add serde behind feature flag for some builtins

Author: jrockett6

godot-core/Cargo.toml

@@ -21,10 +21,12 @@ godot-ffi = { path = "../godot-ffi" }
 
 # See https://docs.rs/glam/latest/glam/index.html#feature-gates
 glam = { version = "0.23", features = ["debug-glam-assert"] }
+serde = { version = "1", features = ["derive"], optional = true }
 
 # Reverse dev dependencies so doctests can use `godot::` prefix
 [dev-dependencies]
 godot = { path = "../godot" }
+serde_json = "1.0"
 
 [build-dependencies]
 godot-codegen = { path = "../godot-codegen" }

godot-core/src/builtin/aabb.rs

@@ -18,6 +18,7 @@ use super::Vector3;
 ///
 /// The 2D counterpart to `Aabb` is [`Rect2`](super::Rect2).
 #[derive(Default, Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Aabb {
     pub position: Vector3,
@@ -101,3 +102,15 @@ impl std::fmt::Display for Aabb {
 unsafe impl GodotFfi for Aabb {
     ffi_methods! { type sys::GDExtensionTypePtr = *mut Self; .. }
 }
+
+#[cfg(test)]
+mod test {
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let aabb = super::Aabb::default();
+        let expected_json = "{\"position\":{\"x\":0.0,\"y\":0.0,\"z\":0.0},\"size\":{\"x\":0.0,\"y\":0.0,\"z\":0.0}}";
+
+        crate::builtin::test_utils::roundtrip(&aabb, expected_json);
+    }
+}

godot-core/src/builtin/basis.rs

@@ -23,6 +23,7 @@ use super::{real, RMat3, RQuat, RVec2, RVec3};
 /// The basis vectors are the columns of the matrix, whereas the [`rows`](Self::rows) field represents
 /// the row vectors.
 #[derive(Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Basis {
     /// The rows of the matrix. These are *not* the basis vectors.  
@@ -835,4 +836,13 @@ mod test {
             "Basis with three components infinite should not be finite."
         );
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let basis = Basis::IDENTITY;
+        let expected_json = "{\"rows\":[{\"x\":1.0,\"y\":0.0,\"z\":0.0},{\"x\":0.0,\"y\":1.0,\"z\":0.0},{\"x\":0.0,\"y\":0.0,\"z\":1.0}]}";
+
+        crate::builtin::test_utils::roundtrip(&basis, expected_json);
+    }
 }

godot-core/src/builtin/color.rs

@@ -16,6 +16,7 @@ use sys::{ffi_methods, GodotFfi};
 /// values outside this range are explicitly allowed for e.g. High Dynamic Range (HDR).
 #[repr(C)]
 #[derive(Copy, Clone, Debug, PartialEq, PartialOrd)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct Color {
     /// The color's red component.
     pub r: f32,
@@ -511,3 +512,15 @@ impl std::fmt::Display for Color {
         write!(f, "({}, {}, {}, {})", self.r, self.g, self.b, self.a)
     }
 }
+
+#[cfg(test)]
+mod test {
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let color = super::Color::WHITE;
+        let expected_json = "{\"r\":1.0,\"g\":1.0,\"b\":1.0,\"a\":1.0}";
+
+        crate::builtin::test_utils::roundtrip(&color, expected_json);
+    }
+}

godot-core/src/builtin/mod.rs

@@ -407,3 +407,22 @@ mod export {
     // TODO investigate whether Signal should impl Export at all, and if so, how
     // impl_export_by_clone!(Signal);
 }
+
+#[cfg(all(test, feature = "serde"))]
+pub(crate) mod test_utils {
+    use serde::{Deserialize, Serialize};
+
+    pub(crate) fn roundtrip<T>(value: &T, expected_json: &str)
+    where
+        T: for<'a> Deserialize<'a> + Serialize + PartialEq + std::fmt::Debug,
+    {
+        let json: String = serde_json::to_string(value).unwrap();
+        let back: T = serde_json::from_str(json.as_str()).unwrap();
+
+        assert_eq!(back, *value, "serde round-trip changes value");
+        assert_eq!(
+            json, expected_json,
+            "value does not conform to expected JSON"
+        );
+    }
+}

