_mode == VK_PRESENT_MODE_MAILBOX_KHR)
        return 3;
    if (present_mode == VK_PRESENT_MODE_FIFO_KHR || present_mode == VK_PRESENT_MODE_FIFO_RELAXED_KHR)
        return 2;
    if (present_mode == VK_PRESENT_MODE_IMMEDIATE_KHR)
        return 1;
    IM_ASSERT(0);
    return 1;
}

// Also destroy old swap chain and in-flight frames data, if any.
void ImGui_ImplVulkanH_CreateWindowSwapChain(VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count)
{
    VkResult err;
    VkSwapchainKHR old_swapchain = wd->Swapchain;
    wd->Swapchain = VK_NULL_HANDLE;
    err = vkDeviceWaitIdle(device);
    check_vk_result(err);

    // We don't use ImGui_ImplVulkanH_DestroyWindow() because we want to preserve the old swapchain to create the new one.
    // Destroy old Framebuffer
    for (uint32_t i = 0; i < wd->ImageCount; i++)
        ImGui_ImplVulkanH_DestroyFrame(device, &wd->Frames[i], allocator);
    for (uint32_t i = 0; i < wd->SemaphoreCount; i++)
        ImGui_ImplVulkanH_DestroyFrameSemaphores(device, &wd->FrameSemaphores[i], allocator);
    wd->Frames.clear();
    wd->FrameSemaphores.clear();
    wd->ImageCount = 0;
    if (wd->RenderPass)
        vkDestroyRenderPass(device, wd->RenderPass, allocator);

    // If min image count was not specified, request different count of images dependent on selected present mode
    if (min_image_count == 0)
        min_image_count = ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(wd->PresentMode);

    // Create Swapchain
    {
        VkSurfaceCapabilitiesKHR cap;
        err = vkGetPhysicalDeviceSurfaceCapabilitiesKHR(physical_device, wd->Surface, &cap);
        check_vk_result(err);

        VkSwapchainCreateInfoKHR info = {};
        info.sType = VK_STRUCTURE_TYPE_SWAPCHAIN_CREATE_INFO_KHR;
        info.surface = wd->Surface;
        info.minImageCount = min_image_count;
        info.imageFormat = wd->SurfaceFormat.format;
        info.imageColorSpace = wd->SurfaceFormat.colorSpace;
        info.imageArrayLayers = 1;
        info.imageUsage = VK_IMAGE_USAGE_COLOR_ATTACHMENT_BIT;
        info.imageSharingMode = VK_SHARING_MODE_EXCLUSIVE;           // Assume that graphics family == present family
        info.preTransform = (cap.supportedTransforms & VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR) ? VK_SURFACE_TRANSFORM_IDENTITY_BIT_KHR : cap.currentTransform;
        info.compositeAlpha = VK_COMPOSITE_ALPHA_OPAQUE_BIT_KHR;
        info.presentMode = wd->PresentMode;
        info.clipped = VK_TRUE;
        info.oldSwapchain = old_swapchain;
        if (info.minImageCount < cap.minImageCount)
            info.minImageCount = cap.minImageCount;
        else if (cap.maxImageCount != 0 && info.minImageCount > cap.maxImageCount)
            info.minImageCount = cap.maxImageCount;
        if (cap.currentExtent.width == 0xffffffff)
        {
            info.imageExtent.width = wd->Width = w;
            info.imageExtent.height = wd->Height = h;
        }
        else
        {
            info.imageExtent.width = wd->Width = cap.currentExtent.width;
            info.imageExtent.height = wd->Height = cap.currentExtent.height;
        }
        err = vkCreateSwapchainKHR(device, &info, allocator, &wd->Swapchain);
        check_vk_result(err);
        err = vkGetSwapchainImagesKHR(device, wd->Swapchain, &wd->ImageCount, nullptr);
        check_vk_result(err);
        VkImage backbuffers[16] = {};
        IM_ASSERT(wd->ImageCount >= min_image_count);
        IM_ASSERT(wd->ImageCount < IM_ARRAYSIZE(backbuffers));
        err = vkGetSwapchainImagesKHR(device, wd->Swapchain, &wd->ImageCount, backbuffers);
        check_vk_result(err);

