add thumbnail for blender icons

.gitignore

@@ -1,7 +1,13 @@
 # My Ban
 bbp_ng/PyBMap/*.dll
+bbp_ng/PyBMap/*.so
+bbp_ng/PyBMap/*.dylib
+bbp_ng/PyBMap/*.bin
 bbp_ng/PyBMap/*.pdb
 
+bbp_ng/icons/*
+!bbp_ng/icons/.gitkeep
+
 # Byte-compiled / optimized / DLL files
 __pycache__/
 *.py[cod]

bbp_ng/raw_icons/README.md

@@ -0,0 +1,7 @@
+# Raw Icons
+
+This folder contain all images used by this Blender plugin.
+
+This folder should not be distributed in production because all of these files are in original size. It is pretty need too much time to load them in blender.  
+So we keep these high quality images here and provide a tools in `tools` folder. Builder should run script to generate thumbnails in `icons` folder.  
+Then this Blender plugin can work normally.

bbp_ng/tools/build_icons.py

@@ -0,0 +1,42 @@
+import os
+import PIL, PIL.Image
+
+# the config for thumbnail
+g_ThumbnailSize: int = 16
+
+def resize_image(src_file: str, dst_file: str) -> None:
+    # open image
+    src_image: PIL.Image.Image = PIL.Image.open(src_file)
+    # create thumbnail
+    src_image.thumbnail((g_ThumbnailSize, g_ThumbnailSize))
+    # save to new file
+    src_image.save(dst_file)
+
+def relative_to_folder(abs_path: str, src_parent: str, dst_parent: str) -> str:
+    return os.path.join(dst_parent, os.path.relpath(abs_path, src_parent))
+
+def create_thumbnails() -> None:
+    # get folder path
+    root_folder: str = os.path.dirname(os.path.dirname(__file__))
+    raw_icons_folder: str = os.path.join(root_folder, 'raw_icons')
+    icons_folder: str = os.path.join(root_folder, 'icons')
+
+    # iterate raw icons folder
+    for root, dirs, files in os.walk(raw_icons_folder, topdown = True):
+        # iterate folder and create it in dest folder
+        for name in dirs:
+            src_folder: str = os.path.join(root, name)
+            dst_folder: str = relative_to_folder(src_folder, raw_icons_folder, icons_folder)
+            print(f'Creating Folder: {src_folder} -> {dst_folder}')
+            os.makedirs(dst_folder, exist_ok = True)
+        for name in files:
+            if not name.endswith('.png'): continue  # skip non-image
+            src_file: str = os.path.join(root, name)
+            dst_file: str = relative_to_folder(src_file, raw_icons_folder, icons_folder)
+            print(f'Processing Thumbnail: {src_file} -> {dst_file}')
+            resize_image(src_file, dst_file)
+
+    print('Done.')
+
+if __name__ == '__main__':
+    create_thumbnails()