godot_core/builtin/variant/

impls.rs

/*
 * Copyright (c) godot-rust; Bromeon and contributors.
 * 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/.
 */

use godot_ffi as sys;

use super::*;
use crate::builtin::*;
use crate::global;
use crate::meta::error::{ConvertError, FromVariantError};
use crate::meta::{
    ArrayElement, GodotFfiVariant, GodotType, PropertyHintInfo, PropertyInfo, RefArg,
};

// For godot-cpp, see https://github.com/godotengine/godot-cpp/blob/master/include/godot_cpp/core/type_info.hpp.

// ----------------------------------------------------------------------------------------------------------------------------------------------
// Macro definitions

// Certain types need to be passed as initialized pointers in their from_variant implementations in 4.0. Because
// 4.0 uses `*ptr = value` to return the type, and some types in C++ override `operator=` in C++ in a way
// that requires the pointer to be initialized. But some other types will cause a memory leak in 4.1 if initialized.
//
// Therefore, we can use `init` to indicate when it must be initialized in 4.0.
macro_rules! impl_ffi_variant {
    (ref $T:ty, $from_fn:ident, $to_fn:ident $(; $GodotTy:ident)?) => {
        impl_ffi_variant!(@impls by_ref; $T, $from_fn, $to_fn $(; $GodotTy)?);
    };
    ($T:ty, $from_fn:ident, $to_fn:ident $(; $GodotTy:ident)?) => {
        impl_ffi_variant!(@impls by_val; $T, $from_fn, $to_fn $(; $GodotTy)?);
    };

    // Implementations
    (@impls $by_ref_or_val:ident; $T:ty, $from_fn:ident, $to_fn:ident $(; $GodotTy:ident)?) => {
        impl GodotFfiVariant for $T {
            fn ffi_to_variant(&self) -> Variant {
                let variant = unsafe {
                    Variant::new_with_var_uninit(|variant_ptr| {
                        let converter = sys::builtin_fn!($from_fn);
                        converter(variant_ptr, sys::SysPtr::force_mut(self.sys()));
                    })
                };

                variant
            }

            fn ffi_from_variant(variant: &Variant) -> Result<Self, ConvertError> {
                // Type check -- at the moment, a strict match is required.
                if variant.get_type() != Self::VARIANT_TYPE.variant_as_nil() {
                    return Err(FromVariantError::BadType {
                        expected: Self::VARIANT_TYPE.variant_as_nil(),
                        actual: variant.get_type(),
                    }
                    .into_error(variant.clone()));
                }

                let result = unsafe {
                    Self::new_with_uninit(|self_ptr| {
                        let converter = sys::builtin_fn!($to_fn);
                        converter(self_ptr, sys::SysPtr::force_mut(variant.var_sys()));
                    })
                };

                Ok(result)
            }
        }

        impl GodotType for $T {
            type Ffi = Self;
            impl_ffi_variant!(@assoc_to_ffi $by_ref_or_val);

            fn into_ffi(self) -> Self::Ffi {
                self
            }

            fn try_from_ffi(ffi: Self::Ffi) -> Result<Self, ConvertError> {
                Ok(ffi)
            }

            impl_ffi_variant!(@godot_type_name $T $(, $GodotTy)?);
        }

        impl ArrayElement for $T {}

        impl_ffi_variant!(@as_arg $by_ref_or_val $T);
    };

    (@godot_type_name $T:ty) => {
        fn godot_type_name() -> String {
            stringify!($T).into()
        }
    };

    (@godot_type_name $T:ty, $godot_type_name:ident) => {
        fn godot_type_name() -> String {
            stringify!($godot_type_name).into()
        }
    };

    (@assoc_to_ffi by_ref) => {
        type ToFfi<'a> =  RefArg<'a, Self>;

        fn to_ffi(&self) -> Self::ToFfi<'_> {
            RefArg::new(self)
        }
    };

    (@assoc_to_ffi by_val) => {
        type ToFfi<'a> = Self;

        fn to_ffi(&self) -> Self::ToFfi<'_> {
            self.clone()
        }
    };

    (@as_arg by_ref $T:ty) => {
        $crate::meta::impl_asarg_by_ref!($T);
    };

    (@as_arg by_val $T:ty) => {
        $crate::meta::impl_asarg_by_value!($T);
    };
}

// ----------------------------------------------------------------------------------------------------------------------------------------------
// General impls

#[rustfmt::skip]
#[allow(clippy::module_inception)]
mod impls {
    use super::*;

    // IMPORTANT: the presence/absence of `ref` here should be aligned with the ArgPassing variant
    // used in codegen get_builtin_arg_passing().

