diff --git a/src/color/color.rs b/src/color/color.rs
index 56306f6..45687ef 100644
--- a/src/color/color.rs
+++ b/src/color/color.rs
@@ -30,6 +30,10 @@ pub mod ycbcr;
 pub trait Color<T> {
     pub fn clamp(&self, lo: T, hi: T) -> Self;
     pub fn inverse(&self) -> Self;
+    // pub fn mix(&self, other: &Self, value: T) -> Self;
+    // pub fn saturation(&self, value: T) -> Self;
+    // pub fn exposure(&self, value: T) -> Self;
+    // pub fn brightness(&self, value: T) -> Self;
 }
 
 pub trait FloatColor<T>: Color<T> {
diff --git a/src/color/hsv.rs b/src/color/hsv.rs
index c5cd5d0..9ada9e4 100644
--- a/src/color/hsv.rs
+++ b/src/color/hsv.rs
@@ -20,12 +20,11 @@ use color::{Color, FloatColor};
 use color::{Channel, FloatChannel};
 use color::{RGB, ToRGB, RGBA, ToRGBA};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 #[deriving(Clone, Eq)]
 pub struct HSV<T> { h: T, s: T, v: T }
 
+impl_approx!(HSV { h, s, v })
+
 impl<T:FloatChannel> HSV<T> {
     pub fn new(h: T, s: T, v: T) -> HSV<T> {
         HSV { h: h, s: s, v: v }
@@ -123,6 +122,8 @@ impl<T:Clone + FloatChannel> ToRGB for HSV<T> {
 #[deriving(Clone, Eq)]
 pub struct HSVA<T> { h: T, s: T, v: T, a: T }
 
+impl_approx!(HSVA { h, s, v, a })
+
 impl<T:FloatChannel> HSVA<T> {
     #[inline]
     pub fn new(h: T, s: T, v: T, a: T) -> HSVA<T> {
diff --git a/src/color/rgb.rs b/src/color/rgb.rs
index f4e0639..2c28388 100644
--- a/src/color/rgb.rs
+++ b/src/color/rgb.rs
@@ -20,12 +20,11 @@ use color::{Color, FloatColor};
 use color::{Channel, FloatChannel};
 use color::{HSV, ToHSV, HSVA, ToHSVA};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 #[deriving(Clone, Eq)]
 pub struct RGB<T> { r: T, g: T, b: T }
 
+impl_approx!(RGB { r, g, b })
+
 impl<T:Channel> RGB<T> {
     #[inline]
     pub fn new(r: T, g: T, b: T) -> RGB<T> {
@@ -120,6 +119,8 @@ impl<T:Clone + Channel> ToHSV for RGB<T> {
 #[deriving(Clone, Eq)]
 pub struct RGBA<T> { r: T, g: T, b: T, a: T }
 
+impl_approx!(RGBA { r, g, b, a })
+
 impl<T:Channel> RGBA<T> {
     #[inline]
     pub fn new(r: T, g: T, b: T, a: T) -> RGBA<T> {
diff --git a/src/color/srgb.rs b/src/color/srgb.rs
index 6702a6f..52f1176 100644
--- a/src/color/srgb.rs
+++ b/src/color/srgb.rs
@@ -23,9 +23,13 @@ impl<T> SRGB<T> {
     }
 }
 
+impl_approx!(SRGB { r, g, b })
+
 #[deriving(Clone, Eq)]
 pub struct SRGBA<T> { r: T, g: T, b: T, a: T }
 
+impl_approx!(SRGBA { r, g, b, a })
+
 impl<T> SRGBA<T> {
     #[inline]
     pub fn new(r: T, g: T, b: T, a: T) -> SRGBA<T> {
diff --git a/src/color/ycbcr.rs b/src/color/ycbcr.rs
index 2311760..a7280e4 100644
--- a/src/color/ycbcr.rs
+++ b/src/color/ycbcr.rs
@@ -18,6 +18,8 @@
 #[deriving(Clone, Eq)]
 pub struct YCbCr<T> { y: T, cb: T, cr: T }
 
