MSH scene reading draft, no blender conversion yet

addons/io_scene_swbf_msh/msh_reader.py

@@ -0,0 +1,118 @@
+
+import io
+import struct
+
+class Reader:
+    def __init__(self, file, chunk_id: str, parent=None, indent=0):
+        self.file = file
+        self.size: int = 0
+        self.size_pos = None
+        self.parent = parent
+        self.header = chunk_id
+        self.indent = "  " * indent
+
+
+    def __enter__(self):
+        self.size_pos = self.file.tell()
+        self.file.seek(4,1) #skip header, will add check later
+        self.size = self.read_u32()
+
+        padding_length = 4 - (self.size % 4) if self.size % 4 > 0 else 0
+        self.end_pos = self.size_pos + padding_length + self.size + 8
+
+        print(self.indent + "Begin " + self.header + ", Size: " + str(self.size) + ", Pos: " + str(self.size_pos))
+
+        return self
+
+
+    def __exit__(self, exc_type, exc_value, traceback):
+        if self.size > self.MAX_SIZE:
+            raise OverflowError(f".msh file overflowed max size. size = {self.size} MAX_SIZE = {self.MAX_SIZE}")
+
+        print(self.indent + "End   " + self.header)
+        self.file.seek(self.end_pos)
+
+
+
+    def read_bytes(self,num_bytes):
+        return self.file.read(num_bytes)
+
+
+    def read_string(self):
+        last_byte = self.read_bytes(1)
+        result = b''
+        while last_byte[0] != 0x0:
+            result += last_byte
+            last_byte = self.read_bytes(1)
+
+        return result.decode("utf-8")
+
+    def read_i8(self, num=1):
+        buf = self.read_bytes(num)
+        result = struct.unpack(f"<{num}b", buf)
+        return result[0] if num == 1 else result
+
+    def read_u8(self, num=1):
+        buf = self.read_bytes(num)
+        result = struct.unpack(f"<{num}B", buf)
+        return result[0] if num == 1 else result
+
+    def read_i16(self, num=1):
+        buf = self.read_bytes(num * 2)
+        result = struct.unpack(f"<{num}h", buf)
+        return result[0] if num == 1 else result
+
+    def read_u16(self, num=1):
+        buf = self.read_bytes(num * 2)
+        result = struct.unpack(f"<{num}H", buf)
+        return result[0] if num == 1 else result
+
+    def read_i32(self, num=1):
+        buf = self.read_bytes(num * 4)
+        result = struct.unpack(f"<{num}i", buf)
+        return result[0] if num == 1 else result
+
+    def read_u32(self, num=1):
+        buf = self.read_bytes(num * 4) 
+        result = struct.unpack(f"<{num}I", buf)
+        return result[0] if num == 1 else result
+
+    def read_f32(self, num=1):
+        buf = self.read_bytes(num * 4)
+        result = struct.unpack(f"<{num}f", buf)
+        return result[0] if num == 1 else result
+
+
+
+    def read_child(self, child_id: str):
+        child = Reader(self.file, chunk_id=child_id, parent=self, indent=int(len(self.indent) / 2) + 1)
+        return child
+
+
+    def skip_bytes(self,num):
+        self.file.seek(num,1)
+
+
+    def peak_next_header(self):
+        buf = self.read_bytes(4);
+        self.file.seek(-4,1)
+        return buf.decode("utf-8")
+
+
+    def could_have_child(self):
+    	return self.end_pos - self.file.tell() >= 8
+
+
+
+    MAX_SIZE: int = 2147483647 - 8
+
+'''
+with open("/Users/will/Desktop/spacedoortest/spa1_prop_impdoor.msh", "rb") as tst_stream:
+    with Reader(tst_stream, "HEDR") as hedr:
+        print(hedr.peak_next_header())
+'''
+
+
+
+
+