    impl_ffi_variant!(bool, bool_to_variant, bool_from_variant);
    impl_ffi_variant!(i64, int_to_variant, int_from_variant; int);
    impl_ffi_variant!(f64, float_to_variant, float_from_variant; float);
    impl_ffi_variant!(Vector2, vector2_to_variant, vector2_from_variant);
    impl_ffi_variant!(Vector3, vector3_to_variant, vector3_from_variant);
    impl_ffi_variant!(Vector4, vector4_to_variant, vector4_from_variant);
    impl_ffi_variant!(Vector2i, vector2i_to_variant, vector2i_from_variant);
    impl_ffi_variant!(Vector3i, vector3i_to_variant, vector3i_from_variant);
    impl_ffi_variant!(Vector4i, vector4i_to_variant, vector4i_from_variant);
    impl_ffi_variant!(Quaternion, quaternion_to_variant, quaternion_from_variant);
    impl_ffi_variant!(Transform2D, transform_2d_to_variant, transform_2d_from_variant);
    impl_ffi_variant!(Transform3D, transform_3d_to_variant, transform_3d_from_variant);
    impl_ffi_variant!(Basis, basis_to_variant, basis_from_variant);
    impl_ffi_variant!(Projection, projection_to_variant, projection_from_variant);
    impl_ffi_variant!(Plane, plane_to_variant, plane_from_variant);
    impl_ffi_variant!(Rect2, rect2_to_variant, rect2_from_variant);
    impl_ffi_variant!(Rect2i, rect2i_to_variant, rect2i_from_variant);
    impl_ffi_variant!(Aabb, aabb_to_variant, aabb_from_variant; AABB);
    impl_ffi_variant!(Color, color_to_variant, color_from_variant);
    impl_ffi_variant!(Rid, rid_to_variant, rid_from_variant; RID);
    impl_ffi_variant!(ref GString, string_to_variant, string_from_variant; String);
    impl_ffi_variant!(ref StringName, string_name_to_variant, string_name_from_variant);
    impl_ffi_variant!(ref NodePath, node_path_to_variant, node_path_from_variant);
    impl_ffi_variant!(ref Dictionary, dictionary_to_variant, dictionary_from_variant);
    impl_ffi_variant!(ref PackedByteArray, packed_byte_array_to_variant, packed_byte_array_from_variant);
    impl_ffi_variant!(ref PackedInt32Array, packed_int32_array_to_variant, packed_int32_array_from_variant);
    impl_ffi_variant!(ref PackedInt64Array, packed_int64_array_to_variant, packed_int64_array_from_variant);
    impl_ffi_variant!(ref PackedFloat32Array, packed_float32_array_to_variant, packed_float32_array_from_variant);
    impl_ffi_variant!(ref PackedFloat64Array, packed_float64_array_to_variant, packed_float64_array_from_variant);
    impl_ffi_variant!(ref PackedStringArray, packed_string_array_to_variant, packed_string_array_from_variant);
    impl_ffi_variant!(ref PackedVector2Array, packed_vector2_array_to_variant, packed_vector2_array_from_variant);
    impl_ffi_variant!(ref PackedVector3Array, packed_vector3_array_to_variant, packed_vector3_array_from_variant);
    impl_ffi_variant!(ref PackedColorArray, packed_color_array_to_variant, packed_color_array_from_variant);
    impl_ffi_variant!(ref Signal, signal_to_variant, signal_from_variant);
    impl_ffi_variant!(ref Callable, callable_to_variant, callable_from_variant);

    #[cfg(since_api = "4.2")] #[cfg_attr(published_docs, doc(cfg(since_api = "4.2")))]
    mod api_4_2 {
        use crate::builtin::Array;
        use crate::meta::ArrayElement;
        use crate::meta::sealed::Sealed;
        use crate::task::{impl_dynamic_send, DynamicSend, IntoDynamicSend, ThreadConfined};


        impl_dynamic_send!(
            Send;
            bool, u8, u16, u32, u64, i8, i16, i32, i64, f32, f64
        );

        impl_dynamic_send!(
            Send;
            builtin::{
                StringName, Transform2D, Transform3D, Vector2, Vector2i, Vector2Axis,
                Vector3, Vector3i, Vector3Axis, Vector4, Vector4i, Rect2, Rect2i, Plane, Quaternion, Aabb, Basis, Projection, Color, Rid
            }
        );

        impl<T: ArrayElement> Sealed for ThreadConfined<Array<T>> {}

        unsafe impl<T:ArrayElement> DynamicSend for ThreadConfined<Array<T>> {
            type Inner = Array<T>;
            fn extract_if_safe(self) -> Option<Self::Inner> {
                self.extract()
            }
        }

        impl<T: ArrayElement> IntoDynamicSend for Array<T> {
            type Target = ThreadConfined<Array<T>>;
            fn into_dynamic_send(self) -> Self::Target {
                crate::task::ThreadConfined::new(self)
            }
        }

        impl_dynamic_send!(
            !Send;
            Variant, GString, Dictionary, Callable, NodePath, PackedByteArray, PackedInt32Array, PackedInt64Array, PackedFloat32Array,
            PackedFloat64Array, PackedStringArray, PackedVector2Array, PackedVector3Array, PackedColorArray, Signal
        );