        wd->SemaphoreCount = wd->ImageCount + 1;
        wd->Frames.resize(wd->ImageCount);
        wd->FrameSemaphores.resize(wd->SemaphoreCount);
        memset(wd->Frames.Data, 0, wd->Frames.size_in_bytes());
        memset(wd->FrameSemaphores.Data, 0, wd->FrameSemaphores.size_in_bytes());
        for (uint32_t i = 0; i < wd->ImageCount; i++)
            wd->Frames[i].Backbuffer = backbuffers[i];
    }
    if (old_swapchain)
        vkDestroySwapchainKHR(device, old_swapchain, allocator);

    // Create the Render Pass
    if (wd->UseDynamicRendering == false)
    {
        VkAttachmentDescription attachment = {};
        attachment.format = wd->SurfaceFormat.format;
        attachment.samples = VK_SAMPLE_COUNT_1_BIT;
        attachment.loadOp = wd->ClearEnable ? VK_ATTACHMENT_LOAD_OP_CLEAR : VK_ATTACHMENT_LOAD_OP_DONT_CARE;
        attachment.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
        attachment.stencilLoadOp = VK_ATTACHMENT_LOAD_OP_DONT_CARE;
        attachment.stencilStoreOp = VK_ATTACHMENT_STORE_OP_DONT_CARE;
        attachment.initialLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        attachment.finalLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
        VkAttachmentReference color_attachment = {};
        color_attachment.attachment = 0;
        color_attachment.layout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
        VkSubpassDescription subpass = {};
        subpass.pipelineBindPoint = VK_PIPELINE_BIND_POINT_GRAPHICS;
        subpass.colorAttachmentCount = 1;
        subpass.pColorAttachments = &color_attachment;
        VkSubpassDependency dependency = {};
        dependency.srcSubpass = VK_SUBPASS_EXTERNAL;
        dependency.dstSubpass = 0;
        dependency.srcStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
        dependency.dstStageMask = VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT;
        dependency.srcAccessMask = 0;
        dependency.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
        VkRenderPassCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO;
        info.attachmentCount = 1;
        info.pAttachments = &attachment;
        info.subpassCount = 1;
        info.pSubpasses = &subpass;
        info.dependencyCount = 1;
        info.pDependencies = &dependency;
        err = vkCreateRenderPass(device, &info, allocator, &wd->RenderPass);
        check_vk_result(err);

        // We do not create a pipeline by default as this is also used by examples' main.cpp,
        // but secondary viewport in multi-viewport mode may want to create one with:
        //ImGui_ImplVulkan_CreatePipeline(device, allocator, VK_NULL_HANDLE, wd->RenderPass, VK_SAMPLE_COUNT_1_BIT, &wd->Pipeline, v->Subpass);
    }

    // Create The Image Views
    {
        VkImageViewCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO;
        info.viewType = VK_IMAGE_VIEW_TYPE_2D;
        info.format = wd->SurfaceFormat.format;
        info.components.r = VK_COMPONENT_SWIZZLE_R;
        info.components.g = VK_COMPONENT_SWIZZLE_G;
        info.components.b = VK_COMPONENT_SWIZZLE_B;
        info.components.a = VK_COMPONENT_SWIZZLE_A;
        VkImageSubresourceRange image_range = { VK_IMAGE_ASPECT_COLOR_BIT, 0, 1, 0, 1 };
        info.subresourceRange = image_range;
        for (uint32_t i = 0; i < wd->ImageCount; i++)
        {
            ImGui_ImplVulkanH_Frame* fd = &wd->Frames[i];
            info.image = fd->Backbuffer;
            err = vkCreateImageView(device, &info, allocator, &fd->BackbufferView);
            check_vk_result(err);
        }
    }

    // Create Framebuffer
    if (wd->UseDynamicRendering == false)
    {
        VkImageView attachment[1];
        VkFramebufferCreateInfo info = {};
        info.sType = VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO;
        info.renderPass = wd->RenderPass;
        info.attachmentCount = 1;
        info.pAttachments = attachment;
        info.width = wd->Width;
        info.height = wd->Height;
        info.layers = 1;
        for (uint32_t i = 0; i < wd->ImageCount; i++)
        {
            ImGui_ImplVulkanH_Frame* fd = &wd->Frames[i];
            attachment[0] = fd->BackbufferView;
            err = vkCreateFramebuffer(device, &info, allocator, &fd->Framebuffer);
            check_vk_result(err);
        }
    }
}

