def pixel_ratio():
"""Get the pixel ratio."""
from mne.viz.backends.tests._utils import has_pyvista
if not has_pyvista() or not _check_qt_version():
return 1.
from qtpy.QtWidgets import QApplication, QMainWindow
_ = QApplication.instance() or QApplication([])
window = QMainWindow()
ratio = float(window.devicePixelRatio())
window.close()
return ratio
