struct ImGui_ImplVulkan_InitInfo
{
    VkInstance                      Instance;
    VkPhysicalDevice                PhysicalDevice;
    VkDevice                        Device;
    uint32_t                        QueueFamily;
    VkQueue                         Queue;
    VkPipelineCache                 PipelineCache;
    VkDescriptorPool                DescriptorPool;
    uint32_t                        Subpass;
    uint32_t                        MinImageCount;          // >= 2
    uint32_t                        ImageCount;             // >= MinImageCount
    VkSampleCountFlagBits           MSAASamples;            // >= VK_SAMPLE_COUNT_1_BIT (0 -> default to VK_SAMPLE_COUNT_1_BIT)
    const VkAllocationCallbacks*    Allocator;
    void                            (*CheckVkResultFn)(VkResult err);
};

// Called by user code
IMGUI_IMPL_API bool         ImGui_ImplVulkan_Init(ImGui_ImplVulkan_InitInfo* info, VkRenderPass render_pass);
IMGUI_IMPL_API void         ImGui_ImplVulkan_Shutdown();
IMGUI_IMPL_API void         ImGui_ImplVulkan_NewFrame();
IMGUI_IMPL_API void         ImGui_ImplVulkan_RenderDrawData(ImDrawData* draw_data, VkCommandBuffer command_buffer, VkPipeline pipeline = VK_NULL_HANDLE);
IMGUI_IMPL_API bool         ImGui_ImplVulkan_CreateFontsTexture(VkCommandBuffer command_buffer);
IMGUI_IMPL_API void         ImGui_ImplVulkan_DestroyFontUploadObjects();
IMGUI_IMPL_API void         ImGui_ImplVulkan_SetMinImageCount(uint32_t min_image_count); // To override MinImageCount after initialization (e.g. if swap chain is recreated)

// Register a texture (VkDescriptorSet == ImTextureID)
// 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.
IMGUI_IMPL_API VkDescriptorSet ImGui_ImplVulkan_AddTexture(VkSampler sampler, VkImageView image_view, VkImageLayout image_layout);

// Optional: load Vulkan functions with a custom function loader
// This is only useful with IMGUI_IMPL_VULKAN_NO_PROTOTYPES / VK_NO_PROTOTYPES
IMGUI_IMPL_API bool         ImGui_ImplVulkan_LoadFunctions(PFN_vkVoidFunction(*loader_func)(const char* function_name, void* user_data), void* user_data = NULL);

//-------------------------------------------------------------------------
// Internal / Miscellaneous Vulkan Helpers
// (Used by example's main.cpp. Used by multi-viewport features. PROBABLY NOT used by your own engine/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 multi-viewport / platform window implementation needs them internally.
// Generally we avoid exposing any kind of superfluous high-level helpers in the bindings,
// 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)
//-------------------------------------------------------------------------

struct ImGui_ImplVulkanH_Frame;
struct ImGui_ImplVulkanH_Window;

// Helpers
IMGUI_IMPL_API void                 ImGui_ImplVulkanH_CreateOrResizeWindow(VkInstance instance, VkPhysicalDevice physical_device, VkDevice device, ImGui_ImplVulkanH_Window* wnd, uint32_t queue_family, const VkAllocationCallbacks* allocator, int w, int h, uint32_t min_image_count);
IMGUI_IMPL_API void                 ImGui_ImplVulkanH_DestroyWindow(VkInstance instance, VkDevice device, ImGui_ImplVulkanH_Window* wnd, const VkAllocationCallbacks* allocator);
IMGUI_IMPL_API VkSurfaceFormatKHR   ImGui_ImplVulkanH_SelectSurfaceFormat(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkFormat* request_formats, int request_formats_count, VkColorSpaceKHR request_color_space);
IMGUI_IMPL_API VkPresentModeKHR     ImGui_ImplVulkanH_SelectPresentMode(VkPhysicalDevice physical_device, VkSurfaceKHR surface, const VkPresentModeKHR* request_modes, int request_modes_count);
IMGUI_IMPL_API int                  ImGui_ImplVulkanH_GetMinImageCountFromPresentMode(VkPresentModeKHR present_mode);

// Helper structure to hold the data needed by one rendering frame
// (Used by example's main.cpp. Used by multi-viewport features. Probably NOT used by your own engine/app.)
// [Please zero-clear before use!]
struct ImGui_ImplVulkanH_Frame
{
    VkCommandPool       CommandPool;
    VkCommandBuffer     CommandBuffer;
    VkFence             Fence;
    VkImage             Backbuffer;
    VkImageView         BackbufferView;
    VkFramebuffer       Framebuffer;
};

struct ImGui_ImplVulkanH_FrameSemaphores
{
    VkSemaphore         ImageAcquiredSemaphore;
    VkSemaphore         RenderCompleteSemaphore;
};

// Helper structure to hold the data needed by one rendering context into one OS window
// (Used by example's main.cpp. Used by multi-viewport features. Probably NOT used by your own engine/app.)
struct ImGui_ImplVulkanH_Window
{
    int                 Width;
    int                 Height;
    VkSwapchainKHR      Swapchain;
    VkSurfaceKHR        Surface;
    VkSurfaceFormatKHR  SurfaceFormat;
    VkPresentModeKHR    PresentMode;
    VkRenderPass        RenderPass;
    VkPipeline          Pipeline;               // The window pipeline may uses a different VkRenderPass than the one passed in ImGui_ImplVulkan_InitInfo
    bool                ClearEnable;
    VkClearValue        ClearValue;
    uint32_t            FrameIndex;             // Current frame being rendered to (0 <= FrameIndex < FrameInFlightCount)
    uint32_t            ImageCount;             // Number of simultaneous in-flight frames (returned by vkGetSwapchainImagesKHR, usually derived from min_image_count)
    uint32_t            SemaphoreIndex;         // Current set of swapchain wait semaphores we're using (needs to be distinct from per frame data)
    ImGui_ImplVulkanH_Frame*            Frames;
    ImGui_ImplVulkanH_FrameSemaphores*  FrameSemaphores;

    ImGui_ImplVulkanH_Window()
    {
        memset(this, 0, sizeof(*this));
        PresentMode = VK_PRESENT_MODE_MAX_ENUM_KHR;
        ClearEnable = true;
    }
};

