From 393f9e263964f8c7e11f2f124c8168afad81b47a Mon Sep 17 00:00:00 2001
From: Revar Desmera <revarbat@gmail.com>
Date: Fri, 14 Feb 2020 23:06:01 -0800
Subject: [PATCH] Q_Slerp() cleanup.

---
 quaternions.scad | 18 +++++++++++-------
 version.scad     |  2 +-
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/quaternions.scad b/quaternions.scad
index a471903..3934880 100644
--- a/quaternions.scad
+++ b/quaternions.scad
@@ -190,13 +190,17 @@ function Q_Dist(q1, q2) = norm(q2-q1);
 //   color("red",0.25) Qrot(b) cylinder(d=1, h=80);
 //   Qrot(Q_Slerp(a, b, 0.6)) cylinder(d=1, h=80);
 function Q_Slerp(q1, q2, u) = let(
-		dot = Q_Dot(q1, q2),
-		qq2 = dot<0? Q_Neg(q2) : q2,
-		dott = dot<0? -dot : dot,
-		theta = u * acos(constrain(dott,-1,1))
-	) (dott>0.9995)?
-		Q_Normalize(q1 + ((qq2-q1) * u)) :
-		(q1*cos(theta) + (Q_Normalize(qq2 - (q1 * dott)) * sin(theta)));
+		q1 = Q_Normalize(q1),
+		q2 = Q_Normalize(q2),
+		dot = Q_Dot(q1, q2)
+	) (dot>0.9995)? Q_Normalize(q1 + (u * (q2-q1))) :
+	let(
+		dot = constrain(dot,-1,1),
+		theta_0 = acos(dot),
+		theta = theta_0 * u,
+		q3 = Q_Normalize(q2 - q1*dot),
+		out = q1*cos(theta) + q3*sin(theta)
+	) out;
 
 
 // Function: Q_Matrix3()
diff --git a/version.scad b/version.scad
index 58ca33e..98b9eda 100644
--- a/version.scad
+++ b/version.scad
@@ -8,7 +8,7 @@
 //////////////////////////////////////////////////////////////////////
 
 
-BOSL_VERSION = [2,0,126];
+BOSL_VERSION = [2,0,127];
 
 
 // Section: BOSL Library Version Functions