Move code for looking_at to Basis

3 files changed, 22 insertions, 30 deletions

diff --git a/core/math/basis.cpp b/core/math/basis.cpp
index aa3831d4cf..b5e25fb837 100644
--- a/core/math/basis.cpp
+++ b/core/math/basis.cpp
@@ -1129,3 +1129,21 @@ void Basis::rotate_sh(real_t *p_values) {
 	p_values[7] = -d3;
 	p_values[8] = d4 * s_scale_dst4;
 }
+
+Basis Basis::looking_at(const Vector3 &p_target, const Vector3 &p_up) {
+#ifdef MATH_CHECKS
+	ERR_FAIL_COND_V_MSG(p_target.is_equal_approx(Vector3()), Basis(), "The target vector can't be zero.");
+	ERR_FAIL_COND_V_MSG(p_up.is_equal_approx(Vector3()), Basis(), "The up vector can't be zero.");
+#endif
+	Vector3 v_z = -p_target.normalized();
+	Vector3 v_x = p_up.cross(v_z);
+#ifdef MATH_CHECKS
+	ERR_FAIL_COND_V_MSG(v_x.is_equal_approx(Vector3()), Basis(), "The target vector and up vector can't be parallel to each other.");
+#endif
+	v_x.normalize();
+	Vector3 v_y = v_z.cross(v_x);
+
+	Basis basis;
+	basis.set(v_x, v_y, v_z);
+	return basis;
+}
diff --git a/core/math/basis.h b/core/math/basis.h
index 2889a4aa5e..3db2227b70 100644
--- a/core/math/basis.h
+++ b/core/math/basis.h
@@ -242,6 +242,8 @@ public:
 
 	operator Quaternion() const { return get_quaternion(); }
 
+	static Basis looking_at(const Vector3 &p_target, const Vector3 &p_up = Vector3(0, 1, 0));
+
 	Basis(const Quaternion &p_quaternion) { set_quaternion(p_quaternion); };
 	Basis(const Quaternion &p_quaternion, const Vector3 &p_scale) { set_quaternion_scale(p_quaternion, p_scale); }
 
diff --git a/core/math/transform_3d.cpp b/core/math/transform_3d.cpp
index 51766b39f4..4f4943c8ef 100644
--- a/core/math/transform_3d.cpp
+++ b/core/math/transform_3d.cpp
@@ -71,40 +71,12 @@ void Transform3D::rotate_basis(const Vector3 &p_axis, real_t p_phi) {
 
 Transform3D Transform3D::looking_at(const Vector3 &p_target, const Vector3 &p_up) const {
 	Transform3D t = *this;
-	t.set_look_at(origin, p_target, p_up);
+	t.basis = Basis::looking_at(p_target - origin, p_up);
 	return t;
 }
 
 void Transform3D::set_look_at(const Vector3 &p_eye, const Vector3 &p_target, const Vector3 &p_up) {
-#ifdef MATH_CHECKS
-	ERR_FAIL_COND(p_eye == p_target);
-	ERR_FAIL_COND(p_up.length() == 0);
-#endif
-	// Reference: MESA source code
-	Vector3 v_x, v_y, v_z;
-
-	/* Make rotation matrix */
-
-	/* Z vector */
-	v_z = p_eye - p_target;
-
-	v_z.normalize();
-
-	v_y = p_up;
-
-	v_x = v_y.cross(v_z);
-#ifdef MATH_CHECKS
-	ERR_FAIL_COND(v_x.length() == 0);
-#endif
-
-	/* Recompute Y = Z cross X */
-	v_y = v_z.cross(v_x);
-
-	v_x.normalize();
-	v_y.normalize();
-
-	basis.set(v_x, v_y, v_z);
-
+	basis = Basis::looking_at(p_target - p_eye, p_up);
 	origin = p_eye;
 }