Moved all the source files into a nested io_scene_psk_psa folder in preparation for CI workflow

Also changed the license to GPLv3

io_scene_psk_psa/psa/writer.py

@@ -0,0 +1,25 @@
+from ctypes import Structure, sizeof
+from typing import Type
+
+from .data import Psa
+from ..shared.data import Section
+
+
+def write_section(fp, name: bytes, data_type: Type[Structure] = None, data: list = None):
+    section = Section()
+    section.name = name
+    if data_type is not None and data is not None:
+        section.data_size = sizeof(data_type)
+        section.data_count = len(data)
+    fp.write(section)
+    if data is not None:
+        for datum in data:
+            fp.write(datum)
+
+
+def write_psa(psa: Psa, path: str):
+    with open(path, 'wb') as fp:
+        write_section(fp, b'ANIMHEAD')
+        write_section(fp, b'BONENAMES', Psa.Bone, psa.bones)
+        write_section(fp, b'ANIMINFO', Psa.Sequence, list(psa.sequences.values()))
+        write_section(fp, b'ANIMKEYS', Psa.Key, psa.keys)