FIX: Reset zoom (#242)

* FIX Brain:  don't reset zoom

* TEST

* DOC:  Brain.show_view() parameters and return values

* also fix Brain.add_contour_overlay()

* TEST:  fix for test backend

* TEST:  view persistence more generally

Author: christianbrodbeck

surfer/tests/test_viz.py

@@ -51,6 +51,30 @@ def _set_backend(backend=None):
     mlab.options.backend = backend
 
 
+def get_view(brain):
+    """Setup for view persistence test"""
+    fig = brain._figures[0][0]
+    if mlab.options.backend == 'test':
+        return
+    fig.scene.camera.parallel_scale = 50
+    assert fig.scene.camera.parallel_scale == 50
+    view, roll = brain.show_view()
+    return fig.scene.camera.parallel_scale, view, roll
+
+
+def check_view(brain, view):
+    """Test view persistence"""
+    fig = brain._figures[0][0]
+    if mlab.options.backend == 'test':
+        return
+    parallel_scale, view, roll = view
+    assert fig.scene.camera.parallel_scale == parallel_scale
+    view_now, roll_now = brain.show_view()
+    assert view_now[:3] == view[:3]
+    assert_array_equal(view_now[3], view[3])
+    assert roll_now == roll
+
+
 @requires_fsaverage
 def test_offscreen():
     """Test offscreen rendering."""
@@ -146,10 +170,15 @@ def test_annot():
     borders = [True, False, 2]
     alphas = [1, 0.5]
     brain = Brain(*std_args)
+    view = get_view(brain)
+
     for a, b, p in zip(annots, borders, alphas):
         brain.add_annotation(a, b, p)
+    check_view(brain, view)
+
     brain.set_surf('white')
-    assert_raises(ValueError, brain.add_annotation, 'aparc', borders=-1)
+    with pytest.raises(ValueError):
+        brain.add_annotation('aparc', borders=-1)
 
     subj_dir = utils._get_subjects_dir()
     annot_path = pjoin(subj_dir, subject_id, 'label', 'lh.aparc.a2009s.annot')
@@ -164,12 +193,16 @@ def test_contour():
     """Test plotting of contour overlay."""
     _set_backend()
     brain = Brain(*std_args)
+    view = get_view(brain)
+
     overlay_file = pjoin(data_dir, "lh.sig.nii.gz")
     brain.add_contour_overlay(overlay_file)
     brain.add_contour_overlay(overlay_file, max=20, n_contours=9,
                               line_width=2)
     brain.contour['surface'].actor.property.line_width = 1
     brain.contour['surface'].contour.number_of_contours = 10
+
+    check_view(brain, view)
     brain.close()
 
 
@@ -228,7 +261,10 @@ def test_label():
     hemi = "lh"
     surf = "inflated"
     brain = Brain(subject_id, hemi, surf)
+    view = get_view(brain)
+
     brain.add_label("BA1")
+    check_view(brain, view)
     brain.add_label("BA1", color="blue", scalar_thresh=.5)
     subj_dir = utils._get_subjects_dir()
     label_file = pjoin(subj_dir, subject_id,

surfer/viz.py

@@ -1768,11 +1768,6 @@ def show_view(self, view=None, roll=None, distance=None, row=-1, col=-1):
             brain surface to view (one of 'lateral', 'medial', 'rostral',
             'caudal', 'dorsal', 'ventral', 'frontal', 'parietal') or kwargs to
             pass to :func:`mayavi.mlab.view()`.
-
-        Returns
-        -------
-        view : tuple
-            tuple returned from mlab.view
         roll : float
             camera roll
         distance : float | 'auto' | None
@@ -1781,6 +1776,13 @@ def show_view(self, view=None, roll=None, distance=None, row=-1, col=-1):
             Row index of which brain to use
         col : int
             Column index of which brain to use
+
+        Returns
+        -------
+        view : tuple
+            tuple returned from mlab.view
+        roll : float
+            camera roll returned from mlab.roll
         """
         return self.brain_matrix[row][col].show_view(view, roll, distance)
 
