1 files changed, 24 insertions, 0 deletions
diff --git a/src/geometry.rs b/src/geometry.rs
index 6f7f658..64414e0 100644
--- a/src/geometry.rs
+++ b/src/geometry.rs
@@ -1,4 +1,5 @@
 use std::ops::*;
+use std::f64;
 
 #[derive(Debug, Clone, Copy, PartialEq)]
 pub struct Vec2d {
@@ -35,6 +36,29 @@ impl Vec2d {
             y: self.y / mag
         }
     }
+
+    pub fn dot(&self, other: Vec2d) -> f64 {
+        (self.x * other.x) + (self.y * other.y)
+    }
+}
+
+pub struct LineSegment {
+    pub start: Vec2d,
+    pub end: Vec2d
+}
+
+impl LineSegment {
+    pub fn distance(&self, other: Vec2d) -> f64 {
+        let length_squared = self.start.distance_squared(self.end);
+        if length_squared == 0.0 {
+            return self.start.distance(other);
+        }
+
+        let t = f64::max(0., f64::min(1., (other - self.start).dot(self.end - self.start) / length_squared));
+        let projection = self.start + (self.end - self.start) * t;
+        other.distance(projection)
+    }
+    
 }
 
 impl Add for Vec2d {