Add rotate_toward method to Vector2, Vector3, Quaternion, and Basis

core/math/basis.h

@@ -189,6 +189,10 @@ struct _NO_DISCARD_ Basis {
 		rows[2].zero();
 	}
 
+	_FORCE_INLINE_ Basis rotate_toward(Basis p_to_basis, real_t p_delta) const {
+		return Basis(get_rotation_quaternion().rotate_toward(p_to_basis.get_rotation_quaternion(), p_delta));
+	}
+
 	_FORCE_INLINE_ Basis transpose_xform(const Basis &m) const {
 		return Basis(
 				rows[0].x * m[0].x + rows[1].x * m[1].x + rows[2].x * m[2].x,

core/math/quaternion.h

@@ -85,6 +85,22 @@ struct _NO_DISCARD_ Quaternion {
 		r_axis.z = z * r;
 	}
 
+	_FORCE_INLINE_ Quaternion rotate_toward(const Quaternion &p_to, real_t p_delta) const {
+		Quaternion to = p_to;
+		if (Math::is_zero_approx(p_delta)) {
+			return *this;
+		}
+		if (p_delta < 0.0) {
+			p_delta = -p_delta;
+			to = p_to.inverse();
+		}
+		real_t angle = this->angle_to(p_to);
+		if (angle < p_delta) {
+			return to;
+		}
+		return this->slerp(to, p_delta / angle);
+	}
+
 	void operator*=(const Quaternion &p_q);
 	Quaternion operator*(const Quaternion &p_q) const;
 

core/math/vector2.h

@@ -114,6 +114,25 @@ struct _NO_DISCARD_ Vector2 {
 	_FORCE_INLINE_ Vector2 bezier_interpolate(const Vector2 &p_control_1, const Vector2 &p_control_2, const Vector2 &p_end, const real_t p_t) const;
 	_FORCE_INLINE_ Vector2 bezier_derivative(const Vector2 &p_control_1, const Vector2 &p_control_2, const Vector2 &p_end, const real_t p_t) const;
 
+	_FORCE_INLINE_ Vector2 rotate_toward(Vector2 p_to, real_t p_delta) const {
+		if (Math::is_zero_approx(p_delta)) {
+			return *this;
+		}
+
+		if (p_delta < 0.0f) {
+			p_delta = -p_delta;
+			p_to = -p_to;
+		}
+
+		real_t angle = angle_to(p_to);
+
+		if (angle < p_delta) {
+			return p_to;
+		}
+
+		return slerp(p_to, p_delta / angle);
+	}
+
 	Vector2 move_toward(const Vector2 &p_to, const real_t p_delta) const;
 
 	Vector2 slide(const Vector2 &p_normal) const;

core/math/vector3.h

@@ -84,6 +84,25 @@ struct _NO_DISCARD_ Vector3 {
 		return Vector3(MAX(x, p_vector3.x), MAX(y, p_vector3.y), MAX(z, p_vector3.z));
 	}
 
+	_FORCE_INLINE_ Vector3 rotate_toward(Vector3 p_to, real_t p_delta) const {
+		if (Math::is_zero_approx(p_delta)) {
+			return *this;
+		}
+
+		if (p_delta < 0.0f) {
+			p_delta = -p_delta;
+			p_to = -p_to;
+		}
+
+		real_t angle = angle_to(p_to);
+
+		if (angle < p_delta) {
+			return p_to;
+		}
+
+		return slerp(p_to, p_delta / angle);
+	}
+
 	_FORCE_INLINE_ real_t length() const;
 	_FORCE_INLINE_ real_t length_squared() const;
 

