Use raw-window-metal to do layer creation in skia

Author: madsmtm

internal/renderers/skia/Cargo.toml

@@ -60,7 +60,7 @@ bytemuck = { workspace = true }
 windows = { version = "0.56.0", features = ["Win32", "Win32_System_Com", "Win32_Graphics", "Win32_Graphics_Dxgi", "Win32_Graphics_Direct3D12", "Win32_Graphics_Direct3D", "Win32_Foundation", "Win32_Graphics_Dxgi_Common", "Win32_System_Threading", "Win32_Security"] }
 skia-safe = { version = "0.75.0", features = ["d3d"] }
 
-[target.'cfg(target_os = "macos")'.dependencies]
+[target.'cfg(target_vendor = "apple")'.dependencies]
 cocoa = { version = "0.25.0" }
 core-foundation = { version = "0.9.1" }
 metal = { version = "0.27.0" }
@@ -69,8 +69,9 @@ foreign-types = { version = "0.5.0" }
 objc = { version = "0.2.7" }
 core-graphics-types = { version = "0.1.1" }
 skia-safe = { version = "0.75.0", features = ["metal"] }
+raw-window-metal = "1.0"
 
-[target.'cfg(not(any(target_os = "macos", target_family = "windows")))'.dependencies]
+[target.'cfg(not(any(target_vendor = "apple", target_family = "windows")))'.dependencies]
 skia-safe = { version = "0.75.0", features = ["gl"] }
 
 [build-dependencies]

internal/renderers/skia/metal_surface.rs

@@ -1,18 +1,29 @@
 // Copyright © SixtyFPS GmbH <info@slint.dev>
 // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
 
-use cocoa::{appkit::NSView, base::id as cocoa_id};
 use core_graphics_types::geometry::CGSize;
-use foreign_types::ForeignTypeRef;
+use foreign_types::{ForeignType, ForeignTypeRef};
 use i_slint_core::api::PhysicalSize as PhysicalWindowSize;
 use metal::MTLPixelFormat;
-use objc::{rc::autoreleasepool, runtime::YES};
+use objc::{msg_send, sel, sel_impl};
+use objc::{
+    rc::autoreleasepool,
+    runtime::{Object, BOOL, NO},
+};
 
 use skia_safe::gpu::mtl;
 
 use std::cell::RefCell;
 use std::rc::Rc;
 
+#[link(name = "QuartzCore", kind = "framework")]
+extern "C" {
+    #[allow(non_upper_case_globals)]
+    static kCAGravityTopLeft: *mut Object;
+    #[allow(non_upper_case_globals)]
+    static kCAGravityBottomLeft: *mut Object;
+}
+
 /// This surface renders into the given window using Metal. The provided display argument
 /// is ignored, as it has no meaning on macOS.
 pub struct MetalSurface {
@@ -27,36 +38,40 @@ impl super::Surface for MetalSurface {
         _display_handle: Rc<dyn raw_window_handle::HasDisplayHandle>,
         size: PhysicalWindowSize,
     ) -> Result<Self, i_slint_core::platform::PlatformError> {
+        let layer = match window_handle
+            .window_handle()
+            .map_err(|e| format!("Error obtaining window handle for skia metal renderer: {e}"))?
+            .as_raw()
+        {
+            raw_window_handle::RawWindowHandle::AppKit(handle) => unsafe {
+                raw_window_metal::Layer::from_ns_view(handle.ns_view)
+            },
+            raw_window_handle::RawWindowHandle::UiKit(handle) => unsafe {
+                raw_window_metal::Layer::from_ui_view(handle.ui_view)
+            },
+            _ => return Err("Skia Renderer: Metal surface is only supported with AppKit".into()),
+        };
+
+        // SAFETY: The layer is an initialized instance of `CAMetalLayer`, and
+        // we transfer the retain count to `MetalLayer` using `into_raw`.
+        let layer = unsafe { metal::MetalLayer::from_ptr(layer.into_raw().cast().as_ptr()) };
+
         let device = metal::Device::system_default()
             .ok_or_else(|| format!("Skia Renderer: No metal device found"))?;
-
-        let layer = metal::MetalLayer::new();
         layer.set_device(&device);
         layer.set_pixel_format(MTLPixelFormat::BGRA8Unorm);
         layer.set_opaque(false);
         layer.set_presents_with_transaction(false);
 
         layer.set_drawable_size(CGSize::new(size.width as f64, size.height as f64));
 
