new angle and angle_rad property in vector2 (#3222)

* Changes to be commited:
	new file:   test.txt

* Delete test.txt

* add angle and angle_rad property for vector2

* syntax error correction

* code modification for properties angle and angle rad and new doc for these properties

* type stubs correction

* add new property vector2_default_angle

* correction math_test.py

* .angle and .angle_rad with math.atan2 behaviour for special cases

* adding helper function _pg_atan2 + docs modification

* Add versionadded doc to angle properties

* Update version to 2.5.5

---------

Co-authored-by: Gabriele <[email protected]>
Co-authored-by: GabrieleLS <[email protected]>
Co-authored-by: aatle <[email protected]>
Co-authored-by: Andrew Coffey <[email protected]>

Author: 5 people

buildconfig/stubs/pygame/math.pyi

@@ -209,6 +209,10 @@ class Vector2(_GenericVector):
     xy: Vector2
     yx: Vector2
     yy: Vector2
+    @property
+    def angle(self) -> float: ...
+    @property
+    def angle_rad(self) -> float: ...
     @overload
     def __init__(
         self: _TVec,

docs/reST/ref/math.rst

@@ -616,6 +616,27 @@ Multiple coordinates can be set using slices or swizzling
       find that either the margin is too large or too small, in which case changing ``epsilon`` slightly
       might help you out.
 
+   .. attribute:: angle
+
+      | :sl:`Gives the angle of the vector in degrees, relative to the X-axis, normalized to the interval [-180, 180].`
+
+      Read-only attribute representing the angle of the vector in degrees relative to the X-axis. This angle is normalized to
+      the interval [-180, 180].
+
+      Usage: Accessing `angle` provides the current angle of the vector in degrees within the predefined range of [-180, 180].
+
+      .. versionadded:: 2.5.5
+
+   .. attribute:: angle_rad
+
+      | :sl:`Gives the angle of the vector in radians, relative to the X-axis, normalized to the interval [-π, π].`
+
+      Read-only attribute representing the angle of the vector in radians relative to the X-axis. This value is equivalent
+      to the `angle` attribute converted to radians and is normalized to the interval [-π, π].
+
+      Usage: Accessing `angle_rad` provides the current angle of the vector in radians within the predefined range of [-π, π].
+
+      .. versionadded:: 2.5.5
 
    .. ## pygame.math.Vector2 ##
 

src_c/doc/math_doc.h

@@ -40,6 +40,8 @@
 #define DOC_MATH_VECTOR2_CLAMPMAGNITUDEIP "clamp_magnitude_ip(max_length, /) -> None\nclamp_magnitude_ip(min_length, max_length, /) -> None\nClamps the vector's magnitude between max_length and min_length"
 #define DOC_MATH_VECTOR2_UPDATE "update() -> None\nupdate(int) -> None\nupdate(float) -> None\nupdate(Vector2) -> None\nupdate(x, y) -> None\nupdate((x, y)) -> None\nSets the coordinates of the vector."
 #define DOC_MATH_VECTOR2_EPSILON "Determines the tolerance of vector calculations."
+#define DOC_MATH_VECTOR2_ANGLE "Gives the angle of the vector in degrees, relative to the X-axis, normalized to the interval [-180, 180]."
+#define DOC_MATH_VECTOR2_ANGLERAD "Gives the angle of the vector in radians, relative to the X-axis, normalized to the interval [-π, π]."
 #define DOC_MATH_VECTOR3 "Vector3() -> Vector3(0, 0, 0)\nVector3(int) -> Vector3\nVector3(float) -> Vector3\nVector3(Vector3) -> Vector3\nVector3(x, y, z) -> Vector3\nVector3((x, y, z)) -> Vector3\na 3-Dimensional Vector"
 #define DOC_MATH_VECTOR3_DOT "dot(Vector3, /) -> float\ncalculates the dot- or scalar-product with the other vector"
 #define DOC_MATH_VECTOR3_CROSS "cross(Vector3, /) -> Vector3\ncalculates the cross- or vector-product"

src_c/math.c

@@ -51,6 +51,9 @@
 
 #define TWO_PI (2. * M_PI)
 
