Add metal surface extension (#288)

ash/src/extensions/ext/metal_surface.rs

@@ -0,0 +1,56 @@
+#![allow(dead_code)]
+use crate::prelude::*;
+use crate::version::{EntryV1_0, InstanceV1_0};
+use crate::vk;
+use crate::RawPtr;
+use std::ffi::CStr;
+use std::mem;
+
+#[derive(Clone)]
+pub struct MetalSurface {
+    handle: vk::Instance,
+    metal_surface_fn: vk::ExtMetalSurfaceFn,
+}
+
+impl MetalSurface {
+    pub fn new<E: EntryV1_0, I: InstanceV1_0>(entry: &E, instance: &I) -> MetalSurface {
+        let surface_fn = vk::ExtMetalSurfaceFn::load(|name| unsafe {
+            mem::transmute(entry.get_instance_proc_addr(instance.handle(), name.as_ptr()))
+        });
+        MetalSurface {
+            handle: instance.handle(),
+            metal_surface_fn: surface_fn,
+        }
+    }
+
+    pub fn name() -> &'static CStr {
+        vk::ExtMetalSurfaceFn::name()
+    }
+
+    #[doc = "<https://www.khronos.org/registry/vulkan/specs/1.2-extensions/man/html/vkCreateMetalSurfaceEXT.html>"]
+    pub unsafe fn create_metal_surface(
+        &self,
+        create_info: &vk::MetalSurfaceCreateInfoEXT,
+        allocation_callbacks: Option<&vk::AllocationCallbacks>,
+    ) -> VkResult<vk::SurfaceKHR> {
+        let mut surface = mem::zeroed();
+        let err_code = self.metal_surface_fn.create_metal_surface_ext(
+            self.handle,
+            create_info,
+            allocation_callbacks.as_raw_ptr(),
+            &mut surface,
+        );
+        match err_code {
+            vk::Result::SUCCESS => Ok(surface),
+            _ => Err(err_code),
+        }
+    }
+
+    pub fn fp(&self) -> &vk::ExtMetalSurfaceFn {
+        &self.metal_surface_fn
+    }
+
+    pub fn instance(&self) -> vk::Instance {
+        self.handle
+    }
+}

ash/src/extensions/ext/mod.rs

@@ -1,7 +1,9 @@
 pub use self::debug_marker::DebugMarker;
 pub use self::debug_report::DebugReport;
 pub use self::debug_utils::DebugUtils;
+pub use self::metal_surface::MetalSurface;
 
 mod debug_marker;
 mod debug_report;
 mod debug_utils;
+mod metal_surface;