#[macro_use]
extern crate ash;
#[cfg(target_os = "windows")]
extern crate winapi;
extern crate winit;

#[cfg(target_os = "macos")]
extern crate cocoa;
#[cfg(target_os = "macos")]
extern crate metal_rs as metal;
#[cfg(target_os = "macos")]
extern crate objc;
#[cfg(target_os = "macos")]
use cocoa::appkit::{NSView, NSWindow};
#[cfg(target_os = "macos")]
use cocoa::base::id as cocoa_id;
#[cfg(target_os = "macos")]
use metal::CoreAnimationLayer;
#[cfg(target_os = "macos")]
use objc::runtime::YES;
#[cfg(target_os = "macos")]
use std::mem;

#[cfg(target_os = "macos")]
use ash::extensions::MacOSSurface;
#[cfg(target_os = "windows")]
use ash::extensions::Win32Surface;
#[cfg(all(unix, not(target_os = "android"), not(target_os = "macos")))]
use ash::extensions::XlibSurface;
use ash::extensions::{DebugReport, Surface, Swapchain};
pub use ash::version::{DeviceV1_0, EntryV1_0, InstanceV1_0};
use ash::vk;
use ash::Device;
use ash::Entry;
use ash::Instance;
use std::cell::RefCell;
use std::default::Default;
use std::ffi::{CStr, CString};
use std::ops::Drop;
use std::os::raw::{c_char, c_void};
use std::ptr;

// Simple offset_of macro akin to C++ offsetof
#[macro_export]
macro_rules! offset_of {
    ($base:path, $field:ident) => {{
        #[allow(unused_unsafe)]
        unsafe {
            let b: $base = mem::uninitialized();
            (&b.$field as *const _ as isize) - (&b as *const _ as isize)
        }
    }};
}

pub fn record_submit_commandbuffer<D: DeviceV1_0, F: FnOnce(&D, vk::CommandBuffer)>(
    device: &D,
    command_buffer: vk::CommandBuffer,
    submit_queue: vk::Queue,
    wait_mask: &[vk::PipelineStageFlags],
    wait_semaphores: &[vk::Semaphore],
    signal_semaphores: &[vk::Semaphore],
    f: F,
) {
    unsafe {
        device
            .reset_command_buffer(
                command_buffer,
                vk::CommandBufferResetFlags::RELEASE_RESOURCES,
            ).expect("Reset command buffer failed.");
        let command_buffer_begin_info = vk::CommandBufferBeginInfo {
            s_type: vk::StructureType::COMMAND_BUFFER_BEGIN_INFO,
            p_next: ptr::null(),
            p_inheritance_info: ptr::null(),
            flags: vk::CommandBufferUsageFlags::ONE_TIME_SUBMIT,
        };
        device
            .begin_command_buffer(command_buffer, &command_buffer_begin_info)
            .expect("Begin commandbuffer");
        f(device, command_buffer);
        device
            .end_command_buffer(command_buffer)
            .expect("End commandbuffer");
        let fence_create_info = vk::FenceCreateInfo {
            s_type: vk::StructureType::FENCE_CREATE_INFO,
            p_next: ptr::null(),
            flags: vk::FenceCreateFlags::empty(),
        };
        let submit_fence = device
            .create_fence(&fence_create_info, None)
            .expect("Create fence failed.");
        let submit_info = vk::SubmitInfo {
            s_type: vk::StructureType::SUBMIT_INFO,
            p_next: ptr::null(),
            wait_semaphore_count: wait_semaphores.len() as u32,
            p_wait_semaphores: wait_semaphores.as_ptr(),
            p_wait_dst_stage_mask: wait_mask.as_ptr(),
            command_buffer_count: 1,
            p_command_buffers: &command_buffer,
            signal_semaphore_count: signal_semaphores.len() as u32,
            p_signal_semaphores: signal_semaphores.as_ptr(),
        };
        device
            .queue_submit(submit_queue, &[submit_info], submit_fence)
            .expect("queue submit failed.");
        device
            .wait_for_fences(&[submit_fence], true, std::u64::MAX)
            .expect("Wait for fence failed.");
        device.destroy_fence(submit_fence, None);
    }
}