+#define RAD_TO_DEG (180.0 / M_PI)
+#define DEG_TO_RAD (M_PI / 180.0)
+
 #ifndef M_PI_2
 #define M_PI_2 (M_PI / 2.0)
 #endif /* M_PI_2 */
@@ -142,6 +145,8 @@ _vector_coords_from_string(PyObject *str, char **delimiter, double *coords,
 static void
 _vector_move_towards_helper(Py_ssize_t dim, double *origin_coords,
                             double *target_coords, double max_distance);
+static double
+_pg_atan2(double y, double x);
 
 /* generic vector functions */
 static PyObject *
@@ -202,6 +207,10 @@ vector_sety(pgVector *self, PyObject *value, void *closure);
 static int
 vector_setz(pgVector *self, PyObject *value, void *closure);
 static PyObject *
+vector_get_angle(pgVector *self, void *closure);
+static PyObject *
+vector_get_angle_rad(pgVector *self, void *closure);
+static PyObject *
 vector_richcompare(PyObject *o1, PyObject *o2, int op);
 static PyObject *
 vector_length(pgVector *self, PyObject *args);
@@ -635,6 +644,40 @@ vector_dealloc(pgVector *self)
     Py_TYPE(self)->tp_free((PyObject *)self);
 }
 
+/*
+ *Returns rhe arctangent of the quotient y / x, in radians, considering the
+ *following special cases: atan2((anything), NaN ) is NaN; atan2(NAN ,
+ *(anything) ) is NaN; atan2(+-0, +(anything but NaN)) is +-0  ; atan2(+-0,
+ *-(anything but NaN)) is +-pi ; atan2(+-(anything but 0 and NaN), 0) is
+ *+-pi/2; atan2(+-(anything but INF and NaN), +INF) is +-0 ; atan2(+-(anything
+ *but INF and NaN), -INF) is +-pi; atan2(+-INF,+INF ) is +-pi/4 ;
+ *      atan2(+-INF,-INF ) is +-3pi/4;
+ *      atan2(+-INF, (anything but,0,NaN, and INF)) is +-pi/2;
+ *
+ */
+static double
+_pg_atan2(double y, double x)
+{
+    if (Py_IS_NAN(x) || Py_IS_NAN(y)) {
+        return Py_NAN;
+    }
+
+    if (Py_IS_INFINITY(y)) {
+        if (Py_IS_INFINITY(x)) {
+            return copysign((copysign(1., x) == 1.) ? 0.25 * Py_MATH_PI
+                                                    : 0.75 * Py_MATH_PI,
+                            y);
+        }
+        return copysign(0.5 * Py_MATH_PI, y);
+    }
+
+    if (Py_IS_INFINITY(x) || y == 0.) {
+        return copysign((copysign(1., x) == 1.) ? 0. : Py_MATH_PI, y);
+    }
+
+    return atan2(y, x);
+}
+
 /**********************************************
  * Generic vector PyNumber emulation routines
  **********************************************/
@@ -1303,6 +1346,23 @@ vector_setz(pgVector *self, PyObject *value, void *closure)
     return vector_set_component(self, value, 2);
 }
 
+static PyObject *
+vector_get_angle_rad(pgVector *self, void *closure)
+{
+    double angle_rad = _pg_atan2(self->coords[1], self->coords[0]);
+
+    return PyFloat_FromDouble(angle_rad);
+}
+
+static PyObject *
+vector_get_angle(pgVector *self, void *closure)
+{
+    double angle_rad = _pg_atan2(self->coords[1], self->coords[0]);
+    double angle_deg = angle_rad * RAD_TO_DEG;
+
+    return PyFloat_FromDouble(angle_deg);
+}
+
 static PyObject *
 vector_richcompare(PyObject *o1, PyObject *o2, int op)
 {
@@ -2675,6 +2735,9 @@ static PyMethodDef vector2_methods[] = {
 static PyGetSetDef vector2_getsets[] = {
     {"x", (getter)vector_getx, (setter)vector_setx, NULL, NULL},
     {"y", (getter)vector_gety, (setter)vector_sety, NULL, NULL},
+    {"angle", (getter)vector_get_angle, NULL, DOC_MATH_VECTOR2_ANGLE, NULL},
+    {"angle_rad", (getter)vector_get_angle_rad, NULL,
+     DOC_MATH_VECTOR2_ANGLERAD, NULL},
     {NULL, 0, NULL, NULL, NULL} /* Sentinel */
 };
 

test/math_test.py

@@ -1410,6 +1410,104 @@ def test_del_y(self):
         exception = ctx.exception
         self.assertEqual(str(exception), "Cannot delete the y attribute")
 
