Merge pull request #193 from hecrj/feature/canvas

Canvas widget for 2D graphics

4 files changed, 67 insertions, 2 deletions

diff --git a/core/src/color.rs b/core/src/color.rs
index d6bdd365..db509b88 100644
--- a/core/src/color.rs
+++ b/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,
         }
     }
 
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 3cbce743..ea5e8b43 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -22,6 +22,7 @@ mod font;
 mod length;
 mod point;
 mod rectangle;
+mod size;
 mod vector;
 
 pub use align::{Align, HorizontalAlignment, VerticalAlignment};
@@ -31,4 +32,5 @@ pub use font::Font;
 pub use length::Length;
 pub use point::Point;
 pub use rectangle::Rectangle;
+pub use size::Size;
 pub use vector::Vector;
diff --git a/core/src/point.rs b/core/src/point.rs
index 47c8b142..b9a8149c 100644
--- a/core/src/point.rs
+++ b/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 }
     }
 }
diff --git a/core/src/size.rs b/core/src/size.rs
new file mode 100644
index 00000000..389b3247
--- /dev/null
+++ b/core/src/size.rs
@@ -0,0 +1,51 @@
+use std::f32;
+
+/// An amount of space in 2 dimensions.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub struct Size {
+    /// The width.
+    pub width: f32,
+    /// The height.
+    pub height: f32,
+}
+
+impl Size {
+    /// A [`Size`] with zero width and height.
+    ///
+    /// [`Size`]: struct.Size.html
+    pub const ZERO: Size = Size::new(0., 0.);
+
+    /// A [`Size`] with infinite width and height.
+    ///
+    /// [`Size`]: struct.Size.html
+    pub const INFINITY: Size = Size::new(f32::INFINITY, f32::INFINITY);
+
+    /// A [`Size`] of infinite width and height.
+    ///
+    /// [`Size`]: struct.Size.html
+    pub const fn new(width: f32, height: f32) -> Self {
+        Size { width, height }
+    }
+
+    /// Increments the [`Size`] to account for the given padding.
+    ///
+    /// [`Size`]: struct.Size.html
+    pub fn pad(&self, padding: f32) -> Self {
+        Size {
+            width: self.width + padding * 2.0,
+            height: self.height + padding * 2.0,
+        }
+    }
+}
+
+impl From<[f32; 2]> for Size {
+    fn from([width, height]: [f32; 2]) -> Self {
+        Size { width, height }
+    }
+}
+
+impl From<[u16; 2]> for Size {
+    fn from([width, height]: [u16; 2]) -> Self {
+        Size::new(width.into(), height.into())
+    }
+}