Fix Basis is_orthogonal and is_rotation methods, add is_orthonormal

godotengine · Oct 13, 2023 · d9a3563 · d9a3563
1 parent 51f81e1
commit d9a3563
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Showing 3 changed files with 90 additions and 4 deletions.
diff --git a/core/math/basis.cpp b/core/math/basis.cpp
@@ -90,10 +90,17 @@ Basis Basis::orthogonalized() const {
 }
 
 bool Basis::is_orthogonal() const {
-	Basis identity;
-	Basis m = (*this) * transposed();
+	const Vector3 x = get_column(0);
+	const Vector3 y = get_column(1);
+	const Vector3 z = get_column(2);
+	return Math::is_zero_approx(x.dot(y)) && Math::is_zero_approx(x.dot(z)) && Math::is_zero_approx(y.dot(z));
+}
 
-	return m.is_equal_approx(identity);
+bool Basis::is_orthonormal() const {
+	const Vector3 x = get_column(0);
+	const Vector3 y = get_column(1);
+	const Vector3 z = get_column(2);
+	return Math::is_equal_approx(x.length_squared(), 1) && Math::is_equal_approx(y.length_squared(), 1) && Math::is_equal_approx(z.length_squared(), 1) && Math::is_zero_approx(x.dot(y)) && Math::is_zero_approx(x.dot(z)) && Math::is_zero_approx(y.dot(z));
 }
 
 bool Basis::is_conformal() const {
@@ -112,7 +119,7 @@ bool Basis::is_diagonal() const {
 }
 
 bool Basis::is_rotation() const {
-	return Math::is_equal_approx(determinant(), 1, (real_t)UNIT_EPSILON) && is_orthogonal();
+	return is_conformal() && Math::is_equal_approx(determinant(), 1, (real_t)UNIT_EPSILON);
 }
 
 #ifdef MATH_CHECKS

diff --git a/core/math/basis.h b/core/math/basis.h
@@ -138,6 +138,7 @@ struct _NO_DISCARD_ Basis {
 	_FORCE_INLINE_ Basis operator*(const real_t p_val) const;
 
 	bool is_orthogonal() const;
+	bool is_orthonormal() const;
 	bool is_conformal() const;
 	bool is_diagonal() const;
 	bool is_rotation() const;

diff --git a/tests/core/math/test_basis.h b/tests/core/math/test_basis.h
@@ -326,6 +326,84 @@ TEST_CASE("[Basis] Is conformal checks") {
 			"Basis with the X axis skewed 45 degrees should not be conformal.");
 }
 
+TEST_CASE("[Basis] Is orthogonal checks") {
+	CHECK_MESSAGE(
+			Basis().is_orthogonal(),
+			"Identity Basis should be orthogonal.");
+
+	CHECK_MESSAGE(
+			Basis::from_euler(Vector3(1.2, 3.4, 5.6)).is_orthogonal(),
+			"Basis with only rotation should be orthogonal.");
+
+	CHECK_MESSAGE(
+			Basis::from_scale(Vector3(-1, -1, -1)).is_orthogonal(),
+			"Basis with only a flip should be orthogonal.");
+
+	CHECK_MESSAGE(
+			Basis::from_scale(Vector3(1.2, 3.4, 5.6)).is_orthogonal(),
+			"Basis with only scale should be orthogonal.");
+
+	CHECK_MESSAGE(
+			Basis(Vector3(3, 4, 0), Vector3(4, -3, 0), Vector3(0, 0, 5)).is_orthogonal(),
+			"Basis with a flip, rotation, and uniform scale should be orthogonal.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis(Vector3(Math_SQRT12, Math_SQRT12, 0), Vector3(0, 1, 0), Vector3(0, 0, 1)).is_orthogonal(),
+			"Basis with the X axis skewed 45 degrees should not be orthogonal.");
+}
+
+TEST_CASE("[Basis] Is orthonormal checks") {
+	CHECK_MESSAGE(
+			Basis().is_orthonormal(),
+			"Identity Basis should be orthonormal.");
+
+	CHECK_MESSAGE(
+			Basis::from_euler(Vector3(1.2, 3.4, 5.6)).is_orthonormal(),
+			"Basis with only rotation should be orthonormal.");
+
+	CHECK_MESSAGE(
+			Basis::from_scale(Vector3(-1, -1, -1)).is_orthonormal(),
+			"Basis with only a flip should be orthonormal.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis::from_scale(Vector3(1.2, 3.4, 5.6)).is_orthonormal(),
+			"Basis with only scale should not be orthonormal.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis(Vector3(3, 4, 0), Vector3(4, -3, 0), Vector3(0, 0, 5)).is_orthonormal(),
+			"Basis with a flip, rotation, and uniform scale should not be orthonormal.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis(Vector3(Math_SQRT12, Math_SQRT12, 0), Vector3(0, 1, 0), Vector3(0, 0, 1)).is_orthonormal(),
+			"Basis with the X axis skewed 45 degrees should not be orthonormal.");
+}
+
+TEST_CASE("[Basis] Is rotation checks") {
+	CHECK_MESSAGE(
+			Basis().is_rotation(),
+			"Identity Basis should be a rotation (a rotation of zero).");
+
+	CHECK_MESSAGE(
+			Basis::from_euler(Vector3(1.2, 3.4, 5.6)).is_rotation(),
+			"Basis with only rotation should be a rotation.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis::from_scale(Vector3(-1, -1, -1)).is_rotation(),
+			"Basis with only a flip should not be a rotation.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis::from_scale(Vector3(1.2, 3.4, 5.6)).is_rotation(),
+			"Basis with only scale should not be a rotation.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis(Vector3(2, 0, 0), Vector3(0, 0.5, 0), Vector3(0, 0, 1)).is_rotation(),
+			"Basis with a squeeze should not be a rotation.");
+
+	CHECK_FALSE_MESSAGE(
+			Basis(Vector3(Math_SQRT12, Math_SQRT12, 0), Vector3(0, 1, 0), Vector3(0, 0, 1)).is_rotation(),
+			"Basis with the X axis skewed 45 degrees should not be a rotation.");
+}
+
 } // namespace TestBasis
 
 #endif // TEST_BASIS_H