06_swap_chain_creation.rs.diff

--- a/05_window_surface.rs
+++ b/06_swap_chain_creation.rs
@@ -21,7 +21,16 @@ use vulkano::instance::debug::{DebugCallback, MessageTypes};
 use vulkano::device::{Device, DeviceExtensions, Queue};
 use vulkano::swapchain::{
     Surface,
+    Capabilities,
+    ColorSpace,
+    SupportedPresentModes,
+    PresentMode,
+    Swapchain,
+    CompositeAlpha,
 };
+use vulkano::format::Format;
+use vulkano::image::{ImageUsage, swapchain::SwapchainImage};
+use vulkano::sync::SharingMode;
 
 const WIDTH: u32 = 800;
 const HEIGHT: u32 = 600;
@@ -30,6 +39,14 @@ const VALIDATION_LAYERS: &[&str] =  &[
     "VK_LAYER_LUNARG_standard_validation"
 ];
 
+/// Required device extensions
+fn device_extensions() -> DeviceExtensions {
+    DeviceExtensions {
+        khr_swapchain: true,
+        .. vulkano::device::DeviceExtensions::none()
+    }
+}
+
 #[cfg(all(debug_assertions))]
 const ENABLE_VALIDATION_LAYERS: bool = true;
 #[cfg(not(debug_assertions))]
@@ -62,6 +79,9 @@ struct HelloTriangleApplication {
 
     graphics_queue: Arc<Queue>,
     present_queue: Arc<Queue>,
+
+    swap_chain: Arc<Swapchain<Window>>,
+    swap_chain_images: Vec<Arc<SwapchainImage<Window>>>,
 }
 
 impl HelloTriangleApplication {
@@ -74,6 +94,9 @@ impl HelloTriangleApplication {
         let (device, graphics_queue, present_queue) = Self::create_logical_device(
             &instance, &surface, physical_device_index);
 
+        let (swap_chain, swap_chain_images) = Self::create_swap_chain(&instance, &surface, physical_device_index,
+            &device, &graphics_queue, &present_queue);
+
         Self {
             instance,
             debug_callback,
@@ -86,6 +109,9 @@ impl HelloTriangleApplication {
 
             graphics_queue,
             present_queue,
+
+            swap_chain,
+            swap_chain_images,
         }
     }
 
@@ -157,7 +183,110 @@ impl HelloTriangleApplication {
 
     fn is_device_suitable(surface: &Arc<Surface<Window>>, device: &PhysicalDevice) -> bool {
         let indices = Self::find_queue_families(surface, device);
-        indices.is_complete()
+        let extensions_supported = Self::check_device_extension_support(device);
+
+        let swap_chain_adequate = if extensions_supported {
+                let capabilities = surface.capabilities(*device)
+                    .expect("failed to get surface capabilities");
+                !capabilities.supported_formats.is_empty() &&
+                    capabilities.present_modes.iter().next().is_some()
+            } else {
+                false
+            };
+
+        indices.is_complete() && extensions_supported && swap_chain_adequate
+    }
+
+    fn check_device_extension_support(device: &PhysicalDevice) -> bool {
+        let available_extensions = DeviceExtensions::supported_by_device(*device);
+        let device_extensions = device_extensions();
+        available_extensions.intersection(&device_extensions) == device_extensions
+    }
+
+    fn choose_swap_surface_format(available_formats: &[(Format, ColorSpace)]) -> (Format, ColorSpace) {
+        // NOTE: the 'preferred format' mentioned in the tutorial doesn't seem to be
+        // queryable in Vulkano (no VK_FORMAT_UNDEFINED enum)
+        *available_formats.iter()
+            .find(|(format, color_space)|
+                *format == Format::B8G8R8A8Unorm && *color_space == ColorSpace::SrgbNonLinear
+            )
+            .unwrap_or_else(|| &available_formats[0])
+    }
+
+    fn choose_swap_present_mode(available_present_modes: SupportedPresentModes) -> PresentMode {
+        if available_present_modes.mailbox {
+            PresentMode::Mailbox
+        } else if available_present_modes.immediate {
+            PresentMode::Immediate
+        } else {
+            PresentMode::Fifo
+        }
+    }
+
+    fn choose_swap_extent(capabilities: &Capabilities) -> [u32; 2] {
+        if let Some(current_extent) = capabilities.current_extent {
+            return current_extent
+        } else {
+            let mut actual_extent = [WIDTH, HEIGHT];
+            actual_extent[0] = capabilities.min_image_extent[0]
+                .max(capabilities.max_image_extent[0].min(actual_extent[0]));
+            actual_extent[1] = capabilities.min_image_extent[1]
+                .max(capabilities.max_image_extent[1].min(actual_extent[1]));
+            actual_extent
+        }
+    }
+
+    fn create_swap_chain(
+        instance: &Arc<Instance>,
+        surface: &Arc<Surface<Window>>,
+        physical_device_index: usize,
+        device: &Arc<Device>,
+        graphics_queue: &Arc<Queue>,
+        present_queue: &Arc<Queue>,
+    ) -> (Arc<Swapchain<Window>>, Vec<Arc<SwapchainImage<Window>>>) {
+        let physical_device = PhysicalDevice::from_index(&instance, physical_device_index).unwrap();
+        let capabilities = surface.capabilities(physical_device)
+            .expect("failed to get surface capabilities");
+
+        let surface_format = Self::choose_swap_surface_format(&capabilities.supported_formats);
+        let present_mode = Self::choose_swap_present_mode(capabilities.present_modes);
+        let extent = Self::choose_swap_extent(&capabilities);
+
+        let mut image_count = capabilities.min_image_count + 1;
+        if capabilities.max_image_count.is_some() && image_count > capabilities.max_image_count.unwrap() {
+            image_count = capabilities.max_image_count.unwrap();
+        }
+
+        let image_usage = ImageUsage {
+            color_attachment: true,
+            .. ImageUsage::none()
+        };
+
+        let indices = Self::find_queue_families(&surface, &physical_device);
+
+        let sharing: SharingMode = if indices.graphics_family != indices.present_family {
+            vec![graphics_queue, present_queue].as_slice().into()
+        } else {
+            graphics_queue.into()
+        };
+
+        let (swap_chain, images) = Swapchain::new(
+            device.clone(),
+            surface.clone(),
+            image_count,
+            surface_format.0, // TODO: color space?
+            extent,
+            1, // layers
+            image_usage,
+            sharing,
+            capabilities.current_transform,
+            CompositeAlpha::Opaque,
+            present_mode,
+            true, // clipped
+            None,
+        ).expect("failed to create swap chain!");
+
+        (swap_chain, images)
     }
 
     fn find_queue_families(surface: &Arc<Surface<Window>>, device: &PhysicalDevice) -> QueueFamilyIndices {
@@ -202,7 +331,7 @@ impl HelloTriangleApplication {
         // for us internally.
 
         let (device, mut queues) = Device::new(physical_device, &Features::none(),
-            &DeviceExtensions::none(), queue_families)
+            &device_extensions(), queue_families)
             .expect("failed to create logical device!");
 
         let graphics_queue = queues.next().unwrap();