#[cfg(all(unix, not(target_os = "android"), not(target_os = "macos")))]
unsafe fn create_surface<E: EntryV1_0, I: InstanceV1_0>(
    entry: &E,
    instance: &I,
    window: &winit::Window,
) -> Result<vk::SurfaceKHR, vk::Result> {
    use winit::os::unix::WindowExt;
    let x11_display = window.get_xlib_display().unwrap();
    let x11_window = window.get_xlib_window().unwrap();
    let x11_create_info = vk::XlibSurfaceCreateInfoKHR {
        s_type: vk::StructureType::XLIB_SURFACE_CREATE_INFO_KHR,
        p_next: ptr::null(),
        flags: Default::default(),
        window: x11_window as vk::Window,
        dpy: x11_display as *mut vk::Display,
    };
    let xlib_surface_loader = XlibSurface::new(entry, instance);
    xlib_surface_loader.create_xlib_surface_khr(&x11_create_info, None)
}

#[cfg(target_os = "macos")]
unsafe fn create_surface<E: EntryV1_0, I: InstanceV1_0>(
    entry: &E,
    instance: &I,
    window: &winit::Window,
) -> Result<vk::SurfaceKHR, vk::Result> {
    use winit::os::macos::WindowExt;

    let wnd: cocoa_id = mem::transmute(window.get_nswindow());

    let layer = CoreAnimationLayer::new();

    layer.set_edge_antialiasing_mask(0);
    layer.set_presents_with_transaction(false);
    layer.remove_all_animations();

    let view = wnd.contentView();

    layer.set_contents_scale(view.backingScaleFactor());
    view.setLayer(mem::transmute(layer.as_ref()));
    view.setWantsLayer(YES);

    let create_info = vk::MacOSSurfaceCreateInfoMVK {
        s_type: vk::StructureType::MACOS_SURFACE_CREATE_INFO_M,
        p_next: ptr::null(),
        flags: Default::default(),
        p_view: window.get_nsview() as *const c_void,
    };

    let macos_surface_loader = MacOSSurface::new(entry, instance);
    macos_surface_loader.create_mac_os_surface_mvk(&create_info, None)
}

#[cfg(target_os = "windows")]
unsafe fn create_surface<E: EntryV1_0, I: InstanceV1_0>(
    entry: &E,
    instance: &I,
    window: &winit::Window,
) -> Result<vk::SurfaceKHR, vk::Result> {
    use winapi::shared::windef::HWND;
    use winapi::um::libloaderapi::GetModuleHandleW;
    use winit::os::windows::WindowExt;

    let hwnd = window.get_hwnd() as HWND;
    let hinstance = GetModuleHandleW(ptr::null()) as *const c_void;
    let win32_create_info = vk::Win32SurfaceCreateInfoKHR {
        s_type: vk::StructureType::WIN32_SURFACE_CREATE_INFO_KHR,
        p_next: ptr::null(),
        flags: Default::default(),
        hinstance: hinstance,
        hwnd: hwnd as *const c_void,
    };
    let win32_surface_loader = Win32Surface::new(entry, instance);
    win32_surface_loader.create_win32_surface_khr(&win32_create_info, None)
}

#[cfg(all(unix, not(target_os = "android"), not(target_os = "macos")))]
fn extension_names() -> Vec<*const i8> {
    vec![
        Surface::name().as_ptr(),
        XlibSurface::name().as_ptr(),
        DebugReport::name().as_ptr(),
    ]
}

#[cfg(target_os = "macos")]
fn extension_names() -> Vec<*const i8> {
    vec![
        Surface::name().as_ptr(),
        MacOSSurface::name().as_ptr(),
        DebugReport::name().as_ptr(),
    ]
}

