Implement Default for most geometry types

CHANGELOG.md

@@ -13,6 +13,8 @@ This project adheres to [Semantic Versioning](https://semver.org/).
   `glam 0.18`. These can be enabled by enabling the `convert-glam018` cargo features.
 - Added the methods `Matrix::product`, `::row_product`, `::row_product_tr`, and `::column_product` to compute the
   product of the components, rows, or columns, of a single matrix or vector.
+- The `Default` trait is now implemented for most geometric types: `Point`, `Isometry`, `Rotation`, `Similarity`,
+  `Transform`, `UnitComplex`, and `UnitQuaternion`.
 
 ## [0.29.0]
 ### Breaking changes

src/geometry/isometry_construction.rs

@@ -21,6 +21,15 @@ use crate::{
     UnitQuaternion,
 };
 
+impl<T: SimdRealField, R: AbstractRotation<T, D>, const D: usize> Default for Isometry<T, R, D>
+where
+    T::Element: SimdRealField,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 impl<T: SimdRealField, R: AbstractRotation<T, D>, const D: usize> Isometry<T, R, D>
 where
     T::Element: SimdRealField,

src/geometry/point_construction.rs

@@ -19,6 +19,15 @@ use simba::scalar::{ClosedDiv, SupersetOf};
 
 use crate::geometry::Point;
 
+impl<T: Scalar + Zero, D: DimName> Default for OPoint<T, D>
+where
+    DefaultAllocator: Allocator<T, D>,
+{
+    fn default() -> Self {
+        Self::origin()
+    }
+}
+
 /// # Other construction methods
 impl<T: Scalar, D: DimName> OPoint<T, D>
 where

src/geometry/quaternion_construction.rs

@@ -197,6 +197,15 @@ where
     }
 }
 
+impl<T: SimdRealField> Default for UnitQuaternion<T>
+where
+    T::Element: SimdRealField,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 impl<T: SimdRealField> UnitQuaternion<T>
 where
     T::Element: SimdRealField,

src/geometry/rotation_construction.rs

@@ -6,6 +6,15 @@ use crate::base::{SMatrix, Scalar};
 
 use crate::geometry::Rotation;
 
+impl<T, const D: usize> Default for Rotation<T, D>
+where
+    T: Scalar + Zero + One,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 /// # Identity
 impl<T, const D: usize> Rotation<T, D>
 where

src/geometry/similarity_construction.rs

@@ -20,6 +20,16 @@ use crate::{
     Translation, UnitComplex, UnitQuaternion,
 };
 
+impl<T: SimdRealField, R, const D: usize> Default for Similarity<T, R, D>
+where
+    T::Element: SimdRealField,
+    R: AbstractRotation<T, D>,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 impl<T: SimdRealField, R, const D: usize> Similarity<T, R, D>
 where
     T::Element: SimdRealField,

src/geometry/transform_construction.rs

@@ -8,6 +8,16 @@ use crate::base::{Const, DefaultAllocator, OMatrix};
 
 use crate::geometry::{TCategory, Transform};
 
+impl<T: RealField, C: TCategory, const D: usize> Default for Transform<T, C, D>
+where
+    Const<D>: DimNameAdd<U1>,
+    DefaultAllocator: Allocator<T, DimNameSum<Const<D>, U1>, DimNameSum<Const<D>, U1>>,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 impl<T: RealField, C: TCategory, const D: usize> Transform<T, C, D>
 where
     Const<D>: DimNameAdd<U1>,

src/geometry/translation_construction.rs

@@ -15,6 +15,12 @@ use simba::scalar::{ClosedAdd, SupersetOf};
 use crate::base::{SVector, Scalar};
 use crate::geometry::Translation;
 
+impl<T: Scalar + Zero, const D: usize> Default for Translation<T, D> {
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 impl<T: Scalar, const D: usize> Translation<T, D> {
     /// Creates a new identity translation.
     ///

src/geometry/unit_complex_construction.rs

@@ -17,6 +17,15 @@ use crate::geometry::{Rotation2, UnitComplex};
 use simba::scalar::{RealField, SupersetOf};
 use simba::simd::SimdRealField;
 
+impl<T: SimdRealField> Default for UnitComplex<T>
+where
+    T::Element: SimdRealField,
+{
+    fn default() -> Self {
+        Self::identity()
+    }
+}
+
 /// # Identity
 impl<T: SimdRealField> UnitComplex<T>
 where