From 8785fda836fe3884bd51444fc55983fe135c6c9d Mon Sep 17 00:00:00 2001
From: Arne Dußin
Date: Sat, 21 Nov 2020 01:08:06 +0100
Subject: Add unit tests for triangle

---
 src/math/triangle.rs | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

(limited to 'src/math')

diff --git a/src/math/triangle.rs b/src/math/triangle.rs
index 53c7560..05e258d 100644
--- a/src/math/triangle.rs
+++ b/src/math/triangle.rs
@@ -30,6 +30,11 @@ impl<T: Scalar + Copy> Triangle<T> {
         }
     }
 
+    /// Get the corners immutably
+    pub fn corners(&self) -> &[Vec2<T>; 3] {
+        &self.corners
+    }
+
     /// Create a new Triangle from a three-point slice, instead of the three points one after
     /// another.
     pub fn from_slice(corners: [Vec2<T>; 3]) -> Self
@@ -60,6 +65,21 @@ impl<T: Scalar + Copy> Triangle<T> {
     }
 }
 
+/// Convert a three-point-slice into a triangle
+impl<T: Scalar + Copy + ClosedSub + ClosedMul + PartialOrd + Zero> From<[Vec2<T>; 3]>
+    for Triangle<T>
+{
+    fn from(corners: [Vec2<T>; 3]) -> Self {
+        Self::new(corners[0], corners[1], corners[2])
+    }
+}
+/// Convert a triangle into a three-point-slice. The corners are in counterclockwise order.
+impl<T: Scalar + Copy> Into<[Vec2<T>; 3]> for Triangle<T> {
+    fn into(self) -> [Vec2<T>; 3] {
+        self.corners
+    }
+}
+
 #[derive(PartialEq, Eq)]
 pub(crate) enum TripletOrientation {
     Clockwise,
@@ -131,6 +151,43 @@ mod test {
     use super::*;
     use std::f64::consts::PI;
 
+    #[test]
+    fn new() {
+        let a = Vec2::new(0., 0.);
+        let b = Vec2::new(0., 1.);
+        let c = Vec2::new(1., 1.);
+
+        // Create with counterclockwise order.
+        let triangle = Triangle::new(a, b, c);
+        assert_eq!(triangle.corners(), &[a, b, c]);
+
+        // Create with clockwise order.
+        let triangle = Triangle::new(a, c, b);
+        assert_eq!(triangle.corners(), &[a, b, c]);
+
+        // Create with different starting corner
+        let triangle = Triangle::from([b, c, a]);
+        assert_eq!(triangle.corners(), &[b, c, a]);
+
+        // Create with collinear corners
+        let triangle = Triangle::new(c, c, b);
+        assert_eq!(triangle.corners(), &[c, c, b]);
+    }
+
+    #[test]
+    fn contains_point() {
+        let a = Vec2::new(0., 0.);
+        let b = Vec2::new(-1., -1.);
+        let c = Vec2::new(-2., 0.);
+
+        let triangle = Triangle::new(a, b, c);
+
+        assert!(triangle.contains_point(b));
+        assert!(triangle.contains_point(Vec2::new(-0.5, -0.5)));
+        assert!(triangle.contains_point(Vec2::new(-1., -0.5)));
+        assert!(!triangle.contains_point(Vec2::new(-2., -2.)));
+    }
+
     #[test]
     fn triplet_angle() {
         assert_eq!(
-- 
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