#[cfg(all(windows))]
fn extension_names() -> Vec<*const i8> {
    vec![
        Surface::name().as_ptr(),
        Win32Surface::name().as_ptr(),
        DebugReport::name().as_ptr(),
    ]
}

unsafe extern "system" fn vulkan_debug_callback(
    _: vk::DebugReportFlagsEXT,
    _: vk::DebugReportObjectTypeEXT,
    _: u64,
    _: usize,
    _: i32,
    _: *const c_char,
    p_message: *const c_char,
    _: *mut c_void,
) -> u32 {
    println!("{:?}", CStr::from_ptr(p_message));
    vk::FALSE
}

pub fn find_memorytype_index(
    memory_req: &vk::MemoryRequirements,
    memory_prop: &vk::PhysicalDeviceMemoryProperties,
    flags: vk::MemoryPropertyFlags,
) -> Option<u32> {
    // Try to find an exactly matching memory flag
    let best_suitable_index =
        find_memorytype_index_f(memory_req, memory_prop, flags, |property_flags, flags| {
            property_flags == flags
        });
    if best_suitable_index.is_some() {
        return best_suitable_index;
    }
    // Otherwise find a memory flag that works
    find_memorytype_index_f(memory_req, memory_prop, flags, |property_flags, flags| {
        property_flags & flags == flags
    })
}

pub fn find_memorytype_index_f<F: Fn(vk::MemoryPropertyFlags, vk::MemoryPropertyFlags) -> bool>(
    memory_req: &vk::MemoryRequirements,
    memory_prop: &vk::PhysicalDeviceMemoryProperties,
    flags: vk::MemoryPropertyFlags,
    f: F,
) -> Option<u32> {
    let mut memory_type_bits = memory_req.memory_type_bits;
    for (index, ref memory_type) in memory_prop.memory_types.iter().enumerate() {
        if memory_type_bits & 1 == 1 {
            if f(memory_type.property_flags, flags) {
                return Some(index as u32);
            }
        }
        memory_type_bits = memory_type_bits >> 1;
    }
    None
}

pub struct ExampleBase {
    pub entry: Entry,
    pub instance: Instance,
    pub device: Device,
    pub surface_loader: Surface,
    pub swapchain_loader: Swapchain,
    pub debug_report_loader: DebugReport,
    pub window: winit::Window,
    pub events_loop: RefCell<winit::EventsLoop>,
    pub debug_call_back: vk::DebugReportCallbackEXT,

    pub pdevice: vk::PhysicalDevice,
    pub device_memory_properties: vk::PhysicalDeviceMemoryProperties,
    pub queue_family_index: u32,
    pub present_queue: vk::Queue,

    pub surface: vk::SurfaceKHR,
    pub surface_format: vk::SurfaceFormatKHR,
    pub surface_resolution: vk::Extent2D,

    pub swapchain: vk::SwapchainKHR,
    pub present_images: Vec<vk::Image>,
    pub present_image_views: Vec<vk::ImageView>,

    pub pool: vk::CommandPool,
    pub draw_command_buffer: vk::CommandBuffer,
    pub setup_command_buffer: vk::CommandBuffer,

    pub depth_image: vk::Image,
    pub depth_image_view: vk::ImageView,
    pub depth_image_memory: vk::DeviceMemory,

    pub present_complete_semaphore: vk::Semaphore,
    pub rendering_complete_semaphore: vk::Semaphore,
}

impl ExampleBase {
    pub fn render_loop<F: Fn()>(&self, f: F) {
        use winit::*;
        self.events_loop.borrow_mut().run_forever(|event| {
            f();
            match event {
                Event::WindowEvent { event, .. } => match event {
                    WindowEvent::KeyboardInput { input, .. } => {
                        if let Some(VirtualKeyCode::Escape) = input.virtual_keycode {
                            ControlFlow::Break
                        } else {
                            ControlFlow::Continue
                        }
                    }
                    WindowEvent::CloseRequested => winit::ControlFlow::Break,
                    _ => ControlFlow::Continue,
                },
                _ => ControlFlow::Continue,
            }
        });
    }

