Final tweeks

Author: cwfitzgerald

CHANGELOG.md

@@ -42,15 +42,23 @@ Bottom level categories:
 
 ### Major Changes
 
-#### Builtin Support for DirectComposition/DXGI swapchains in DX12
+#### Builtin Support for DXGI swapchains on top of of DirectComposition Visuals in DX12
 
-By selecting DirectComposition, the compositor cannot optimize your Swapchain as much, but you can support transparent windows.
+By enabling DirectComposition support, the dx12 backend can now support transparent windows.
 
-This creates a single `IDCompositionVisual` over the entire window that is used by the `Surface`. If a user wants to manage the composition tree themselves, they should create their own device and composition, and pass the relevant visual down into `wgpu` via `IDCompositionTarget::CompositionVisual` or `IDCompositionTarget::SurfaceHandle`.
+This creates a single `IDCompositionVisual` over the entire window that is used by the mf`Surface`. If a user wants to manage the composition tree themselves, they should create their own device and composition, and pass the relevant visual down into `wgpu` via `SurfaceTargetUnsafe::CompositionVisual`.
 
-```diff
--pub struct Dx12BackendOptions { pub shader_compiler: Dx12Compiler }
-+pub struct Dx12BackendOptions { pub shader_compiler: Dx12Compiler, pub presentation_system: Dx12SwapchainKind }
+```rust
+let instance = wgpu::Instance::new(&wgpu::InstanceDescriptor {
+    backend_options: wgpu::BackendOptions {
+        dx12: wgpu::Dx12BackendOptions {
+            presentation_system: wgpu::Dx12SwapchainKind::DxgiFromVisual,
+            ..
+        },
+        ..
+    },
+    ..
+});
 ```
 
 By @n1ght-hunter in [#7550](https://github.com/gfx-rs/wgpu/pull/7550).

wgpu-hal/src/dx12/instance.rs

@@ -124,13 +124,11 @@ impl crate::Instance for super::Instance {
                 // https://github.com/rust-windowing/raw-window-handle/issues/171
                 let handle = Foundation::HWND(handle.hwnd.get() as *mut _);
                 let target = match self.presentation_system {
-                    wgt::Dx12SwapchainKind::Dxgi => SurfaceTarget::WndHandle(handle),
-                    wgt::Dx12SwapchainKind::DirectComposition => {
-                        SurfaceTarget::VisualFromWndHandle {
-                            handle,
-                            dcomp_state: Default::default(),
-                        }
-                    }
+                    wgt::Dx12SwapchainKind::DxgiFromHwnd => SurfaceTarget::WndHandle(handle),
+                    wgt::Dx12SwapchainKind::DxgiFromVisual => SurfaceTarget::VisualFromWndHandle {
+                        handle,
+                        dcomp_state: Default::default(),
+                    },
                 };
 
                 Ok(super::Surface {

wgpu-types/src/instance.rs

@@ -449,29 +449,36 @@ impl NoopBackendOptions {
 pub enum Dx12SwapchainKind {
     /// Use a DXGI swapchain made directly from the window's HWND.
     ///
-    /// This supports fullscreen optimization, making borderless windows just as efficient as exclusive fullscreen. It does not support transparent windows.
+    /// This does not support transparency but has better support from developer tooling from RenderDoc.
     #[default]
-    Dxgi,
-    /// Use a DXGI swapchain made from a DirectComposition visual made from the window.
+    DxgiFromHwnd,
+    /// Use a DXGI swapchain made from a DirectComposition visual made automatically from the window's HWND.
     ///
-    /// This supports transparent windows, but does not support fullscreen optimization.
-    DirectComposition,
+    /// This creates a single [`IDCompositionVisual`] over the entire window that is used by the `Surface`.
+    /// If a user wants to manage the composition tree themselves, they should create their own device and
+    /// composition, and pass the relevant visual down via [`SurfaceTargetUnsafe::CompositionVisual`][CV].
+    ///
+    /// This supports transparent windows, but does not have support from RenderDoc.
+    ///
+    /// [`IDCompositionVisual`]: https://learn.microsoft.com/en-us/windows/win32/api/dcomp/nn-dcomp-idcompositionvisual
+    /// [CV]: ../wgpu/struct.SurfaceTargetUnsafe.html#variant.CompositionVisual
+    DxgiFromVisual,
 }
 
 impl Dx12SwapchainKind {
     /// Choose which presentation system to use from the environment variable `WGPU_DX12_PRESENTATION_SYSTEM`.
     ///
     /// Valid values, case insensitive:
-    /// - `Dxgi`
-    /// - `DirectComposition`
+    /// - `DxgiFromVisual` or `Visual`
+    /// - `DxgiFromHwnd` or `Hwnd` for [`Self::DxgiFromHwnd`]
     #[must_use]
     pub fn from_env() -> Option<Self> {
         let value = crate::env::var("WGPU_DX12_PRESENTATION_SYSTEM")
             .as_deref()?
             .to_lowercase();
         match value.as_str() {
-            "dcomp" | "directcomposition" => Some(Self::DirectComposition),
-            "dxgi" => Some(Self::Dxgi),
+            "dxgifromvisual" | "visual" => Some(Self::DxgiFromVisual),
+            "dxgifromhwnd" | "hwnd" => Some(Self::DxgiFromHwnd),
             _ => None,
         }
     }