// Create or resize window
void ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int width, int height, uint32_t min_image_count)
{
    IM_ASSERT(g_FunctionsLoaded && "Need to call ImGui_ImplVulkan_LoadFunctions() if IMGUI_IMPL_VULKAN_NO_PROTOTYPES or VK_NO_PROTOTYPES are set!");
    (void)instance;
    ImGui_ImplVulkanH_CreateWindowSwapChain(physical_device, device, wd, allocator, width, height, min_image_count);
    //ImGui_ImplVulkan_CreatePipeline(device, allocator, VK_NULL_HANDLE, wd->RenderPass, VK_SAMPLE_COUNT_1_BIT, &wd->Pipeline, g_VulkanInitInfo.Subpass);
    ImGui_ImplVulkanH_CreateWindowCommandBuffers(physical_device, device, wd, queue_family, allocator);

    // FIXME: to submit the command buffer, we need a queue. In the examples folder, the ImGui_ImplVulkanH_CreateOrResizeWindow function is called
    // before the ImGui_ImplVulkan_Init function, so we don't have access to the queue yet. Here we have the queue_family that we can use to grab
    // a queue from the device and submit the command buffer. It would be better to have access to the queue as suggested in the FIXME below.
    VkCommandPool command_pool;
    VkCommandPoolCreateInfo pool_info = {};
    pool_info.sType = VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO;
    pool_info.queueFamilyIndex = queue_family;
    pool_info.flags = VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT;
    VkResult err = vkCreateCommandPool(device, &pool_info, allocator, &command_pool);
    check_vk_result(err);

    VkFenceCreateInfo fence_info = {};
    fence_info.sType = VK_STRUCTURE_TYPE_FENCE_CREATE_INFO;
    VkFence fence;
    err = vkCreateFence(device, &fence_info, allocator, &fence);
    check_vk_result(err);

    VkCommandBufferAllocateInfo alloc_info = {};
    alloc_info.sType = VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO;
    alloc_info.commandPool = command_pool;
    alloc_info.level = VK_COMMAND_BUFFER_LEVEL_PRIMARY;
    alloc_info.commandBufferCount = 1;
    VkCommandBuffer command_buffer;
    err = vkAllocateCommandBuffers(device, &alloc_info, &command_buffer);
    check_vk_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);
    check_vk_result(err);

    // Transition the images to the correct layout for rendering
    for (uint32_t i = 0; i < wd->ImageCount; i++)
    {
        VkImageMemoryBarrier barrier = {};
        barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
        barrier.image = wd->Frames[i].Backbuffer;
        barrier.oldLayout = VK_IMAGE_LAYOUT_UNDEFINED;
        barrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
        barrier.srcQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        barrier.dstQueueFamilyIndex = VK_QUEUE_FAMILY_IGNORED;
        barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
        barrier.subresourceRange.levelCount = 1;
        barrier.subresourceRange.layerCount = 1;
        vkCmdPipelineBarrier(command_buffer, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
    }

    err = vkEndCommandBuffer(command_buffer);
    check_vk_result(err);
    VkSubmitInfo submit_info = {};
    submit_info.sType = VK_STRUCTURE_TYPE_SUBMIT_INFO;
    submit_info.commandBufferCount = 1;
    submit_info.pCommandBuffers = &command_buffer;

    VkQueue queue;
    vkGetDeviceQueue(device, queue_family, 0, &queue);
    err = vkQueueSubmit(queue, 1, &submit_info, fence);
    check_vk_result(err);
    err = vkWaitForFences(device, 1, &fence, VK_TRUE, UINT64_MAX);
    check_vk_result(err);
    err = vkResetFences(device, 1, &fence);
    check_vk_result(err);

    err = vkResetCommandPool(device, command_pool, 0);
    check_vk_result(err);

