Fix Metal backend Surface::frome_uiview can not guarantee set correct…

… view's contentScaleFactor (#2470)
gfx-rs · Feb 10, 2022 · 48f8811 · 48f8811
1 parent 6931e57
commit 48f8811
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Showing 2 changed files with 36 additions and 70 deletions.
diff --git a/wgpu-hal/src/metal/mod.rs b/wgpu-hal/src/metal/mod.rs
@@ -87,12 +87,12 @@ impl crate::Instance<Api> for Instance {
             #[cfg(target_os = "ios")]
             raw_window_handle::RawWindowHandle::UiKit(handle) => {
                 let _ = &self.managed_metal_layer_delegate;
-                Ok(Surface::from_uiview(handle.ui_view))
+                Ok(Surface::from_view(handle.ui_view, None))
             }
             #[cfg(target_os = "macos")]
-            raw_window_handle::RawWindowHandle::AppKit(handle) => Ok(Surface::from_nsview(
+            raw_window_handle::RawWindowHandle::AppKit(handle) => Ok(Surface::from_view(
                 handle.ns_view,
-                &self.managed_metal_layer_delegate,
+                Some(&self.managed_metal_layer_delegate),
             )),
             _ => Err(crate::InstanceError),
         }

diff --git a/wgpu-hal/src/metal/surface.rs b/wgpu-hal/src/metal/surface.rs
@@ -74,88 +74,54 @@ impl super::Surface {
         }
     }
 
-    #[cfg(target_os = "ios")]
     #[allow(clippy::transmute_ptr_to_ref)]
-    pub unsafe fn from_uiview(uiview: *mut c_void) -> Self {
-        let view = uiview as *mut Object;
+    pub unsafe fn from_view(
+        view: *mut c_void,
+        delegate: Option<&HalManagedMetalLayerDelegate>,
+    ) -> Self {
+        let view = view as *mut Object;
         if view.is_null() {
             panic!("window does not have a valid contentView");
         }
 
         let main_layer: *mut Object = msg_send![view, layer];
         let class = class!(CAMetalLayer);
         let is_valid_layer: BOOL = msg_send![main_layer, isKindOfClass: class];
+
         let render_layer = if is_valid_layer == YES {
             mem::transmute::<_, &mtl::MetalLayerRef>(main_layer).to_owned()
         } else {
-            // If the main layer is not a CAMetalLayer, we create a CAMetalLayer sublayer and use it instead.
-            // Unlike on macOS, we cannot replace the main view as UIView does not allow it (when NSView does).
+            // If the main layer is not a CAMetalLayer, we create a CAMetalLayer and use it.
             let new_layer: mtl::MetalLayer = msg_send![class, new];
-            let bounds: CGRect = msg_send![main_layer, bounds];
-            let () = msg_send![new_layer.as_ref(), setFrame: bounds];
-            let () = msg_send![main_layer, addSublayer: new_layer.as_ref()];
-            new_layer
-        };
-
-        let window: *mut Object = msg_send![view, window];
-        if !window.is_null() {
-            let screen: *mut Object = msg_send![window, screen];
-            assert!(!screen.is_null(), "window is not attached to a screen");
-
-            let scale_factor: CGFloat = msg_send![screen, nativeScale];
-            let () = msg_send![view, setContentScaleFactor: scale_factor];
-        }
-
-        let _: *mut c_void = msg_send![view, retain];
-        Self::new(NonNull::new(view), render_layer)
-    }
-
-    #[cfg(target_os = "macos")]
-    #[allow(clippy::transmute_ptr_to_ref)]
-    pub unsafe fn from_nsview(
-        nsview: *mut c_void,
-        delegate: &HalManagedMetalLayerDelegate,
-    ) -> Self {
-        let view = nsview as *mut Object;
-        if view.is_null() {
-            panic!("window does not have a valid contentView");
-        }
-
-        let class = class!(CAMetalLayer);
-        // Deprecated! Clients should use `create_surface_from_layer` instead.
-        let is_actually_layer: BOOL = msg_send![view, isKindOfClass: class];
-        if is_actually_layer == YES {
-            return Self::from_layer(mem::transmute(view));
-        }
-
-        let existing: *mut Object = msg_send![view, layer];
-        let use_current = if existing.is_null() {
-            false
-        } else {
-            let result: BOOL = msg_send![existing, isKindOfClass: class];
-            result == YES
-        };
-
-        let render_layer: mtl::MetalLayer = if use_current {
-            mem::transmute::<_, &mtl::MetalLayerRef>(existing).to_owned()
-        } else {
-            let layer: mtl::MetalLayer = msg_send![class, new];
-            let () = msg_send![view, setLayer: layer.as_ref()];
-            let () = msg_send![view, setWantsLayer: YES];
-            let bounds: CGRect = msg_send![view, bounds];
-            let () = msg_send![layer.as_ref(), setBounds: bounds];
-
-            let window: *mut Object = msg_send![view, window];
-            if !window.is_null() {
-                let scale_factor: CGFloat = msg_send![window, backingScaleFactor];
-                let () = msg_send![layer, setContentsScale: scale_factor];
+            let frame: CGRect = msg_send![main_layer, bounds];
+            let () = msg_send![new_layer.as_ref(), setFrame: frame];
+            #[cfg(target_os = "ios")]
+            {
+                // Unlike NSView, UIView does not allow to replace main layer.
+                let () = msg_send![main_layer, addSublayer: new_layer.as_ref()];
+                // On iOS, "from_view" may be called before the application initialization is complete,
+                // `msg_send![view, window]` and `msg_send![window, screen]` will get null.
+                let screen: *mut Object = msg_send![class!(UIScreen), mainScreen];
+                let scale_factor: CGFloat = msg_send![screen, nativeScale];
+                let () = msg_send![view, setContentScaleFactor: scale_factor];
+            };
+            #[cfg(target_os = "macos")]
+            {
+                let () = msg_send![view, setLayer: new_layer.as_ref()];
+                let () = msg_send![view, setWantsLayer: YES];
+                let () = msg_send![new_layer.as_ref(), setContentsGravity: kCAGravityTopLeft];
+                let window: *mut Object = msg_send![view, window];
+                if !window.is_null() {
+                    let scale_factor: CGFloat = msg_send![window, backingScaleFactor];
+                    let () = msg_send![new_layer, setContentsScale: scale_factor];
+                }
+            };
+            if let Some(delegate) = delegate {
+                let () = msg_send![new_layer, setDelegate: delegate.0];
             }
-            let () = msg_send![layer, setDelegate: delegate.0];
-            layer
+            new_layer
         };
 
-        let () = msg_send![render_layer, setContentsGravity: kCAGravityTopLeft];
-
         let _: *mut c_void = msg_send![view, retain];
         Self::new(NonNull::new(view), render_layer)
     }