Create separate ToHomogeneous trait

src/vec.rs

@@ -199,7 +199,7 @@ pub trait NumericVector2<T>: NumericVector<T> {
 /**
  * A 3-dimensional vector with numeric components
  */
-pub trait NumericVector3<T,HV>: NumericVector<T> {
+pub trait NumericVector3<T>: NumericVector<T> {
     // static pure fn unit_x() -> self;
     // static pure fn unit_y() -> self;
     // static pure fn unit_z() -> self;
@@ -210,11 +210,6 @@ pub trait NumericVector3<T,HV>: NumericVector<T> {
      * The cross product of the vector and `other`
      */
     pure fn cross(&self, other: &self) -> self;
-    
-    /**
-     * Convert the vector to its homogeneous form
-     */
-    pure fn to_homogeneous(&self) -> HV;
 }
 
 /**
@@ -237,6 +232,13 @@ pub trait NumericVector4<T>: NumericVector<T> {
     // static pure fn unit_w() -> self;
 }
 
+pub trait ToHomogeneous<H> {
+    /**
+     * Convert to a homogenous coordinate
+     */
+    pure fn to_homogeneous(&self) -> H;
+}
+
 /**
  * A Euclidean (or Affine) vector
  *

src/vec2.rs

@@ -191,6 +191,13 @@ pub impl<T:Copy Number> Vec2<T>: NumericVector2<T> {
     }
 }
 
+pub impl<T:Copy Number> Vec2<T>: ToHomogeneous<Vec3<T>> {
+    #[inline(always)]
+    pure fn to_homogeneous(&self) -> Vec3<T> {
+        Vec3::new(self.x, self.y, zero())
+    }
+}
+
 pub impl<T:Copy Float> Vec2<T>: EuclideanVector<T> {
     #[inline(always)]
     pure fn length2(&self) -> T {

src/vec3.rs

@@ -203,17 +203,13 @@ pub impl<T:Copy Number> Vec3<T>: MutableNumericVector<&self/T> {
     }
 }
 
-pub impl<T:Copy Number> Vec3<T>: NumericVector3<T,Vec4<T>> {
+pub impl<T:Copy Number> Vec3<T>: NumericVector3<T> {
     #[inline(always)]
     pure fn cross(&self, other: &Vec3<T>) -> Vec3<T> {
         Vec3::new((self[1] * other[2]) - (self[2] * other[1]),
                   (self[2] * other[0]) - (self[0] * other[2]),
                   (self[0] * other[1]) - (self[1] * other[0]))
     }
-    
-    pure fn to_homogeneous(&self) -> Vec4<T> {
-        Vec4::new(self.x, self.y, self.z, zero())
-    }
 }
 
 pub impl<T:Copy Number> Vec3<T>: MutableNumericVector3<&self/T> {
@@ -223,6 +219,13 @@ pub impl<T:Copy Number> Vec3<T>: MutableNumericVector3<&self/T> {
     }
 }
 
+pub impl<T:Copy Number> Vec3<T>: ToHomogeneous<Vec4<T>> {
+    #[inline(always)]
+    pure fn to_homogeneous(&self) -> Vec4<T> {
+        Vec4::new(self.x, self.y, self.z, zero())
+    }
+}
+
 pub impl<T:Copy Float> Vec3<T>: EuclideanVector<T> {
     #[inline(always)]
     pure fn length2(&self) -> T {