    // Destroy command buffer and fence and command pool
    vkFreeCommandBuffers(device, command_pool, 1, &command_buffer);
    vkDestroyCommandPool(device, command_pool, allocator);
    vkDestroyFence(device, fence, allocator);
    command_pool = VK_NULL_HANDLE;
    command_buffer = VK_NULL_HANDLE;
    fence = VK_NULL_HANDLE;
    queue = VK_NULL_HANDLE;
}

void ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wd, const VkAllocationCallbacks* allocator)
{
    vkDeviceWaitIdle(device); // FIXME: We could wait on the Queue if we had the queue in wd-> (otherwise VulkanH functions can't use globals)
    //vkQueueWaitIdle(bd->Queue);

    for (uint32_t i = 0; i < wd->ImageCount; i++)
        ImGui_ImplVulkanH_DestroyFrame(device, &wd->Frames[i], allocator);
    for (uint32_t i = 0; i < wd->SemaphoreCount; i++)
        ImGui_ImplVulkanH_DestroyFrameSemaphores(device, &wd->FrameSemaphores[i], allocator);
    wd->Frames.clear();
    wd->FrameSemaphores.clear();
    vkDestroyRenderPass(device, wd->RenderPass, allocator);
    vkDestroySwapchainKHR(device, wd->Swapchain, allocator);
    vkDestroySurfaceKHR(instance, wd->Surface, allocator);

    *wd = ImGui_ImplVulkanH_Window();
}

void ImGui_ImplVulkanH_DestroyFrame(VkDevice device, ImGui_ImplVulkanH_Frame* fd, const VkAllocationCallbacks* allocator)
{
    vkDestroyFence(device, fd->Fence, allocator);
    vkFreeCommandBuffers(device, fd->CommandPool, 1, &fd->CommandBuffer);
    vkDestroyCommandPool(device, fd->CommandPool, allocator);
    fd->Fence = VK_NULL_HANDLE;
    fd->CommandBuffer = VK_NULL_HANDLE;
    fd->CommandPool = VK_NULL_HANDLE;

    vkDestroyImageView(device, fd->BackbufferView, allocator);
    vkDestroyFramebuffer(device, fd->Framebuffer, allocator);
}

void ImGui_ImplVulkanH_DestroyFrameSemaphores(VkDevice device, ImGui_ImplVulkanH_FrameSemaphores* fsd, const VkAllocationCallbacks* allocator)
{
    vkDestroySemaphore(device, fsd->ImageAcquiredSemaphore, allocator);
    vkDestroySemaphore(device, fsd->RenderCompleteSemaphore, allocator);
    fsd->ImageAcquiredSemaphore = fsd->RenderCompleteSemaphore = VK_NULL_HANDLE;
}

void ImGui_ImplVulkanH_DestroyAllViewportsRenderBuffers(VkDevice device, const VkAllocationCallbacks* allocator)
{
    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
    for (int n = 0; n < platform_io.Viewports.Size; n++)
        if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)platform_io.Viewports[n]->RendererUserData)
            ImGui_ImplVulkan_DestroyWindowRenderBuffers(device, &vd->RenderBuffers, allocator);
}

//--------------------------------------------------------------------------------------------------------
// MULTI-VIEWPORT / PLATFORM INTERFACE SUPPORT
// This is an _advanced_ and _optional_ feature, allowing the backend to create and handle multiple viewports simultaneously.
// If you are new to dear imgui or creating a new binding for dear imgui, it is recommended that you completely ignore this section first..
//--------------------------------------------------------------------------------------------------------

static void ImGui_ImplVulkan_CreateWindow(ImGuiViewport* viewport)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_ViewportData* vd = IM_NEW(ImGui_ImplVulkan_ViewportData)();
    viewport->RendererUserData = vd;
    ImGui_ImplVulkanH_Window* wd = &vd->Window;
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;

    // Create surface
    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
    VkResult err = (VkResult)platform_io.Platform_CreateVkSurface(viewport, (ImU64)v->Instance, (const void*)v->Allocator, (ImU64*)&wd->Surface);
    check_vk_result(err);

