Fix inverted transfunc condition in render_shapes; add transfunc to render_labels

src/spatialdata_plot/pl/basic.py

@@ -854,6 +854,7 @@ def render_labels(
                 scale=param_values["scale"],
                 table_name=param_values["table_name"],
                 table_layer=param_values["table_layer"],
+                transfunc=kwargs.get("transfunc"),
                 zorder=n_steps,
                 colorbar=param_values["colorbar"],
                 colorbar_params=param_values["colorbar_params"],

src/spatialdata_plot/pl/render.py

@@ -402,7 +402,7 @@ def _render_shapes(
         sdata_filt[element] = shapes
 
     # color_source_vector is None when the values aren't categorical
-    if values_are_categorical and render_params.transfunc is not None:
+    if not values_are_categorical and render_params.transfunc is not None:
         color_vector = render_params.transfunc(color_vector)
 
     norm = copy(render_params.cmap_params.norm)
@@ -1702,6 +1702,10 @@ def _render_labels(
         if isinstance(color_vector.dtype, pd.CategoricalDtype):
             color_vector = color_vector.remove_unused_categories()
 
+    # color_source_vector is None when the values aren't categorical
+    if color_source_vector is None and render_params.transfunc is not None:
+        color_vector = render_params.transfunc(color_vector)
+
     def _draw_labels(
         seg_erosionpx: int | None,
         seg_boundaries: bool,

src/spatialdata_plot/pl/render_params.py

@@ -304,6 +304,7 @@ class LabelsRenderParams:
     scale: str | None = None
     table_name: str | None = None
     table_layer: str | None = None
+    transfunc: Callable[[float], float] | None = None
     zorder: int = 0
     colorbar: bool | str | None = "auto"
     colorbar_params: dict[str, object] | None = None

tests/pl/test_render_labels.py

@@ -295,6 +295,11 @@ 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=lambda x: x * 100).pl.show(
+            title="transfunc: x * 100"
+        )
+
     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()
@@ -454,3 +459,17 @@ def test_groups_warns_when_no_groups_match_labels(sdata_blobs: SpatialData, capl
         sdata_blobs.pl.render_labels(
             labels_name, color="cat", groups=["nonexistent"], table_name="label_table", na_color=None
         ).pl.show()
+
+
+def test_transfunc_is_applied_for_continuous_labels(sdata_blobs: SpatialData):
+    called = []
+
+    def track(x):
+        called.append(True)
+        return x
+
+    fig, ax = plt.subplots()
+    sdata_blobs.pl.render_labels("blobs_labels", color="channel_0_sum", transfunc=track).pl.show(ax=ax)
+    plt.close(fig)
+
+    assert called, "transfunc was not called for continuous labels data"

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=lambda x: x * 100
+        ).pl.show(title="transfunc: x * 100")
+
     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",
@@ -1310,3 +1315,17 @@ def test_datashader_na_color_nan_overlay(sdata_blobs: SpatialData, na_color: str
         f"Expected {expected_images} image(s), got {len(ax.get_images())} for na_color={na_color!r}"
     )
     plt.close(fig)
+
+
+def test_transfunc_is_applied_for_continuous_shapes(sdata_blobs_shapes_annotated: SpatialData):
+    called = []
+
+    def track(x):
+        called.append(True)
+        return x
+
+    fig, ax = plt.subplots()
+    sdata_blobs_shapes_annotated.pl.render_shapes("blobs_polygons", color="value", transfunc=track).pl.show(ax=ax)
+    plt.close(fig)
+
+    assert called, "transfunc was not called for continuous shapes data"