+    def test_angle_rad_property(self):
+        v0 = Vector2(1, 0)
+        self.assertEqual(v0.angle_rad, 0.0)
+
+        v1 = Vector2(0, 1)
+        self.assertEqual(v1.angle_rad, math.pi / 2)
+
+        v2 = Vector2(-1, 0)
+        self.assertEqual(v2.angle_rad, math.pi)
+
+        v3 = Vector2(0, -1)
+        self.assertEqual(v3.angle_rad, -math.pi / 2)
+
+        v4 = Vector2(1, 1)
+        self.assertEqual(v4.angle_rad, math.pi / 4)
+
+        v5 = Vector2(-1, 1)
+        self.assertEqual(v5.angle_rad, 3 * math.pi / 4)
+
+        v6 = Vector2(-1, -1)
+        self.assertEqual(v6.angle_rad, -3 * math.pi / 4)
+
+        v7 = Vector2(1, -1)
+        self.assertEqual(v7.angle_rad, -math.pi / 4)
+
+        v8 = Vector2(float('inf'), float('inf'))
+        self.assertEqual(v8.angle_rad, math.pi / 4)
+
+        v9 = Vector2(float('-inf'), float('inf'))
+        self.assertEqual(v9.angle_rad, 3 * math.pi / 4)
+
+        v10 = Vector2(float('-inf'), float('-inf'))
+        self.assertEqual(v10.angle_rad, -3 * math.pi / 4)
+
+        v11 = Vector2(float('inf'), float('-inf'))
+        self.assertEqual(v11.angle_rad, -math.pi / 4)
+
+        v12 = Vector2(0, 0)
+        self.assertEqual(v12.angle_rad, 0.0)
+
+        v13 = Vector2(float('nan'), 1)
+        self.assertTrue(math.isnan(v13.angle_rad))
+
+        v14 = Vector2(1, float('nan'))
+        self.assertTrue(math.isnan(v14.angle_rad))
+
+        v15 = Vector2(float('nan'), float('nan'))
+        self.assertTrue(math.isnan(v15.angle_rad))
+
+    def test_angle_property(self):
+        v0 = pygame.math.Vector2(1, 0)
+        self.assertEqual(v0.angle, 0.0)
+
+        v1 = pygame.math.Vector2(0, 1)
+        self.assertEqual(v1.angle, 90.0)
+
+        v2 = pygame.math.Vector2(-1, 0)
+        self.assertEqual(v2.angle, 180.0)
+
+        v3 = pygame.math.Vector2(0, -1)
+        self.assertEqual(v3.angle, -90.0)
+
+        v4 = pygame.math.Vector2(1, 1)
+        self.assertEqual(v4.angle, 45.0)
+
+        v5 = pygame.math.Vector2(-1, 1)
+        self.assertEqual(v5.angle, 135.0)
+
+        v6 = pygame.math.Vector2(-1, -1)
+        self.assertEqual(v6.angle, -135.0)
+
+        v7 = pygame.math.Vector2(1, -1)
+        self.assertEqual(v7.angle, -45.0)
+
+        v8 = pygame.math.Vector2(float('inf'), float('inf'))
+        self.assertEqual(v8.angle, 45.0)
+
+        v9 = pygame.math.Vector2(float('-inf'), float('inf'))
+        self.assertEqual(v9.angle, 135.0)
+
+        v10 = pygame.math.Vector2(float('-inf'), float('-inf'))
+        self.assertEqual(v10.angle, -135.0)
+
+        v11 = pygame.math.Vector2(float('inf'), float('-inf'))
+        self.assertEqual(v11.angle, -45.0)
+
+        v12 = pygame.math.Vector2(0, 0)
+        self.assertEqual(v12.angle, 0.0)
+
+        v13 = pygame.math.Vector2(float('nan'), 1)
+        self.assertTrue(math.isnan(v13.angle))
+
+        v14 = pygame.math.Vector2(1, float('nan'))
+        self.assertTrue(math.isnan(v14.angle))
+
+        v15 = pygame.math.Vector2(float('nan'), float('nan'))
+        self.assertTrue(math.isnan(v15.angle))
+
 
 class Vector3TypeTest(unittest.TestCase):
     def setUp(self):