From 5cb98d09cfd471751c219f6401bc118ba6ac551c Mon Sep 17 00:00:00 2001
From: Brendan Zabarauskas <bjzaba@yahoo.com.au>
Date: Wed, 12 Jun 2013 11:30:18 +1000
Subject: [PATCH] Add conversion traits

---
 src/mat.rs  |  6 +++---
 src/mat2.rs | 11 ++++++++++-
 src/mat3.rs | 12 ++++++++++--
 src/mat4.rs |  4 ++++
 src/quat.rs | 26 ++++++++++++++++----------
 5 files changed, 43 insertions(+), 16 deletions(-)

diff --git a/src/mat.rs b/src/mat.rs
index ea03488..2e6d5ed 100644
--- a/src/mat.rs
+++ b/src/mat.rs
@@ -13,9 +13,9 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-pub use self::mat2::Mat2;
-pub use self::mat3::Mat3;
-pub use self::mat4::Mat4;
+pub use self::mat2::{Mat2, ToMat2};
+pub use self::mat3::{Mat3, ToMat3};
+pub use self::mat4::{Mat4, ToMat4};
 
 pub mod mat2;
 pub mod mat3;
diff --git a/src/mat2.rs b/src/mat2.rs
index c80b460..9b2fe09 100644
--- a/src/mat2.rs
+++ b/src/mat2.rs
@@ -18,7 +18,8 @@ use std::cmp::ApproxEq;
 use std::num::{Zero, One};
 
 use vec::*;
-use super::{Mat3, Mat4};
+use super::{Mat3, ToMat3};
+use super::{Mat4, ToMat4};
 
 #[deriving(Eq)]
 pub struct Mat2<T> {
@@ -26,6 +27,10 @@ pub struct Mat2<T> {
     y: Vec2<T>,
 }
 
+pub trait ToMat2<T> {
+    pub fn to_mat2(&self) -> Mat2<T>;
+}
+
 impl<T> Mat2<T> {
     /// Construct a 2 x 2 matrix
     ///
@@ -265,7 +270,9 @@ impl<T:Copy + Num> Mat2<T> {
     pub fn to_zero(&mut self) {
         *self = Mat2::zero();
     }
+}
 
+impl<T:Copy + Num> ToMat3<T> for Mat2<T> {
     /// Returns the the matrix with an extra row and column added
     /// ~~~
     ///       c0   c1                 c0   c1   c2
@@ -283,7 +290,9 @@ impl<T:Copy + Num> Mat2<T> {
                   *self.elem(1, 0), *self.elem(1, 1), Zero::zero(),
                   Zero::zero(), Zero::zero(), One::one())
     }
+}
 
+impl<T:Copy + Num> ToMat4<T> for Mat2<T> {
     /// Returns the the matrix with an extra two rows and columns added
     /// ~~~
     ///       c0   c1                 c0   c1   c2   c3
diff --git a/src/mat3.rs b/src/mat3.rs
index f612ac2..839a2dc 100644
--- a/src/mat3.rs
+++ b/src/mat3.rs
@@ -18,8 +18,8 @@ use std::cmp::ApproxEq;
 use std::num::{Zero, One};
 
 use vec::*;
-use quat::Quat;
-use super::Mat4;
+use quat::{Quat, ToQuat};
+use super::{Mat4, ToMat4};
 
 #[deriving(Eq)]
 pub struct Mat3<T> {
@@ -28,6 +28,10 @@ pub struct Mat3<T> {
     z: Vec3<T>,
 }
 
+pub trait ToMat3<T> {
+    pub fn to_mat3(&self) -> Mat3<T>;
+}
+
 impl<T> Mat3<T> {
     /// Construct a 3 x 3 matrix
     ///
@@ -320,7 +324,9 @@ impl<T:Copy + Num> Mat3<T> {
     pub fn to_zero(&mut self) {
         *self = Mat3::zero();
     }
+}
 
+impl<T:Copy + Num> ToMat4<T> for Mat3<T> {
     /// Returns the the matrix with an extra row and column added
     /// ~~~
     ///       c0   c1   c2                 c0   c1   c2   c3
@@ -432,7 +438,9 @@ impl<T:Copy + Real> Mat3<T> {
 
         Mat3::from_axes(up_, side, dir_)
     }
+}
 
+impl<T:Copy + Real> ToQuat<T> for Mat3<T> {
     /// Convert the matrix to a quaternion
     pub fn to_quat(&self) -> Quat<T> {
         // Implemented using a mix of ideas from jMonkeyEngine and Ken Shoemake's
diff --git a/src/mat4.rs b/src/mat4.rs
index 49b032a..babb2b1 100644
--- a/src/mat4.rs
+++ b/src/mat4.rs
@@ -29,6 +29,10 @@ pub struct Mat4<T> {
     w: Vec4<T>,
 }
 
+pub trait ToMat4<T> {
+    pub fn to_mat4(&self) -> Mat4<T>;
+}
+
 impl<T> Mat4<T> {
     /// Construct a 4 x 4 matrix
     ///
diff --git a/src/quat.rs b/src/quat.rs
index ab229ec..88e29a0 100644
--- a/src/quat.rs
+++ b/src/quat.rs
@@ -17,7 +17,7 @@ use std::cast::transmute;
 use std::cmp::ApproxEq;
 use std::num::{Zero, One, cast};
 
-use mat::Mat3;
+use mat::{Mat3, ToMat3};
 use vec::Vec3;
 
 // GLSL-style type aliases
@@ -44,6 +44,10 @@ pub type Quatf64 = Quat<f64>;
 #[deriving(Eq)]
 pub struct Quat<T> { s: T, v: Vec3<T> }
 
+pub trait ToQuat<T> {
+    pub fn to_quat(&self) -> Quat<T>;
+}
+
 impl<T> Quat<T> {
     /// Construct the quaternion from one scalar component and three
     /// imaginary components
@@ -267,6 +271,17 @@ impl<T:Copy + Real> Quat<T> {
         self.mul_t(One::one::<T>() / self.magnitude())
     }
 
+    /// Normalised linear interpolation
+    ///
+    /// # Return value
+    ///
+    /// The intoperlated quaternion
+    pub fn nlerp(&self, other: &Quat<T>, amount: T) -> Quat<T> {
+        self.mul_t(One::one::<T>() - amount).add_q(&other.mul_t(amount)).normalize()
+    }
+}
+
+impl<T:Copy + Num> ToMat3<T> for Quat<T> {
     /// Convert the quaternion to a 3 x 3 rotation matrix
     pub fn to_mat3(&self) -> Mat3<T> {
         let x2 = self.v.x + self.v.x;
@@ -291,15 +306,6 @@ impl<T:Copy + Real> Quat<T> {
                   xy2 - sz2, _1 - xx2 - zz2, yz2 + sx2,
                   xz2 + sy2, yz2 - sx2, _1 - xx2 - yy2)
     }
-
-    /// Normalised linear interpolation
-    ///
-    /// # Return value
-    ///
-    /// The intoperlated quaternion
-    pub fn nlerp(&self, other: &Quat<T>, amount: T) -> Quat<T> {
-        self.mul_t(One::one::<T>() - amount).add_q(&other.mul_t(amount)).normalize()
-    }
 }
 
 impl<T:Copy + Float> Neg<Quat<T>> for Quat<T> {