add user warning and tests

Author: Sonja Stockhaus

src/spatialdata_plot/pl/render.py

@@ -166,7 +166,10 @@ def _render_shapes(
         current_type = shapes["geometry"].type
         if not (render_params.shape == "circle" and (current_type == "Point").all()):
             logger.info(f"Converting {shapes.shape[0]} shapes to {render_params.shape}.")
-            shapes = _convert_shapes(shapes, render_params.shape)
+            max_extent = np.max(
+                [shapes.total_bounds[2] - shapes.total_bounds[0], shapes.total_bounds[3] - shapes.total_bounds[1]]
+            )
+            shapes = _convert_shapes(shapes, render_params.shape, max_extent)
 
     # Determine which method to use for rendering
     method = render_params.method

src/spatialdata_plot/pl/utils.py

@@ -2493,8 +2493,16 @@ def _hex_no_alpha(hex: str) -> str:
     raise ValueError("Invalid hex color length: must be either '#RRGGBB' or '#RRGGBBAA'")
 
 
-def _convert_shapes(shapes: GeoDataFrame, target_shape: str) -> GeoDataFrame:
+def _convert_shapes(
+    shapes: GeoDataFrame, target_shape: str, max_extent: float, warn_above_extent_fraction: float = 0.5
+) -> GeoDataFrame:
     """Convert the shapes stored in a GeoDataFrame (geometry column) to the target_shape."""
+    # NOTE: possible follow-up: when converting equally sized shapes to hex, automatically scale resulting hexagons
+    # so that they are perfectly adjacent to each other
+
+    if warn_above_extent_fraction < 0.0 or warn_above_extent_fraction > 1.0:
+        warn_above_extent_fraction = 0.5  # set to default if the value is outside [0, 1]
+    warn_shape_size = False
 
     # define individual conversion methods
     def _circle_to_hexagon(center: shapely.Point, radius: float) -> tuple[shapely.Polygon, None]:
@@ -2528,6 +2536,9 @@ def _polygon_to_circle(polygon: shapely.Polygon) -> tuple[shapely.Point, float]:
         center = np.mean(circle_points, axis=0)
         radius = max(float(np.linalg.norm(p - center)) for p in circle_points)
         assert isinstance(radius, float)  # shut up mypy
+        if 2 * radius > max_extent * warn_above_extent_fraction:
+            nonlocal warn_shape_size
+            warn_shape_size = True
         return shapely.Point(center), radius
 
     def _multipolygon_to_hexagon(multipolygon: shapely.MultiPolygon) -> tuple[shapely.Polygon, None]:
@@ -2547,6 +2558,9 @@ def _multipolygon_to_circle(multipolygon: shapely.MultiPolygon) -> tuple[shapely
         center = np.mean(circle_points, axis=0)
         radius = max(float(np.linalg.norm(p - center)) for p in circle_points)
         assert isinstance(radius, float)  # shut up mypy
+        if 2 * radius > max_extent * warn_above_extent_fraction:
+            nonlocal warn_shape_size
+            warn_shape_size = True
         return shapely.Point(center), radius
 
     # define dict with all conversion methods
@@ -2587,4 +2601,11 @@ def _multipolygon_to_circle(multipolygon: shapely.MultiPolygon) -> tuple[shapely
                 shapes["radius"] = np.nan
             shapes["radius"][i] = radius
 
+    if warn_shape_size:
+        logger.info(
+            f"When converting the shapes, the size of at least one target shape extends "
+            f"{warn_above_extent_fraction * 100}% of the original total bound of the shapes. The conversion"
+            " might not give satisfying results in this scenario."
+        )
+
     return shapes

tests/pl/test_render_shapes.py

@@ -562,3 +562,51 @@ def test_plot_can_annotate_shapes_with_table_layer(self, sdata_blobs: SpatialDat
         sdata_blobs["circle_table"].layers["normalized"] = RNG.random((nrows, ncols))
 
         sdata_blobs.pl.render_shapes("blobs_circles", color="feature0", table_layer="normalized").pl.show()
+
+    def test_plot_can_render_circles_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_circles", shape="hex").pl.show()
+
+    def test_plot_can_render_circles_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_circles", shape="square").pl.show()
+
+    def test_plot_can_render_polygons_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="hex").pl.show()
+
+    def test_plot_can_render_polygons_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="square").pl.show()
+
+    def test_plot_can_render_polygons_to_circle(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="circle").pl.show()
+
+    def test_plot_can_render_multipolygons_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="hex").pl.show()
+
+    def test_plot_can_render_multipolygons_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="square").pl.show()
+
+    def test_plot_can_render_multipolygons_to_circle(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="circle").pl.show()
+
+    def test_plot_datashader_can_render_circles_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_circles", shape="hex", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_circles_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_circles", shape="square", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_polygons_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="hex", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_polygons_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="square", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_polygons_to_circle(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_polygons", shape="circle", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_multipolygons_to_hex(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="hex", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_multipolygons_to_square(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="square", method="datashader").pl.show()
+
+    def test_plot_datashader_can_render_multipolygons_to_circle(self, sdata_blobs: SpatialData):
+        sdata_blobs.pl.render_shapes(element="blobs_multipolygons", shape="circle", method="datashader").pl.show()