6 files changed, 99 insertions, 23 deletions
diff --git a/wgpu/src/widget/canvas/fill.rs b/wgpu/src/widget/canvas/fill.rs
index 5ce24cf3..a2010e45 100644
--- a/wgpu/src/widget/canvas/fill.rs
+++ b/wgpu/src/widget/canvas/fill.rs
@@ -12,3 +12,9 @@ impl Default for Fill {
         Fill::Color(Color::BLACK)
     }
 }
+
+impl From<Color> for Fill {
+    fn from(color: Color) -> Fill {
+        Fill::Color(color)
+    }
+}
diff --git a/wgpu/src/widget/canvas/frame.rs b/wgpu/src/widget/canvas/frame.rs
index f6495bdc..24fd0d7e 100644
--- a/wgpu/src/widget/canvas/frame.rs
+++ b/wgpu/src/widget/canvas/frame.rs
@@ -89,14 +89,14 @@ impl Frame {
     ///
     /// [`Path`]: path/struct.Path.html
     /// [`Frame`]: struct.Frame.html
-    pub fn fill(&mut self, path: &Path, fill: Fill) {
+    pub fn fill(&mut self, path: &Path, fill: impl Into<Fill>) {
         use lyon::tessellation::{
             BuffersBuilder, FillOptions, FillTessellator,
         };
 
         let mut buffers = BuffersBuilder::new(
             &mut self.buffers,
-            FillVertex(match fill {
+            FillVertex(match fill.into() {
                 Fill::Color(color) => color.into_linear(),
             }),
         );
@@ -127,11 +127,13 @@ impl Frame {
     ///
     /// [`Path`]: path/struct.Path.html
     /// [`Frame`]: struct.Frame.html
-    pub fn stroke(&mut self, path: &Path, stroke: Stroke) {
+    pub fn stroke(&mut self, path: &Path, stroke: impl Into<Stroke>) {
         use lyon::tessellation::{
             BuffersBuilder, StrokeOptions, StrokeTessellator,
         };
 
+        let stroke = stroke.into();
+
         let mut buffers = BuffersBuilder::new(
             &mut self.buffers,
             StrokeVertex(stroke.color.into_linear()),
@@ -173,9 +175,11 @@ impl Frame {
     /// [`Text`]: struct.Text.html
     /// [`Frame`]: struct.Frame.html
     /// [`Canvas`]: struct.Canvas.html
-    pub fn fill_text(&mut self, text: Text) {
+    pub fn fill_text(&mut self, text: impl Into<Text>) {
         use std::f32;
 
+        let text = text.into();
+
         let position = if self.transforms.current.is_identity {
             text.position
         } else {
@@ -262,13 +266,15 @@ impl Frame {
     ///
     /// [`Frame`]: struct.Frame.html
     pub fn into_primitive(mut self) -> Primitive {
-        self.primitives.push(Primitive::Mesh2D {
-            origin: Point::ORIGIN,
-            buffers: triangle::Mesh2D {
-                vertices: self.buffers.vertices,
-                indices: self.buffers.indices,
-            },
-        });
+        if !self.buffers.indices.is_empty() {
+            self.primitives.push(Primitive::Mesh2D {
+                origin: Point::ORIGIN,
+                buffers: triangle::Mesh2D {
+                    vertices: self.buffers.vertices,
+                    indices: self.buffers.indices,
+                },
+            });
+        }
 
         Primitive::Group {
             primitives: self.primitives,
diff --git a/wgpu/src/widget/canvas/layer/cache.rs b/wgpu/src/widget/canvas/layer/cache.rs
index 20a095bd..4f8c2bec 100644
--- a/wgpu/src/widget/canvas/layer/cache.rs
+++ b/wgpu/src/widget/canvas/layer/cache.rs
@@ -6,6 +6,19 @@ use crate::{
 use iced_native::Size;
 use std::{cell::RefCell, marker::PhantomData, sync::Arc};
 
+enum State {
+    Empty,
+    Filled {
+        bounds: Size,
+        primitive: Arc<Primitive>,
+    },
+}
+
+impl Default for State {
+    fn default() -> Self {
+        State::Empty
+    }
+}
 /// A simple cache that stores generated geometry to avoid recomputation.
 ///
 /// A [`Cache`] will not redraw its geometry unless the dimensions of its layer
@@ -19,12 +32,16 @@ pub struct Cache<T: Drawable> {
     state: RefCell<State>,
 }
 
