04_logical_device.rs

extern crate vulkano;
extern crate vulkano_win;
extern crate winit;

use std::sync::Arc;

use winit::{EventsLoop, WindowBuilder, dpi::LogicalSize, Event, WindowEvent};

use vulkano::instance::{
    Instance,
    InstanceExtensions,
    ApplicationInfo,
    Version,
    layers_list,
    PhysicalDevice,
};
use vulkano::instance::debug::{DebugCallback, MessageTypes};
use vulkano::device::{Device, DeviceExtensions, Queue, Features};

const WIDTH: u32 = 800;
const HEIGHT: u32 = 600;

const VALIDATION_LAYERS: &[&str] =  &[
    "VK_LAYER_LUNARG_standard_validation"
];

#[cfg(all(debug_assertions))]
const ENABLE_VALIDATION_LAYERS: bool = true;
#[cfg(not(debug_assertions))]
const ENABLE_VALIDATION_LAYERS: bool = false;

struct QueueFamilyIndices {
    graphics_family: i32,
}
impl QueueFamilyIndices {
    fn new() -> Self {
        Self { graphics_family: -1 }
    }

    fn is_complete(&self) -> bool {
        self.graphics_family >= 0
    }
}

#[allow(unused)]
struct HelloTriangleApplication {
    instance: Arc<Instance>,
    debug_callback: Option<DebugCallback>,

    events_loop: EventsLoop,

    physical_device_index: usize, // can't store PhysicalDevice directly (lifetime issues)
    device: Arc<Device>,

    graphics_queue: Arc<Queue>,
}

impl HelloTriangleApplication {
    pub fn initialize() -> Self {
        let instance = Self::create_instance();
        let debug_callback = Self::setup_debug_callback(&instance);

        let events_loop = Self::init_window();

        let physical_device_index = Self::pick_physical_device(&instance);
        let (device, graphics_queue) = Self::create_logical_device(
            &instance, physical_device_index);

        Self {
            instance,
            debug_callback,

            events_loop,

            physical_device_index,
            device,

            graphics_queue,
        }
    }

    fn init_window() -> EventsLoop {
        let events_loop = EventsLoop::new();
        let _window_builder = WindowBuilder::new()
            .with_title("Vulkan")
            .with_dimensions(LogicalSize::new(f64::from(WIDTH), f64::from(HEIGHT)));
            // .build(&self.events_loop.as_ref().unwrap());
        events_loop
    }

    fn create_instance() -> Arc<Instance> {
        if ENABLE_VALIDATION_LAYERS && !Self::check_validation_layer_support() {
            println!("Validation layers requested, but not available!")
        }

        let supported_extensions = InstanceExtensions::supported_by_core()
            .expect("failed to retrieve supported extensions");
        println!("Supported extensions: {:?}", supported_extensions);

        let app_info = ApplicationInfo {
            application_name: Some("Hello Triangle".into()),
            application_version: Some(Version { major: 1, minor: 0, patch: 0 }),
            engine_name: Some("No Engine".into()),
            engine_version: Some(Version { major: 1, minor: 0, patch: 0 }),
        };

        let required_extensions = Self::get_required_extensions();

        if ENABLE_VALIDATION_LAYERS && Self::check_validation_layer_support() {
            Instance::new(Some(&app_info), &required_extensions, VALIDATION_LAYERS.iter().cloned())
                .expect("failed to create Vulkan instance")
        } else {
            Instance::new(Some(&app_info), &required_extensions, None)
                .expect("failed to create Vulkan instance")
        }
    }

    fn check_validation_layer_support() -> bool {
        let layers: Vec<_> = layers_list().unwrap().map(|l| l.name().to_owned()).collect();
        VALIDATION_LAYERS.iter()
            .all(|layer_name| layers.contains(&layer_name.to_string()))
    }

    fn get_required_extensions() -> InstanceExtensions {
        let mut extensions = vulkano_win::required_extensions();
        if ENABLE_VALIDATION_LAYERS {
            // TODO!: this should be ext_debug_utils (_report is deprecated), but that doesn't exist yet in vulkano
            extensions.ext_debug_report = true;
        }

        extensions
    }

    fn setup_debug_callback(instance: &Arc<Instance>) -> Option<DebugCallback> {
        if !ENABLE_VALIDATION_LAYERS  {
            return None;
        }

        let msg_types = MessageTypes {
            error: true,
            warning: true,
            performance_warning: true,
            information: false,
            debug: true,
        };
        DebugCallback::new(&instance, msg_types, |msg| {
            println!("validation layer: {:?}", msg.description);
        }).ok()
    }

    fn pick_physical_device(instance: &Arc<Instance>) -> usize {
        PhysicalDevice::enumerate(&instance)
            .position(|device| Self::is_device_suitable(&device))
            .expect("failed to find a suitable GPU!")
    }

    fn is_device_suitable(device: &PhysicalDevice) -> bool {
        let indices = Self::find_queue_families(device);
        indices.is_complete()
    }

    fn find_queue_families(device: &PhysicalDevice) -> QueueFamilyIndices {
        let mut indices = QueueFamilyIndices::new();
        // TODO: replace index with id to simplify?
        for (i, queue_family) in device.queue_families().enumerate() {
            if queue_family.supports_graphics() {
                indices.graphics_family = i as i32;
            }

            if indices.is_complete() {
                break;
            }
        }

        indices
    }

    fn create_logical_device(
        instance: &Arc<Instance>,
        physical_device_index: usize,
    ) -> (Arc<Device>, Arc<Queue>) {
        let physical_device = PhysicalDevice::from_index(&instance, physical_device_index).unwrap();
        let indices = Self::find_queue_families(&physical_device);

        let queue_family = physical_device.queue_families()
            .nth(indices.graphics_family as usize).unwrap();

        let queue_priority = 1.0;

        // NOTE: the tutorial recommends passing the validation layers as well
        // for legacy reasons (if ENABLE_VALIDATION_LAYERS is true). Vulkano handles that
        // for us internally.

        let (device, mut queues) = Device::new(physical_device, &Features::none(), &DeviceExtensions::none(),
            [(queue_family, queue_priority)].iter().cloned())
            .expect("failed to create logical device!");

        let graphics_queue = queues.next().unwrap();

        (device, graphics_queue)
    }

    #[allow(unused)]
    fn main_loop(&mut self) {
        loop {
            let mut done = false;
            self.events_loop.poll_events(|ev| {
                if let Event::WindowEvent { event: WindowEvent::CloseRequested, .. } = ev {
                    done = true
                }
            });
            if done {
                return;
            }
        }
    }
}

fn main() {
    let mut _app = HelloTriangleApplication::initialize();
    // app.main_loop();
}