Vector2: Added angleTo()

puxiao · web-flow · commit 7e32385ca8d5 · 2021-07-29T11:38:56.000+08:00
diff --git a/src/math/Vector2.js b/src/math/Vector2.js
@@ -1,3 +1,5 @@
+import * as MathUtils from './MathUtils.js';
+
 class Vector2 {
 
 	constructor( x = 0, y = 0 ) {
@@ -364,6 +366,20 @@ class Vector2 {
 		return angle;
 
 	}
+	
+	angleTo( v ) {
+
+		const denominator = Math.sqrt( this.lengthSq() * v.lengthSq() )
+
+		if (denominator === 0) return Math.PI / 2;
+
+		const theta = this.dot(v) / denominator;
+		
+		// clamp, to handle numerical problems
+
+		return Math.acos( MathUtils.clamp( theta, - 1, 1 ) );
+
+	}
 
 	distanceTo( v ) {
 
