Rename `Perspective3::unwrap` to `Perspective3::into_inner` and deprecate `Perspective3::unwrap`

See #460

src/base/cg.rs

@@ -121,7 +121,7 @@ impl<N: Real> Matrix4<N> {
     /// Creates a new homogeneous matrix for a perspective projection.
     #[inline]
     pub fn new_perspective(aspect: N, fovy: N, znear: N, zfar: N) -> Self {
-        Perspective3::new(aspect, fovy, znear, zfar).unwrap()
+        Perspective3::new(aspect, fovy, znear, zfar).into_inner()
     }
 
     /// Creates an isometry that corresponds to the local frame of an observer standing at the

src/geometry/perspective.rs

@@ -141,6 +141,14 @@ impl<N: Real> Perspective3<N> {
 
     /// Retrieves the underlying homogeneous matrix.
     #[inline]
+    pub fn into_inner(self) -> Matrix4<N> {
+        self.matrix
+    }
+
+    /// Retrieves the underlying homogeneous matrix.
+    /// Deprecated: Use [Perspective3::into_inner] instead.
+    #[deprecated(note="use `.into_inner()` instead")]
+    #[inline]
     pub fn unwrap(self) -> Matrix4<N> {
         self.matrix
     }
@@ -279,6 +287,6 @@ impl<N: Real + Arbitrary> Arbitrary for Perspective3<N> {
 impl<N: Real> From<Perspective3<N>> for Matrix4<N> {
     #[inline]
     fn from(orth: Perspective3<N>) -> Self {
-        orth.unwrap()
+        orth.into_inner()
     }
 }

tests/geometry/projection.rs

@@ -5,7 +5,7 @@ fn perspective_inverse() {
     let proj = Perspective3::new(800.0 / 600.0, 3.14 / 2.0, 1.0, 1000.0);
     let inv = proj.inverse();
 
-    let id = inv * proj.unwrap();
+    let id = inv * proj.into_inner();
 
     assert!(id.is_identity(1.0e-7));
 }