+impl_approx!(YCbCr { y, cb, cr })
+
 impl<T> YCbCr<T> {
     #[inline]
     pub fn new(y: T, cb: T, cr: T) -> YCbCr<T> {
diff --git a/src/core/mat.rs b/src/core/mat.rs
index 1e6f1de..5fd3a9a 100644
--- a/src/core/mat.rs
+++ b/src/core/mat.rs
@@ -17,9 +17,6 @@ use core::{Dimensional, Swap};
 use core::{Quat, ToQuat};
 use core::{Vec2, Vec3, Vec4};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 macro_rules! impl_mat(
     ($Mat:ident, $Vec:ident) => (
         impl<T> $Mat<T> {
@@ -126,6 +123,7 @@ pub type Mat2f64 = Mat2<f64>;
 
 impl_mat!(Mat2, Vec2)
 impl_mat_swap!(Mat2, Vec2)
+impl_approx!(Mat3 { x, y, z })
 
 pub trait ToMat2<T> {
     pub fn to_mat2(&self) -> Mat2<T>;
@@ -330,24 +328,6 @@ impl<T:Clone + Real + ApproxEq<T>> Mat2<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Mat2<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Mat2<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Mat2<T>, epsilon: &T) -> bool {
-        self.col(0).approx_eq_eps(other.col(0), epsilon) &&
-        self.col(1).approx_eq_eps(other.col(1), epsilon)
-    }
-}
-
 #[cfg(test)]
 mod mat2_tests{
     use core::mat::*;
@@ -554,6 +534,7 @@ pub type Mat3f64 = Mat3<f64>;
 
 impl_mat!(Mat3, Vec3)
 impl_mat_swap!(Mat3, Vec3)
+impl_approx!(Mat2 { x, y })
 
 pub trait ToMat3<T> {
     pub fn to_mat3(&self) -> Mat3<T>;
@@ -909,25 +890,6 @@ impl<T:Clone + Real + ApproxEq<T>> Mat3<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Mat3<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Mat3<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Mat3<T>, epsilon: &T) -> bool {
-        self.col(0).approx_eq_eps(other.col(0), epsilon) &&
-        self.col(1).approx_eq_eps(other.col(1), epsilon) &&
-        self.col(2).approx_eq_eps(other.col(2), epsilon)
-    }
-}
-
 #[cfg(test)]
 mod mat3_tests{
     use core::mat::*;
@@ -1159,6 +1121,7 @@ pub type Mat4f64 = Mat4<f64>;
 
 impl_mat!(Mat4, Vec4)
 impl_mat_swap!(Mat4, Vec4)
+impl_approx!(Mat4 { x, y, z, w })
 
 pub trait ToMat4<T> {
     pub fn to_mat4(&self) -> Mat4<T>;
@@ -1454,26 +1417,6 @@ impl<T:Clone + Real + ApproxEq<T>> Mat4<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Mat4<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Mat4<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Mat4<T>, epsilon: &T) -> bool {
-        self.col(0).approx_eq_eps(other.col(0), epsilon) &&
-        self.col(1).approx_eq_eps(other.col(1), epsilon) &&
-        self.col(2).approx_eq_eps(other.col(2), epsilon) &&
-        self.col(3).approx_eq_eps(other.col(3), epsilon)
-    }
-}
-
 #[cfg(test)]
 mod mat4_tests {
     use core::mat::*;
diff --git a/src/core/quat.rs b/src/core/quat.rs
index 365e7a2..993db72 100644
--- a/src/core/quat.rs
+++ b/src/core/quat.rs
@@ -17,9 +17,6 @@ use core::Dimensional;
 use core::{Mat3, ToMat3};
 use core::Vec3;
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 // GLSL-style type aliases
 
 pub type quat  = Quat<f32>;
diff --git a/src/core/vec.rs b/src/core/vec.rs
index ff123c7..f064878 100644
--- a/src/core/vec.rs
+++ b/src/core/vec.rs
@@ -20,9 +20,6 @@ use core::Dimensional;
 #[cfg(geom)]
 use geom::{Point2, Point3};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 #[deriving(Clone, Eq)]
 pub struct Vec2<T> { x: T, y: T }
 
