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Line.rotate() / ip() (#213)
* base impl and docs * tests pt. 1 * base impl and docs * .pyi, docs and tests round 1 * format * added missing tests * added missing doc
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‎docs/geometry.rst‎

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@@ -162,6 +162,10 @@ other objects.
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as_points: returns the line as a list of points.
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rotate: Rotates the line by the given amount.
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rotate_ip: Rotates the line by the given amount in place.
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Additionally to these, the line shape can also be used as a collider for the ``geometry.raycast`` function.
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Polygon

‎docs/line.rst‎

Lines changed: 29 additions & 1 deletion
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@@ -436,4 +436,32 @@ Line Methods
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least 0.
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.. ## Line.as_points ##
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.. ## Line.as_points ##
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.. method:: rotate
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| :sl:`rotates the line around its center`
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| :sg:`rotate(angle, rotation_point) -> None`
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Returns a new `Line` that is rotated by the given angle around the given point.
447+
The angle can be positive or negative. If the angle is positive the line will be
448+
rotated clockwise and if it is negative the line will be rotated counter-clockwise.
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The rotation point can be a tuple, list, or Vector2. If no rotation point is
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specified the line will be rotated around its center point.
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.. ## Line.rotate ##
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.. method:: rotate_ip
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| :sl:`rotates the line around its center`
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| :sg:`rotate_ip(angle, rotation_point) -> None`
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Rotates the line by the given angle around the given point.
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The angle can be positive or negative. If the angle is positive the line will be
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rotated clockwise and if it is negative the line will be rotated counter-clockwise.
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The rotation point can be a tuple, list, or Vector2. If no rotation point is
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specified the line will be rotated around its center point.
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.. ## Line.rotate_ip ##

‎geometry.pyi‎

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@@ -137,6 +137,12 @@ class Line(Sequence[float]):
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def is_perpendicular(self, line: LineValue) -> bool: ...
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def as_points(self, n_points: int) -> List[Tuple[float, float]]: ...
139139
def as_segments(self, n_segments: int) -> List[Line]: ...
140+
def rotate(
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self, angle: float, rotation_point: Coordinate = Line.center
142+
) -> Line: ...
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def rotate_ip(
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self, angle: float, rotation_point: Coordinate = Line.center
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) -> None: ...
140146

141147
class Circle:
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x: float

‎src_c/line.c‎

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Original file line numberDiff line numberDiff line change
@@ -745,6 +745,101 @@ pg_line_as_circle(pgLineObject *self, PyObject *_null)
745745
return (PyObject *)circle_obj;
746746
}
747747

