Vector times scalar and unit vectors

1 files changed, 11 insertions, 13 deletions

diff --git a/src/entities/bug.rs b/src/entities/bug.rs
index 913253c..f64669d 100644
--- a/src/entities/bug.rs
+++ b/src/entities/bug.rs
@@ -5,31 +5,29 @@ use hitbox::*;
 pub struct Bug {
     pub pos: Vec2d,
     pub rotation: f64,
+    pub velocity: Vec2d,
     pub alive: bool
 }
 
 const SPEED: f64 = 175.;
 
 impl Bug {
-    pub fn new(x: f64, y: f64, facing: f64) -> Bug {
+    pub fn new(x: f64, y: f64) -> Bug {
+        let pos = Vec2d {
+            x: x,
+            y: y
+        };
+        let pos_unit = pos.unit();
         Bug {
-            pos: Vec2d {
-                x: x,
-                y: y
-            },
-            rotation: facing,
+            pos: pos,
+            rotation: (-pos).angle(),
+            velocity: -pos_unit * SPEED,
             alive: true
         }
     }
 
     pub fn advance(&mut self, seconds: f64) {
-        self.rotation = (-self.pos).angle();
-        let distance = SPEED*seconds;
-        let delta_pos = Vec2d {
-            x: distance * self.rotation.cos(),
-            y: distance * self.rotation.sin()
-        };
-        self.pos = self.pos + delta_pos;
+        self.pos = self.pos + self.velocity * seconds;
     }
 }