Merge #128

128: Tweaks to glamconv and indexing for vectors r=Bromeon a=sayaks

Add bool as glam type
Add glamconv/glamtype for Vector2/3/4
Add assert_eq/ne_approx
Add lerp_angle

Split from #124 

Co-authored-by: Lili Zoey <[email protected]>

Author: bors[bot]

godot-core/src/builtin/glam_helpers.rs

@@ -71,4 +71,5 @@ macro_rules! impl_glam_map_self {
 }
 
 impl_glam_map_self!(f32);
+impl_glam_map_self!(bool);
 impl_glam_map_self!((f32, f32, f32));

godot-core/src/builtin/math.rs

@@ -4,6 +4,8 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+use std::f32::consts::TAU;
+
 pub const CMP_EPSILON: f32 = 0.00001;
 
 pub fn lerp(a: f32, b: f32, t: f32) -> f32 {
@@ -119,3 +121,99 @@ pub fn cubic_interpolate_in_time(
     let b2 = lerp(a2, a3, if post_t == 0.0 { 1.0 } else { t / post_t });
     lerp(b1, b2, if to_t == 0.0 { 0.5 } else { t / to_t })
 }
+
+/// Linearly interpolates between two angles (in radians) by a `weight` value
+/// between 0.0 and 1.0.
+///
+/// Similar to [`lerp`], but interpolates correctly when the angles wrap around
+/// [`TAU`].
+///
+/// The resulting angle is not normalized.
+///
+/// Note: This function lerps through the shortest path between `from` and
+/// `to`. However, when these two angles are approximately `PI + k * TAU` apart
+/// for any integer `k`, it's not obvious which way they lerp due to
+/// floating-point precision errors. For example, `lerp_angle(0.0, PI, weight)`
+/// lerps clockwise, while `lerp_angle(0.0, PI + 3.0 * TAU, weight)` lerps
+/// counter-clockwise.
+///
+/// _Godot equivalent: @GlobalScope.lerp_angle()_
+pub fn lerp_angle(from: f32, to: f32, weight: f32) -> f32 {
+    let difference = (to - from) % TAU;
+    let distance = (2.0 * difference) % TAU - difference;
+    from + distance * weight
+}
+
+/// Asserts that two values are approximately equal, using the provided `func`
+/// for equality checking.
+#[macro_export]
+macro_rules! assert_eq_approx {
+    ($a:expr, $b:expr, $func:expr $(,)?) => {
+        match ($a, $b) {
+            (a, b) => {
+                assert!(($func)(a,b), "\n  left: {:?},\n right: {:?}", $a, $b);
+            }
+        }
+    };
+    ($a:expr, $b:expr, $func:expr, $($t:tt)+) => {
+        match ($a, $b) {
+            (a, b) => {
+                assert!(($func)(a,b), "\n  left: {:?},\n right: {:?},\n{}", $a, $b, format_args!($($t)+));
+            }
+        }
+    };
+}
+
+/// Asserts that two values are not approximately equal, using the provided
+/// `func` for equality checking.
+#[macro_export]
+macro_rules! assert_ne_approx {
+    ($a:expr, $b:expr, $func:expr $(, $($t:tt)*)?) => {
+        #[allow(clippy::redundant_closure_call)]
+        {
+            assert_eq_approx!($a, $b, |a,b| !($func)(a,b) $(, $($t)*)?)
+        }
+    };
+}
+
+#[cfg(test)]
+mod test {
+    use std::f32::consts::{FRAC_PI_2, PI};
+
+    use super::*;
+
+    #[test]
+    fn equal_approx() {
+        assert_eq_approx!(1.0, 1.000001, is_equal_approx);
+        assert_ne_approx!(1.0, 2.0, is_equal_approx);
+        assert_eq_approx!(1.0, 1.000001, is_equal_approx, "Message {}", "formatted");
+        assert_ne_approx!(1.0, 2.0, is_equal_approx, "Message {}", "formatted");
+    }
+
+    #[test]
+    #[should_panic(expected = "I am inside format")]
+    fn eq_approx_fail_with_message() {
+        assert_eq_approx!(1.0, 2.0, is_equal_approx, "I am inside {}", "format");
+    }
+
+    #[test]
+    fn lerp_angle_test() {
+        assert_eq_approx!(lerp_angle(0.0, PI, 0.5), -FRAC_PI_2, is_equal_approx);
+        assert_eq_approx!(
+            lerp_angle(0.0, PI + 3.0 * TAU, 0.5),
+            FRAC_PI_2,
+            is_equal_approx
+        );
+        let angle = PI * 2.0 / 3.0;
+        assert_eq_approx!(
+            lerp_angle(-5.0 * TAU, angle + 3.0 * TAU, 0.5).sin(),
+            (angle / 2.0).sin(),
+            is_equal_approx
+        );
+        assert_eq_approx!(
+            lerp_angle(-5.0 * TAU, angle + 3.0 * TAU, 0.5).cos(),
+            (angle / 2.0).cos(),
+            is_equal_approx
+        );
+    }
+}

godot-core/src/builtin/vector2.rs

@@ -6,12 +6,16 @@
 use std::fmt;
 use std::ops::*;
 