    pub fn new(window_width: u32, window_height: u32) -> Self {
        unsafe {
            let events_loop = winit::EventsLoop::new();
            let window = winit::WindowBuilder::new()
                .with_title("Ash - Example")
                .with_dimensions(winit::dpi::LogicalSize::new(
                    window_width as f64,
                    window_height as f64,
                )).build(&events_loop)
                .unwrap();
            let entry = Entry::new().unwrap();
            let app_name = CString::new("VulkanTriangle").unwrap();
            let raw_name = app_name.as_ptr();

            let layer_names = [CString::new("VK_LAYER_LUNARG_standard_validation").unwrap()];
            let layers_names_raw: Vec<*const i8> = layer_names
                .iter()
                .map(|raw_name| raw_name.as_ptr())
                .collect();

            let extension_names_raw = extension_names();
            let appinfo = vk::ApplicationInfo {
                p_application_name: raw_name,
                s_type: vk::StructureType::APPLICATION_INFO,
                p_next: ptr::null(),
                application_version: 0,
                p_engine_name: raw_name,
                engine_version: 0,
                api_version: vk_make_version!(1, 0, 36),
            };
            let create_info = vk::InstanceCreateInfo {
                s_type: vk::StructureType::INSTANCE_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
                p_application_info: &appinfo,
                pp_enabled_layer_names: layers_names_raw.as_ptr(),
                enabled_layer_count: layers_names_raw.len() as u32,
                pp_enabled_extension_names: extension_names_raw.as_ptr(),
                enabled_extension_count: extension_names_raw.len() as u32,
            };
            let instance: Instance = entry
                .create_instance(&create_info, None)
                .expect("Instance creation error");
            let debug_info = vk::DebugReportCallbackCreateInfoEXT {
                s_type: vk::StructureType::DEBUG_REPORT_CALLBACK_CREATE_INFO_EXT,
                p_next: ptr::null(),
                flags: vk::DebugReportFlagsEXT::ERROR
                    | vk::DebugReportFlagsEXT::WARNING
                    | vk::DebugReportFlagsEXT::PERFORMANCE_WARNING,
                pfn_callback: Some(vulkan_debug_callback),
                p_user_data: ptr::null_mut(),
            };
            let debug_report_loader = DebugReport::new(&entry, &instance);
            let debug_call_back = debug_report_loader
                .create_debug_report_callback_ext(&debug_info, None)
                .unwrap();
            let surface = create_surface(&entry, &instance, &window).unwrap();
            let pdevices = instance
                .enumerate_physical_devices()
                .expect("Physical device error");
            let surface_loader = Surface::new(&entry, &instance);
            let (pdevice, queue_family_index) = pdevices
                .iter()
                .map(|pdevice| {
                    instance
                        .get_physical_device_queue_family_properties(*pdevice)
                        .iter()
                        .enumerate()
                        .filter_map(|(index, ref info)| {
                            let supports_graphic_and_surface =
                                info.queue_flags.contains(vk::QueueFlags::GRAPHICS)
                                    && surface_loader.get_physical_device_surface_support_khr(
                                        *pdevice,
                                        index as u32,
                                        surface,
                                    );
                            match supports_graphic_and_surface {
                                true => Some((*pdevice, index)),
                                _ => None,
                            }
                        }).nth(0)
                }).filter_map(|v| v)
                .nth(0)
                .expect("Couldn't find suitable device.");
            let queue_family_index = queue_family_index as u32;
            let device_extension_names_raw = [Swapchain::name().as_ptr()];
            let features = vk::PhysicalDeviceFeatures {
                shader_clip_distance: 1,
                ..Default::default()
            };
            let priorities = [1.0];
            let queue_info = vk::DeviceQueueCreateInfo {
                s_type: vk::StructureType::DEVICE_QUEUE_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
                queue_family_index: queue_family_index as u32,
                p_queue_priorities: priorities.as_ptr(),
                queue_count: priorities.len() as u32,
            };
            let device_create_info = vk::DeviceCreateInfo {
                s_type: vk::StructureType::DEVICE_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
                queue_create_info_count: 1,
                p_queue_create_infos: &queue_info,
                enabled_layer_count: 0,
                pp_enabled_layer_names: ptr::null(),
                enabled_extension_count: device_extension_names_raw.len() as u32,
                pp_enabled_extension_names: device_extension_names_raw.as_ptr(),
                p_enabled_features: &features,
            };
            let device: Device = instance
                .create_device(pdevice, &device_create_info, None)
                .unwrap();
            let present_queue = device.get_device_queue(queue_family_index as u32, 0);

