4 files changed, 30 insertions, 0 deletions
diff --git a/client/lib/utils/dotProduct.ts b/client/lib/utils/dotProduct.ts
new file mode 100644
index 0000000..59f8857
--- /dev/null
+++ b/client/lib/utils/dotProduct.ts
@@ -0,0 +1,4 @@
+import type { Coord2D } from "../interfaces";
+
+export const dotProduct = (vector1: Coord2D, vector2: Coord2D): number =>
+  vector1.x * vector2.x + vector1.y * vector2.y;
diff --git a/client/lib/utils/index.ts b/client/lib/utils/index.ts
new file mode 100644
index 0000000..1f8e2f0
--- /dev/null
+++ b/client/lib/utils/index.ts
@@ -0,0 +1,3 @@
+export * from "./rotateVector";
+export * from "./normalizeVector";
+export * from "./dotProduct";
diff --git a/client/lib/utils/normalizeVector.ts b/client/lib/utils/normalizeVector.ts
new file mode 100644
index 0000000..e6dfd7f
--- /dev/null
+++ b/client/lib/utils/normalizeVector.ts
@@ -0,0 +1,8 @@
+import type { Coord2D } from "../interfaces";
+
+export const normalizeVector = (vector: Coord2D): Coord2D => {
+  const { x, y } = vector;
+  const length = Math.sqrt(x * x + y * y);
+
+  return { x: x / length, y: y / length };
+};
diff --git a/client/lib/utils/rotateVector.ts b/client/lib/utils/rotateVector.ts
new file mode 100644
index 0000000..82bb54d
--- /dev/null
+++ b/client/lib/utils/rotateVector.ts
@@ -0,0 +1,15 @@
+import type { Coord2D } from "../interfaces";
+
+/**
+ * ([[cos(θ), -sin(θ),])  ([x,)
+ * ([sin(θ),  cos(θ)] ])  ( y])
+ */
+export const rotateVector = (vector: Coord2D, theta: number): Coord2D => {
+  const rads = (theta * Math.PI) / 180;
+  const [cos, sin] = [Math.cos(rads), Math.sin(rads)];
+
+  return {
+    x: vector.x * cos - vector.y * sin,
+    y: vector.x * sin + vector.y * cos,
+  };
+};