    // Check for WSI support
    VkBool32 res;
    vkGetPhysicalDeviceSurfaceSupportKHR(v->PhysicalDevice, v->QueueFamily, wd->Surface, &res);
    if (res != VK_TRUE)
    {
        IM_ASSERT(0); // Error: no WSI support on physical device
        return;
    }

    // Select Surface Format
    ImVector<VkFormat> requestSurfaceImageFormats;
#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
    for (uint32_t n = 0; n < v->PipelineRenderingCreateInfo.colorAttachmentCount; n++)
        requestSurfaceImageFormats.push_back(v->PipelineRenderingCreateInfo.pColorAttachmentFormats[n]);
#endif
    const VkFormat defaultFormats[] = { VK_FORMAT_B8G8R8A8_UNORM, VK_FORMAT_R8G8B8A8_UNORM, VK_FORMAT_B8G8R8_UNORM, VK_FORMAT_R8G8B8_UNORM };
    for (VkFormat format : defaultFormats)
        requestSurfaceImageFormats.push_back(format);

    const VkColorSpaceKHR requestSurfaceColorSpace = VK_COLORSPACE_SRGB_NONLINEAR_KHR;
    wd->SurfaceFormat = ImGui_ImplVulkanH_SelectSurfaceFormat(v->PhysicalDevice, wd->Surface, requestSurfaceImageFormats.Data, (size_t)requestSurfaceImageFormats.Size, requestSurfaceColorSpace);

    // Select Present Mode
    // FIXME-VULKAN: Even thought mailbox seems to get us maximum framerate with a single window, it halves framerate with a second window etc. (w/ Nvidia and SDK 1.82.1)
    VkPresentModeKHR present_modes[] = { VK_PRESENT_MODE_MAILBOX_KHR, VK_PRESENT_MODE_IMMEDIATE_KHR, VK_PRESENT_MODE_FIFO_KHR };
    wd->PresentMode = ImGui_ImplVulkanH_SelectPresentMode(v->PhysicalDevice, wd->Surface, &present_modes[0], IM_ARRAYSIZE(present_modes));
    //printf("[vulkan] Secondary window selected PresentMode = %d\n", wd->PresentMode);

    // Create SwapChain, RenderPass, Framebuffer, etc.
    wd->ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
    wd->UseDynamicRendering = v->UseDynamicRendering;
    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
    vd->WindowOwned = true;

    // Create pipeline (shared by all secondary viewports)
    if (bd->PipelineForViewports == VK_NULL_HANDLE)
        ImGui_ImplVulkan_CreatePipeline(v->Device, v->Allocator, VK_NULL_HANDLE, wd->RenderPass, VK_SAMPLE_COUNT_1_BIT, &bd->PipelineForViewports, 0);
}

static void ImGui_ImplVulkan_DestroyWindow(ImGuiViewport* viewport)
{
    // The main viewport (owned by the application) will always have RendererUserData == 0 since we didn't create the data for it.
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    if (ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData)
    {
        ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
        if (vd->WindowOwned)
            ImGui_ImplVulkanH_DestroyWindow(v->Instance, v->Device, &vd->Window, v->Allocator);
        ImGui_ImplVulkan_DestroyWindowRenderBuffers(v->Device, &vd->RenderBuffers, v->Allocator);
        IM_DELETE(vd);
    }
    viewport->RendererUserData = nullptr;
}

static void ImGui_ImplVulkan_SetWindowSize(ImGuiViewport* viewport, ImVec2 size)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
    if (vd == nullptr) // This is nullptr for the main viewport (which is left to the user/app to handle)
        return;
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    vd->Window.ClearEnable = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? false : true;
    ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, &vd->Window, v->QueueFamily, v->Allocator, (int)size.x, (int)size.y, v->MinImageCount);
}

static void ImGui_ImplVulkan_RenderWindow(ImGuiViewport* viewport, void*)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
    ImGui_ImplVulkanH_Window* wd = &vd->Window;
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;
    VkResult err;

    if (vd->SwapChainNeedRebuild || vd->SwapChainSuboptimal)
    {
        ImGui_ImplVulkanH_CreateOrResizeWindow(v->Instance, v->PhysicalDevice, v->Device, wd, v->QueueFamily, v->Allocator, (int)viewport->Size.x, (int)viewport->Size.y, v->MinImageCount);
        vd->SwapChainNeedRebuild = vd->SwapChainSuboptimal = false;
    }

