1 files changed, 148 insertions, 0 deletions
diff --git a/libs/basic_games/games/stalkeranomaly/XRIO.py b/libs/basic_games/games/stalkeranomaly/XRIO.py
new file mode 100644
index 0000000..870f28d
--- /dev/null
+++ b/libs/basic_games/games/stalkeranomaly/XRIO.py
@@ -0,0 +1,148 @@
+# -*- encoding: utf-8 -*-
+from __future__ import annotations
+
+import io
+import struct
+from typing import Optional, Tuple
+
+from .XRMath import IVec3
+
+
+class XRReader:
+    def __init__(self, buffer: bytes):
+        self._buffer = buffer
+        self._pos = 0
+
+    def __len__(self) -> int:
+        return len(self._buffer)
+
+    def _read(self, size: int) -> Tuple[bytes, int]:
+        pos = min(len(self._buffer), self._pos + size)
+        buffer = self._buffer[self._pos : pos]
+        return (buffer, pos)
+
+    def read(self, size: int = -1) -> bytes:
+        if size < 0:
+            size = len(self._buffer)
+        if len(self._buffer) <= self._pos:
+            return b""
+        (buffer, pos) = self._read(size)
+        self._pos = pos
+        return buffer
+
+    def peek(self, size: int = -1) -> bytes:
+        if size < 0:
+            size = len(self._buffer)
+        if len(self._buffer) <= self._pos:
+            return b""
+        (buffer, _pos) = self._read(size)
+        return buffer
+
+    def seek(self, pos: int, whence: int = io.SEEK_SET) -> int:
+        if whence == 0:
+            if pos < 0:
+                raise ValueError(f"negative seek position {pos}")
+            self._pos = pos
+        elif whence == 1:
+            self._pos = max(0, self._pos + pos)
+        elif whence == 2:
+            self._pos = max(0, len(self._buffer) + pos)
+        else:
+            raise ValueError("unsupported whence value")
+        return self._pos
+
+    def elapsed(self) -> int:
+        return len(self._buffer) - self._pos
+
+    def eof(self) -> bool:
+        return self.elapsed() <= 0
+
+    def u8(self) -> int:
+        return int(struct.unpack("<B", self.read(1))[0])
+
+    def s8(self) -> int:
+        return int(struct.unpack("<b", self.read(1))[0])
+
+    def u16(self) -> int:
+        return int(struct.unpack("<H", self.read(2))[0])
+
+    def s16(self) -> int:
+        return int(struct.unpack("<h", self.read(2))[0])
+
+    def u32(self) -> int:
+        return int(struct.unpack("<I", self.read(4))[0])
+
+    def s32(self) -> int:
+        return int(struct.unpack("<i", self.read(4))[0])
+
+    def u64(self) -> int:
+        return int(struct.unpack("<Q", self.read(8))[0])
+
+    def s64(self) -> int:
+        return int(struct.unpack("<q", self.read(8))[0])
+
+    def bool(self) -> bool:
+        return bool(struct.unpack("<?", self.read(1))[0])
+
+    def float(self) -> float:
+        return float(struct.unpack("<f", self.read(4))[0])
+
+    def str(self) -> str:
+        chars = bytearray()
+        while not self.eof():
+            c = self.read(1)
+            if c == b"\x00":
+                return str(chars, "utf-8")
+            else:
+                chars += c
+        return ""
+
+    def fvec3(self) -> IVec3:
+        (f1, f2, f3) = struct.unpack("<fff", self.read(12))
+        return IVec3(f1, f2, f3)
+
+
+class XRStream(XRReader):
+    def __init__(self, buffer: bytes):
+        super().__init__(buffer)
+        self.last_pos: int = 0
+
+    def find_chunk(self, id: int) -> Optional[int]:
+        dw_type = 0
+        dw_size = 0
+        success = False
+        if self.last_pos != 0:
+            self.seek(self.last_pos)
+            dw_type = self.u32()
+            dw_size = self.u32()
+            if (dw_type & (~(1 << 31))) == id:
+                success = True
+
+        if not success:
+            self.seek(0)
+            while not self.eof():
+                dw_type = self.u32()
+                dw_size = self.u32()
+                if (dw_type & (~(1 << 31))) == id:
+                    success = True
+                    break
+                else:
+                    self.seek(dw_size, io.SEEK_CUR)
+
+            if not success:
+                self.last_pos = 0
+                return None
+
+        if (self._pos + dw_size) < len(self._buffer):
+            self.last_pos = self._pos + dw_size
+        else:
+            self.last_pos = 0
+
+        return dw_size
+
+    def open_chunk(self, id: int) -> Optional[XRStream]:
+        size = self.find_chunk(id)
+        if size and size != 0:
+            data = self.read(size)
+            return XRStream(data)
+        return None