From 74ff6ae1992130a6ede057c240796e03dba3e5e2 Mon Sep 17 00:00:00 2001
From: Jack Wrenn <me@jswrenn.com>
Date: Wed, 21 Nov 2018 15:22:42 -0500
Subject: [PATCH] Implement `Point` swizzling

---
 src/geometry/mod.rs     |  2 ++
 src/geometry/swizzle.rs | 69 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 71 insertions(+)
 create mode 100644 src/geometry/swizzle.rs

diff --git a/src/geometry/mod.rs b/src/geometry/mod.rs
index af712461..3100eb9c 100644
--- a/src/geometry/mod.rs
+++ b/src/geometry/mod.rs
@@ -53,6 +53,8 @@ mod similarity_construction;
 mod similarity_conversion;
 mod similarity_ops;
 
+mod swizzle;
+
 mod transform;
 mod transform_alga;
 mod transform_alias;
diff --git a/src/geometry/swizzle.rs b/src/geometry/swizzle.rs
new file mode 100644
index 00000000..d471f32e
--- /dev/null
+++ b/src/geometry/swizzle.rs
@@ -0,0 +1,69 @@
+use base::allocator::Allocator;
+use base::{DefaultAllocator, DimName, Scalar};
+use geometry::{Point, Point2, Point3};
+use typenum::{self, Cmp, Greater};
+
+macro_rules! impl_swizzle {
+    ($(where $BaseDim: ident: $name: ident() -> $Result: ident[$($i: expr),*]);*) => {
+        $(
+            impl<N: Scalar, D: DimName> Point<N, D>
+            where DefaultAllocator: Allocator<N, D>
+            {
+                /// Builds a new vector from components of `self`.
+                #[inline]
+                pub fn $name(&self) -> $Result<N>
+                    where D::Value: Cmp<typenum::$BaseDim, Output=Greater> {
+                    $Result::new($(self[$i]),*)
+                }
+            }
+        )*
+    }
+}
+
+impl_swizzle!(
+    where U0: xx() -> Point2[0, 0];
+    where U1: xy() -> Point2[0, 1];
+    where U2: xz() -> Point2[0, 2];
+    where U1: yx() -> Point2[1, 0];
+    where U1: yy() -> Point2[1, 1];
+    where U1: yz() -> Point2[1, 2];
+    where U2: zx() -> Point2[2, 0];
+    where U2: zy() -> Point2[2, 1];
+    where U2: zz() -> Point2[2, 2];
+
+    where U0: xxx() -> Point3[0, 0, 0];
+    where U1: xxy() -> Point3[0, 0, 1];
+    where U2: xxz() -> Point3[0, 0, 2];
+
+    where U1: xyx() -> Point3[0, 1, 0];
+    where U1: xyy() -> Point3[0, 1, 1];
+    where U2: xyz() -> Point3[0, 1, 2];
+
+    where U2: xzx() -> Point3[0, 2, 0];
+    where U2: xzy() -> Point3[0, 2, 1];
+    where U2: xzz() -> Point3[0, 2, 2];
+
+    where U1: yxx() -> Point3[1, 0, 0];
+    where U1: yxy() -> Point3[1, 0, 1];
+    where U2: yxz() -> Point3[1, 0, 2];
+
+    where U1: yyx() -> Point3[1, 1, 0];
+    where U1: yyy() -> Point3[1, 1, 1];
+    where U2: yyz() -> Point3[1, 1, 2];
+
+    where U2: yzx() -> Point3[1, 2, 0];
+    where U2: yzy() -> Point3[1, 2, 1];
+    where U2: yzz() -> Point3[1, 2, 2];
+
+    where U2: zxx() -> Point3[2, 0, 0];
+    where U2: zxy() -> Point3[2, 0, 1];
+    where U2: zxz() -> Point3[2, 0, 2];
+
+    where U2: zyx() -> Point3[2, 1, 0];
+    where U2: zyy() -> Point3[2, 1, 1];
+    where U2: zyz() -> Point3[2, 1, 2];
+
+    where U2: zzx() -> Point3[2, 2, 0];
+    where U2: zzy() -> Point3[2, 2, 1];
+    where U2: zzz() -> Point3[2, 2, 2]
+);