    ImGui_ImplVulkanH_Frame* fd = nullptr;
    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
    {
        {
            err = vkAcquireNextImageKHR(v->Device, wd->Swapchain, UINT64_MAX, fsd->ImageAcquiredSemaphore, VK_NULL_HANDLE, &wd->FrameIndex);
            if (err == VK_ERROR_OUT_OF_DATE_KHR)
            {
                vd->SwapChainNeedRebuild = true; // Since we are not going to swap this frame anyway, it's ok that recreation happens on next frame.
                return;
            }
            if (err == VK_SUBOPTIMAL_KHR)
                vd->SwapChainSuboptimal = true;
            else
                check_vk_result(err);
            fd = &wd->Frames[wd->FrameIndex];
        }
        for (;;)
        {
            err = vkWaitForFences(v->Device, 1, &fd->Fence, VK_TRUE, 100);
            if (err == VK_SUCCESS) break;
            if (err == VK_TIMEOUT) continue;
            check_vk_result(err);
        }
        {
            err = vkResetCommandPool(v->Device, fd->CommandPool, 0);
            check_vk_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);
            check_vk_result(err);
        }
        {
            ImVec4 clear_color = ImVec4(0.0f, 0.0f, 0.0f, 1.0f);
            memcpy(&wd->ClearValue.color.float32[0], &clear_color, 4 * sizeof(float));
        }
#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
        if (v->UseDynamicRendering)
        {
            // Transition swapchain image to a layout suitable for drawing.
            VkImageMemoryBarrier barrier = {};
            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
            barrier.dstAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
            barrier.oldLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
            barrier.newLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
            barrier.image = fd->Backbuffer;
            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            barrier.subresourceRange.levelCount = 1;
            barrier.subresourceRange.layerCount = 1;
            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT | VK_PIPELINE_STAGE_NONE, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);

            VkRenderingAttachmentInfo attachmentInfo = {};
            attachmentInfo.sType = VK_STRUCTURE_TYPE_RENDERING_ATTACHMENT_INFO_KHR;
            attachmentInfo.imageView = fd->BackbufferView;
            attachmentInfo.imageLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
            attachmentInfo.resolveMode = VK_RESOLVE_MODE_NONE;
            attachmentInfo.loadOp = VK_ATTACHMENT_LOAD_OP_CLEAR;
            attachmentInfo.storeOp = VK_ATTACHMENT_STORE_OP_STORE;
            attachmentInfo.clearValue = wd->ClearValue;

            VkRenderingInfo renderingInfo = {};
            renderingInfo.sType = VK_STRUCTURE_TYPE_RENDERING_INFO_KHR;
            renderingInfo.renderArea.extent.width = wd->Width;
            renderingInfo.renderArea.extent.height = wd->Height;
            renderingInfo.layerCount = 1;
            renderingInfo.viewMask = 0;
            renderingInfo.colorAttachmentCount = 1;
            renderingInfo.pColorAttachments = &attachmentInfo;

            ImGuiImplVulkanFuncs_vkCmdBeginRenderingKHR(fd->CommandBuffer, &renderingInfo);
        }
        else
#endif
        {
            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 = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? 0 : 1;
            info.pClearValues = (viewport->Flags & ImGuiViewportFlags_NoRendererClear) ? nullptr : &wd->ClearValue;
            vkCmdBeginRenderPass(fd->CommandBuffer, &info, VK_SUBPASS_CONTENTS_INLINE);
        }
    }

    ImGui_ImplVulkan_RenderDrawData(viewport->DrawData, fd->CommandBuffer, bd->PipelineForViewports);

    {
#ifdef IMGUI_IMPL_VULKAN_HAS_DYNAMIC_RENDERING
        if (v->UseDynamicRendering)
        {
            ImGuiImplVulkanFuncs_vkCmdEndRenderingKHR(fd->CommandBuffer);