+use glam::Vec2;
 use godot_ffi as sys;
 use sys::{ffi_methods, GodotFfi};
 
 use crate::builtin::math::*;
 use crate::builtin::{inner, Vector2i};
 
+use super::glam_helpers::GlamConv;
+use super::glam_helpers::GlamType;
+
 /// Vector used for 2D math using floating point coordinates.
 ///
 /// 2-element structure that can be used to represent positions in 2D space or any other pair of
@@ -97,6 +101,10 @@ impl Vector2 {
         self.x / self.y
     }
 
+    pub fn lerp(self, other: Self, weight: f32) -> Self {
+        Self::new(lerp(self.x, other.x, weight), lerp(self.y, other.y, weight))
+    }
+
     pub fn bezier_derivative(self, control_1: Self, control_2: Self, end: Self, t: f32) -> Self {
         let x = bezier_derivative(self.x, control_1.x, control_2.x, end.x, t);
         let y = bezier_derivative(self.y, control_1.y, control_2.y, end.y, t);
@@ -199,10 +207,6 @@ impl Vector2 {
         self.to_glam().length_squared()
     }
 
-    pub fn lerp(self, to: Self, weight: f32) -> Self {
-        Self::from_glam(self.to_glam().lerp(to.to_glam(), weight))
-    }
-
     pub fn limit_length(self, length: Option<f32>) -> Self {
         Self::from_glam(self.to_glam().clamp_length_max(length.unwrap_or(1.0)))
     }
@@ -323,3 +327,19 @@ pub enum Vector2Axis {
 impl GodotFfi for Vector2Axis {
     ffi_methods! { type sys::GDExtensionTypePtr = *mut Self; .. }
 }
+
+impl GlamType for Vec2 {
+    type Mapped = Vector2;
+
+    fn to_front(&self) -> Self::Mapped {
+        Vector2::new(self.x, self.y)
+    }
+
+    fn from_front(mapped: &Self::Mapped) -> Self {
+        Vec2::new(mapped.x, mapped.y)
+    }
+}
+
+impl GlamConv for Vector2 {
+    type Glam = Vec2;
+}

godot-core/src/builtin/vector3.rs

@@ -7,12 +7,17 @@ use std::ops::*;
 
 use std::fmt;
 
+use glam::f32::Vec3;
+use glam::Vec3A;
 use godot_ffi as sys;
 use sys::{ffi_methods, GodotFfi};
 
 use crate::builtin::math::*;
 use crate::builtin::Vector3i;
 
+use super::glam_helpers::GlamConv;
+use super::glam_helpers::GlamType;
+
 /// Vector used for 3D math using floating point coordinates.
 ///
 /// 3-element structure that can be used to represent positions in 3D space or any other triple of
@@ -336,3 +341,31 @@ pub enum Vector3Axis {
 impl GodotFfi for Vector3Axis {
     ffi_methods! { type sys::GDExtensionTypePtr = *mut Self; .. }
 }
+
+impl GlamType for Vec3 {
+    type Mapped = Vector3;
+
+    fn to_front(&self) -> Self::Mapped {
+        Vector3::new(self.x, self.y, self.z)
+    }
+
+    fn from_front(mapped: &Self::Mapped) -> Self {
+        Vec3::new(mapped.x, mapped.y, mapped.z)
+    }
+}
+
+impl GlamType for Vec3A {
+    type Mapped = Vector3;
+
+    fn to_front(&self) -> Self::Mapped {
+        Vector3::new(self.x, self.y, self.z)
+    }
+
+    fn from_front(mapped: &Self::Mapped) -> Self {
+        Vec3A::new(mapped.x, mapped.y, mapped.z)
+    }
+}
+
+impl GlamConv for Vector3 {
+    type Glam = Vec3;
+}

godot-core/src/builtin/vector4.rs

@@ -6,11 +6,14 @@
 
 use std::fmt;
 
+use glam::Vec4;
 use godot_ffi as sys;
 use sys::{ffi_methods, GodotFfi};
 
 use crate::builtin::Vector4i;
 
+use super::glam_helpers::{GlamConv, GlamType};
+
 /// Vector used for 4D math using floating point coordinates.
 ///
 /// 4-element structure that can be used to represent any quadruplet of numeric values.
@@ -107,3 +110,19 @@ pub enum Vector4Axis {
 impl GodotFfi for Vector4Axis {
     ffi_methods! { type sys::GDExtensionTypePtr = *mut Self; .. }
 }
+
+impl GlamType for Vec4 {
+    type Mapped = Vector4;
+
+    fn to_front(&self) -> Self::Mapped {
+        Vector4::new(self.x, self.y, self.z, self.w)
+    }
+
+    fn from_front(mapped: &Self::Mapped) -> Self {
+        Vec4::new(mapped.x, mapped.y, mapped.z, mapped.w)
+    }
+}
+
+impl GlamConv for Vector4 {
+    type Glam = Vec4;
+}