            let surface_formats = surface_loader
                .get_physical_device_surface_formats_khr(pdevice, surface)
                .unwrap();
            let surface_format = surface_formats
                .iter()
                .map(|sfmt| match sfmt.format {
                    vk::Format::UNDEFINED => vk::SurfaceFormatKHR {
                        format: vk::Format::B8G8R8_UNORM,
                        color_space: sfmt.color_space,
                    },
                    _ => sfmt.clone(),
                }).nth(0)
                .expect("Unable to find suitable surface format.");
            let surface_capabilities = surface_loader
                .get_physical_device_surface_capabilities_khr(pdevice, surface)
                .unwrap();
            let mut desired_image_count = surface_capabilities.min_image_count + 1;
            if surface_capabilities.max_image_count > 0
                && desired_image_count > surface_capabilities.max_image_count
            {
                desired_image_count = surface_capabilities.max_image_count;
            }
            let surface_resolution = match surface_capabilities.current_extent.width {
                std::u32::MAX => vk::Extent2D {
                    width: window_width,
                    height: window_height,
                },
                _ => surface_capabilities.current_extent,
            };
            let pre_transform = if surface_capabilities
                .supported_transforms
                .contains(vk::SurfaceTransformFlagsKHR::IDENTITY)
            {
                vk::SurfaceTransformFlagsKHR::IDENTITY
            } else {
                surface_capabilities.current_transform
            };
            let present_modes = surface_loader
                .get_physical_device_surface_present_modes_khr(pdevice, surface)
                .unwrap();
            let present_mode = present_modes
                .iter()
                .cloned()
                .find(|&mode| mode == vk::PresentModeKHR::MAILBOX)
                .unwrap_or(vk::PresentModeKHR::FIFO);
            let swapchain_loader = Swapchain::new(&instance, &device);
            let swapchain_create_info = vk::SwapchainCreateInfoKHR {
                s_type: vk::StructureType::SWAPCHAIN_CREATE_INFO_KHR,
                p_next: ptr::null(),
                flags: Default::default(),
                surface: surface,
                min_image_count: desired_image_count,
                image_color_space: surface_format.color_space,
                image_format: surface_format.format,
                image_extent: surface_resolution.clone(),
                image_usage: vk::ImageUsageFlags::COLOR_ATTACHMENT,
                image_sharing_mode: vk::SharingMode::EXCLUSIVE,
                pre_transform: pre_transform,
                composite_alpha: vk::CompositeAlphaFlagsKHR::OPAQUE,
                present_mode: present_mode,
                clipped: 1,
                old_swapchain: vk::SwapchainKHR::null(),
                image_array_layers: 1,
                p_queue_family_indices: ptr::null(),
                queue_family_index_count: 0,
            };
            let swapchain = swapchain_loader
                .create_swapchain_khr(&swapchain_create_info, None)
                .unwrap();
            let pool_create_info = vk::CommandPoolCreateInfo {
                s_type: vk::StructureType::COMMAND_POOL_CREATE_INFO,
                p_next: ptr::null(),
                flags: vk::CommandPoolCreateFlags::RESET_COMMAND_BUFFER,
                queue_family_index: queue_family_index,
            };
            let pool = device.create_command_pool(&pool_create_info, None).unwrap();
            let command_buffer_allocate_info = vk::CommandBufferAllocateInfo {
                s_type: vk::StructureType::COMMAND_BUFFER_ALLOCATE_INFO,
                p_next: ptr::null(),
                command_buffer_count: 2,
                command_pool: pool,
                level: vk::CommandBufferLevel::PRIMARY,
            };
            let command_buffers = device
                .allocate_command_buffers(&command_buffer_allocate_info)
                .unwrap();
            let setup_command_buffer = command_buffers[0];
            let draw_command_buffer = command_buffers[1];

