Fix typo in vec2.test.ts

src/vec2.test.ts

@@ -125,31 +125,31 @@ test('rotate', () => {
 })
 
 describe('angle', () => {
-	it('shoud work in the case of 0°', () => {
+	it('should work in the case of 0°', () => {
 		expect(vec2.angle([1, 0])).toEqual(0)
 	})
 
-	it('shoud returns 0° for same vectors', () => {
+	it('should returns 0° for same vectors', () => {
 		expect(vec2.angle([1, 2], [1, 2])).toEqual(0)
 	})
 
-	it('shoud returns 0° for collinear vectors', () => {
+	it('should returns 0° for collinear vectors', () => {
 		expect(vec2.angle([1, 2], [3, 6])).toEqual(0)
 	})
 
-	it('shoud returns 0° for zero vector', () => {
+	it('should returns 0° for zero vector', () => {
 		expect(vec2.angle([0, 0])).toEqual(0)
 	})
 
-	it('shoud returns 0° for vectors one of whom is zero', () => {
+	it('should returns 0° for vectors one of whom is zero', () => {
 		expect(vec2.angle([0, 0], [1, 0])).toEqual(0)
 	})
 
-	it('shoud returns 0° for vectors one of whom is zero', () => {
+	it('should returns 0° for vectors one of whom is zero', () => {
 		expect(vec2.angle([3, 4], [0, 0])).toEqual(0)
 	})
 
-	it('shoud work in the case of 90°', () => {
+	it('should work in the case of 90°', () => {
 		expect(vec2.angle([0, 1])).toEqual(90)
 	})
 

src/vec2.ts

@@ -579,7 +579,7 @@ export namespace vec2 {
 		if (!b) return Math.atan2(a[1], a[0]) * Common.RAD2DEG
 
 		if (eq(a, b)) {
-			// Exactly vectors
+			// Exactly the same vectors
 			return 0
 		}
 
@@ -595,8 +595,8 @@ export namespace vec2 {
 		}
 
 		const sign = x1 * y2 - y1 * x2 >= 0 ? 1 : -1
-		const acos = Math.acos(scalar.clamp(dot(a, b), -1, 1) / mag)
 
+		const acos = Math.acos(scalar.clamp(dot(a, b) / mag, -1, 1))
 		const angle = sign * acos * Common.RAD2DEG
 
 		return angle <= -180 ? angle + 360 : angle