FIX: scalar_bar (#8643)

* Fix scalar bar mapped from polydata actor

* Touch example

* DRY

* LUT still needs to be set for glyphs

* Touch example

* Improve coverage

examples/inverse/plot_source_space_snr.py

@@ -53,7 +53,7 @@
 ax.set(xlabel='Time (sec)', ylabel='SNR MEG-EEG')
 fig.tight_layout()
 
-# Find time point of maximum SNR:
+# Find time point of maximum SNR
 maxidx = np.argmax(ave)
 
 # Plot SNR on source space at the time point of maximum SNR:

examples/inverse/plot_vector_mne_solution.py

@@ -67,7 +67,7 @@
 
 stc_max, directions = stc.project('pca', src=inv['src'])
 # These directions must by design be close to the normals because this
-# inverse was computed with loose=0.2:
+# inverse was computed with loose=0.2
 print('Absolute cosine similarity between source normals and directions: '
       f'{np.abs(np.sum(directions * inv["source_nn"][2::3], axis=-1)).mean()}')
 brain_max = stc_max.plot(

mne/viz/_brain/_brain.py

@@ -2407,7 +2407,8 @@ def update_lut(self, fmin=None, fmid=None, fmax=None):
                     mesh = self._layered_meshes[hemi]
                     mesh.update_overlay(name='data',
                                         colormap=self._data['ctable'])
-                    _set_colormap_range(mesh._actor, ctable, scalar_bar, rng)
+                    _set_colormap_range(mesh._actor, ctable, scalar_bar, rng,
+                                        self._brain_color)
                     scalar_bar = None
 
                 grid_volume_pos = hemi_data.get('grid_volume_pos')

mne/viz/backends/_pysurfer_mayavi.py

@@ -24,7 +24,7 @@
 from tvtk.pyface.tvtk_scene import TVTKScene
 
 from .base_renderer import _BaseRenderer
-from ._utils import _check_color, ALLOWED_QUIVER_MODES
+from ._utils import _check_color, _alpha_blend_background, ALLOWED_QUIVER_MODES
 from ...surface import _normalize_vectors
 from ...utils import (_import_mlab, _validate_type, SilenceStdout,
                       copy_base_doc_to_subclass_doc, _check_option)
@@ -301,10 +301,7 @@ def scalarbar(self, source, color="white", title=None, n_labels=4,
             ctable = lut.table.to_array()
             cbar_lut = tvtk.LookupTable()
             cbar_lut.deep_copy(lut)
-            alphas = ctable[:, -1][:, np.newaxis] / 255.
-            use_lut = ctable.copy()
-            use_lut[:, -1] = 255.
-            vals = (use_lut * alphas) + bgcolor * (1 - alphas)
+            vals = _alpha_blend_background(ctable, bgcolor)
             cbar_lut.table.from_array(vals)
             cmap.scalar_bar.lookup_table = cbar_lut
 

mne/viz/backends/_pyvista.py

@@ -21,7 +21,8 @@
 import vtk
 
 from .base_renderer import _BaseRenderer
-from ._utils import _get_colormap_from_array, ALLOWED_QUIVER_MODES
+from ._utils import (_get_colormap_from_array, _alpha_blend_background,
+                     ALLOWED_QUIVER_MODES)
 from ...fixes import _get_args
 from ...utils import copy_base_doc_to_subclass_doc, _check_option
 from ...externals.decorator import decorator
@@ -874,20 +875,21 @@ def _process_events(plotter):
             plotter.app.processEvents()
 
 
-def _set_colormap_range(actor, ctable, scalar_bar, rng=None):
+def _set_colormap_range(actor, ctable, scalar_bar, rng=None,
+                        background_color=None):
     from vtk.util.numpy_support import numpy_to_vtk
-    mapper = actor.GetMapper()
-    lut = mapper.GetLookupTable()
-    # Catch:  FutureWarning: Conversion of the second argument of
-    # issubdtype from `complex` to `np.complexfloating` is deprecated.
-    with warnings.catch_warnings():
-        warnings.filterwarnings("ignore", category=FutureWarning)
-        lut.SetTable(numpy_to_vtk(ctable))
     if rng is not None:
-        mapper.SetScalarRange(rng[0], rng[1])
-        lut.SetRange(rng[0], rng[1])
+        mapper = actor.GetMapper()
+        mapper.SetScalarRange(*rng)
+        lut = mapper.GetLookupTable()
+        lut.SetTable(numpy_to_vtk(ctable))
     if scalar_bar is not None:
-        scalar_bar.SetLookupTable(actor.GetMapper().GetLookupTable())
+        lut = scalar_bar.GetLookupTable()
+        if background_color is not None:
+            background_color = np.array(background_color) * 255
+            ctable = _alpha_blend_background(ctable, background_color)
+        lut.SetTable(numpy_to_vtk(ctable, array_type=vtk.VTK_UNSIGNED_CHAR))
+        lut.SetRange(*rng)
 
 
 def _set_volume_range(volume, ctable, alpha, scalar_bar, rng):

mne/viz/backends/_utils.py

@@ -56,3 +56,10 @@ def _check_color(color):
         raise TypeError("Expected type is `str` or iterable but "
                         "{} was given.".format(type(color)))
     return color
+
+
+def _alpha_blend_background(ctable, background_color):
+    alphas = ctable[:, -1][:, np.newaxis] / 255.
+    use_table = ctable.copy()
+    use_table[:, -1] = 255.
+    return (use_table * alphas) + background_color * (1 - alphas)

mne/viz/backends/tests/test_renderer.py

@@ -157,7 +157,8 @@ def test_3d_backend(renderer):
                      scalars=np.array([[1.0, 1.0]]))
 
     # scalar bar
-    rend.scalarbar(source=tube, title="Scalar Bar")
+    rend.scalarbar(source=tube, title="Scalar Bar",
+                   bgcolor=[1, 1, 1])
 
     # use text
     rend.text2d(x_window=txt_x, y_window=txt_y, text=txt_text,

tutorials/misc/plot_seeg.py

@@ -122,7 +122,7 @@
                              surfaces=["pial", "head"])
 
 ###############################################################################
-# Next, we will get the raw data and plot its amplitude over time.
+# Next, we'll get the raw data and plot its amplitude over time.
 
 raw.plot()
 

tutorials/source-modeling/plot_visualize_stc.py

@@ -54,7 +54,7 @@
                  clim=dict(kind='value', lims=[3, 6, 9]))
 
 ###############################################################################
-# You can also morph it to fsaverage and visualize it using a flatmap:
+# You can also morph it to fsaverage and visualize it using a flatmap
 
 # sphinx_gallery_thumbnail_number = 3
 stc_fs = mne.compute_source_morph(stc, 'sample', 'fsaverage', subjects_dir,