Add wgpu adapter getter API (#340)

Co-authored-by: Jay Oster <jay@kodewerx.org>

src/builder.rs

@@ -345,6 +345,7 @@ impl<'req, 'dev, 'win, W: HasRawWindowHandle + HasRawDisplayHandle>
 
         let pixels = Pixels {
             context,
+            adapter,
             surface_size,
             present_mode,
             render_texture_format,

src/lib.rs

@@ -100,6 +100,7 @@ pub struct Pixels {
     surface_texture_format: wgpu::TextureFormat,
     blend_state: wgpu::BlendState,
     alpha_mode: wgpu::CompositeAlphaMode,
+    adapter: wgpu::Adapter,
 
     // Pixel buffer
     pixels: Vec<u8>,
@@ -275,6 +276,24 @@ impl Pixels {
         self.context.scaling_renderer.clear_color = color;
     }
 
+    /// Returns a reference of the `wgpu` adapter used by the crate.
+    ///
+    /// The adapter can be used to retrieve runtime information about the host system
+    /// or the WGPU backend.
+    ///
+    /// ```no_run
+    /// # use pixels::Pixels;
+    /// # let window = pixels_mocks::Rwh;
+    /// # let surface_texture = pixels::SurfaceTexture::new(320, 240, &window);
+    /// let mut pixels = Pixels::new(320, 240, surface_texture)?;
+    /// let adapter = pixels.adapter();
+    /// // Do something with the adapter.
+    /// # Ok::<(), pixels::Error>(())
+    /// ```
+    pub fn adapter(&self) -> &wgpu::Adapter {
+        &self.adapter
+    }
+
     /// Resize the pixel buffer and zero its contents.
     ///
     /// This does not resize the surface upon which the pixel buffer texture is rendered. Use