Started on proposal on interface to expose raw function pointers for extensions.

Added raw_fp() to Surface and Swapchain
Àdded instance_handle() to Surface
Added device_handle() to Device

Signed-off-by: Nils Petter Skålerud <np_skalerud@hotmail.com>

ash/src/extensions/khr/surface.rs

@@ -138,4 +138,12 @@ impl Surface {
             allocation_callbacks.as_raw_ptr(),
         );
     }
+
+    pub fn raw_fp(&self) -> &vk::KhrSurfaceFn {
+        &self.surface_fn
+    }
+
+    pub fn instance_handle(&self) -> vk::Instance {
+        self.handle
+    }
 }

ash/src/extensions/khr/swapchain.rs

@@ -126,4 +126,12 @@ impl Swapchain {
             _ => Err(err_code),
         }
     }
+
+    pub fn raw_fp(&self) -> &vk::KhrSwapchainFn {
+        &self.swapchain_fn
+    }
+
+    pub fn device_handle(&self) -> vk::Device {
+        self.handle
+    }
 }