PR #2/5 Astolfo feature/builtin-macro

godot-core/Cargo.toml

@@ -18,6 +18,7 @@ unit-test = ["godot-ffi/unit-test"] # If this crate is built for a downstream un
 [dependencies]
 godot-ffi = { path = "../godot-ffi" }
 once_cell = "1.8"
+paste = "1.0"
 
 # See https://docs.rs/glam/latest/glam/index.html#feature-gates
 glam = { version = "0.22", features = ["debug-glam-assert", "scalar-math"] }

godot-core/src/builtin/real.rs

@@ -0,0 +1,27 @@
+/*
+ * 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/.
+ */
+
+pub use single::*;
+
+mod single {
+    /// Floating-point type used throughout the engine. This is the equivalent of `real_t` in the
+    /// engine's C++ code.
+    ///
+    /// Currently, this is always `f32`; working with an engine compiled with `precision=double` is
+    /// not supported yet.
+    pub type Real = f32;
+
+    pub(crate) type Vec2 = glam::f32::Vec2;
+    pub(crate) type Vec3 = glam::f32::Vec3;
+    pub(crate) type Vec4 = glam::f32::Vec4;
+}
+
+// mod double {
+//     pub type Real = f64;
+//     pub(crate) type Vec2 = glam::f64::DVec2;
+//     pub(crate) type Vec3 = glam::f64::DVec3;
+//     pub(crate) type Vec4 = glam::f64::DVec4;
+// }