@@ -3125,7 +3127,8 @@ def add_overlay(self, old):
                 pos_thresh = threshold_filter(mesh, low=old.pos_lims[0])
                 pos = mlab.pipeline.surface(
                     pos_thresh, colormap="YlOrRd", figure=self._f,
-                    vmin=old.pos_lims[1], vmax=old.pos_lims[2])
+                    vmin=old.pos_lims[1], vmax=old.pos_lims[2],
+                    reset_zoom=False)
                 pos.actor.property.backface_culling = False
                 pos_bar = mlab.scalarbar(pos, nb_labels=5)
             pos_bar.reverse_lut = True
@@ -3140,7 +3143,8 @@ def add_overlay(self, old):
                 neg_thresh = threshold_filter(mesh, up=old.neg_lims[0])
                 neg = mlab.pipeline.surface(
                     neg_thresh, colormap="PuBu", figure=self._f,
-                    vmin=old.neg_lims[1], vmax=old.neg_lims[2])
+                    vmin=old.neg_lims[1], vmax=old.neg_lims[2],
+                    reset_zoom=False)
                 neg.actor.property.backface_culling = False
                 neg_bar = mlab.scalarbar(neg, nb_labels=5)
             neg_bar.scalar_bar_representation.position = (0.05, 0.01)
@@ -3196,7 +3200,7 @@ def add_data(self, array, fmin, fmid, fmax, thresh, lut, colormap, alpha,
         with warnings.catch_warnings(record=True):
             surf = mlab.pipeline.surface(
                 pipe, colormap=colormap, vmin=fmin, vmax=fmax,
-                opacity=float(alpha), figure=self._f)
+                opacity=float(alpha), figure=self._f, reset_zoom=False)
             surf.actor.property.backface_culling = False
 
         # apply look up table if given
@@ -3226,7 +3230,8 @@ def add_annotation(self, annot, ids, cmap):
         # Add scalar values to dataset
         array_id, pipe = self._add_scalar_data(ids)
         with warnings.catch_warnings(record=True):
-            surf = mlab.pipeline.surface(pipe, name=annot, figure=self._f)
+            surf = mlab.pipeline.surface(pipe, name=annot, figure=self._f,
+                                         reset_zoom=False)
             surf.actor.property.backface_culling = False
 
         # Set the color table
@@ -3242,7 +3247,8 @@ def add_label(self, label, label_name, color, alpha):
         from matplotlib.colors import colorConverter
         array_id, pipe = self._add_scalar_data(label)
         with warnings.catch_warnings(record=True):
-            surf = mlab.pipeline.surface(pipe, name=label_name, figure=self._f)
+            surf = mlab.pipeline.surface(pipe, name=label_name, figure=self._f,
+                                         reset_zoom=False)
             surf.actor.property.backface_culling = False
         color = colorConverter.to_rgba(color, alpha)
         cmap = np.array([(0, 0, 0, 0,), color])
@@ -3258,9 +3264,9 @@ def add_morphometry(self, morph_data, colormap, measure,
         """Add a morphometry overlay to the image"""
         array_id, pipe = self._add_scalar_data(morph_data)
         with warnings.catch_warnings(record=True):
-            surf = mlab.pipeline.surface(pipe, colormap=colormap,
-                                         vmin=min, vmax=max,
-                                         name=measure, figure=self._f)
+            surf = mlab.pipeline.surface(
+                pipe, colormap=colormap, vmin=min, vmax=max, name=measure,
+                figure=self._f, reset_zoom=False)
 
         # Get the colorbar
         if colorbar:
@@ -3291,8 +3297,9 @@ def add_contour_overlay(self, scalar_data, min=None, max=None,
         array_id, pipe = self._add_scalar_data(scalar_data)
         with warnings.catch_warnings(record=True):
             thresh = threshold_filter(pipe, low=min)
-            surf = mlab.pipeline.contour_surface(thresh, contours=n_contours,
-                                                 line_width=line_width)
+            surf = mlab.pipeline.contour_surface(
+                thresh, contours=n_contours, line_width=line_width,
+                reset_zoom=False)
         if lut is not None:
             l_m = surf.module_manager.scalar_lut_manager
             l_m.load_lut_from_list(lut / 255.)