Make Quaternion work with latest master; new experimental glam pattern

Author: Bromeon

godot-core/src/builtin/glam_helpers.rs

@@ -0,0 +1,74 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+// TODO this is experimental -- do not refactor existing types to this yet
+// Need to see if ergonomics are worth the generic complexity.
+//
+// Nice:
+//   self.glam2(&with, |a, b| a.dot(b))
+//   self.glam2(&with, glam::f32::Quat::dot)
+//
+// Alternative with only conversions:
+//   self.glam().dot(b.glam())
+//   GlamType::dot(self.glam(), b.glam())
+
+pub(crate) trait GlamConv {
+    type Glam: GlamType<Mapped = Self>;
+
+    fn to_glam(&self) -> Self::Glam {
+        Self::Glam::from_front(self)
+    }
+
+    fn glam<F, R>(&self, unary_fn: F) -> R::Mapped
+    where
+        R: GlamType,
+        F: FnOnce(Self::Glam) -> R,
+    {
+        let arg = Self::Glam::from_front(self);
+        let result = unary_fn(arg);
+
+        result.to_front()
+    }
+
+    fn glam2<F, P, R>(&self, rhs: &P, binary_fn: F) -> R::Mapped
+    where
+        P: GlamConv,
+        R: GlamType,
+        F: FnOnce(Self::Glam, P::Glam) -> R,
+    {
+        let arg0 = Self::Glam::from_front(self);
+        let arg1 = P::Glam::from_front(rhs);
+
+        let result = binary_fn(arg0, arg1);
+        result.to_front()
+    }
+}
+
+pub(crate) trait GlamType {
+    type Mapped;
+
+    fn to_front(&self) -> Self::Mapped;
+    fn from_front(mapped: &Self::Mapped) -> Self;
+}
+
+macro_rules! impl_glam_map_self {
+    ($T:ty) => {
+        impl GlamType for $T {
+            type Mapped = $T;
+
+            fn to_front(&self) -> $T {
+                *self
+            }
+
+            fn from_front(mapped: &$T) -> Self {
+                *mapped
+            }
+        }
+    };
+}
+
+impl_glam_map_self!(f32);
+impl_glam_map_self!((f32, f32, f32));

godot-core/src/builtin/mod.rs

@@ -80,6 +80,7 @@ mod array_inner;
 mod dictionary_inner;
 
 mod color;
+mod glam_helpers;
 mod math;
 mod node_path;
 mod others;