@@ -49,6 +46,8 @@ pub type Vec2u32 = Vec2<u32>;
 pub type Vec2u64 = Vec2<u64>;
 pub type Vec2b   = Vec2<bool>;
 
+impl_approx!(Vec2 { x, y })
+
 impl<T> Vec2<T> {
     #[inline]
     pub fn new(x: T, y: T) -> Vec2<T> {
@@ -586,6 +585,8 @@ pub type Vec3u32 = Vec3<u32>;
 pub type Vec3u64 = Vec3<u64>;
 pub type Vec3b   = Vec3<bool>;
 
+impl_approx!(Vec3 { x, y, z })
+
 impl<T> Vec3<T> {
     #[inline]
     pub fn new(x: T, y: T, z: T) -> Vec3<T> {
@@ -1188,6 +1189,8 @@ pub type Vec4u32 = Vec4<u32>;
 pub type Vec4u64 = Vec4<u64>;
 pub type Vec4b   = Vec4<bool>;
 
+impl_approx!(Vec4 { x, y, z, w })
+
 impl<T> Vec4<T> {
     #[inline]
     pub fn new(x: T, y: T, z: T, w: T) -> Vec4<T> {
diff --git a/src/geom/aabb.rs b/src/geom/aabb.rs
index df8fbf5..a02a8fc 100644
--- a/src/geom/aabb.rs
+++ b/src/geom/aabb.rs
@@ -18,14 +18,13 @@
 use core::{Vec2, Vec3};
 use geom::{Point2, Point3};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 pub struct AABB2<T> {
     center: Point2<T>,
     size: Vec2<T>,
 }
 
+impl_approx!(AABB2 { center, size })
+
 impl<T> AABB2<T> {
     #[inline]
     pub fn new(center: Point2<T>, size: Vec2<T>) -> AABB2<T> {
@@ -50,6 +49,8 @@ pub struct AABB3<T> {
     size: Vec3<T>,
 }
 
+impl_approx!(AABB3 { center, size })
+
 impl<T> AABB3<T> {
     #[inline]
     pub fn new(center: Point3<T>, size: Vec3<T>) -> AABB3<T> {
diff --git a/src/geom/frustum.rs b/src/geom/frustum.rs
index d316bef..572ec6b 100644
--- a/src/geom/frustum.rs
+++ b/src/geom/frustum.rs
@@ -16,9 +16,6 @@
 use core::Mat4;
 use geom::{Plane3, Point3};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 #[deriving(Clone, Eq)]
 pub struct Frustum<T> {
     left:   Plane3<T>,
@@ -29,6 +26,12 @@ pub struct Frustum<T> {
     far:    Plane3<T>,
 }
 
+impl_approx!(Frustum {
+    left, right,
+    top, bottom,
+    near, far
+})
+
 #[deriving(Clone, Eq)]
 pub struct FrustumPoints<T> {
     near_top_left:     Point3<T>,
@@ -41,6 +44,17 @@ pub struct FrustumPoints<T> {
     far_bottom_right:  Point3<T>,
 }
 
