From 6e3860f232b99c4150f03ba4769b314ce415b6a3 Mon Sep 17 00:00:00 2001
From: Brendan Zabarauskas <bjzaba@yahoo.com.au>
Date: Tue, 10 Sep 2013 14:49:53 +1000
Subject: [PATCH] Remove util::half

---
 src/cgmath/matrix.rs | 26 +++++++++++++-------------
 src/cgmath/util.rs   |  2 --
 2 files changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/cgmath/matrix.rs b/src/cgmath/matrix.rs
index 7e20fd0..edeb263 100644
--- a/src/cgmath/matrix.rs
+++ b/src/cgmath/matrix.rs
@@ -15,13 +15,12 @@
 
 //! Column major, square matrix types and traits.
 
-use std::num::{Zero, zero, One, one, sqrt};
+use std::num::{Zero, zero, One, one, cast, sqrt};
 
 use angle::{Rad, sin, cos};
 use array::Array;
 use quaternion::{Quat, ToQuat};
 use vector::*;
-use util::half;
 
 /// A 2 x 2, column major matrix
 #[deriving(Clone, Eq, Zero)]
@@ -609,38 +608,39 @@ impl<S:Clone + Float> ToQuat<S> for Mat3<S> {
         // Implemented using a mix of ideas from jMonkeyEngine and Ken Shoemake's
         // paper on Quaternions: http://www.cs.ucr.edu/~vbz/resources/Quatut.pdf
         let trace = self.trace();
+        let half: S = cast(0.5);
         cond! (
             (trace >= zero::<S>()) {
                 let s = sqrt(one::<S>() + trace);
-                let w = half::<S>() * s;
-                let s = half::<S>() / s;
+                let w = half * s;
+                let s = half / s;
                 let x = (*self.cr(1, 2) - *self.cr(2, 1)) * s;
                 let y = (*self.cr(2, 0) - *self.cr(0, 2)) * s;
                 let z = (*self.cr(0, 1) - *self.cr(1, 0)) * s;
                 Quat::new(w, x, y, z)
             }
             ((*self.cr(0, 0) > *self.cr(1, 1)) && (*self.cr(0, 0) > *self.cr(2, 2))) {
-                let s = sqrt(half::<S>() + (*self.cr(0, 0) - *self.cr(1, 1) - *self.cr(2, 2)));
-                let w = half::<S>() * s;
-                let s = half::<S>() / s;
+                let s = sqrt(half + (*self.cr(0, 0) - *self.cr(1, 1) - *self.cr(2, 2)));
+                let w = half * s;
+                let s = half / s;
                 let x = (*self.cr(0, 1) - *self.cr(1, 0)) * s;
                 let y = (*self.cr(2, 0) - *self.cr(0, 2)) * s;
                 let z = (*self.cr(1, 2) - *self.cr(2, 1)) * s;
                 Quat::new(w, x, y, z)
             }
             (*self.cr(1, 1) > *self.cr(2, 2)) {
-                let s = sqrt(half::<S>() + (*self.cr(1, 1) - *self.cr(0, 0) - *self.cr(2, 2)));
-                let w = half::<S>() * s;
-                let s = half::<S>() / s;
+                let s = sqrt(half + (*self.cr(1, 1) - *self.cr(0, 0) - *self.cr(2, 2)));
+                let w = half * s;
+                let s = half / s;
                 let x = (*self.cr(0, 1) - *self.cr(1, 0)) * s;
                 let y = (*self.cr(1, 2) - *self.cr(2, 1)) * s;
                 let z = (*self.cr(2, 0) - *self.cr(0, 2)) * s;
                 Quat::new(w, x, y, z)
             }
             _ {
-                let s = sqrt(half::<S>() + (*self.cr(2, 2) - *self.cr(0, 0) - *self.cr(1, 1)));
-                let w = half::<S>() * s;
-                let s = half::<S>() / s;
+                let s = sqrt(half + (*self.cr(2, 2) - *self.cr(0, 0) - *self.cr(1, 1)));
+                let w = half * s;
+                let s = half / s;
                 let x = (*self.cr(2, 0) - *self.cr(0, 2)) * s;
                 let y = (*self.cr(1, 2) - *self.cr(2, 1)) * s;
                 let z = (*self.cr(0, 1) - *self.cr(1, 0)) * s;
diff --git a/src/cgmath/util.rs b/src/cgmath/util.rs
index 2e85022..4925bfe 100644
--- a/src/cgmath/util.rs
+++ b/src/cgmath/util.rs
@@ -20,5 +20,3 @@ use std::num::one;
 
 #[inline]
 pub fn two<T: Num>() -> T { one::<T>() + one::<T>() }
-#[inline]
-pub fn half<T: Real>() -> T { one::<T>() / two::<T>() }