From 2ed5e94710407537deec56dd44d4628e17078a2a Mon Sep 17 00:00:00 2001
From: Brendan Zabarauskas <bjzaba@yahoo.com.au>
Date: Fri, 12 Jul 2013 14:07:21 +1000
Subject: [PATCH] Add ray_to method to point types

---
 src/geom/geom.rs  |  2 +-
 src/geom/point.rs | 30 ++++++++++++++++++++++--------
 src/geom/ray.rs   | 20 ++++++++++++++++++--
 3 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/src/geom/geom.rs b/src/geom/geom.rs
index 9d0f5fc..fbd27c9 100644
--- a/src/geom/geom.rs
+++ b/src/geom/geom.rs
@@ -17,7 +17,7 @@ pub use self::aabb::{AABB2, AABB3};
 pub use self::frustum::{Frustum, FrustumPoints};
 pub use self::plane::Plane3;
 pub use self::point::{Point, Point2, Point3};
-pub use self::ray::Ray3;
+pub use self::ray::{Ray2, Ray3};
 pub use self::sphere::Sphere;
 
 pub mod aabb;
diff --git a/src/geom/point.rs b/src/geom/point.rs
index abca3ad..b599f4b 100644
--- a/src/geom/point.rs
+++ b/src/geom/point.rs
@@ -26,19 +26,21 @@ use core::{Mat2, Mat3, Quat};
 use core::{Vec2, ToVec2, AsVec2};
 use core::{Vec3, ToVec3, AsVec3};
 use core::{Vec4, ToVec4};
+use geom::{Ray2, Ray3};
 
 /// A geometric point
-pub trait Point<T, Vec>: Eq
-                       + Add<Vec, Self>
-                       + Sub<Self, Vec>
-                       + Mul<Vec, Self>
-                       + ApproxEq<T>
-                       + ToStr {
+pub trait Point<T, Vec, Ray>: Eq
+                            + Add<Vec, Self>
+                            + Sub<Self, Vec>
+                            + Mul<Vec, Self>
+                            + ApproxEq<T>
+                            + ToStr {
     pub fn translate(&self, offset: &Vec) -> Self;
     pub fn scale(&self, factor: &Vec) -> Self;
     pub fn distance2(&self, other: &Self) -> T;
     pub fn distance(&self, other: &Self) -> T;
     pub fn direction(&self, other: &Self) -> Vec;
+    pub fn ray_to(&self, other: &Self) -> Ray;
 }
 
 /// A two-dimensional point
@@ -107,7 +109,7 @@ impl<T:Clone + Float> Point2<T> {
     }
 }
 
-impl<T:Clone + Float> Point<T, Vec2<T>> for Point2<T> {
+impl<T:Clone + Float> Point<T, Vec2<T>, Ray2<T>> for Point2<T> {
     #[inline]
     pub fn translate(&self, offset: &Vec2<T>) -> Point2<T> {
         (*self) + (*offset)
@@ -134,6 +136,12 @@ impl<T:Clone + Float> Point<T, Vec2<T>> for Point2<T> {
     pub fn direction(&self, other: &Point2<T>) -> Vec2<T> {
         ((*other) - (*self)).normalize()
     }
+
+    /// Projects a normalized ray towards the other point
+    #[inline]
+    pub fn ray_to(&self, other: &Point2<T>) -> Ray2<T> {
+        Ray2::new(self.clone(), self.direction(other))
+    }
 }
 
 impl<T:Num> Add<Vec2<T>, Point2<T>> for Point2<T> {
@@ -241,7 +249,7 @@ impl<T:Clone + Float> Point3<T> {
     }
 }
 
-impl<T:Clone + Float> Point<T, Vec3<T>> for Point3<T> {
+impl<T:Clone + Float> Point<T, Vec3<T>, Ray3<T>> for Point3<T> {
     #[inline]
     pub fn translate(&self, offset: &Vec3<T>) -> Point3<T> {
         (*self) + (*offset)
@@ -268,6 +276,12 @@ impl<T:Clone + Float> Point<T, Vec3<T>> for Point3<T> {
     pub fn direction(&self, other: &Point3<T>) -> Vec3<T> {
         ((*other) - (*self)).normalize()
     }
+
+    /// Projects a normalized ray towards the other point
+    #[inline]
+    pub fn ray_to(&self, other: &Point3<T>) -> Ray3<T> {
+        Ray3::new(self.clone(), self.direction(other))
+    }
 }
 
 impl<T:Num> Add<Vec3<T>, Point3<T>> for Point3<T> {
diff --git a/src/geom/ray.rs b/src/geom/ray.rs
index 128f98c..cf5ad12 100644
--- a/src/geom/ray.rs
+++ b/src/geom/ray.rs
@@ -13,8 +13,24 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-use core::Vec3;
-use geom::Point3;
+use core::{Vec2, Vec3};
+use geom::{Point2, Point3};
+
+#[deriving(Clone, Eq)]
+pub struct Ray2<T> {
+    origin: Point2<T>,
+    direction: Vec2<T>,
+}
+
+impl_approx!(Ray2 { origin, direction })
+
+impl<T> Ray2<T> {
+    #[inline]
+    pub fn new(origin: Point2<T>, direction: Vec2<T>) -> Ray2<T> {
+        Ray2 { origin: origin, direction: direction }
+    }
+}
+
 
 #[deriving(Clone, Eq)]
 pub struct Ray3<T> {