Fix #322.

There were logic problems around exporting references to objects that
exist only in disabled pages (or default pages that are disabled because
no enabled objects are exported into the default page).

korman/exporter/manager.py

@@ -75,13 +75,22 @@ class ExportManager:
 
     def add_object(self, pl, name=None, bl=None, loc=None, so=None):
         """Automates adding a converted Blender object to our Plasma Resource Manager"""
-        assert (bl or loc or so)
         if loc is not None:
             location = loc
         elif so is not None:
             location = so.key.location
+        elif bl is not None:
+            page_name = bl.plasma_object.page
+            location = self._pages.get(page_name)
+
+            # location can be None if we've been passed an object in a disabled page, or, in some
+            # cases, a disabled object in the default page. If we got this far, someone is demanding
+            # that this object be created, so we need its page to exist, no matter what the user
+            # otherwise requested.
+            if location is None:
+                location = self._force_create_page(page_name, bl.name)
         else:
-            location = self._pages[bl.plasma_object.page]
+            raise ValueError("bl, so, or loc must be specified.")
 
         # pl can be a class or an instance.
         # This is one of those "sanity" things to ensure we don't suddenly startpassing around the
@@ -206,14 +215,17 @@ class ExportManager:
 
     def find_key(self, pClass, bl=None, name=None, so=None, loc=None):
         """Given a blender Object and a Plasma class, find (or create) an exported plKey"""
-        assert loc or bl or so
-
         if loc is not None:
             location = loc
         elif so is not None:
             location = so.key.location
+        elif bl is not None:
+            location = self._pages.get(bl.plasma_object.page)
+            if location is None:
+                # This page has never been created, so the key search will obviously fail.
+                return None
         else:
-            location = self._pages[bl.plasma_object.page]
+            raise ValueError("bl, so, or loc must be specified.")
 
         if name is None:
             if bl is not None:
@@ -253,6 +265,40 @@ class ExportManager:
             return replace_python2_identifier(name)
         return name
 
+    def _force_create_page(self, page_name: str, requestor_name: str) -> plLocation:
+        """Forcibly creates a page (that you KNOW does not exist yet) during the convert process."""
+        age_name = self._exporter().age_name
+        if page_name:
+            # This page has a name, but hasn't yet been created.
+            self._exporter().report.warn(
+                "'{}': trying to export into an unknown, potentially disabled page '{}'. Attempting to create it.",
+                requestor_name,
+                page_name
+            )
+            age_info = bpy.context.scene.world.plasma_age
+            page_info = next((i for i in age_info.pages if i.name == page_name), None)
+            if page_info is None:
+                error = explosions.UndefinedPageError()
+                error.add(page_name, requestor_name)
+                error.raise_if_error()
+            location = self.create_page(age_name, page_name, page_info.id)
+        else:
+            # This is a default page that wasn't exported... for some reason...
+            self._exporter().report.warn(
+                "'{}': trying to export into the default page, but it seems to not exist. Attempting to create it.",
+                requestor_name
+            )
+
+            # See if a default page exists by name. That means that it doesn't have ID = 0.
+            location = next((j for i, j in self._pages.items() if i.lower() == "default"), None)
+            if location is None:
+                # OK, we can be fairly certain that page ID 0 and page name "Default" don't exist.
+                location = self.create_page(age_name, "Default", 0)
+            else:
+                # Avoid doing this stupid lookup in the future.
+                self._pages[""] = location
+        return location
+
     def get_location(self, bl):
         """Returns the Page Location of a given Blender Object"""
         return self._pages[bl.plasma_object.page]