Implement Canvas support for iced_tiny_skia

core/src/gradient.rs

@@ -0,0 +1,117 @@
+//! For creating a Gradient.
+pub mod linear;
+
+pub use linear::Linear;
+
+use crate::{Color, Point, Size};
+
+#[derive(Debug, Clone, PartialEq)]
+/// A fill which transitions colors progressively along a direction, either linearly, radially (TBD),
+/// or conically (TBD).
+pub enum Gradient {
+    /// A linear gradient interpolates colors along a direction from its `start` to its `end`
+    /// point.
+    Linear(Linear),
+}
+
+impl Gradient {
+    /// Creates a new linear [`linear::Builder`].
+    pub fn linear(position: impl Into<Position>) -> linear::Builder {
+        linear::Builder::new(position.into())
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq)]
+/// A point along the gradient vector where the specified [`color`] is unmixed.
+///
+/// [`color`]: Self::color
+pub struct ColorStop {
+    /// Offset along the gradient vector.
+    pub offset: f32,
+
+    /// The color of the gradient at the specified [`offset`].
+    ///
+    /// [`offset`]: Self::offset
+    pub color: Color,
+}
+
+#[derive(Debug)]
+/// The position of the gradient within its bounds.
+pub enum Position {
+    /// The gradient will be positioned with respect to two points.
+    Absolute {
+        /// The starting point of the gradient.
+        start: Point,
+        /// The ending point of the gradient.
+        end: Point,
+    },
+    /// The gradient will be positioned relative to the provided bounds.
+    Relative {
+        /// The top left position of the bounds.
+        top_left: Point,
+        /// The width & height of the bounds.
+        size: Size,
+        /// The start [Location] of the gradient.
+        start: Location,
+        /// The end [Location] of the gradient.
+        end: Location,
+    },
+}
+
+impl From<(Point, Point)> for Position {
+    fn from((start, end): (Point, Point)) -> Self {
+        Self::Absolute { start, end }
+    }
+}
+
+#[derive(Debug, Clone, Copy)]
+/// The location of a relatively-positioned gradient.
+pub enum Location {
+    /// Top left.
+    TopLeft,
+    /// Top.
+    Top,
+    /// Top right.
+    TopRight,
+    /// Right.
+    Right,
+    /// Bottom right.
+    BottomRight,
+    /// Bottom.
+    Bottom,
+    /// Bottom left.
+    BottomLeft,
+    /// Left.
+    Left,
+}
+
+impl Location {
+    fn to_absolute(self, top_left: Point, size: Size) -> Point {
+        match self {
+            Location::TopLeft => top_left,
+            Location::Top => {
+                Point::new(top_left.x + size.width / 2.0, top_left.y)
+            }
+            Location::TopRight => {
+                Point::new(top_left.x + size.width, top_left.y)
+            }
+            Location::Right => Point::new(
+                top_left.x + size.width,
+                top_left.y + size.height / 2.0,
+            ),
+            Location::BottomRight => {
+                Point::new(top_left.x + size.width, top_left.y + size.height)
+            }
+            Location::Bottom => Point::new(
+                top_left.x + size.width / 2.0,
+                top_left.y + size.height,
+            ),
+            Location::BottomLeft => {
+                Point::new(top_left.x, top_left.y + size.height)
+            }
+            Location::Left => {
+                Point::new(top_left.x, top_left.y + size.height / 2.0)
+            }
+        }
+    }
+}