        // This should be kept in sync with crate::registry::signal::variadic.
        impl_dynamic_send!(tuple; );
        impl_dynamic_send!(tuple; arg1: A1);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, arg6: A6);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, arg6: A6, arg7: A7);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, arg6: A6, arg7: A7, arg8: A8);
        impl_dynamic_send!(tuple; arg1: A1, arg2: A2, arg3: A3, arg4: A4, arg5: A5, arg6: A6, arg7: A7, arg8: A8, arg9: A9);
    }

    #[cfg(since_api = "4.3")] #[cfg_attr(published_docs, doc(cfg(since_api = "4.3")))]
    mod api_4_3 {
        use crate::task::impl_dynamic_send;

        use super::*;

        impl_ffi_variant!(ref PackedVector4Array, packed_vector4_array_to_variant, packed_vector4_array_from_variant);

        impl_dynamic_send!(!Send; PackedVector4Array);
    }
}

// Compile time check that we cover all the Variant types with trait implementations for:
// - IntoDynamicSend
// - DynamicSend
// - GodotType
// - ArrayElement
const _: () = {
    use crate::classes::Object;
    use crate::obj::{Gd, IndexEnum};

    #[cfg(before_api = "4.2")] #[cfg_attr(published_docs, doc(cfg(before_api = "4.2")))]
    const fn variant_type<T: GodotType + ArrayElement>() -> VariantType {
        <T::Ffi as sys::GodotFfi>::VARIANT_TYPE.variant_as_nil()
    }

    #[cfg(since_api = "4.2")] #[cfg_attr(published_docs, doc(cfg(since_api = "4.2")))]
    const fn variant_type<T: crate::task::IntoDynamicSend + GodotType + ArrayElement>(
    ) -> VariantType {
        <T::Ffi as sys::GodotFfi>::VARIANT_TYPE.variant_as_nil()
    }

    const NIL: VariantType = variant_type::<Variant>();
    const BOOL: VariantType = variant_type::<bool>();
    const I64: VariantType = variant_type::<i64>();
    const F64: VariantType = variant_type::<f64>();
    const GSTRING: VariantType = variant_type::<GString>();

    const VECTOR2: VariantType = variant_type::<Vector2>();
    const VECTOR2I: VariantType = variant_type::<Vector2i>();
    const RECT2: VariantType = variant_type::<Rect2>();
    const RECT2I: VariantType = variant_type::<Rect2i>();
    const VECTOR3: VariantType = variant_type::<Vector3>();
    const VECTOR3I: VariantType = variant_type::<Vector3i>();
    const TRANSFORM2D: VariantType = variant_type::<Transform2D>();
    const TRANSFORM3D: VariantType = variant_type::<Transform3D>();
    const VECTOR4: VariantType = variant_type::<Vector4>();
    const VECTOR4I: VariantType = variant_type::<Vector4i>();
    const PLANE: VariantType = variant_type::<Plane>();
    const QUATERNION: VariantType = variant_type::<Quaternion>();
    const AABB: VariantType = variant_type::<Aabb>();
    const BASIS: VariantType = variant_type::<Basis>();
    const PROJECTION: VariantType = variant_type::<Projection>();
    const COLOR: VariantType = variant_type::<Color>();
    const STRING_NAME: VariantType = variant_type::<StringName>();
    const NODE_PATH: VariantType = variant_type::<NodePath>();
    const RID: VariantType = variant_type::<Rid>();
    const OBJECT: VariantType = variant_type::<Gd<Object>>();
    const CALLABLE: VariantType = variant_type::<Callable>();
    const SIGNAL: VariantType = variant_type::<Signal>();
    const DICTIONARY: VariantType = variant_type::<Dictionary>();
    const ARRAY: VariantType = variant_type::<VariantArray>();
    const PACKED_BYTE_ARRAY: VariantType = variant_type::<PackedByteArray>();
    const PACKED_INT32_ARRAY: VariantType = variant_type::<PackedInt32Array>();
    const PACKED_INT64_ARRAY: VariantType = variant_type::<PackedInt64Array>();
    const PACKED_FLOAT32_ARRAY: VariantType = variant_type::<PackedFloat32Array>();
    const PACKED_FLOAT64_ARRAY: VariantType = variant_type::<PackedFloat64Array>();
    const PACKED_STRING_ARRAY: VariantType = variant_type::<PackedStringArray>();
    const PACKED_VECTOR2_ARRAY: VariantType = variant_type::<PackedVector2Array>();
    const PACKED_VECTOR3_ARRAY: VariantType = variant_type::<PackedVector3Array>();
    const PACKED_COLOR_ARRAY: VariantType = variant_type::<PackedColorArray>();

