Remove circular dependency: rectangle <-> angle

Author: hecrj

core/src/angle.rs

@@ -1,6 +1,4 @@
-use crate::{Point, Rectangle, Vector};
-
-use std::f32::consts::{FRAC_PI_2, PI};
+use std::f32::consts::PI;
 use std::fmt::Display;
 use std::ops::{Add, AddAssign, Div, Mul, RangeInclusive, Rem, Sub, SubAssign};
 
@@ -93,22 +91,6 @@ impl Radians {
 
     /// The amount of radians in half a circle.
     pub const PI: Self = Self(PI);
-
-    /// Calculates the line in which the angle intercepts the `bounds`.
-    pub fn to_distance(&self, bounds: &Rectangle) -> (Point, Point) {
-        let angle = self.0 - FRAC_PI_2;
-        let r = Vector::new(f32::cos(angle), f32::sin(angle));
-
-        let distance_to_rect = f32::max(
-            f32::abs(r.x * bounds.width / 2.0),
-            f32::abs(r.y * bounds.height / 2.0),
-        );
-
-        let start = bounds.center() - r * distance_to_rect;
-        let end = bounds.center() + r * distance_to_rect;
-
-        (start, end)
-    }
 }
 
 impl From<Degrees> for Radians {

core/src/rectangle.rs

@@ -337,6 +337,30 @@ impl Rectangle<f32> {
 
         Point::new(x, y)
     }
+
+    /// Returns the two endpoints of a chord through the rectangle's center
+    /// at the given `angle`.
+    ///
+    /// The angle is measured clockwise from the negative y-axis, so `0`
+    /// produces a vertical chord and `π/2` a horizontal one. The returned
+    /// points are `(start, end)`, symmetric about [`Rectangle::center`].
+    pub fn chord(&self, angle: impl Into<Radians>) -> (Point, Point) {
+        use std::f32::consts::FRAC_PI_2;
+
+        let angle = angle.into().0 - FRAC_PI_2;
+        let r = Vector::new(f32::cos(angle), f32::sin(angle));
+
+        let distance_to_rect = f32::max(
+            f32::abs(r.x * self.width / 2.0),
+            f32::abs(r.y * self.height / 2.0),
+        );
+
+        let center = self.center();
+        let start = center - r * distance_to_rect;
+        let end = center + r * distance_to_rect;
+
+        (start, end)
+    }
 }
 
 impl std::ops::Mul<f32> for Rectangle<f32> {

graphics/src/gradient.rs

@@ -160,7 +160,7 @@ pub fn pack(gradient: &core::Gradient, bounds: Rectangle) -> Packed {
                 pack_f16s([offsets[6], offsets[7]]),
             ];
 
-            let (start, end) = linear.angle.to_distance(&bounds);
+            let (start, end) = bounds.chord(linear.angle);
 
             let direction = [start.x, start.y, end.x, end.y];
 

tiny_skia/src/engine.rs

@@ -136,7 +136,7 @@ impl Engine {
                 shader: match background {
                     Background::Color(color) => tiny_skia::Shader::SolidColor(into_color(*color)),
                     Background::Gradient(Gradient::Linear(linear)) => {
-                        let (start, end) = linear.angle.to_distance(&quad.bounds);
+                        let (start, end) = quad.bounds.chord(linear.angle);
 
                         let stops: Vec<tiny_skia::GradientStop> = linear
                             .stops