Allow `iced_wgpu` to render to any `TextureView`

1 files changed, 55 insertions, 0 deletions

diff --git a/native/src/window/backend.rs b/native/src/window/backend.rs
new file mode 100644
index 00000000..690dbdab
--- /dev/null
+++ b/native/src/window/backend.rs
@@ -0,0 +1,55 @@
+use crate::MouseCursor;
+
+use raw_window_handle::HasRawWindowHandle;
+
+/// A graphics backend that can render to windows.
+pub trait Backend: Sized {
+    /// The settings of the backend.
+    type Settings: Default;
+
+    /// The iced renderer of the backend.
+    type Renderer: crate::Renderer;
+
+    /// The surface of the backend.
+    type Surface;
+
+    /// The swap chain of the backend.
+    type SwapChain;
+
+    /// Creates a new [`Backend`] and an associated iced renderer.
+    ///
+    /// [`Backend`]: trait.Backend.html
+    fn new(settings: Self::Settings) -> (Self, Self::Renderer);
+
+    /// Crates a new [`Surface`] for the given window.
+    ///
+    /// [`Surface`]: #associatedtype.Surface
+    fn create_surface<W: HasRawWindowHandle>(
+        &mut self,
+        window: &W,
+    ) -> Self::Surface;
+
+    /// Crates a new [`SwapChain`] for the given [`Surface`].
+    ///
+    /// [`SwapChain`]: #associatedtype.SwapChain
+    /// [`Surface`]: #associatedtype.Surface
+    fn create_swap_chain(
+        &mut self,
+        surface: &Self::Surface,
+        width: u32,
+        height: u32,
+        scale_factor: f64,
+    ) -> Self::SwapChain;
+
+    /// Draws the output primitives to the next frame of the given [`SwapChain`].
+    ///
+    /// [`SwapChain`]: #associatedtype.SwapChain
+    /// [`Surface`]: #associatedtype.Surface
+    fn draw<T: AsRef<str>>(
+        &mut self,
+        renderer: &mut Self::Renderer,
+        swap_chain: &mut Self::SwapChain,
+        output: &<Self::Renderer as crate::Renderer>::Output,
+        overlay: &[T],
+    ) -> MouseCursor;
+}