godot-core/src/builtin/plane.rs

@@ -23,6 +23,7 @@ use super::{is_equal_approx, real, Vector3};
 /// unit length and will panic if this invariant is violated. This is not separately
 /// annotated for each method.
 #[derive(Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Plane {
     pub normal: Vector3,
@@ -189,4 +190,16 @@ mod test {
             Vector3::new(0.0, 0.0, 2.0),
         );
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let plane = Plane {
+            normal: Vector3::ONE,
+            d: 0.0,
+        };
+        let expected_json = "{\"normal\":{\"x\":1.0,\"y\":1.0,\"z\":1.0},\"d\":0.0}";
+
+        crate::builtin::test_utils::roundtrip(&plane, expected_json);
+    }
 }

godot-core/src/builtin/projection.rs

@@ -25,6 +25,7 @@ use super::{real, RMat4, RealConv};
 /// Note: The current implementation largely makes calls to godot for its
 /// methods and as such are not as performant as other types.
 #[derive(Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Projection {
     /// The columns of the projection matrix.
@@ -960,6 +961,15 @@ mod test {
             }
         }
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let projection = Projection::IDENTITY;
+        let expected_json = "{\"cols\":[{\"x\":1.0,\"y\":0.0,\"z\":0.0,\"w\":0.0},{\"x\":0.0,\"y\":1.0,\"z\":0.0,\"w\":0.0},{\"x\":0.0,\"y\":0.0,\"z\":1.0,\"w\":0.0},{\"x\":0.0,\"y\":0.0,\"z\":0.0,\"w\":1.0}]}";
+
+        crate::builtin::test_utils::roundtrip(&projection, expected_json);
+    }
 }
 
 impl std::fmt::Display for Projection {

godot-core/src/builtin/quaternion.rs

@@ -15,6 +15,7 @@ use super::{real, RQuat};
 use super::{Basis, EulerOrder};
 
 #[derive(Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Quaternion {
     pub x: real,
@@ -347,3 +348,15 @@ impl Neg for Quaternion {
         Self::new(-self.x, -self.y, -self.z, -self.w)
     }
 }
+
+#[cfg(test)]
+mod test {
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let quaternion = super::Quaternion::new(1.0, 1.0, 1.0, 1.0);
+        let expected_json = "{\"x\":1.0,\"y\":1.0,\"z\":1.0,\"w\":1.0}";
+
+        crate::builtin::test_utils::roundtrip(&quaternion, expected_json);
+    }
+}

godot-core/src/builtin/rect2.rs

@@ -18,6 +18,7 @@ use super::{real, Rect2i, Vector2};
 ///
 /// The 3D counterpart to `Rect2` is [`Aabb`](super::Aabb).
 #[derive(Default, Copy, Clone, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Rect2 {
     pub position: Vector2,
@@ -125,3 +126,15 @@ impl std::fmt::Display for Rect2 {
         write!(f, "[P: {}, S: {}]", self.position, self.size)
     }
 }
+
+#[cfg(test)]
+mod test {
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let rect = super::Rect2::default();
+        let expected_json = "{\"position\":{\"x\":0.0,\"y\":0.0},\"size\":{\"x\":0.0,\"y\":0.0}}";
+
+        crate::builtin::test_utils::roundtrip(&rect, expected_json);
+    }
+}

godot-core/src/builtin/rect2i.rs

@@ -15,6 +15,7 @@ use super::{Rect2, RectSide, Vector2i};
 /// `Rect2i` consists of a position, a size, and several utility functions. It is typically used for
 /// fast overlap tests.
 #[derive(Default, Copy, Clone, Eq, PartialEq, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[repr(C)]
 pub struct Rect2i {
     /// The position of the rectangle.
@@ -583,4 +584,13 @@ mod test {
         let rect = Rect2i::from_components(0, 0, -5, -5);
         Rect2i::default().merge(rect);
     }
+
+    #[cfg(feature = "serde")]
+    #[test]
+    fn serde_roundtrip() {
+        let rect = Rect2i::default();
+        let expected_json = "{\"position\":{\"x\":0,\"y\":0},\"size\":{\"x\":0,\"y\":0}}";
+
+        crate::builtin::test_utils::roundtrip(&rect, expected_json);
+    }
 }