+impl_approx!(FrustumPoints {
+    near_top_left,
+    near_top_right,
+    near_bottom_left,
+    near_bottom_right,
+    far_top_left,
+    far_top_right,
+    far_bottom_left,
+    far_bottom_right
+})
+
 impl<T:Clone + Float> Frustum<T> {
     /// Constructs a frustum
     pub fn from_planes(left:   Plane3<T>, right:  Plane3<T>,
@@ -96,25 +110,3 @@ impl<T:Clone + Float> Frustum<T> {
         }
     }
 }
-
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Frustum<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Frustum<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Frustum<T>, epsilon: &T) -> bool {
-        self.left.approx_eq_eps(&other.left, epsilon) &&
-        self.right.approx_eq_eps(&other.right, epsilon) &&
-        self.bottom.approx_eq_eps(&other.bottom, epsilon) &&
-        self.top.approx_eq_eps(&other.top, epsilon) &&
-        self.near.approx_eq_eps(&other.near, epsilon) &&
-        self.far.approx_eq_eps(&other.far, epsilon)
-    }
-}
diff --git a/src/geom/plane.rs b/src/geom/plane.rs
index b8ee7d3..3849710 100644
--- a/src/geom/plane.rs
+++ b/src/geom/plane.rs
@@ -16,9 +16,6 @@
 use core::{Vec3, Vec4, Mat3};
 use geom::{Point, Point3, Ray3};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 /// A plane formed from the equation: `Ax + Bx + Cx + D = 0`
 ///
 /// # Fields
@@ -34,6 +31,8 @@ pub struct Plane3<T> {
     distance: T,
 }
 
+impl_approx!(Plane3 { normal, distance })
+
 impl<T:Clone + Float> Plane3<T> {
     /// # Arguments
     ///
@@ -143,24 +142,6 @@ impl<T:Clone + Float> Plane3<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Plane3<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Plane3<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Plane3<T>, epsilon: &T) -> bool {
-        self.normal.approx_eq_eps(&other.normal, epsilon) &&
-        self.distance.approx_eq_eps(&other.distance, epsilon)
-    }
-}
-
 impl<T> ToStr for Plane3<T> {
     pub fn to_str(&self) -> ~str {
         fmt!("%?x + %?y + %?z + %? = 0",
diff --git a/src/geom/point.rs b/src/geom/point.rs
index 8d0b6ca..1c84d07 100644
--- a/src/geom/point.rs
+++ b/src/geom/point.rs
@@ -24,9 +24,6 @@ use std::cast;
 
 use core::{Mat2, Mat3, Quat, Vec2, Vec3, Vec4};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 /// A geometric point
 pub trait Point<T, Vec>: Eq
                        + Add<Vec, Self>
@@ -48,6 +45,8 @@ pub trait Point<T, Vec>: Eq
 #[deriving(Clone, Eq)]
 pub struct Point2<T> { x: T, y: T }
 
+impl_approx!(Point2 { x, y })
+
 impl<T:Num> Point2<T> {
     #[inline]
     pub fn new(x: T, y: T) -> Point2<T> {
@@ -149,24 +148,6 @@ impl<T:Num> Mul<Vec2<T>, Point2<T>> for Point2<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Point2<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Point2<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Point2<T>, epsilon: &T) -> bool {
-        self.x.approx_eq_eps(&other.x, epsilon) &&
-        self.y.approx_eq_eps(&other.y, epsilon)
-    }
-}
-
 impl<T> ToStr for Point2<T> {
     pub fn to_str(&self) -> ~str {
         fmt!("[%?, %?]", self.x, self.y)
@@ -187,6 +168,8 @@ mod test_point2 {
 #[deriving(Clone, Eq)]
 pub struct Point3<T> { x: T, y: T, z: T }
 
+impl_approx!(Point3 { x, y, z })
+
 impl<T:Num> Point3<T> {
     #[inline]
     pub fn new(x: T, y: T, z: T) -> Point3<T> {
@@ -291,25 +274,6 @@ impl<T:Num> Mul<Vec3<T>, Point3<T>> for Point3<T> {
     }
 }
 