            // Transition image to a layout suitable for presentation
            VkImageMemoryBarrier barrier = {};
            barrier.sType = VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER;
            barrier.srcAccessMask = VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT;
            barrier.oldLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
            barrier.newLayout = VK_IMAGE_LAYOUT_PRESENT_SRC_KHR;
            barrier.image = fd->Backbuffer;
            barrier.subresourceRange.aspectMask = VK_IMAGE_ASPECT_COLOR_BIT;
            barrier.subresourceRange.levelCount = 1;
            barrier.subresourceRange.layerCount = 1;
            vkCmdPipelineBarrier(fd->CommandBuffer, VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT, VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT, 0, 0, nullptr, 0, nullptr, 1, &barrier);
        }
        else
#endif
        {
            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 = &fsd->ImageAcquiredSemaphore;
            info.pWaitDstStageMask = &wait_stage;
            info.commandBufferCount = 1;
            info.pCommandBuffers = &fd->CommandBuffer;
            info.signalSemaphoreCount = 1;
            info.pSignalSemaphores = &fsd->RenderCompleteSemaphore;

            err = vkEndCommandBuffer(fd->CommandBuffer);
            check_vk_result(err);
            err = vkResetFences(v->Device, 1, &fd->Fence);
            check_vk_result(err);
            err = vkQueueSubmit(v->Queue, 1, &info, fd->Fence);
            check_vk_result(err);
        }
    }
}

static void ImGui_ImplVulkan_SwapBuffers(ImGuiViewport* viewport, void*)
{
    ImGui_ImplVulkan_Data* bd = ImGui_ImplVulkan_GetBackendData();
    ImGui_ImplVulkan_ViewportData* vd = (ImGui_ImplVulkan_ViewportData*)viewport->RendererUserData;
    ImGui_ImplVulkanH_Window* wd = &vd->Window;
    ImGui_ImplVulkan_InitInfo* v = &bd->VulkanInitInfo;

    if (vd->SwapChainNeedRebuild) // Frame data became invalid in the middle of rendering
        return;

    VkResult err;
    uint32_t present_index = wd->FrameIndex;

    ImGui_ImplVulkanH_FrameSemaphores* fsd = &wd->FrameSemaphores[wd->SemaphoreIndex];
    VkPresentInfoKHR info = {};
    info.sType = VK_STRUCTURE_TYPE_PRESENT_INFO_KHR;
    info.waitSemaphoreCount = 1;
    info.pWaitSemaphores = &fsd->RenderCompleteSemaphore;
    info.swapchainCount = 1;
    info.pSwapchains = &wd->Swapchain;
    info.pImageIndices = &present_index;
    err = vkQueuePresentKHR(v->Queue, &info);
    if (err == VK_ERROR_OUT_OF_DATE_KHR)
    {
        vd->SwapChainNeedRebuild = true;
        return;
    }
    if (err == VK_SUBOPTIMAL_KHR)
        vd->SwapChainSuboptimal = true;
    else
        check_vk_result(err);
    wd->SemaphoreIndex = (wd->SemaphoreIndex + 1) % wd->SemaphoreCount; // Now we can use the next set of semaphores
}

void ImGui_ImplVulkan_InitMultiViewportSupport()
{
    ImGuiPlatformIO& platform_io = ImGui::GetPlatformIO();
    if (ImGui::GetIO().BackendFlags & ImGuiBackendFlags_PlatformHasViewports)
        IM_ASSERT(platform_io.Platform_CreateVkSurface != nullptr && "Platform needs to setup the CreateVkSurface handler.");
    platform_io.Renderer_CreateWindow = ImGui_ImplVulkan_CreateWindow;
    platform_io.Renderer_DestroyWindow = ImGui_ImplVulkan_DestroyWindow;
    platform_io.Renderer_SetWindowSize = ImGui_ImplVulkan_SetWindowSize;
    platform_io.Renderer_RenderWindow = ImGui_ImplVulkan_RenderWindow;
    platform_io.Renderer_SwapBuffers = ImGui_ImplVulkan_SwapBuffers;
}

void ImGui_ImplVulkan_ShutdownMultiViewportSupport()
{
    ImGui::DestroyPlatformWindows();
}

//-----------------------------------------------------------------------------

#endif // #ifndef IMGUI_DISABLE