Create new spritesheet fields

Author: pablodiegoss

src/core/migrations/0030_object_spritesheet_fields.py

@@ -0,0 +1,51 @@
+# Generated by Django 6.0.6 on 2026-07-01 11:30
+
+import pgtrigger.compiler
+import pgtrigger.migrations
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0029_marker_insert_insert_marker_update_update'),
+    ]
+
+    operations = [
+        pgtrigger.migrations.RemoveTrigger(
+            model_name='object',
+            name='insert_insert',
+        ),
+        pgtrigger.migrations.RemoveTrigger(
+            model_name='object',
+            name='update_update',
+        ),
+        migrations.AddField(
+            model_name='object',
+            name='spritesheet_file',
+            field=models.FileField(blank=True, null=True, upload_to='objects/spritesheets/'),
+        ),
+        migrations.AddField(
+            model_name='object',
+            name='spritesheet_metadata',
+            field=models.FileField(blank=True, null=True, upload_to='objects/spritesheets/'),
+        ),
+        migrations.AddField(
+            model_name='objectevent',
+            name='spritesheet_file',
+            field=models.FileField(blank=True, null=True, upload_to='objects/spritesheets/'),
+        ),
+        migrations.AddField(
+            model_name='objectevent',
+            name='spritesheet_metadata',
+            field=models.FileField(blank=True, null=True, upload_to='objects/spritesheets/'),
+        ),
+        pgtrigger.migrations.AddTrigger(
+            model_name='object',
+            trigger=pgtrigger.compiler.Trigger(name='insert_insert', sql=pgtrigger.compiler.UpsertTriggerSql(func='INSERT INTO "core_objectevent" ("audio_description", "author", "created", "file_extension", "file_name_original", "file_size", "id", "modified", "owner_id", "pgh_context_id", "pgh_created_at", "pgh_label", "pgh_obj_id", "sound_id", "source", "spritesheet_file", "spritesheet_metadata", "thumbnail", "title") VALUES (NEW."audio_description", NEW."author", NEW."created", NEW."file_extension", NEW."file_name_original", NEW."file_size", NEW."id", NEW."modified", NEW."owner_id", _pgh_attach_context(), NOW(), \'insert\', NEW."id", NEW."sound_id", NEW."source", NEW."spritesheet_file", NEW."spritesheet_metadata", NEW."thumbnail", NEW."title"); RETURN NULL;', hash='9961658bf4959d63d6a95cc2197b1650cacc1a3d', operation='INSERT', pgid='pgtrigger_insert_insert_25a7e', table='core_object', when='AFTER')),
+        ),
+        pgtrigger.migrations.AddTrigger(
+            model_name='object',
+            trigger=pgtrigger.compiler.Trigger(name='update_update', sql=pgtrigger.compiler.UpsertTriggerSql(condition='WHEN (OLD.* IS DISTINCT FROM NEW.*)', func='INSERT INTO "core_objectevent" ("audio_description", "author", "created", "file_extension", "file_name_original", "file_size", "id", "modified", "owner_id", "pgh_context_id", "pgh_created_at", "pgh_label", "pgh_obj_id", "sound_id", "source", "spritesheet_file", "spritesheet_metadata", "thumbnail", "title") VALUES (NEW."audio_description", NEW."author", NEW."created", NEW."file_extension", NEW."file_name_original", NEW."file_size", NEW."id", NEW."modified", NEW."owner_id", _pgh_attach_context(), NOW(), \'update\', NEW."id", NEW."sound_id", NEW."source", NEW."spritesheet_file", NEW."spritesheet_metadata", NEW."thumbnail", NEW."title"); RETURN NULL;', hash='b5beaa6a354a1fe2c1a4a7de9f16c4d4b620801b', operation='UPDATE', pgid='pgtrigger_update_update_27852', table='core_object', when='AFTER')),
+        ),
+    ]

src/core/migrations/0031_backfill_object_spritesheets.py

@@ -0,0 +1,79 @@
+"""
+Data migration: generate spritesheets and metadata JSON files for all
+existing GIF Objects that don't have them yet.
+"""
+
+import json
+import logging
+
+from django.core.files.base import ContentFile
+from django.db import migrations
+from src.core.spritesheet_converter import gif_to_spritesheet
+
+logger = logging.getLogger(__name__)
+
+
+def generate_spritesheets_for_existing_gifs(apps, schema_editor):
+    # Import inline so that the migration doesn't break if the module is
+    # moved or renamed later — the function body is self-contained.
+    
+
+    Object = apps.get_model("core", "Object")
+
+    for obj in Object.objects.filter(file_extension="gif").iterator():
+        if not obj.source:
+            logger.warning("Object %s: no source file, skipping.", obj.pk)
+            continue
+
+        try:
+            storage = obj.source.storage
+
+            with obj.source.open("rb") as f:
+                png_bytes, metadata = gif_to_spritesheet(f)
+
+            base_name = obj.source.name.rsplit(".", 1)[0].split("/")[-1]
+
+            # Save spritesheet PNG
+            spritesheet_path = f"objects/spritesheets/{base_name}_spritesheet.png"
+            _save_to_storage(storage, spritesheet_path, png_bytes)
+            obj.spritesheet_file.name = spritesheet_path
+
+            # Save metadata JSON
+            metadata_path = f"objects/spritesheets/{base_name}_spritesheet.json"
+            _save_to_storage(
+                storage, metadata_path, json.dumps(metadata).encode("utf-8")
+            )
+            obj.spritesheet_metadata.name = metadata_path
+
+            obj.save()
+            logger.info("Object %s (%s): spritesheet generated.", obj.pk, base_name)
+
+        except Exception as e:
+            logger.error(
+                "Object %s: failed to generate spritesheet: %s", obj.pk, e
+            )
+            continue
+
+
+def _save_to_storage(storage, path, content_bytes):
+    """Save content to storage, deleting existing file first for idempotency."""
+    try:
+        if storage.exists(path):
+            storage.delete(path)
+    except Exception:
+        pass
+    storage.save(path, ContentFile(content_bytes))
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("core", "0030_object_spritesheet_fields"),
+    ]
+
+    operations = [
+        migrations.RunPython(
+            generate_spritesheets_for_existing_gifs,
+            reverse_code=migrations.RunPython.noop,
+        ),
+    ]

src/core/models.py

@@ -309,6 +309,16 @@ class Object(TimeStampedModel, ContentMixin):
         blank=True,
         null=True,
     )
+    spritesheet_file = models.FileField(
+        upload_to="objects/spritesheets/",
+        blank=True,
+        null=True,
+    )
+    spritesheet_metadata = models.FileField(
+        upload_to="objects/spritesheets/",
+        blank=True,
+        null=True,
+    )
 
     def __str__(self):
         return self.source.name
@@ -602,5 +612,9 @@ def remove_source_file(sender, instance, **kwargs):
         # source file we just removed. See #849.
         if instance.audio_description:
             instance.audio_description.delete(False)
+        if instance.spritesheet_file:
+            instance.spritesheet_file.delete(False)
+        if instance.spritesheet_metadata:
+            instance.spritesheet_metadata.delete(False)
     if isinstance(instance, Sound):
         instance.file.delete(False)