Add visual tests for transfunc on continuous shapes and labels

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: timtreis

tests/pl/test_render_labels.py

@@ -295,6 +295,9 @@ def test_plot_can_color_with_norm_no_clipping(self, sdata_blobs: SpatialData):
             cmap=_viridis_with_under_over(),
         ).pl.show()
 
+    def test_plot_transfunc_applied_to_continuous_labels(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_labels("blobs_labels", color="channel_0_sum", transfunc=np.sqrt).pl.show()
+
     def test_plot_can_annotate_labels_with_table_layer(self, sdata_blobs: SpatialData):
         sdata_blobs["table"].layers["normalized"] = get_standard_RNG().random(sdata_blobs["table"].X.shape)
         sdata_blobs.pl.render_labels("blobs_labels", color="channel_0_sum", table_layer="normalized").pl.show()

tests/pl/test_render_shapes.py

@@ -732,6 +732,11 @@ def test_plot_can_color_with_norm_no_clipping(self, sdata_blobs_shapes_annotated
             element="blobs_polygons", color="value", norm=Normalize(2, 4, clip=False), cmap=_viridis_with_under_over()
         ).pl.show()
 
+    def test_plot_transfunc_applied_to_continuous_shapes(self, sdata_blobs_shapes_annotated: SpatialData):
+        sdata_blobs_shapes_annotated.pl.render_shapes(
+            element="blobs_polygons", color="value", transfunc=np.sqrt
+        ).pl.show()
+
     def test_plot_datashader_can_color_with_norm_and_clipping(self, sdata_blobs_shapes_annotated: SpatialData):
         sdata_blobs_shapes_annotated.pl.render_shapes(
             element="blobs_polygons",