WIP no-copy in public API

Currently only for `wayland` and the `winit` example.

examples/winit.rs

@@ -32,21 +32,21 @@ fn main() {
                     let size = window.inner_size();
                     (size.width, size.height)
                 };
-                let buffer = (0..((width * height) as usize))
-                    .map(|index| {
-                        let y = index / (width as usize);
-                        let x = index % (width as usize);
-                        let red = x % 255;
-                        let green = y % 255;
-                        let blue = (x * y) % 255;
 
-                        let color = blue | (green << 8) | (red << 16);
+                surface.resize(width, height);
 
-                        color as u32
-                    })
-                    .collect::<Vec<_>>();
+                let buffer = surface.buffer_mut();
+                for index in 0..(width * height) {
+                    let y = index as u32 / width;
+                    let x = index as u32 % width;
+                    let red = x % 255;
+                    let green = y % 255;
+                    let blue = (x * y) % 255;
 
-                surface.set_buffer(&buffer, width as u16, height as u16);
+                    buffer[index as usize] = blue | (green << 8) | (red << 16);
+                }
+
+                surface.present();
             }
             Event::WindowEvent {
                 event: WindowEvent::CloseRequested,

src/lib.rs

@@ -71,6 +71,33 @@ macro_rules! make_dispatch {
         }
 
         impl SurfaceDispatch {
+            pub fn resize(&mut self, width: u32, height: u32) {
+                match self {
+                    $(
+                        $(#[$attr])*
+                        Self::$name(inner) => inner.resize(width, height),
+                    )*
+                }
+            }
+
+            pub fn buffer_mut(&mut self) -> &mut [u32] {
+                match self {
+                    $(
+                        $(#[$attr])*
+                        Self::$name(inner) => inner.buffer_mut(),
+                    )*
+                }
+            }
+
+            pub fn present(&mut self) {
+                match self {
+                    $(
+                        $(#[$attr])*
+                        Self::$name(inner) => inner.present(),
+                    )*
+                }
+            }
+
             unsafe fn set_buffer(&mut self, buffer: &[u32], width: u16, height: u16) {
                 match self {
                     $(
@@ -235,6 +262,18 @@ impl Surface {
         })
     }
 
+    pub fn resize(&mut self, width: u32, height: u32) {
+        self.surface_impl.resize(width, height);
+    }
+
+    pub fn buffer_mut(&mut self) -> &mut [u32] {
+        self.surface_impl.buffer_mut()
+    }
+
+    pub fn present(&mut self) {
+        self.surface_impl.present();
+    }
+
     /// Shows the given buffer with the given width and height on the window corresponding to this
     /// graphics context. Panics if buffer.len() ≠ width*height. If the size of the buffer does
     /// not match the size of the window, the buffer is drawn in the upper-left corner of the window.

src/wayland/mod.rs

@@ -87,12 +87,12 @@ impl WaylandImpl {
         ));
     }
 
-    fn resize(&mut self, width: u32, height: u32) {
+    pub fn resize(&mut self, width: u32, height: u32) {
         self.width = width as i32;
         self.height = height as i32;
     }
 
-    fn buffer_mut(&mut self) -> &mut [u32] {
+    pub fn buffer_mut(&mut self) -> &mut [u32] {
         if let Some((_front, back)) = &mut self.buffers {
             // Block if back buffer not released yet
             if !back.released() {
@@ -111,7 +111,7 @@ impl WaylandImpl {
         unsafe { self.buffers.as_mut().unwrap().1.mapped_mut() }
     }
 
-    fn present(&mut self) {
+    pub fn present(&mut self) {
         let _ = self
             .display
             .event_queue