Add point conversion methods for vec2 and vec3 types

src/core/vec.rs

@@ -13,7 +13,12 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#[cfg(geom)]
+use std::cast;
+
 use core::Dimensional;
+#[cfg(geom)]
+use geom::{Point2, Point3};
 
 #[path = "../num_macros.rs"]
 mod num_macros;
@@ -56,6 +61,24 @@ impl<T> Vec2<T> {
     }
 }
 
+#[cfg(geom)]
+impl<T> Vec2<T> {
+    #[inline]
+    pub fn from_point(point: Point2<T>) -> Vec2<T> {
+        unsafe { cast::transmute(point) }
+    }
+
+    #[inline]
+    pub fn as_point<'a>(&'a self) -> &'a Point2<T> {
+        unsafe { cast::transmute(self) }
+    }
+
+    #[inline]
+    pub fn as_mut_point<'a>(&'a mut self) -> &'a mut Point2<T> {
+        unsafe { cast::transmute(self) }
+    }
+}
+
 impl<T:Clone> Vec2<T> {
     #[inline]
     pub fn from_value(value: T) -> Vec2<T> {
@@ -561,6 +584,24 @@ impl<T> Vec3<T> {
     }
 }
 
+#[cfg(geom)]
+impl<T> Vec3<T> {
+    #[inline]
+    pub fn from_point(point: Point3<T>) -> Vec3<T> {
+        unsafe { cast::transmute(point) }
+    }
+
+    #[inline]
+    pub fn as_point<'a>(&'a self) -> &'a Point3<T> {
+        unsafe { cast::transmute(self) }
+    }
+
+    #[inline]
+    pub fn as_mut_point<'a>(&'a mut self) -> &'a mut Point3<T> {
+        unsafe { cast::transmute(self) }
+    }
+}
+
 impl<T:Clone> Vec3<T> {
     #[inline]
     pub fn from_value(value: T) -> Vec3<T> {