748+
static void
749+
_pg_rotate_line_helper(pgLineBase *line, double angle, double rx, double ry)
750+
{
751+
if (angle == 0.0 || fmod(angle, 360.0) == 0.0) {
752+
return;
753+
}
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double angle_rad = DEG_TO_RAD(angle);
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double x1 = line->x1, y1 = line->y1;
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double x2 = line->x2, y2 = line->y2;
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double cos_a = cos(angle_rad);
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double sin_a = sin(angle_rad);
762+
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x1 -= rx;
764+
y1 -= ry;
765+
x2 -= rx;
766+
y2 -= ry;
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double x1_new = x1 * cos_a - y1 * sin_a;
769+
double y1_new = x1 * sin_a + y1 * cos_a;
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double x2_new = x2 * cos_a - y2 * sin_a;
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double y2_new = x2 * sin_a + y2 * cos_a;
772+
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line->x1 = x1_new + rx;
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line->y1 = y1_new + ry;
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line->x2 = x2_new + rx;
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line->y2 = y2_new + ry;
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}
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780+
static PyObject *
781+
pg_line_rotate(pgLineObject *self, PyObject *const *args, Py_ssize_t nargs)
782+
{
783+
if (!nargs || nargs > 2) {
784+
return RAISE(PyExc_TypeError, "rotate requires 1 or 2 arguments");
785+
}
786+
787+
pgLineBase *line = &self->line;
788+
double angle, rx, ry;
789+
790+
rx = (line->x1 + line->x2) / 2;
791+
ry = (line->y1 + line->y2) / 2;
792+
793+
if (!pg_DoubleFromObj(args[0], &angle)) {
794+
return RAISE(PyExc_TypeError,
795+
"Invalid angle argument, must be numeric");
796+
}
797+
798+
if (nargs == 2 && !pg_TwoDoublesFromObj(args[1], &rx, &ry)) {
799+
return RAISE(PyExc_TypeError,
800+
"Invalid rotation_point argument, must be a sequence of "
801+
"two numbers");
802+
}
803+
804+
PyObject *line_obj;
805+
if (!(line_obj = pgLine_New(line))) {
806+
return NULL;
807+
}
808+
809+
_pg_rotate_line_helper(&pgLine_AsLine(line_obj), angle, rx, ry);
810+
811+
return line_obj;
812+
}
813+
814+
static PyObject *
815+
pg_line_rotate_ip(pgLineObject *self, PyObject *const *args, Py_ssize_t nargs)
816+
{
817+
if (!nargs || nargs > 2) {
818+
return RAISE(PyExc_TypeError, "rotate requires 1 or 2 arguments");
819+
}
820+
821+
pgLineBase *line = &self->line;
822+
double angle, rx, ry;
823+
824+
rx = (line->x1 + line->x2) / 2;
825+
ry = (line->y1 + line->y2) / 2;
826+
827+
if (!pg_DoubleFromObj(args[0], &angle)) {
828+
return RAISE(PyExc_TypeError,
829+
"Invalid angle argument, must be numeric");
830+
}
831+
832+
if (nargs == 2 && !pg_TwoDoublesFromObj(args[1], &rx, &ry)) {
833+
return RAISE(PyExc_TypeError,
834+
"Invalid rotation_point argument, must be a sequence of "
835+
"two numbers");
836+
}
837+
838+
_pg_rotate_line_helper(line, angle, rx, ry);
839+
840+
Py_RETURN_NONE;
841+
}
842+
748843
static struct PyMethodDef pg_line_methods[] = {
749844
{"__copy__", (PyCFunction)pg_line_copy, METH_NOARGS, NULL},
750845
{"copy", (PyCFunction)pg_line_copy, METH_NOARGS, NULL},
@@ -770,6 +865,8 @@ static struct PyMethodDef pg_line_methods[] = {
770865
{"scale", (PyCFunction)pg_line_scale, METH_FASTCALL, NULL},
771866
{"scale_ip", (PyCFunction)pg_line_scale_ip, METH_FASTCALL, NULL},
772867
{"as_circle", (PyCFunction)pg_line_as_circle, METH_NOARGS, NULL},
868+
{"rotate", (PyCFunction)pg_line_rotate, METH_FASTCALL, NULL},
869+
{"rotate_ip", (PyCFunction)pg_line_rotate_ip, METH_FASTCALL, NULL},
773870
{NULL, NULL, 0, NULL}};
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/* sequence functions */

‎test/test_line.py‎

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Original file line numberDiff line numberDiff line change
@@ -1,3 +1,4 @@
1+
import math
12
import unittest
23
from math import sqrt
34

@@ -20,6 +21,15 @@ def get_points_between(line, n_pts):
2021
return [(line.xa + i * dx, line.ya + i * dy) for i in range(n_pts + 2)]
2122

2223

24+
def float_range(a, b, step):
25+
result = []
26+
current_value = a
27+
while current_value < b:
28+
result.append(current_value)
29+
current_value += step
30+
return result
31+
32+
2333
class LineTypeTest(unittest.TestCase):
2434
class ClassWithLineAttrib:
2535
def __init__(self, line):
@@ -1381,6 +1391,187 @@ def test_meth_as_segments_argvalue(self):
13811391
with self.assertRaises(ValueError):
13821392
l.as_segments(value)
13831393

