Add transform stack to canvas::Frame

core/src/color.rs

@@ -44,11 +44,18 @@ impl Color {
     ///
     /// [`Color`]: struct.Color.html
     pub fn from_rgb8(r: u8, g: u8, b: u8) -> Color {
+        Color::from_rgba8(r, g, b, 1.0)
+    }
+
+    /// Creates a [`Color`] from its RGB8 components and an alpha value.
+    ///
+    /// [`Color`]: struct.Color.html
+    pub fn from_rgba8(r: u8, g: u8, b: u8, a: f32) -> Color {
         Color {
             r: f32::from(r) / 255.0,
             g: f32::from(g) / 255.0,
             b: f32::from(b) / 255.0,
-            a: 1.0,
+            a,
         }
     }
 

core/src/point.rs

@@ -11,10 +11,15 @@ pub struct Point {
 }
 
 impl Point {
+    /// The origin (i.e. a [`Point`] with both X=0 and Y=0).
+    ///
+    /// [`Point`]: struct.Point.html
+    pub const ORIGIN: Point = Point::new(0.0, 0.0);
+
     /// Creates a new [`Point`] with the given coordinates.
     ///
     /// [`Point`]: struct.Point.html
-    pub fn new(x: f32, y: f32) -> Self {
+    pub const fn new(x: f32, y: f32) -> Self {
         Self { x, y }
     }
 }