            let present_images = swapchain_loader
                .get_swapchain_images_khr(swapchain)
                .unwrap();
            let present_image_views: Vec<vk::ImageView> = present_images
                .iter()
                .map(|&image| {
                    let create_view_info = vk::ImageViewCreateInfo {
                        s_type: vk::StructureType::IMAGE_VIEW_CREATE_INFO,
                        p_next: ptr::null(),
                        flags: Default::default(),
                        view_type: vk::ImageViewType::TYPE_2D,
                        format: surface_format.format,
                        components: vk::ComponentMapping {
                            r: vk::ComponentSwizzle::R,
                            g: vk::ComponentSwizzle::G,
                            b: vk::ComponentSwizzle::B,
                            a: vk::ComponentSwizzle::A,
                        },
                        subresource_range: vk::ImageSubresourceRange {
                            aspect_mask: vk::ImageAspectFlags::COLOR,
                            base_mip_level: 0,
                            level_count: 1,
                            base_array_layer: 0,
                            layer_count: 1,
                        },
                        image: image,
                    };
                    device.create_image_view(&create_view_info, None).unwrap()
                }).collect();
            let device_memory_properties = instance.get_physical_device_memory_properties(pdevice);
            let depth_image_create_info = vk::ImageCreateInfo {
                s_type: vk::StructureType::IMAGE_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
                image_type: vk::ImageType::TYPE_2D,
                format: vk::Format::D16_UNORM,
                extent: vk::Extent3D {
                    width: surface_resolution.width,
                    height: surface_resolution.height,
                    depth: 1,
                },
                mip_levels: 1,
                array_layers: 1,
                samples: vk::SampleCountFlags::TYPE_1,
                tiling: vk::ImageTiling::OPTIMAL,
                usage: vk::ImageUsageFlags::DEPTH_STENCIL_ATTACHMENT,
                sharing_mode: vk::SharingMode::EXCLUSIVE,
                queue_family_index_count: 0,
                p_queue_family_indices: ptr::null(),
                initial_layout: vk::ImageLayout::UNDEFINED,
            };
            let depth_image = device.create_image(&depth_image_create_info, None).unwrap();
            let depth_image_memory_req = device.get_image_memory_requirements(depth_image);
            let depth_image_memory_index = find_memorytype_index(
                &depth_image_memory_req,
                &device_memory_properties,
                vk::MemoryPropertyFlags::DEVICE_LOCAL,
            ).expect("Unable to find suitable memory index for depth image.");

