Add circle fill mode

src/fill/circle.rs

@@ -0,0 +1,40 @@
+use crate::fill::FillMode;
+use crate::vec::Vector;
+
+const INTERVAL: f32 = 4.0;
+
+pub struct CircleFillMode {
+    center: Vector,
+    interval: f32
+}
+
+impl CircleFillMode {
+    pub fn new(size: Vector) -> Self {
+        Self {
+            center: size.center(),
+            interval: size.smaller() / INTERVAL,
+        }
+    }
+}
+
+impl FillMode for CircleFillMode {
+    fn sample(&self, _: f32, pos: Vector) -> f32 {
+        ((pos - self.center).length() % self.interval) / self.interval
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn sample() {
+        let fill = CircleFillMode::new(Vector::new(10.0, 8.0));
+
+        let sample_1 = fill.sample(0.0, Vector::new(5.0, 3.0));
+        let sample_2 = fill.sample(0.0, Vector::new(8.5, 4.0));
+
+        assert!(0.4 < sample_1 && sample_1 < 0.6);
+        assert!(0.7 < sample_2 && sample_2 < 0.8);
+    }
+}

src/fill/mod.rs

@@ -1,4 +1,5 @@
 mod level;
+mod circle;
 
 use crate::vec::Vector;
 

src/vec.rs

@@ -22,6 +22,10 @@ impl Vector {
         (self.x * self.x + self.y * self.y).sqrt()
     }
 
+    pub fn smaller(self) -> f32 {
+        self.x.min(self.y)
+    }
+
     /// Creates a vector with the on screen coordinates based on the terminal coordinates.
     /// # Arguments
     /// * `x`: The x axis of the terminal character.
@@ -51,6 +55,27 @@ mod test {
         assert_eq!(5.0, vec.y);
     }
 
+    #[test]
+    fn center() {
+        let vec = Vector::new(3.0, 8.0);
+
+        assert_eq!(1.5, vec.center().x);
+        assert_eq!(4.0, vec.center().y);
+    }
+
+    #[test]
+    fn length() {
+        let vec = Vector::new(3.0, 6.0);
+
+        assert!(6.7 < vec.length() && vec.length() < 6.8);
+    }
+
+    #[test]
+    fn smaller() {
+        assert_eq!(4.0, Vector::new(7.0, 4.0).smaller());
+        assert_eq!(2.0, Vector::new(2.0, 9.0).smaller());
+    }
+
     #[test]
     fn from_terminal() {
         let vec = Vector::from_terminal(2, 4);
@@ -60,20 +85,12 @@ mod test {
     }
 
     #[test]
-    fn copy() {
-        let vec = Vector::new(2.0, 4.0);
-        let copy = vec;
+    fn sub() {
+        let left = Vector::new(8.0, 15.0);
+        let right = Vector::new(2.0, 4.0);
+        let result = left - right;
 
-        assert_eq!(vec.x, copy.x);
-        assert_eq!(vec.y, copy.y);
-    }
-
-    #[test]
-    fn clone() {
-        let vec = Vector::new(2.0, 4.0);
-        let clone = vec.clone();
-
-        assert_eq!(vec.x, clone.x);
-        assert_eq!(vec.y, clone.y);
+        assert_eq!(6.0, result.x);
+        assert_eq!(11.0, result.y);
     }
 }