Add two functions : Vector2.angle and Vector2.angle_rad and the tests…

… needed

src_c/doc/math_doc.h

@@ -34,6 +34,8 @@
 #define DOC_MATH_VECTOR2_ANGLETO "angle_to(Vector2, /) -> float\ncalculates the angle to a given vector in degrees."
 #define DOC_MATH_VECTOR2_ASPOLAR "as_polar() -> (r, phi)\nreturns a tuple with radial distance and azimuthal angle."
 #define DOC_MATH_VECTOR2_FROMPOLAR "from_polar((r, phi), /) -> None\nSets x and y from a polar coordinates tuple."
+#define DOC_MATH_VECTOR2_ANGLERAD "angle_rad() -> float\nreturns the angle of the vector in radians relative to the positive X-axis."
+#define DOC_MAT_VECTOR2_ANGLE "angle_rad() -> float\nreturns the angle of the vector in degrees relative to the positive X-axis, within interval (-180, 180]."
 #define DOC_MATH_VECTOR2_PROJECT "project(Vector2, /) -> Vector2\nprojects a vector onto another."
 #define DOC_MATH_VECTOR2_COPY "copy() -> Vector2\nReturns a copy of itself."
 #define DOC_MATH_VECTOR2_CLAMPMAGNITUDE "clamp_magnitude(max_length, /) -> Vector2\nclamp_magnitude(min_length, max_length, /) -> Vector2\nReturns a copy of a vector with the magnitude clamped between max_length and min_length."

src_c/math.c

@@ -2499,6 +2499,30 @@ vector2_from_polar(pgVector *self, PyObject *args)
 
     Py_RETURN_NONE;
 }
+
+static PyObject *
+vector2_angle_rad(pgVector *self, PyObject *_null)
+{
+    double angle_rad;
+    angle_rad = atan2(self->coords[1], self->coords[0]);
+    return PyFloat_FromDouble(angle_rad);
+}
+
+static PyObject *
+vector2_angle(pgVector *self, PyObject *_null)
+{
+    double angle_rad = atan2(self->coords[1], self->coords[0]);
+    double angle_deg = RAD2DEG(angle_rad);
+
+    if (angle_deg > 180) {
+        angle_deg -= 360;
+    }
+    else if (angle_deg <= -180) {
+        angle_deg += 360;
+    }
+    return Py_BuildValue("d", angle_deg);
+}
+
 static PyObject *
 vector_getsafepickle(pgRectObject *self, void *_null)
 {
@@ -2566,6 +2590,9 @@ static PyMethodDef vector2_methods[] = {
      DOC_MATH_VECTOR2_ASPOLAR},
     {"from_polar", (PyCFunction)vector2_from_polar, METH_VARARGS,
      DOC_MATH_VECTOR2_FROMPOLAR},
+    {"angle_rad", (PyCFunction)vector2_angle_rad, METH_NOARGS,
+     DOC_MATH_VECTOR2_ANGLERAD},
+    {"angle", (PyCFunction)vector2_angle, METH_NOARGS, DOC_MATH_VECTOR2_ANGLE},
     {"project", (PyCFunction)vector2_project, METH_O,
      DOC_MATH_VECTOR2_PROJECT},
     {"copy", (PyCFunction)vector_copy, METH_NOARGS, DOC_MATH_VECTOR2_COPY},

test/math_test.py

@@ -1132,6 +1132,77 @@ def test_polar(self):
         v.from_polar((1, 0))
         self.assertEqual(v, self.e1)
 
+    def test_angle_rad(self):
+        v1 = Vector2(1, 0)
+        self.assertEqual(v1.angle_rad(), 0)
+
+        v2 = Vector2(0, 1)
+        self.assertEqual(v2.angle_rad(), math.pi / 2)
+
+        v3 = Vector2(-1, 0)
+        self.assertEqual(v3.angle_rad(), math.pi)
+
+        v4 = Vector2(1, 1)
+        self.assertEqual(v4.angle_rad(), math.pi / 4)
+
+        v5 = pygame.math.Vector2(0, 0)
+        self.assertEqual(v5.angle_rad(), 0)
+
+        v6 = pygame.math.Vector2(1, 1e-6)
+        self.assertAlmostEqual(v6.angle_rad(), 0, places=5)
+
+        v7 = pygame.math.Vector2(1e6, 1e6)
+        self.assertAlmostEqual(v7.angle_rad(), math.pi / 4, places=5)
+
+        v8 = pygame.math.Vector2(1, -1)
+        self.assertEqual(v8.angle_rad(), -math.pi / 4)
+
+        v9 = pygame.math.Vector2(-1, 1)
+        self.assertEqual(v9.angle_rad(), 3 * math.pi / 4)
+
+        v10 = pygame.math.Vector2(-1, -1)
+        self.assertEqual(v10.angle_rad(), -3 * math.pi / 4)
+
+        v11 = pygame.math.Vector2(1, 1)
+        self.assertEqual(v11.angle_rad(), math.pi / 4)
+
+        v12 = pygame.math.Vector2(1e-6, 1)
+        self.assertAlmostEqual(v12.angle_rad(), math.pi / 2, places=5)
+
+    def test_angle(self):
+        v1 = Vector2(0, 0)
+        self.assertTrue(v1.angle() == 0)
+
+        v2 = Vector2(1, 0)
+        self.assertTrue(v2.angle() == 0)
+
+        v3 = Vector2(1, 1)
+        self.assertTrue(v3.angle() == 45)
+
+        v4 = Vector2(0, 1)
+        self.assertTrue(v4.angle() == 90)
+
+        v5 = Vector2(-1, 1)
+        self.assertTrue(v5.angle() == 135)
+
+        v6 = Vector2(-1, 0)
+        self.assertTrue(v6.angle() == 180)
+
+        v7 = Vector2(-1, -1)
+        self.assertTrue(v7.angle() == -135)
+
+        v8 = Vector2(0, -1)
+        self.assertTrue(v8.angle() == -90)
+
+        v9 = Vector2(1, -1)
+        self.assertTrue(v9.angle() == -45)
+
+        v10 = Vector2(-0.005235964, 0.9999863)
+        self.assertAlmostEqual(v10.angle(), 90.3, places=5)
+
+        v11 = Vector2(math.cos(math.radians(-20)), math.sin(math.radians(-20)))
+        self.assertAlmostEqual(v11.angle(), -20, places=5)
+
     def test_subclass_operation(self):
         class Vector(pygame.math.Vector2):
             pass