Check we don't go over the max number of entities

2 files changed, 12 insertions, 1 deletions

diff --git a/src/Makefile b/src/Makefile
index 5815e88..6984376 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -35,7 +35,7 @@ $(IMG_OBJS): %.o: ../data/%.png
 	../tools/pngpix.py $< $@
 
 $(MAP_OBJS): %.o: ../data/%.json
-	../tools/map.py $< $@
+	../tools/map.py --max-ents 15 $< $@
 
 $(WAV_OBJS): %.o: ../data/%.wav
 	../tools/raw.py $< $@
diff --git a/tools/map.py b/tools/map.py
index 825f307..c959c50 100755
--- a/tools/map.py
+++ b/tools/map.py
@@ -49,6 +49,13 @@ def main():
     parser.add_argument(
         "--version", action="version", version="%(prog)s " + __version__
     )
+    parser.add_argument(
+        "--max-ents",
+        dest="max_ents",
+        type=int,
+        default=None,
+        help="limit of entities in the map",
+    )
     parser.add_argument("file_json", help="JSON map to convert")
     parser.add_argument("output", help="object name for the map data")
 
@@ -82,6 +89,10 @@ def main():
     # some entities will never change their y coordinate, so sorting them by y
     # should help the drawing order in the game
     objs_sorted = sorted(entity_layer["objects"], key=lambda o: o["y"])
+
+    if args.max_ents and len(objs_sorted) > args.max_ents:
+        parser.error("Too many entities (limit: %s)" % args.max_ents)
+
     for ent in objs_sorted:
         try:
             typ = entity_types.index(ent["name"])