Merge pull request #385 from Marckvdv/patch-1

Implement component wise number casting for the Point and Matrix types.

src/matrix.rs

@@ -14,7 +14,7 @@
 // limitations under the License.
 
 use rand::{Rand, Rng};
-use num_traits::cast;
+use num_traits::{cast, NumCast};
 use std::fmt;
 use std::mem;
 use std::ops::*;
@@ -917,7 +917,7 @@ impl<S: BaseFloat> Transform3<S> for Matrix3<S> {}
 
 impl<S: BaseFloat> Transform3<S> for Matrix4<S> {}
 
-macro_rules! impl_operators {
+macro_rules! impl_matrix {
     ($MatrixN:ident, $VectorN:ident { $($field:ident : $row_index:expr),+ }) => {
         impl_operator!(<S: BaseFloat> Neg for $MatrixN<S> {
             fn neg(matrix) -> $MatrixN<S> { $MatrixN { $($field: -matrix.$field),+ } }
@@ -971,6 +971,15 @@ macro_rules! impl_operators {
         impl_scalar_ops!($MatrixN<i64> { $($field),+ });
         impl_scalar_ops!($MatrixN<f32> { $($field),+ });
         impl_scalar_ops!($MatrixN<f64> { $($field),+ });
+
+
+        impl<S: NumCast + Copy> $MatrixN<S> {
+            /// Component-wise casting to another type
+            #[inline]
+            pub fn cast<T: NumCast>(&self) -> $MatrixN<T> {
+                $MatrixN { $($field: self.$field.cast() ),+ }
+            }
+        }
     }
 }
 
@@ -988,9 +997,9 @@ macro_rules! impl_scalar_ops {
     };
 }
 
-impl_operators!(Matrix2, Vector2 { x: 0, y: 1 });
-impl_operators!(Matrix3, Vector3 { x: 0, y: 1, z: 2 });
-impl_operators!(Matrix4, Vector4 { x: 0, y: 1, z: 2, w: 3 });
+impl_matrix!(Matrix2, Vector2 { x: 0, y: 1 });
+impl_matrix!(Matrix3, Vector3 { x: 0, y: 1, z: 2 });
+impl_matrix!(Matrix4, Vector4 { x: 0, y: 1, z: 2, w: 3 });
 
 impl_operator!(<S: BaseFloat> Mul<Matrix2<S> > for Matrix2<S> {
     fn mul(lhs, rhs) -> Matrix2<S> {

src/point.rs

@@ -17,6 +17,7 @@
 //! disinguishes them from vectors, which have a length and direction, but do
 //! not have a fixed position.
 
+use num_traits::NumCast;
 use std::fmt;
 use std::mem;
 use std::ops::*;
@@ -128,6 +129,14 @@ macro_rules! impl_point {
             }
         }
 
+        impl<S: NumCast + Copy> $PointN<S> {
+            /// Component-wise casting to another type
+            #[inline]
+            pub fn cast<T: NumCast>(&self) -> $PointN<T> {
+                $PointN { $($field: NumCast::from(self.$field).unwrap()),+ }
+            }
+        }
+
         impl<S: BaseFloat> MetricSpace for $PointN<S> {
             type Metric = S;
 

tests/matrix.rs

@@ -704,6 +704,33 @@ pub mod matrix4 {
         assert_eq!(res, Vector4::new(1., 2., 3., 1.));
     }
 
+    #[test]
+    fn test_cast() {
+        assert_ulps_eq!(Matrix2::new(0.2f64, 1.5, 4.7, 2.3).cast(), Matrix2::new(0.2f32, 1.5, 4.7, 2.3));
+        assert_ulps_eq!(Matrix3::new(
+            0.2f64, 1.5, 4.7,
+            2.3,    5.7, 2.1,
+            4.6,    5.2, 6.6,
+        ).cast(), Matrix3::new(
+            0.2f32, 1.5, 4.7,
+            2.3,    5.7, 2.1,
+            4.6,    5.2, 6.6,
+        ));
+
+        assert_ulps_eq!(Matrix4::new(
+            0.2f64, 1.5, 4.7, 2.5,
+            2.3,    5.7, 2.1, 1.1,
+            4.6,    5.2, 6.6, 0.2,
+            3.2,    1.8, 0.4, 2.9,
+        ).cast(), Matrix4::new(
+            0.2f32, 1.5, 4.7, 2.5,
+            2.3,    5.7, 2.1, 1.1,
+            4.6,    5.2, 6.6, 0.2,
+            3.2,    1.8, 0.4, 2.9,
+        ));
+
+    }
+
     mod from {
         use cgmath::*;
 

tests/point.rs

@@ -17,7 +17,7 @@
 extern crate approx;
 extern crate cgmath;
 
-use cgmath::{Point2, Point3};
+use cgmath::{Point1, Point2, Point3};
 
 macro_rules! impl_test_mul {
     ($PointN:ident { $($field:ident),+ }, $s:expr, $v:expr) => (
@@ -74,3 +74,10 @@ fn test_rem() {
     impl_test_rem!(Point3 { x, y, z }, 2.0f32, Point3::new(2.0f32, 4.0, 6.0));
     impl_test_rem!(Point2 { x, y }, 2.0f32, Point2::new(2.0f32, 4.0));
 }
+
+#[test]
+fn test_cast() {
+    assert_ulps_eq!(Point1::new(0.9f64).cast(), Point1::new(0.9f32));
+    assert_ulps_eq!(Point2::new(0.9f64, 1.5).cast(), Point2::new(0.9f32, 1.5));
+    assert_ulps_eq!(Point3::new(1.0f64, 2.4, -3.13).cast(), Point3::new(1.0f32, 2.4, -3.13));
+}