core/variant/variant_call.cpp

@@ -1770,6 +1770,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Vector2, cubic_interpolate_in_time, sarray("b", "pre_a", "post_b", "weight", "b_t", "pre_a_t", "post_b_t"), varray());
 	bind_method(Vector2, bezier_interpolate, sarray("control_1", "control_2", "end", "t"), varray());
 	bind_method(Vector2, bezier_derivative, sarray("control_1", "control_2", "end", "t"), varray());
+	bind_method(Vector2, rotate_toward, sarray("to", "delta"), varray());
 	bind_method(Vector2, max_axis_index, sarray(), varray());
 	bind_method(Vector2, min_axis_index, sarray(), varray());
 	bind_method(Vector2, move_toward, sarray("to", "delta"), varray());
@@ -1865,6 +1866,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Vector3, bezier_interpolate, sarray("control_1", "control_2", "end", "t"), varray());
 	bind_method(Vector3, bezier_derivative, sarray("control_1", "control_2", "end", "t"), varray());
 	bind_method(Vector3, move_toward, sarray("to", "delta"), varray());
+	bind_method(Vector3, rotate_toward, sarray("to", "delta"), varray());
 	bind_method(Vector3, dot, sarray("with"), varray());
 	bind_method(Vector3, cross, sarray("with"), varray());
 	bind_method(Vector3, outer, sarray("with"), varray());
@@ -1959,6 +1961,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Quaternion, log, sarray(), varray());
 	bind_method(Quaternion, exp, sarray(), varray());
 	bind_method(Quaternion, angle_to, sarray("to"), varray());
+	bind_method(Quaternion, rotate_toward, sarray("to", "delta"), varray());
 	bind_method(Quaternion, dot, sarray("with"), varray());
 	bind_method(Quaternion, slerp, sarray("to", "weight"), varray());
 	bind_method(Quaternion, slerpni, sarray("to", "weight"), varray());
@@ -2087,6 +2090,7 @@ static void _register_variant_builtin_methods() {
 	bind_method(Basis, orthonormalized, sarray(), varray());
 	bind_method(Basis, determinant, sarray(), varray());
 	bind_methodv(Basis, rotated, static_cast<Basis (Basis::*)(const Vector3 &, real_t) const>(&Basis::rotated), sarray("axis", "angle"), varray());
+	bind_method(Basis, rotate_toward, sarray("to", "delta"), varray());
 	bind_method(Basis, scaled, sarray("scale"), varray());
 	bind_method(Basis, get_scale, sarray(), varray());
 	bind_method(Basis, get_euler, sarray("order"), varray((int64_t)EulerOrder::YXZ));

doc/classes/Basis.xml

@@ -142,6 +142,15 @@
 				Returns the orthonormalized version of the matrix (useful to call from time to time to avoid rounding error for orthogonal matrices). This performs a Gram-Schmidt orthonormalization on the basis of the matrix.
 			</description>
 		</method>
+		<method name="rotate_toward" qualifiers="const">
+			<return type="Basis" />
+			<param index="0" name="to" type="Basis" />
+			<param index="1" name="delta" type="float" />
+			<description>
+				Assuming that the matrix is a proper rotation matrix, rotates toward [param to] by [param delta].
+				Passing a negative [param delta] will rotate toward the inverse of [param to].
+			</description>
+		</method>
 		<method name="rotated" qualifiers="const">
 			<return type="Basis" />
 			<param index="0" name="axis" type="Vector3" />

doc/classes/Quaternion.xml

@@ -153,6 +153,16 @@
 				Returns a copy of the quaternion, normalized to unit length.
 			</description>
 		</method>
+		<method name="rotate_toward" qualifiers="const">
+			<return type="Quaternion" />
+			<param index="0" name="to" type="Quaternion" />
+			<param index="1" name="delta" type="float" />
+			<description>
+				Returns the result of rotating toward [param to] by [param delta].
+				Passing a negative [param delta] will rotate toward the inverse of [param to].
+				[b]Note:[/b] Both quaternions must be normalized.
+			</description>
+		</method>
 		<method name="slerp" qualifiers="const">
 			<return type="Quaternion" />
 			<param index="0" name="to" type="Quaternion" />

doc/classes/Vector2.xml

@@ -325,6 +325,15 @@
 				Returns the result of reflecting the vector from a line defined by the given direction vector [param n].
 			</description>
 		</method>
+		<method name="rotate_toward" qualifiers="const">
+			<return type="Vector2" />
+			<param index="0" name="to" type="Vector2" />
+			<param index="1" name="delta" type="float" />
+			<description>
+				Returns the result of rotating this vector towards [param to], by increment [param delta] (in radians).
+				Passing a negative [param delta] will rotate toward the opposite of [param to].
+			</description>
+		</method>
 		<method name="rotated" qualifiers="const">
 			<return type="Vector2" />
 			<param index="0" name="angle" type="float" />

doc/classes/Vector3.xml

@@ -309,6 +309,15 @@
 				Returns the result of reflecting the vector from a plane defined by the given normal [param n].
 			</description>
 		</method>
+		<method name="rotate_toward" qualifiers="const">
+			<return type="Vector3" />
+			<param index="0" name="to" type="Vector3" />
+			<param index="1" name="delta" type="float" />
+			<description>
+				Returns the result of rotating this vector towards [param to], by increment [param delta] (in radians).
+				Passing a negative [param delta] will rotate toward the opposite of [param to].
+			</description>
+		</method>
 		<method name="rotated" qualifiers="const">
 			<return type="Vector3" />
 			<param index="0" name="axis" type="Vector3" />