use submodule

excalidraw/packages/math/src/angle.ts

@@ -0,0 +1,77 @@
+import { PRECISION } from "./utils";
+
+import type {
+  Degrees,
+  GlobalPoint,
+  LocalPoint,
+  PolarCoords,
+  Radians,
+} from "./types";
+
+export const normalizeRadians = (angle: Radians): Radians =>
+  angle < 0
+    ? (((angle % (2 * Math.PI)) + 2 * Math.PI) as Radians)
+    : ((angle % (2 * Math.PI)) as Radians);
+
+/**
+ * Return the polar coordinates for the given cartesian point represented by
+ * (x, y) for the center point 0,0 where the first number returned is the radius,
+ * the second is the angle in radians.
+ */
+export const cartesian2Polar = <P extends GlobalPoint | LocalPoint>([
+  x,
+  y,
+]: P): PolarCoords => [
+  Math.hypot(x, y),
+  normalizeRadians(Math.atan2(y, x) as Radians),
+];
+
+export function degreesToRadians(degrees: Degrees): Radians {
+  return ((degrees * Math.PI) / 180) as Radians;
+}
+
+export function radiansToDegrees(degrees: Radians): Degrees {
+  return ((degrees * 180) / Math.PI) as Degrees;
+}
+
+/**
+ * Determines if the provided angle is a right angle.
+ *
+ * @param rads The angle to measure
+ * @returns TRUE if the provided angle is a right angle
+ */
+export function isRightAngleRads(rads: Radians): boolean {
+  return Math.abs(Math.sin(2 * rads)) < PRECISION;
+}
+
+export function radiansBetweenAngles(
+  a: Radians,
+  min: Radians,
+  max: Radians,
+): boolean {
+  a = normalizeRadians(a);
+  min = normalizeRadians(min);
+  max = normalizeRadians(max);
+
+  if (min < max) {
+    return a >= min && a <= max;
+  }
+
+  // The range wraps around the 0 angle
+  return a >= min || a <= max;
+}
+
+export function radiansDifference(a: Radians, b: Radians): Radians {
+  a = normalizeRadians(a);
+  b = normalizeRadians(b);
+
+  let diff = a - b;
+
+  if (diff < -Math.PI) {
+    diff = (diff + 2 * Math.PI) as Radians;
+  } else if (diff > Math.PI) {
+    diff = (diff - 2 * Math.PI) as Radians;
+  }
+
+  return Math.abs(diff) as Radians;
+}