implemented decode_data in img (tpl -> png) and added img-decode operation (useful if a texture modification need the original game image as a base)

source/mkw/Patch/PatchOperation.py

@@ -261,16 +261,28 @@ class PatchOperation:
             """
             # remove the last extension of the filename
             patched_file_name = file_name.rsplit(".", 1)[0]
-            patch_content = BytesIO()
+            patch_content = BytesIO(img.encode_data(file_content.read(), self.encoding))
 
-            # write the encoded image into the file
-            patch_content.write(
-                img.encode_data(file_content.read(), self.encoding)
-            )
-
-            patch_content.seek(0)
             return patched_file_name, patch_content
 
+    class ImageDecoder(Operation):
+        """
+        decode a game image to a image file
+        """
+
+        type = "img-decode"
+
+        def patch(self, patch: "Patch", file_name: str, file_content: IO) -> (str, IO):
+            """
+            Patch a file to encode it in a game image file
+            :param patch: the patch that is applied
+            :param file_name: the file_name of the file
+            :param file_content: the content of the file
+            :return: the new name and new content of the file
+            """
+            patch_content = BytesIO(img.decode_data(file_content.read()))
+            return f"{file_name}.png", patch_content
+
     class BmgEditor(Operation):
         """
         edit a bmg

source/wt/img.py

@@ -24,6 +24,22 @@ def encode_data(image_data: bytes, transform: str = "CMPR") -> bytes:
     return stdout
 
 
+@better_wt_error(tools_path)
+def decode_data(image_data: bytes) -> bytes:
+    """
+    Convert the game image data and return the decoded image data
+    :param image_data: the original game image data
+    :return: the decoded image data
+    """
+    process = _tools_run_popen("DECODE", "-", "--DEST", "-")
+    stdout, _ = process.communicate(input=image_data)
+
+    if process.returncode != 0:
+        raise WTError(tools_path, process.returncode)
+
+    return stdout
+
+
 class IMGPath:
     """
     Represent a path to a normal image, that can be converted into game image data