Fix deprecated look_at usage + remove repeated code

Remove a repated instance of Matrix4 look_at transform.

Author: elrnv

src/matrix.rs

@@ -204,7 +204,7 @@ impl<S: BaseFloat> Matrix3<S> {
 
     /// Create a rotation matrix that will cause a vector to point at
     /// `dir`, using `up` for orientation.
-    #[deprecated = "Use Matrix3::look_to_lh"]
+    #[deprecated = "Use Matrix3::look_to_lh or Matrix3::look_to_rh for the right handed variation"]
     pub fn look_at(dir: Vector3<S>, up: Vector3<S>) -> Matrix3<S> {
         Matrix3::look_to_lh(dir, up)
     }
@@ -361,19 +361,9 @@ impl<S: BaseFloat> Matrix4<S> {
 
     /// Create a homogeneous transformation matrix that will cause a vector to point at
     /// `dir`, using `up` for orientation.
-    #[deprecated = "Use Matrix4::look_to_rh"]
+    #[deprecated = "Use Matrix4::look_to_rh or Matrix3::look_to_lh for the left handed variation"]
     pub fn look_at_dir(eye: Point3<S>, dir: Vector3<S>, up: Vector3<S>) -> Matrix4<S> {
-        let f = dir.normalize();
-        let s = f.cross(up).normalize();
-        let u = s.cross(f);
-
-        #[cfg_attr(rustfmt, rustfmt_skip)]
-        Matrix4::new(
-            s.x.clone(), u.x.clone(), -f.x.clone(), S::zero(),
-            s.y.clone(), u.y.clone(), -f.y.clone(), S::zero(),
-            s.z.clone(), u.z.clone(), -f.z.clone(), S::zero(),
-            -eye.dot(s), -eye.dot(u), eye.dot(f), S::one(),
-        )
+        Self::look_to_rh(eye, dir, up)
     }
 
     /// Create a homogeneous transformation matrix that will cause a vector to point at
@@ -400,9 +390,9 @@ impl<S: BaseFloat> Matrix4<S> {
 
     /// Create a homogeneous transformation matrix that will cause a vector to point at
     /// `center`, using `up` for orientation.
-    #[deprecated = "Use Matrix4::look_at_rh"]
+    #[deprecated = "Use Matrix4::look_at_rh or look_at_lh for the left handed variation"]
     pub fn look_at(eye: Point3<S>, center: Point3<S>, up: Vector3<S>) -> Matrix4<S> {
-        Matrix4::look_at_dir(eye, center - eye, up)
+        Matrix4::look_to_rh(eye, center - eye, up)
     }
 
     /// Create a homogeneous transformation matrix that will cause a vector to point at
@@ -1145,7 +1135,7 @@ impl<S: BaseFloat> Transform<Point3<S>> for Matrix3<S> {
 
     fn look_at(eye: Point3<S>, center: Point3<S>, up: Vector3<S>) -> Matrix3<S> {
         let dir = center - eye;
-        Matrix3::look_at(dir, up)
+        Matrix3::look_to_lh(dir, up)
     }
 
     fn look_at_lh(eye: Point3<S>, center: Point3<S>, up: Vector3<S>) -> Matrix3<S> {

src/quaternion.rs

@@ -475,7 +475,7 @@ impl<S: BaseFloat> From<Quaternion<S>> for Basis3<S> {
 impl<S: BaseFloat> Rotation<Point3<S>> for Quaternion<S> {
     #[inline]
     fn look_to(dir: Vector3<S>, up: Vector3<S>) -> Quaternion<S> {
-        Matrix3::look_at(dir, up).into()
+        Matrix3::look_to_lh(dir, up).into()
     }
 
     #[inline]

src/rotation.rs

@@ -344,7 +344,7 @@ impl<S: BaseFloat> Rotation<Point3<S>> for Basis3<S> {
     #[inline]
     fn look_to(dir: Vector3<S>, up: Vector3<S>) -> Basis3<S> {
         Basis3 {
-            mat: Matrix3::look_at(dir, up),
+            mat: Matrix3::look_to_lh(dir, up),
         }
     }
 

src/transform.rs

@@ -33,7 +33,9 @@ pub trait Transform<P: EuclideanSpace>: Sized {
     /// Create a transformation that rotates a vector to look at `center` from
     /// `eye`, using `up` for orientation.
     #[deprecated = "Use look_at_rh or look_at_lh"]
-    fn look_at(eye: P, center: P, up: P::Diff) -> Self;
+    fn look_at(eye: P, center: P, up: P::Diff) -> Self {
+        Self::look_at_lh(eye, center, up)
+    }
 
     /// Create a transformation that rotates a vector to look at `center` from
     /// `eye`, using `up` for orientation.
@@ -95,7 +97,7 @@ where
 
     #[inline]
     fn look_at(eye: P, center: P, up: P::Diff) -> Decomposed<P::Diff, R> {
-        let rot = R::look_at(center - eye, up);
+        let rot = R::look_to(center - eye, up);
         let disp = rot.rotate_vector(P::origin() - eye);
         Decomposed {
             scale: P::Scalar::one(),
@@ -106,7 +108,7 @@ where
 
     #[inline]
     fn look_at_lh(eye: P, center: P, up: P::Diff) -> Decomposed<P::Diff, R> {
-        let rot = R::look_at(center - eye, up);
+        let rot = R::look_to(center - eye, up);
         let disp = rot.rotate_vector(P::origin() - eye);
         Decomposed {
             scale: P::Scalar::one(),
@@ -117,7 +119,7 @@ where
 
     #[inline]
     fn look_at_rh(eye: P, center: P, up: P::Diff) -> Decomposed<P::Diff, R> {
-        let rot = R::look_at(eye - center, up);
+        let rot = R::look_to(eye - center, up);
         let disp = rot.rotate_vector(P::origin() - eye);
         Decomposed {
             scale: P::Scalar::one(),

tests/matrix.rs

@@ -740,7 +740,7 @@ pub mod matrix3 {
         ]));
 
         #[allow(deprecated)]
-        assert_ulps_eq!(m, Matrix3::look_at(dir, up));
+        assert_ulps_eq!(m, Matrix3::look_to_lh(dir, up));
     }
 
     #[test]
@@ -1164,7 +1164,7 @@ pub mod matrix4 {
 
         let m = Matrix4::look_to_rh(eye, dir, up);
         #[allow(deprecated)]
-        assert_ulps_eq!(m, Matrix4::look_at_dir(eye, dir, up));
+        assert_ulps_eq!(m, Matrix4::look_to_rh(eye, dir, up));
 
         let expected = Matrix4::from([
             [-0.9486833, -0.16903086, -0.26726127, 0.0],