1394+
def test_meth_rotate_ip_invalid_argnum(self):
1395+
"""Ensures that the rotate_ip method correctly deals with invalid numbers of arguments."""
1396+
l = Line(0, 0, 1, 1)
1397+
1398+
with self.assertRaises(TypeError):
1399+
l.rotate_ip()
1400+
1401+
invalid_args = [
1402+
(1, (2, 2), 2),
1403+
(1, (2, 2), 2, 2),
1404+
(1, (2, 2), 2, 2, 2),
1405+
(1, (2, 2), 2, 2, 2, 2),
1406+
(1, (2, 2), 2, 2, 2, 2, 2),
1407+
(1, (2, 2), 2, 2, 2, 2, 2, 2),
1408+
]
1409+
1410+
for args in invalid_args:
1411+
with self.assertRaises(TypeError):
1412+
l.rotate_ip(*args)
1413+
1414+
def test_meth_rotate_ip_invalid_argtype(self):
1415+
"""Ensures that the rotate_ip method correctly deals with invalid argument types."""
1416+
l = Line(0, 0, 1, 1)
1417+
1418+
invalid_args = [
1419+
("a",), # angle str
1420+
(None,), # angle str
1421+
((1, 2)), # angle tuple
1422+
([1, 2]), # angle list
1423+
(1, "a"), # origin str
1424+
(1, None), # origin None
1425+
(1, True), # origin True
1426+
(1, False), # origin False
1427+
(1, (1, 2, 3)), # origin tuple
1428+
(1, [1, 2, 3]), # origin list
1429+
(1, (1, "a")), # origin str
1430+
(1, ("a", 1)), # origin str
1431+
(1, (1, None)), # origin None
1432+
(1, (None, 1)), # origin None
1433+
(1, (1, (1, 2))), # origin tuple
1434+
(1, (1, [1, 2])), # origin list
1435+
]
1436+
1437+
for value in invalid_args:
1438+
with self.assertRaises(TypeError):
1439+
l.rotate_ip(*value)
1440+
1441+
def test_meth_rotate_ip_return(self):
1442+
"""Ensures that the rotate_ip method always returns None."""
1443+
l = Line(0, 0, 1, 1)
1444+
1445+
for angle in float_range(-360, 360, 1):
1446+
self.assertIsNone(l.rotate_ip(angle))
1447+
self.assertIsInstance(l.rotate_ip(angle), type(None))
1448+
1449+
def test_meth_rotate_invalid_argnum(self):
1450+
"""Ensures that the rotate method correctly deals with invalid numbers of arguments."""
1451+
l = Line(0, 0, 1, 1)
1452+
1453+
with self.assertRaises(TypeError):
1454+
l.rotate()
1455+
1456+
invalid_args = [
1457+
(1, (2, 2), 2),
1458+
(1, (2, 2), 2, 2),
1459+
(1, (2, 2), 2, 2, 2),
1460+
(1, (2, 2), 2, 2, 2, 2),
1461+
(1, (2, 2), 2, 2, 2, 2, 2),
1462+
(1, (2, 2), 2, 2, 2, 2, 2, 2),
1463+
]
1464+
1465+
for args in invalid_args:
1466+
with self.assertRaises(TypeError):
1467+
l.rotate(*args)
1468+
1469+
def test_meth_rotate_invalid_argtype(self):
1470+
"""Ensures that the rotate method correctly deals with invalid argument types."""
1471+
l = Line(0, 0, 1, 1)
1472+
1473+
invalid_args = [
1474+
("a",), # angle str
1475+
(None,), # angle str
1476+
((1, 2)), # angle tuple
1477+
([1, 2]), # angle list
1478+
(1, "a"), # origin str
1479+
(1, None), # origin None
1480+
(1, True), # origin True
1481+
(1, False), # origin False
1482+
(1, (1, 2, 3)), # origin tuple
1483+
(1, [1, 2, 3]), # origin list
1484+
(1, (1, "a")), # origin str
1485+
(1, ("a", 1)), # origin str
1486+
(1, (1, None)), # origin None
1487+
(1, (None, 1)), # origin None
1488+
(1, (1, (1, 2))), # origin tuple
1489+
(1, (1, [1, 2])), # origin list
1490+
]
1491+
1492+
for value in invalid_args:
1493+
with self.assertRaises(TypeError):
1494+
l.rotate(*value)
1495+
1496+
