Merge pull request #431 from dataphract/fix/vector-reflect

fix vector{2,3} reflect() implementations

Author: Bromeon

godot-core/src/builtin/vectors/vector2.rs

@@ -192,7 +192,7 @@ impl Vector2 {
     }
 
     pub fn reflect(self, normal: Self) -> Self {
-        Self::from_glam(self.to_glam().reject_from(normal.to_glam()))
+        2.0 * normal * self.dot(normal) - self
     }
 
     pub fn round(self) -> Self {

godot-core/src/builtin/vectors/vector3.rs

@@ -194,7 +194,7 @@ impl Vector3 {
     }
 
     pub fn reflect(self, normal: Self) -> Self {
-        Self::from_glam(self.to_glam().reject_from(normal.to_glam()))
+        2.0 * normal * self.dot(normal) - self
     }
 
     pub fn round(self) -> Self {

itest/rust/src/builtin_tests/geometry/vector_test.rs

@@ -0,0 +1,69 @@
+/*
+ * 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 crate::framework::itest;
+
+use godot::builtin::inner::{InnerVector2, InnerVector3};
+use godot::builtin::{real, real_consts::PI, Vector2, Vector3};
+use godot::private::class_macros::assert_eq_approx;
+
+#[itest]
+fn vector2_equiv() {
+    for c in 0..10 {
+        let angle = 0.2 * c as real * PI;
+
+        let outer = Vector2::new(angle.cos(), angle.sin());
+        let inner = InnerVector2::from_outer(&outer);
+
+        let x_axis = Vector2::new(1.0, 0.0);
+        let y_axis = Vector2::new(0.0, 1.0);
+
+        assert_eq_approx!(
+            outer.reflect(x_axis),
+            inner.reflect(x_axis),
+            "reflect (x-axis)\n",
+        );
+
+        assert_eq_approx!(
+            outer.reflect(y_axis),
+            inner.reflect(y_axis),
+            "reflect (y-axis)\n",
+        );
+    }
+}
+
+#[itest]
+fn vector3_equiv() {
+    for c in 0..10 {
+        let angle = 0.2 * c as real * PI;
+        let z = 0.2 * c as real - 1.0;
+
+        let outer = Vector3::new(angle.cos(), angle.sin(), z);
+        let inner = InnerVector3::from_outer(&outer);
+
+        let x_axis = Vector3::new(1.0, 0.0, 0.0);
+        let y_axis = Vector3::new(0.0, 1.0, 0.0);
+        let z_axis = Vector3::new(0.0, 0.0, 1.0);
+
+        assert_eq_approx!(
+            outer.reflect(x_axis),
+            inner.reflect(x_axis),
+            "reflect (x-axis)\n",
+        );
+
+        assert_eq_approx!(
+            outer.reflect(y_axis),
+            inner.reflect(y_axis),
+            "reflect (y-axis)\n",
+        );
+
+        assert_eq_approx!(
+            outer.reflect(z_axis),
+            inner.reflect(z_axis),
+            "reflect (z-axis)\n",
+        );
+    }
+}

itest/rust/src/builtin_tests/mod.rs

@@ -13,6 +13,7 @@ mod geometry {
     mod rect2i_test;
     mod transform2d_test;
     mod transform3d_test;
+    mod vector_test;
 }
 
 mod containers {