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Point3<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Point3<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Point3<T>, epsilon: &T) -> bool {
-        self.x.approx_eq_eps(&other.x, epsilon) &&
-        self.y.approx_eq_eps(&other.y, epsilon) &&
-        self.z.approx_eq_eps(&other.z, epsilon)
-    }
-}
-
 impl<T> ToStr for Point3<T> {
     pub fn to_str(&self) -> ~str {
         fmt!("[%?, %?, %?]", self.x, self.y, self.z)
diff --git a/src/geom/ray.rs b/src/geom/ray.rs
index 643ae1a..128f98c 100644
--- a/src/geom/ray.rs
+++ b/src/geom/ray.rs
@@ -22,27 +22,11 @@ pub struct Ray3<T> {
     direction: Vec3<T>,
 }
 
+impl_approx!(Ray3 { origin, direction })
+
 impl<T> Ray3<T> {
     #[inline]
     pub fn new(origin: Point3<T>, direction: Vec3<T>) -> Ray3<T> {
         Ray3 { origin: origin, direction: direction }
     }
 }
-
-impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for Ray3<T> {
-    #[inline]
-    pub fn approx_epsilon() -> T {
-        ApproxEq::approx_epsilon::<T,T>()
-    }
-
-    #[inline]
-    pub fn approx_eq(&self, other: &Ray3<T>) -> bool {
-        self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
-    }
-
-    #[inline]
-    pub fn approx_eq_eps(&self, other: &Ray3<T>, epsilon: &T) -> bool {
-        self.origin.approx_eq_eps(&other.origin, epsilon) &&
-        self.direction.approx_eq_eps(&other.direction, epsilon)
-    }
-}
diff --git a/src/geom/sphere.rs b/src/geom/sphere.rs
index 862e1ca..1faea1b 100644
--- a/src/geom/sphere.rs
+++ b/src/geom/sphere.rs
@@ -22,6 +22,8 @@ pub struct Sphere<T> {
     radius: T,
 }
 
+impl_approx!(Sphere { center, radius })
+
 impl<T> Sphere<T> {
     #[inline]
     pub fn new(center: Point3<T>, radius: T) -> Sphere<T> {
diff --git a/src/lmath.rs b/src/lmath.rs
index a01ad87..e97c4fa 100644
--- a/src/lmath.rs
+++ b/src/lmath.rs
@@ -23,6 +23,8 @@
 #[license = "ASL2"];
 #[crate_type = "lib"];
 
+mod macros;
+
 #[path = "core/core.rs"]
 pub mod core;
 
diff --git a/src/num_macros.rs b/src/macros.rs
similarity index 60%
rename from src/num_macros.rs
rename to src/macros.rs
index 86dd893..d81afa0 100644
--- a/src/num_macros.rs
+++ b/src/macros.rs
@@ -32,3 +32,24 @@ macro_rules! one(
 macro_rules! two(
     ($T:ty) => (one!(T) + one!(T));
 )
+
+macro_rules! impl_approx(
+    ($T:ident { $($field:ident),+ }) => (
+        impl<T:Clone + Eq + ApproxEq<T>> ApproxEq<T> for $T<T> {
+            #[inline]
+            pub fn approx_epsilon() -> T {
+                ApproxEq::approx_epsilon::<T,T>()
+            }
+
+            #[inline]
+            pub fn approx_eq(&self, other: &$T<T>) -> bool {
+                self.approx_eq_eps(other, &ApproxEq::approx_epsilon::<T,T>())
+            }
+
+            #[inline]
+            pub fn approx_eq_eps(&self, other: &$T<T>, epsilon: &T) -> bool {
+                $( self.$field.approx_eq_eps(&other.$field, epsilon) )&&+
+            }
+        }
+    )
+)
diff --git a/src/transform/projection.rs b/src/transform/projection.rs
index fb5b619..176668c 100644
--- a/src/transform/projection.rs
+++ b/src/transform/projection.rs
@@ -16,9 +16,6 @@
 use core::Mat4;
 use geom::{Plane3, Frustum};
 
-#[path = "../num_macros.rs"]
-mod num_macros;
-
 ///
 /// Create a perspective projection matrix
 ///