            let depth_image_allocate_info = vk::MemoryAllocateInfo {
                s_type: vk::StructureType::MEMORY_ALLOCATE_INFO,
                p_next: ptr::null(),
                allocation_size: depth_image_memory_req.size,
                memory_type_index: depth_image_memory_index,
            };
            let depth_image_memory = device
                .allocate_memory(&depth_image_allocate_info, None)
                .unwrap();
            device
                .bind_image_memory(depth_image, depth_image_memory, 0)
                .expect("Unable to bind depth image memory");
            record_submit_commandbuffer(
                &device,
                setup_command_buffer,
                present_queue,
                &[vk::PipelineStageFlags::BOTTOM_OF_PIPE],
                &[],
                &[],
                |device, setup_command_buffer| {
                    let layout_transition_barrier = vk::ImageMemoryBarrier {
                        s_type: vk::StructureType::IMAGE_MEMORY_BARRIER,
                        p_next: ptr::null(),
                        src_access_mask: Default::default(),
                        dst_access_mask: vk::AccessFlags::DEPTH_STENCIL_ATTACHMENT_READ
                            | vk::AccessFlags::DEPTH_STENCIL_ATTACHMENT_WRITE,
                        old_layout: vk::ImageLayout::UNDEFINED,
                        new_layout: vk::ImageLayout::DEPTH_STENCIL_ATTACHMENT_OPTIMAL,
                        src_queue_family_index: vk::QUEUE_FAMILY_IGNORED,
                        dst_queue_family_index: vk::QUEUE_FAMILY_IGNORED,
                        image: depth_image,
                        subresource_range: vk::ImageSubresourceRange {
                            aspect_mask: vk::ImageAspectFlags::DEPTH,
                            base_mip_level: 0,
                            level_count: 1,
                            base_array_layer: 0,
                            layer_count: 1,
                        },
                    };
                    device.cmd_pipeline_barrier(
                        setup_command_buffer,
                        vk::PipelineStageFlags::BOTTOM_OF_PIPE,
                        vk::PipelineStageFlags::LATE_FRAGMENT_TESTS,
                        vk::DependencyFlags::empty(),
                        &[],
                        &[],
                        &[layout_transition_barrier],
                    );
                },
            );
            let depth_image_view_info = vk::ImageViewCreateInfo {
                s_type: vk::StructureType::IMAGE_VIEW_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
                view_type: vk::ImageViewType::TYPE_2D,
                format: depth_image_create_info.format,
                components: vk::ComponentMapping {
                    r: vk::ComponentSwizzle::IDENTITY,
                    g: vk::ComponentSwizzle::IDENTITY,
                    b: vk::ComponentSwizzle::IDENTITY,
                    a: vk::ComponentSwizzle::IDENTITY,
                },
                subresource_range: vk::ImageSubresourceRange {
                    aspect_mask: vk::ImageAspectFlags::DEPTH,
                    base_mip_level: 0,
                    level_count: 1,
                    base_array_layer: 0,
                    layer_count: 1,
                },
                image: depth_image,
            };
            let depth_image_view = device
                .create_image_view(&depth_image_view_info, None)
                .unwrap();
            let semaphore_create_info = vk::SemaphoreCreateInfo {
                s_type: vk::StructureType::SEMAPHORE_CREATE_INFO,
                p_next: ptr::null(),
                flags: Default::default(),
            };
            let present_complete_semaphore = device
                .create_semaphore(&semaphore_create_info, None)
                .unwrap();
            let rendering_complete_semaphore = device
                .create_semaphore(&semaphore_create_info, None)
                .unwrap();
            ExampleBase {
                events_loop: RefCell::new(events_loop),
                entry: entry,
                instance: instance,
                device: device,
                queue_family_index: queue_family_index,
                pdevice: pdevice,
                device_memory_properties: device_memory_properties,
                window: window,
                surface_loader: surface_loader,
                surface_format: surface_format,
                present_queue: present_queue,
                surface_resolution: surface_resolution,
                swapchain_loader: swapchain_loader,
                swapchain: swapchain,
                present_images: present_images,
                present_image_views: present_image_views,
                pool: pool,
                draw_command_buffer: draw_command_buffer,
                setup_command_buffer: setup_command_buffer,
                depth_image: depth_image,
                depth_image_view: depth_image_view,
                present_complete_semaphore: present_complete_semaphore,
                rendering_complete_semaphore: rendering_complete_semaphore,
                surface: surface,
                debug_call_back: debug_call_back,
                debug_report_loader: debug_report_loader,
                depth_image_memory: depth_image_memory,
            }
        }
    }
}

impl Drop for ExampleBase {
    fn drop(&mut self) {
        unsafe {
            self.device.device_wait_idle().unwrap();
            self.device
                .destroy_semaphore(self.present_complete_semaphore, None);
            self.device
                .destroy_semaphore(self.rendering_complete_semaphore, None);
            self.device.free_memory(self.depth_image_memory, None);
            self.device.destroy_image_view(self.depth_image_view, None);
            self.device.destroy_image(self.depth_image, None);
            for &image_view in self.present_image_views.iter() {
                self.device.destroy_image_view(image_view, None);
            }
            self.device.destroy_command_pool(self.pool, None);
            self.swapchain_loader
                .destroy_swapchain_khr(self.swapchain, None);
            self.device.destroy_device(None);
            self.surface_loader.destroy_surface_khr(self.surface, None);
            self.debug_report_loader
                .destroy_debug_report_callback_ext(self.debug_call_back, None);
            self.instance.destroy_instance(None);
        }
    }
}