Draft `Canvas` types and `clock` example

1 files changed, 78 insertions, 0 deletions

diff --git a/wgpu/src/widget/canvas/path.rs b/wgpu/src/widget/canvas/path.rs
new file mode 100644
index 00000000..2732b1bd
--- /dev/null
+++ b/wgpu/src/widget/canvas/path.rs
@@ -0,0 +1,78 @@
+use iced_native::{Point, Vector};
+
+#[allow(missing_debug_implementations)]
+pub struct Path {
+    raw: lyon::path::Builder,
+}
+
+impl Path {
+    pub fn new() -> Path {
+        Path {
+            raw: lyon::path::Path::builder(),
+        }
+    }
+
+    #[inline]
+    pub fn move_to(&mut self, point: Point) {
+        let _ = self.raw.move_to(lyon::math::Point::new(point.x, point.y));
+    }
+
+    #[inline]
+    pub fn line_to(&mut self, point: Point) {
+        let _ = self.raw.line_to(lyon::math::Point::new(point.x, point.y));
+    }
+
+    #[inline]
+    pub fn arc(&mut self, arc: Arc) {
+        self.ellipse(arc.into())
+    }
+
+    #[inline]
+    pub fn ellipse(&mut self, ellipse: Ellipse) {
+        let arc = lyon::geom::Arc {
+            center: lyon::math::Point::new(ellipse.center.x, ellipse.center.y),
+            radii: lyon::math::Vector::new(ellipse.radii.x, ellipse.radii.y),
+            x_rotation: lyon::math::Angle::radians(ellipse.rotation),
+            start_angle: lyon::math::Angle::radians(ellipse.start_angle),
+            sweep_angle: lyon::math::Angle::radians(ellipse.end_angle),
+        };
+
+        arc.for_each_quadratic_bezier(&mut |curve| {
+            let _ = self.raw.quadratic_bezier_to(curve.ctrl, curve.to);
+        });
+    }
+
+    #[inline]
+    pub fn close(&mut self) {
+        self.raw.close()
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Arc {
+    pub center: Point,
+    pub radius: f32,
+    pub start_angle: f32,
+    pub end_angle: f32,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct Ellipse {
+    pub center: Point,
+    pub radii: Vector,
+    pub rotation: f32,
+    pub start_angle: f32,
+    pub end_angle: f32,
+}
+
+impl From<Arc> for Ellipse {
+    fn from(arc: Arc) -> Ellipse {
+        Ellipse {
+            center: arc.center,
+            radii: Vector::new(arc.radius, arc.radius),
+            rotation: 0.0,
+            start_angle: arc.start_angle,
+            end_angle: arc.end_angle,
+        }
+    }
+}