From f0f48c0fb4b04ebed449a03d7a4507588eb4dedd Mon Sep 17 00:00:00 2001
From: Lars Mueller <appgurulars@gmx.de>
Date: Wed, 24 Mar 2021 10:36:28 +0100
Subject: [PATCH] Add vector.angle

---
 vector.lua | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/vector.lua b/vector.lua
index 4446718..0c50e60 100644
--- a/vector.lua
+++ b/vector.lua
@@ -175,6 +175,13 @@ function dot(v, other_v)
     return sum
 end
 
+--+ Angle between two vectors
+--> Signed angle in radians
+function angle(v, other_v)
+    -- Based on dot(v, w) = |v| * |w| * cos(x)
+    return math.acos(dot(v, other_v) / length(v) / length(other_v))
+end
+
 function box_box_collision(diff, box, other_box)
     for index, diff in pairs(diff) do
         if box[index] + diff > other_box[index + 3] or other_box[index] > box[index + 3] + diff then