-enum State {
-    Empty,
-    Filled {
-        bounds: Size,
-        primitive: Arc<Primitive>,
-    },
+impl<T> Default for Cache<T>
+where
+    T: Drawable,
+{
+    fn default() -> Self {
+        Self {
+            input: PhantomData,
+            state: Default::default(),
+        }
+    }
 }
 
 impl<T> Cache<T>
@@ -37,7 +54,7 @@ where
     pub fn new() -> Self {
         Cache {
             input: PhantomData,
-            state: RefCell::new(State::Empty),
+            state: Default::default(),
         }
     }
 
diff --git a/wgpu/src/widget/canvas/path.rs b/wgpu/src/widget/canvas/path.rs
index e7ff47f3..c26bf187 100644
--- a/wgpu/src/widget/canvas/path.rs
+++ b/wgpu/src/widget/canvas/path.rs
@@ -7,6 +7,8 @@ mod builder;
 pub use arc::Arc;
 pub use builder::Builder;
 
+use iced_native::{Point, Size};
+
 /// An immutable set of points that may or may not be connected.
 ///
 /// A single [`Path`] can represent different kinds of 2D shapes!
@@ -33,6 +35,33 @@ impl Path {
         builder.build()
     }
 
+    /// Creates a new [`Path`] representing a line segment given its starting
+    /// and end points.
+    ///
+    /// [`Path`]: struct.Path.html
+    pub fn line(from: Point, to: Point) -> Self {
+        Self::new(|p| {
+            p.move_to(from);
+            p.line_to(to);
+        })
+    }
+
+    /// Creates a new [`Path`] representing a rectangle given its top-left
+    /// corner coordinate and its `Size`.
+    ///
+    /// [`Path`]: struct.Path.html
+    pub fn rectangle(top_left: Point, size: Size) -> Self {
+        Self::new(|p| p.rectangle(top_left, size))
+    }
+
+    /// Creates a new [`Path`] representing a circle given its center
+    /// coordinate and its radius.
+    ///
+    /// [`Path`]: struct.Path.html
+    pub fn circle(center: Point, radius: f32) -> Self {
+        Self::new(|p| p.circle(center, radius))
+    }
+
     #[inline]
     pub(crate) fn raw(&self) -> &lyon::path::Path {
         &self.raw
diff --git a/wgpu/src/widget/canvas/path/builder.rs b/wgpu/src/widget/canvas/path/builder.rs
index a013149e..6511fa52 100644
--- a/wgpu/src/widget/canvas/path/builder.rs
+++ b/wgpu/src/widget/canvas/path/builder.rs
@@ -133,11 +133,14 @@ impl Builder {
     ///
     /// [`Path`]: struct.Path.html
     #[inline]
-    pub fn rectangle(&mut self, p: Point, size: Size) {
-        self.move_to(p);
-        self.line_to(Point::new(p.x + size.width, p.y));
-        self.line_to(Point::new(p.x + size.width, p.y + size.height));
-        self.line_to(Point::new(p.x, p.y + size.height));
+    pub fn rectangle(&mut self, top_left: Point, size: Size) {
+        self.move_to(top_left);
+        self.line_to(Point::new(top_left.x + size.width, top_left.y));
+        self.line_to(Point::new(
+            top_left.x + size.width,
+            top_left.y + size.height,
+        ));
+        self.line_to(Point::new(top_left.x, top_left.y + size.height));
         self.close();
     }
 
diff --git a/wgpu/src/widget/canvas/text.rs b/wgpu/src/widget/canvas/text.rs
index d1cf1a0f..c4cae30e 100644
--- a/wgpu/src/widget/canvas/text.rs
+++ b/wgpu/src/widget/canvas/text.rs
@@ -32,3 +32,18 @@ impl Default for Text {
         }
     }
 }
+
+impl From<String> for Text {
+    fn from(content: String) -> Text {
+        Text {
+            content,
+            ..Default::default()
+        }
+    }
+}
+
+impl From<&str> for Text {
+    fn from(content: &str) -> Text {
+        String::from(content).into()
+    }
+}