godot-core/src/builtin/vector_macros.rs

@@ -0,0 +1,213 @@
+/*
+ * 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/.
+ */
+
+#![macro_use]
+
+/// Helper for `impl_vector` to create format strings for `format!` and friends.
+macro_rules! format_string {
+    ($a:ident, $b:ident) => { "({}, {})" };
+    ($a:ident, $b:ident, $c: ident) => { "({}, {}, {})" };
+    ($a:ident, $b:ident, $c: ident, $d:ident) => { "({}, {}, {}, {})" };
+}
+
+/// Helper for `impl_vector` to implement a set of operators for a vector type.
+macro_rules! impl_vector_operators {
+    (
+        // Name of the vector type.
+        $vector:ty,
+        // Type of each individual component, for example `i32`.
+        $component_type:ty,
+        // Name of the operator trait.
+        $operator:ident
+    ) => {
+        // `paste` is used for conversion to snake-case: AddAssign -> add_assign.
+        paste::paste! {
+            // vector + vector
+            impl std::ops::$operator for $vector {
+                type Output = Self;
+                fn [<$operator:snake>](self, rhs: $vector) -> Self::Output {
+                    self.0.[<$operator:snake>](rhs.0).into()
+                }
+            }
+
+            // vector + scalar
+            impl std::ops::$operator<$component_type> for $vector {
+                type Output = Self;
+                fn [<$operator:snake>](self, rhs: $component_type) -> Self::Output {
+                    self.0.[<$operator:snake>](rhs).into()
+                }
+            }
+
+            // scalar + vector
+            impl std::ops::$operator<$vector> for $component_type {
+                type Output = $vector;
+                fn [<$operator:snake>](self, rhs: $vector) -> Self::Output {
+                    self.[<$operator:snake>](rhs.0).into()
+                }
+            }
+
+            // vector += vector
+            impl std::ops::[<$operator Assign>] for $vector {
+                fn [<$operator:snake _assign>](&mut self, rhs: $vector) {
+                    self.0.[<$operator:snake _assign>](rhs.0);
+                }
+            }
+
+            // vector += scalar
+            impl std::ops::[<$operator Assign>]<$component_type> for $vector {
+                fn [<$operator:snake _assign>](&mut self, rhs: $component_type) {
+                    self.0.[<$operator:snake _assign>](rhs);
+                }
+            }
+        }
+    }
+}
+
+/// Implements the basics of a built-in vector type.
+macro_rules! impl_vector {
+    (
+        // Name of the vector type to be created.
+        $vector:ident,
+        // Name of the inner (wrapped) type, typically from glam.
+        $inner_type:ty,
+        // Type of each individual component, for example `i32`.
+        $component_type:ty,
+        // Names of the components, for example `(x, y)`.
+        ($($components:ident),*)$(,)?
+    ) => {
+        // Inside a `paste!` invocation, everything between [<...>] gets concatenated.
+        paste::paste! {
+            #[derive(Default, Copy, Clone, Debug, PartialEq)]
+            #[repr(C)]
+            pub struct $vector($inner_type);
+
+            impl $vector {
+                /// Creates a new vector with the given components.
+                #[inline]
+                pub const fn new($($components: $component_type),*) -> Self {
+                    Self($inner_type::new($($components),*))
+                }
+
+                /// Creates a new vector with all components set to `v`.
+                #[inline]
+                pub const fn splat(v: $component_type) -> Self {
+                    Self($inner_type::splat(v))
+                }
+
+                $(
+                    #[doc = "Returns the `" $components "` component of this vector."]
+                    #[inline]
+                    pub fn $components(&self) -> $component_type {
+                        self.0.$components
+                    }
+
+                    #[doc = "Sets the `" $components "` component of this vector."]
+                    #[inline]
+                    pub fn [<set_ $components>](&mut self, $components: $component_type) {
+                        self.0.$components = $components;
+                    }
+                )*
+            }
+
+            impl From<$inner_type> for $vector {
+                /// Wraps an inner type in a Godot vector.
+                fn from(inner: $inner_type) -> Self {
+                    Self(inner)
+                }
+            }
+
+            impl From<$vector> for $inner_type {
+                /// Unwraps a Godot vector into its inner type.
+                fn from(vector: $vector) -> Self {
+                    vector.0
+                }
+            }
+
+            impl std::fmt::Display for $vector {
+                /// Formats this vector in the same way the Godot engine would.
+                fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+                    write!(
+                        f,
+                        format_string!($($components),*),
+                        $(self.$components()),*)
+                }
+            }
+
+            impl_vector_operators!($vector, $component_type, Add);
+            impl_vector_operators!($vector, $component_type, Sub);
+            impl_vector_operators!($vector, $component_type, Mul);
+            impl_vector_operators!($vector, $component_type, Div);
+
+            impl std::ops::Neg for $vector {
+                type Output = Self;
+                fn neg(self) -> Self {
+                    self.0.neg().into()
+                }
+            }
+
+            impl godot_ffi::GodotFfi for $vector {
+                godot_ffi::ffi_methods! { type godot_ffi::GDExtensionTypePtr = *mut Self; .. }
+            }
+        }
+    }
+}
+
+/// Implements `From` that does a component-wise cast to convert one vector type to another.
+macro_rules! impl_vector_from {
+    (
+        // Name of the vector type.
+        $vector:ty,
+        // Name of the original type.
+        $from:ty,
+        // Type of target component, for example `Real`.
+        $component_type:ty,
+        // Names of the components, for example `(x, y)`.
+        ($($components:ident),*)$(,)?
+    ) => {
+        paste::paste! {
+            impl From<$from> for $vector {
+                #[doc = "Converts a `" $from "` into a `" $vector "`. Note that this might be a lossy operation."]
+                fn from(from: $from) -> Self {
+                    Self::new($(from.$components() as $component_type),*)
+                }
+            }
+        }
+    }
+}
+
+/// Implements common constants and methods for floating-point type vectors.
+macro_rules! impl_float_vector {
+    (
+        // Name of the vector type.
+        $vector:ty,
+        // Type of target component, for example `Real`.
+        $component_type:ty
+    ) => {
+        impl $vector {
+            /// Zero vector, a vector with all components set to `0.0`.
+            pub const ZERO: Self = Self::splat(0.0);
+
+            /// One vector, a vector with all components set to `1.0`.
+            pub const ONE: Self = Self::splat(1.0);
+
+            /// Infinity vector, a vector with all components set to `INFIINTY`.
+            pub const INF: Self = Self::splat(<$component_type>::INFINITY);
+
+            /// Returns the length (magnitude) of this vector.
+            #[inline]
+            pub fn length(&self) -> $component_type {
+                self.0.length()
+            }
+
+            /// Returns the vector scaled to unit length. Equivalent to `self / self.length()`. See
+            /// also `is_normalized()`.
+            #[inline]
+            pub fn normalized(&self) -> Self {
+                self.0.normalize().into()
+            }
+        }
+    }
+}