2 files changed, 87 insertions, 0 deletions
diff --git a/third_party/rust/uniffi-example-sprites/src/lib.rs b/third_party/rust/uniffi-example-sprites/src/lib.rs
new file mode 100644
index 0000000000..7aa3741d19
--- /dev/null
+++ b/third_party/rust/uniffi-example-sprites/src/lib.rs
@@ -0,0 +1,65 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use std::sync::RwLock;
+
+// A point in two-dimensional space.
+#[derive(Debug, Clone)]
+pub struct Point {
+    x: f64,
+    y: f64,
+}
+
+// A magnitude and direction in two-dimensional space.
+// For simplicity we represent this as a point relative to the origin.
+#[derive(Debug, Clone)]
+pub struct Vector {
+    dx: f64,
+    dy: f64,
+}
+
+// Move from the given Point, according to the given Vector.
+pub fn translate(p: &Point, v: Vector) -> Point {
+    Point {
+        x: p.x + v.dx,
+        y: p.y + v.dy,
+    }
+}
+
+// An entity in our imaginary world, which occupies a position in space
+// and which can move about over time.
+#[derive(Debug)]
+pub struct Sprite {
+    // We must use interior mutability for managing mutable state, hence the `RwLock`.
+    current_position: RwLock<Point>,
+}
+
+impl Sprite {
+    fn new(initial_position: Option<Point>) -> Sprite {
+        Sprite {
+            current_position: RwLock::new(initial_position.unwrap_or(Point { x: 0.0, y: 0.0 })),
+        }
+    }
+
+    fn new_relative_to(reference: Point, direction: Vector) -> Sprite {
+        Sprite {
+            current_position: RwLock::new(translate(&reference, direction)),
+        }
+    }
+
+    fn get_position(&self) -> Point {
+        self.current_position.read().unwrap().clone()
+    }
+
+    fn move_to(&self, position: Point) {
+        *self.current_position.write().unwrap() = position;
+    }
+
+    fn move_by(&self, direction: Vector) {
+        let mut current_position = self.current_position.write().unwrap();
+        *current_position = translate(&current_position, direction)
+    }
+}
+
+include!(concat!(env!("OUT_DIR"), "/sprites.uniffi.rs"));
diff --git a/third_party/rust/uniffi-example-sprites/src/sprites.udl b/third_party/rust/uniffi-example-sprites/src/sprites.udl
new file mode 100644
index 0000000000..6781c6cee5
--- /dev/null
+++ b/third_party/rust/uniffi-example-sprites/src/sprites.udl
@@ -0,0 +1,22 @@
+
+namespace sprites {
+  Point translate([ByRef] Point position, Vector direction);
+};
+
+dictionary Point {
+  double x;
+  double y;
+};
+
+dictionary Vector {
+  double dx;
+  double dy;
+};
+
+interface Sprite {
+  constructor(Point? initial_position);
+  [Name=new_relative_to] constructor(Point reference, Vector direction);
+  Point get_position();
+  void move_to(Point position);
+  void move_by(Vector direction);
+};