better plot scaling logic (#938)

kushalkolar · web-flow · commit c924c66803be · 2025-11-15T09:25:08.000-05:00
* better plot scaling logic for when a subplot controller manages multiple cameras

* skip scaling in empty subplots
diff --git a/fastplotlib/layouts/_plot_area.py b/fastplotlib/layouts/_plot_area.py
@@ -607,14 +607,33 @@ def center_scene(self, *, zoom: float = 1.0):
         if not len(self._fpl_graphics_scene.children) > 0:
             return
 
-        # scale all cameras associated with this controller
-        # else it looks wonky
-        for camera in self.controller.cameras:
-            camera.show_object(self._fpl_graphics_scene)
+        if self.parent.__class__.__name__.endswith("Figure"):
+            # always use figure._subplots.ravel() in internal fastplotlib code
+            # otherwise if we use `for subplot in figure`, this could conflict
+            # with a user's iterator where they are doing `for subplot in figure` !!!
+            for subplot in self.parent._subplots.ravel():
+                # scale all cameras associated with this controller
+                if subplot.camera in self.controller.cameras:
+                    # skip if the scene is empty
+                    if len(subplot._fpl_graphics_scene.children) < 1:
+                        continue
+
+                    # center the camera in the other subplot w.r.t. the scene in that other subplot!
+                    self._auto_center_scene(
+                        subplot.camera, subplot._fpl_graphics_scene, zoom
+                    )
+        else:
+            # just change for this plot area
+            # this is probably a dock area
+            self._auto_center_scene(self.camera, self._fpl_graphics_scene, zoom)
 
-            # camera.show_object can cause the camera width and height to increase so apply a zoom to compensate
-            # probably because camera.show_object uses bounding sphere
-            camera.zoom = zoom
+    def _auto_center_scene(
+        self, camera: pygfx.PerspectiveCamera, scene: pygfx.Scene, zoom: float
+    ):
+        camera.show_object(scene)
+        # camera.show_object can cause the camera width and height to increase so apply a zoom to compensate
+        # probably because camera.show_object uses bounding sphere
+        camera.zoom = zoom
 
     def auto_scale(
         self,
@@ -642,16 +661,43 @@ def auto_scale(
         self.center_scene()
 
         if maintain_aspect is None:  # if not provided keep current setting
+            # use the same maintain apsect for all other cameras that this controller manages
+            # I think this make sense for most use cases, even when the other controllers are
+            # only managing one or 2 axes
             maintain_aspect = self.camera.maintain_aspect
 
-        # scale all cameras associated with this controller else it looks wonky
-        for camera in self.controller.cameras:
-            camera.maintain_aspect = maintain_aspect
+        if self.parent.__class__.__name__.endswith("Figure"):
+            # always use figure._subplots.ravel() in internal fastplotlib code
+            # otherwise if we use `for subplot in figure`, this could conflict
+            # with a user's iterator where they are doing `for subplot in figure` !!!
+            for subplot in self.parent._subplots.ravel():
+                # skip if the scene is empty
+                if len(subplot._fpl_graphics_scene.children) < 1:
+                    continue
 
-        if len(self._fpl_graphics_scene.children) > 0:
-            width, height, depth = np.ptp(
-                self._fpl_graphics_scene.get_world_bounding_box(), axis=0
+                # scale the camera in the other subplot w.r.t. the scene in that other subplot!
+                if subplot.camera in self.controller.cameras:
+                    camera = subplot.camera
+                    self._auto_scale_scene(
+                        camera, subplot._fpl_graphics_scene, zoom, maintain_aspect
+                    )
+        else:
+            # just change for this plot area, this is probably a dock area
+            self._auto_scale_scene(
+                self.camera, self._fpl_graphics_scene, zoom, maintain_aspect
             )
+
+    def _auto_scale_scene(
+        self,
+        camera: pygfx.PerspectiveCamera,
+        scene: pygfx.Scene,
+        zoom: float,
+        maintain_aspect: bool,
+    ):
+        camera.maintain_aspect = maintain_aspect
+
+        if len(scene.children) > 0:
+            width, height, depth = np.ptp(scene.get_world_bounding_box(), axis=0)
         else:
             width, height, depth = (1, 1, 1)
 
@@ -661,12 +707,10 @@ def auto_scale(
         if height < 0.01:
             height = 1
 
-        # scale all cameras associated with this controller else it looks wonky
-        for camera in self.controller.cameras:
-            camera.width = width
-            camera.height = height
+        camera.width = width
+        camera.height = height
 
-            camera.zoom = zoom
+        camera.zoom = zoom
 
     def remove_graphic(self, graphic: Graphic):
         """
