init

venv/lib/python3.11/site-packages/pyvista/plotting/utilities/gl_checks.py

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+"""Plotting GL checks."""
+
+from __future__ import annotations
+
+from pyvista.plotting import _vtk
+
+
+def check_depth_peeling(number_of_peels=100, occlusion_ratio=0.0):
+    """Check if depth peeling is available.
+
+    Attempts to use depth peeling to see if it is available for the
+    current environment. Returns ``True`` if depth peeling is
+    available and has been successfully leveraged, otherwise
+    ``False``.
+
+    Parameters
+    ----------
+    number_of_peels : int, default: 100
+        Maximum number of depth peels.
+
+    occlusion_ratio : float, default: 0.0
+        Occlusion ratio.
+
+    Returns
+    -------
+    bool
+        ``True`` when system supports depth peeling with the specified
+        settings.
+
+    """
+    # Try Depth Peeling with a basic scene
+    source = _vtk.vtkSphereSource()
+    mapper = _vtk.vtkPolyDataMapper()
+    mapper.SetInputConnection(source.GetOutputPort())
+    actor = _vtk.vtkActor()
+    actor.SetMapper(mapper)
+    # requires opacity < 1
+    actor.GetProperty().SetOpacity(0.5)
+    renderer = _vtk.vtkRenderer()
+    renderWindow = _vtk.vtkRenderWindow()
+    renderWindow.AddRenderer(renderer)
+    renderWindow.SetOffScreenRendering(True)
+    renderWindow.SetAlphaBitPlanes(True)
+    renderWindow.SetMultiSamples(0)
+    renderer.AddActor(actor)
+    renderer.SetUseDepthPeeling(True)
+    renderer.SetMaximumNumberOfPeels(number_of_peels)
+    renderer.SetOcclusionRatio(occlusion_ratio)
+    renderWindow.Render()
+    return renderer.GetLastRenderingUsedDepthPeeling() == 1
+
+
+def uses_egl() -> bool:
+    """Check if VTK has been compiled with EGL support via OSMesa.
+
+    Returns
+    -------
+    bool
+        ``True`` if VTK has been compiled with EGL support via OSMesa,
+        otherwise ``False``.
+
+    """
+    ren_win_str = str(type(_vtk.vtkRenderWindow()))
+    return 'EGL' in ren_win_str or 'OSOpenGL' in ren_win_str