From 754a4bad801064b2027cb0d9f26bcb574b796aeb Mon Sep 17 00:00:00 2001
From: Xiaopeng Li <x.friday@outlook.com>
Date: Thu, 20 Oct 2022 04:06:23 +0800
Subject: [PATCH] Add Surface::as_hal_mut (#3123)

---
 wgpu-core/src/resource.rs  | 19 +++++++++++++++++++
 wgpu/src/backend/direct.rs | 14 ++++++++++++++
 wgpu/src/lib.rs            | 15 +++++++++++++++
 3 files changed, 48 insertions(+)

diff --git a/wgpu-core/src/resource.rs b/wgpu-core/src/resource.rs
index 85d4d97157..bda619f5b0 100644
--- a/wgpu-core/src/resource.rs
+++ b/wgpu-core/src/resource.rs
@@ -428,6 +428,25 @@ impl<G: GlobalIdentityHandlerFactory> Global<G> {
 
         hal_device_callback(hal_device)
     }
+
+    /// # Safety
+    /// - The raw surface handle must not be manually destroyed
+    pub unsafe fn surface_as_hal_mut<A: HalApi, F: FnOnce(Option<&mut A::Surface>) -> R, R>(
+        &self,
+        id: SurfaceId,
+        hal_surface_callback: F,
+    ) -> R {
+        profiling::scope!("Surface::as_hal_mut");
+
+        let mut token = Token::root();
+        let (mut guard, _) = self.surfaces.write(&mut token);
+        let surface = guard.get_mut(id).ok();
+        let hal_surface = surface
+            .and_then(|surface| A::get_surface_mut(surface))
+            .map(|surface| &mut surface.raw);
+
+        hal_surface_callback(hal_surface)
+    }
 }
 
 #[derive(Clone, Copy, Debug)]
diff --git a/wgpu/src/backend/direct.rs b/wgpu/src/backend/direct.rs
index 06fcbb6f36..6daab45c5d 100644
--- a/wgpu/src/backend/direct.rs
+++ b/wgpu/src/backend/direct.rs
@@ -154,6 +154,20 @@ impl Context {
             .device_as_hal::<A, F, R>(device.id, hal_device_callback)
     }
 
+    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    pub unsafe fn surface_as_hal_mut<
+        A: wgc::hub::HalApi,
+        F: FnOnce(Option<&mut A::Surface>) -> R,
+        R,
+    >(
+        &self,
+        surface: &Surface,
+        hal_surface_callback: F,
+    ) -> R {
+        self.0
+            .surface_as_hal_mut::<A, F, R>(surface.id, hal_surface_callback)
+    }
+
     #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
     pub unsafe fn texture_as_hal<A: wgc::hub::HalApi, F: FnOnce(Option<&A::Texture>)>(
         &self,
diff --git a/wgpu/src/lib.rs b/wgpu/src/lib.rs
index 2804244573..d5b6a16aca 100644
--- a/wgpu/src/lib.rs
+++ b/wgpu/src/lib.rs
@@ -3773,6 +3773,21 @@ impl Surface {
             })
             .ok_or(SurfaceError::Lost)
     }
+
+    /// Returns the inner hal Surface using a callback. The hal surface will be `None` if the
+    /// backend type argument does not match with this wgpu Surface
+    ///
+    /// # Safety
+    ///
+    /// - The raw handle obtained from the hal Surface must not be manually destroyed
+    #[cfg(any(not(target_arch = "wasm32"), feature = "emscripten"))]
+    pub unsafe fn as_hal_mut<A: wgc::hub::HalApi, F: FnOnce(Option<&mut A::Surface>) -> R, R>(
+        &mut self,
+        hal_surface_callback: F,
+    ) -> R {
+        self.context
+            .surface_as_hal_mut::<A, F, R>(&self.id, hal_surface_callback)
+    }
 }
 
 /// Type for the callback of uncaptured error handler