From 7275b5146e24bf5b0125e7b4fdf1dbcdd2a63dbd Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Crozet?= <developer@crozet.re>
Date: Thu, 14 Oct 2021 11:35:56 +0200
Subject: [PATCH] Implement Default for most geometry types

---
 CHANGELOG.md                              |  2 ++
 src/geometry/isometry_construction.rs     |  9 +++++++++
 src/geometry/point_construction.rs        |  9 +++++++++
 src/geometry/quaternion_construction.rs   |  9 +++++++++
 src/geometry/rotation_construction.rs     |  9 +++++++++
 src/geometry/similarity_construction.rs   | 10 ++++++++++
 src/geometry/transform_construction.rs    | 10 ++++++++++
 src/geometry/translation_construction.rs  |  6 ++++++
 src/geometry/unit_complex_construction.rs |  9 +++++++++
 9 files changed, 73 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b248ab25..281c8f8e 100644
--- a/CHANGELOG.md
+++ b/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
diff --git a/src/geometry/isometry_construction.rs b/src/geometry/isometry_construction.rs
index 9b855599..cce2932d 100644
--- a/src/geometry/isometry_construction.rs
+++ b/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,
diff --git a/src/geometry/point_construction.rs b/src/geometry/point_construction.rs
index e4e729aa..2136080a 100644
--- a/src/geometry/point_construction.rs
+++ b/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
diff --git a/src/geometry/quaternion_construction.rs b/src/geometry/quaternion_construction.rs
index 6de21bd5..8bf62e58 100644
--- a/src/geometry/quaternion_construction.rs
+++ b/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,
diff --git a/src/geometry/rotation_construction.rs b/src/geometry/rotation_construction.rs
index 1fc033e4..84e42693 100644
--- a/src/geometry/rotation_construction.rs
+++ b/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
diff --git a/src/geometry/similarity_construction.rs b/src/geometry/similarity_construction.rs
index feb5719b..8d1d38b8 100644
--- a/src/geometry/similarity_construction.rs
+++ b/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,
diff --git a/src/geometry/transform_construction.rs b/src/geometry/transform_construction.rs
index e9601864..45d61fcf 100644
--- a/src/geometry/transform_construction.rs
+++ b/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>,
diff --git a/src/geometry/translation_construction.rs b/src/geometry/translation_construction.rs
index 5371b648..128937bf 100644
--- a/src/geometry/translation_construction.rs
+++ b/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.
     ///
diff --git a/src/geometry/unit_complex_construction.rs b/src/geometry/unit_complex_construction.rs
index 0bf0188c..ebf4e81d 100644
--- a/src/geometry/unit_complex_construction.rs
+++ b/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