def test_meth_rotate_return(self):
1497+
"""Ensures that the rotate method always returns a Line."""
1498+
l = Line(0, 0, 1, 1)
1499+
1500+
for angle in float_range(-360, 360, 1):
1501+
self.assertIsInstance(l.rotate(angle), Line)
1502+
1503+
def test_meth_rotate(self):
1504+
"""Ensures the Line.rotate() method rotates the line correctly."""
1505+
1506+
def rotate_line(line: Line, angle, center):
1507+
def rotate_point(x, y, rang, cx, cy):
1508+
x -= cx
1509+
y -= cy
1510+
x_new = x * math.cos(rang) - y * math.sin(rang)
1511+
y_new = x * math.sin(rang) + y * math.cos(rang)
1512+
return x_new + cx, y_new + cy
1513+
1514+
angle = math.radians(angle)
1515+
x1, y1 = line.a
1516+
x2, y2 = line.b
1517+
cx, cy = center if center is not None else line.center
1518+
x1, y1 = rotate_point(x1, y1, angle, cx, cy)
1519+
x2, y2 = rotate_point(x2, y2, angle, cx, cy)
1520+
return Line(x1, y1, x2, y2)
1521+
1522+
def assert_approx_equal(line1, line2, eps=1e-12):
1523+
self.assertAlmostEqual(line1.x1, line2.x1, delta=eps)
1524+
self.assertAlmostEqual(line1.y1, line2.y1, delta=eps)
1525+
self.assertAlmostEqual(line1.x2, line2.x2, delta=eps)
1526+
self.assertAlmostEqual(line1.y2, line2.y2, delta=eps)
1527+
1528+
l = Line(0, 0, 1, 1)
1529+
angles = float_range(-360, 360, 0.5)
1530+
centers = [(a, b) for a in range(-10, 10) for b in range(-10, 10)]
1531+
for angle in angles:
1532+
assert_approx_equal(l.rotate(angle), rotate_line(l, angle, None))
1533+
for center in centers:
1534+
assert_approx_equal(
1535+
l.rotate(angle, center), rotate_line(l, angle, center)
1536+
)
1537+
1538+
def test_meth_rotate_ip(self):
1539+
"""Ensures the Line.rotate_ip() method rotates the line correctly."""
1540+
1541+
def rotate_line(line: Line, angle, center):
1542+
def rotate_point(x, y, rang, cx, cy):
1543+
x -= cx
1544+
y -= cy
1545+
x_new = x * math.cos(rang) - y * math.sin(rang)
1546+
y_new = x * math.sin(rang) + y * math.cos(rang)
1547+
return x_new + cx, y_new + cy
1548+
1549+
angle = math.radians(angle)
1550+
x1, y1 = line.a
1551+
x2, y2 = line.b
1552+
cx, cy = center if center is not None else line.center
1553+
x1, y1 = rotate_point(x1, y1, angle, cx, cy)
1554+
x2, y2 = rotate_point(x2, y2, angle, cx, cy)
1555+
return Line(x1, y1, x2, y2)
1556+
1557+
def assert_approx_equal(line1, line2, eps=1e-12):
1558+
self.assertAlmostEqual(line1.x1, line2.x1, delta=eps)
1559+
self.assertAlmostEqual(line1.y1, line2.y1, delta=eps)
1560+
self.assertAlmostEqual(line1.x2, line2.x2, delta=eps)
1561+
self.assertAlmostEqual(line1.y2, line2.y2, delta=eps)
1562+
1563+
l = Line(0, 0, 1, 1)
1564+
angles = float_range(-360, 360, 0.5)
1565+
centers = [(a, b) for a in range(-10, 10) for b in range(-10, 10)]
1566+
for angle in angles:
1567+
new_l = l.copy()
1568+
new_l.rotate_ip(angle)
1569+
assert_approx_equal(new_l, rotate_line(l, angle, None))
1570+
for center in centers:
1571+
new_l = l.copy()
1572+
new_l.rotate_ip(angle, center)
1573+
assert_approx_equal(new_l, rotate_line(l, angle, center))
1574+
13841575

13851576
if __name__ == "__main__":
13861577
unittest.main()

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