    #[cfg(since_api = "4.3")] #[cfg_attr(published_docs, doc(cfg(since_api = "4.3")))]
    const PACKED_VECTOR4_ARRAY: VariantType = variant_type::<PackedVector4Array>();

    const MAX: i32 = VariantType::ENUMERATOR_COUNT as i32;

    // The matched value is not relevant, we just want to ensure that the full list from 0 to MAX is covered.
    #[deny(unreachable_patterns)]
    match VariantType::STRING {
        VariantType { ord: i32::MIN..0 } => panic!("ord is out of defined range!"),
        NIL => (),
        BOOL => (),
        I64 => (),
        F64 => (),
        GSTRING => (),
        VECTOR2 => (),
        VECTOR2I => (),
        RECT2 => (),
        RECT2I => (),
        VECTOR3 => (),
        VECTOR3I => (),
        TRANSFORM2D => (),
        VECTOR4 => (),
        VECTOR4I => (),
        PLANE => (),
        QUATERNION => (),
        AABB => (),
        BASIS => (),
        TRANSFORM3D => (),
        PROJECTION => (),
        COLOR => (),
        STRING_NAME => (),
        NODE_PATH => (),
        RID => (),
        OBJECT => (),
        CALLABLE => (),
        SIGNAL => (),
        DICTIONARY => (),
        ARRAY => (),
        PACKED_BYTE_ARRAY => (),
        PACKED_INT32_ARRAY => (),
        PACKED_INT64_ARRAY => (),
        PACKED_FLOAT32_ARRAY => (),
        PACKED_FLOAT64_ARRAY => (),
        PACKED_STRING_ARRAY => (),
        PACKED_VECTOR2_ARRAY => (),
        PACKED_VECTOR3_ARRAY => (),
        PACKED_COLOR_ARRAY => (),

        #[cfg(since_api = "4.3")] #[cfg_attr(published_docs, doc(cfg(since_api = "4.3")))]
        PACKED_VECTOR4_ARRAY => (),
        VariantType { ord: MAX.. } => panic!("ord is out of defined range!"),
    }
};

// ----------------------------------------------------------------------------------------------------------------------------------------------
// Explicit impls

// Unit
impl GodotFfiVariant for () {
    fn ffi_to_variant(&self) -> Variant {
        Variant::nil()
    }

    fn ffi_from_variant(variant: &Variant) -> Result<Self, ConvertError> {
        if variant.is_nil() {
            return Ok(());
        }

        Err(FromVariantError::BadType {
            expected: VariantType::NIL,
            actual: variant.get_type(),
        }
        .into_error(variant.clone()))
    }
}

impl GodotType for () {
    type Ffi = ();
    type ToFfi<'a> = ();

    fn to_ffi(&self) -> Self::ToFfi<'_> {}

    fn into_ffi(self) -> Self::Ffi {}

    fn try_from_ffi(_: Self::Ffi) -> Result<Self, ConvertError> {
        Ok(())
    }

    fn godot_type_name() -> String {
        "Variant".to_string()
    }
}

impl GodotFfiVariant for Variant {
    fn ffi_to_variant(&self) -> Variant {
        self.clone()
    }

    fn ffi_from_variant(variant: &Variant) -> Result<Self, ConvertError> {
        Ok(variant.clone())
    }
}

impl GodotType for Variant {
    type Ffi = Variant;
    type ToFfi<'a> = RefArg<'a, Variant>;

    fn to_ffi(&self) -> Self::ToFfi<'_> {
        RefArg::new(self)
    }

    fn into_ffi(self) -> Self::Ffi {
        self
    }

    fn try_from_ffi(ffi: Self::Ffi) -> Result<Self, ConvertError> {
        Ok(ffi)
    }

    fn param_metadata() -> sys::GDExtensionClassMethodArgumentMetadata {
        sys::GDEXTENSION_METHOD_ARGUMENT_METADATA_NONE
    }

    fn property_info(property_name: &str) -> PropertyInfo {
        PropertyInfo {
            variant_type: Self::VARIANT_TYPE.variant_as_nil(),
            class_name: Self::class_name(),
            property_name: StringName::from(property_name),
            hint_info: PropertyHintInfo::none(),
            usage: global::PropertyUsageFlags::DEFAULT | global::PropertyUsageFlags::NIL_IS_VARIANT,
        }
    }

    fn godot_type_name() -> String {
        "Variant".to_string()
    }
}