From a545baebbf07fd53e2b3a5db3bd7d3a827d90faa Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Sun, 16 Jan 2022 08:18:06 +0100
Subject: [PATCH] VTK polishing

avoid segmentation fault (also allows testing)
---
 python/damask/__init__.py |  2 +-
 python/damask/_grid.py    |  2 +-
 python/damask/_vtk.py     | 18 ++++++++++--------
 python/tests/test_VTK.py  |  4 ++++
 4 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/python/damask/__init__.py b/python/damask/__init__.py
index 584a97e87..aa3c36b07 100644
--- a/python/damask/__init__.py
+++ b/python/damask/__init__.py
@@ -21,8 +21,8 @@ from ._rotation        import Rotation         # noqa
 from ._crystal         import Crystal          # noqa
 from ._orientation     import Orientation      # noqa
 from ._table           import Table            # noqa
-from ._vtk             import VTK              # noqa
 from ._colormap        import Colormap         # noqa
+from ._vtk             import VTK              # noqa
 from ._config          import Config           # noqa
 from ._configmaterial  import ConfigMaterial   # noqa
 from ._grid            import Grid             # noqa
diff --git a/python/damask/_grid.py b/python/damask/_grid.py
index 5006e1b40..002d00259 100644
--- a/python/damask/_grid.py
+++ b/python/damask/_grid.py
@@ -674,7 +674,7 @@ class Grid:
 
     def show(self) -> None:
         """Show on screen."""
-        VTK.from_rectilinear_grid(self.cells,self.size,self.origin).show()
+        VTK.from_image_data(self.cells,self.size,self.origin).show()
 
 
     def add_primitive(self,
diff --git a/python/damask/_vtk.py b/python/damask/_vtk.py
index dbbfb1b10..6bb7a5d1c 100644
--- a/python/damask/_vtk.py
+++ b/python/damask/_vtk.py
@@ -442,22 +442,24 @@ class VTK:
 
         mapper = vtk.vtkDataSetMapper()
         mapper.SetInputData(self.vtk_data)
+
         actor = vtk.vtkActor()
         actor.SetMapper(mapper)
+        actor.GetProperty().SetColor(230/255,150/255,68/255)
 
         ren = vtk.vtkRenderer()
+        ren.AddActor(actor)
+        ren.SetBackground(67/255,128/255,208/255)
 
         window = vtk.vtkRenderWindow()
         window.AddRenderer(ren)
-
-        ren.AddActor(actor)
-        ren.SetBackground(0.2,0.2,0.2)
-
         window.SetSize(width,height)
+        window.SetWindowName(util.execution_stamp('VTK','show'))
 
         iren = vtk.vtkRenderWindowInteractor()
         iren.SetRenderWindow(window)
-
-        iren.Initialize()
-        window.Render()
-        iren.Start()
+        if os.name == 'posix' and 'DISPLAY' not in os.environ:
+            print('Found no rendering device')
+        else:
+            window.Render()
+            iren.Start()
diff --git a/python/tests/test_VTK.py b/python/tests/test_VTK.py
index 68224ff33..e59409a20 100644
--- a/python/tests/test_VTK.py
+++ b/python/tests/test_VTK.py
@@ -28,6 +28,10 @@ class TestVTK:
     def _patch_execution_stamp(self, patch_execution_stamp):
         print('patched damask.util.execution_stamp')
 
+    def test_show(sef,default,monkeypatch):
+        monkeypatch.delenv('DISPLAY',raising=False)
+        default.show()
+
     def test_rectilinearGrid(self,tmp_path):
         cells  = np.random.randint(5,10,3)*2
         size   = np.random.random(3) + 1.0