-        unsafe {
-            let view = match window_handle
-                .window_handle()
-                .map_err(|e| format!("Error obtaining window handle for skia metal renderer: {e}"))?
-                .as_raw()
-            {
-                raw_window_handle::RawWindowHandle::AppKit(
-                    raw_window_handle::AppKitWindowHandle { ns_view, .. },
-                ) => ns_view.as_ptr(),
-                _ => {
-                    return Err("Skia Renderer: Metal surface is only supported with AppKit".into())
-                }
-            } as cocoa_id;
-            view.setWantsLayer(YES);
-            view.setLayer(layer.as_ref() as *const _ as _);
-            view.setLayerContentsPlacement(
-                cocoa::appkit::NSViewLayerContentsPlacement::NSViewLayerContentsPlacementTopLeft,
-            );
-        }
+        let flipped: BOOL = unsafe { msg_send![layer.as_ptr(), contentsAreFlipped] };
+        let gravity = if flipped == NO {
+            unsafe { kCAGravityTopLeft }
+        } else {
+            unsafe { kCAGravityBottomLeft }
+        };
+        let _: () = unsafe { msg_send![layer.as_ptr(), setContentsGravity: gravity] };
 
         let command_queue = device.new_command_queue();
 
@@ -85,10 +100,6 @@ impl super::Surface for MetalSurface {
         Ok(())
     }
 
-    fn set_scale_factor(&self, scale_factor: f32) {
-        self.layer.set_contents_scale(scale_factor.into());
-    }
-
     fn render(
         &self,
         _size: PhysicalWindowSize,

internal/renderers/skia/vulkan_surface.rs

@@ -395,30 +395,22 @@ impl super::Surface for VulkanSurface {
     }
 }
 
+// FIXME(madsmtm): Why are we doing this instead of using `Surface::from_window`?
 fn create_surface(
     instance: &Arc<Instance>,
     window_handle: raw_window_handle::WindowHandle<'_>,
     display_handle: raw_window_handle::DisplayHandle<'_>,
 ) -> Result<Arc<Surface>, vulkano::Validated<vulkano::VulkanError>> {
     match (window_handle.as_raw(), display_handle.as_raw()) {
-        #[cfg(target_os = "macos")]
-        (
-            raw_window_handle::RawWindowHandle::AppKit(raw_window_handle::AppKitWindowHandle {
-                ns_view,
-                ..
-            }),
-            _,
-        ) => unsafe {
-            use cocoa::{appkit::NSView, base::id as cocoa_id};
-            use objc::runtime::YES;
-
-            let layer = metal::MetalLayer::new();
-            layer.set_opaque(false);
-            layer.set_presents_with_transaction(false);
-            let view = ns_view.as_ptr() as cocoa_id;
-            view.setWantsLayer(YES);
-            view.setLayer(layer.as_ref() as *const _ as _);
-            Surface::from_metal(instance.clone(), layer.as_ref(), None)
+        #[cfg(target_vendor = "apple")]
+        (raw_window_handle::RawWindowHandle::AppKit(handle), _) => unsafe {
+            let layer = raw_window_metal::Layer::from_ns_view(handle.ns_view);
+            Surface::from_metal(instance.clone(), layer.as_ptr().as_ptr(), None)
+        },
+        #[cfg(target_vendor = "apple")]
+        (raw_window_handle::RawWindowHandle::UiKit(handle), _) => unsafe {
+            let layer = raw_window_metal::Layer::from_ui_view(handle.ui_view);
+            Surface::from_metal(instance.clone(), layer.as_ptr().as_ptr(), None)
         },
         (
             raw_window_handle::RawWindowHandle::Xlib(raw_window_handle::XlibWindowHandle {