Added a new method for calculating the gesture triangle shape

and moved gesture data to a separate file

src/helpers/vector2.js

@@ -0,0 +1,20 @@
+export function lengthSquared(p) {
+  return p.x * p.x + p.y * p.y;
+}
+
+export function length(p) {
+  return Math.sqrt(lengthSquared(p));
+}
+
+export function normalize(p) {
+  const l = length(p);
+  return { x: p.x / l, y: p.y / l };
+}
+
+export function dot(a, b) {
+  return a.x * b.x + a.y * b.y;
+}
+
+export function subtract(a, b) {
+  return { x: a.x - b.x, y: a.y - b.y };
+}