def create_grid_halo(crs):
min_x = -180
min_y = -90
max_x = 180
max_y = 90
step = 2
coords = []
for y in range(min_y, max_y + step, step):
coords.append((min_x, y))
for x in range(min_x + step, max_x + step, step):
coords.append((x, max_y))
for y in reversed(range(min_y, max_y + step, step)):
coords.append((max_x, y))
for x in reversed(range(min_x + step, max_x + step, step)):
coords.append((x, min_y))
coords.append(coords[0])
# noinspection PyCallByClass,PyArgumentList
geom = QgsGeometry.fromPolygonXY(
[[QgsPointXY(pair[0], pair[1]) for pair in coords]]).asQPolygonF()
# noinspection PyArgumentList
transformer = QgsCoordinateTransform(WGS84, crs, QgsProject.instance())
transformer.transformPolygon(geom)
# noinspection PyArgumentList
return QgsGeometry.fromQPolygonF(geom)
