From 0a6902acaeb1233540bcabfbbb28a7055e0240ad Mon Sep 17 00:00:00 2001
From: c0d3d3v <c0d3d3v@mag-keinen-spam.de>
Date: Tue, 3 May 2022 13:47:28 +0200
Subject: [PATCH] Optimization of the closest_point_on_line function

---
 src/base/vmath.h | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/base/vmath.h b/src/base/vmath.h
index e684e30b3..ec02c950a 100644
--- a/src/base/vmath.h
+++ b/src/base/vmath.h
@@ -145,16 +145,16 @@ typedef vector2_base<bool> bvec2;
 typedef vector2_base<int> ivec2;
 
 template<typename T>
-inline bool closest_point_on_line(vector2_base<T> line_point0, vector2_base<T> line_point1, vector2_base<T> target_point, vector2_base<T> &out_pos)
+inline bool closest_point_on_line(vector2_base<T> line_pointA, vector2_base<T> line_pointB, vector2_base<T> target_point, vector2_base<T> &out_pos)
 {
-	vector2_base<T> c = target_point - line_point0;
-	vector2_base<T> v = (line_point1 - line_point0);
-	T d = length(line_point0 - line_point1);
-	if(d > 0)
+	vector2_base<T> AP = target_point - line_pointA;
+	vector2_base<T> AB = line_pointB - line_pointA;
+	T SquaredMagnitudeAB = dot(AB, AB);
+	if(SquaredMagnitudeAB > 0)
 	{
-		v = normalize_pre_length<T>(v, d);
-		T t = dot(v, c) / d;
-		out_pos = mix(line_point0, line_point1, clamp(t, (T)0, (T)1));
+		T APdotAB = dot(AP, AB);
+		T t = APdotAB / SquaredMagnitudeAB;
+		out_pos = line_pointA + AB * clamp(t, (T)0, (T)1);
 		return true;
 	}
 	else