From dd569f0fa4758fe9dfd771b68518c37fe2e356b7 Mon Sep 17 00:00:00 2001
From: Ingo Ruhnke <grumbel@gmx.de>
Date: Thu, 19 May 2011 19:52:10 +0200
Subject: [PATCH] Added endian clean unpack routines

---
 src/unpack.hpp       | 104 +++++++++++++++++++++++++++++++++++++++++++
 test/unpack_test.cpp |  37 +++++++++++++++
 2 files changed, 141 insertions(+)
 create mode 100644 src/unpack.hpp
 create mode 100644 test/unpack_test.cpp

diff --git a/src/unpack.hpp b/src/unpack.hpp
new file mode 100644
index 0000000..57f5f74
--- /dev/null
+++ b/src/unpack.hpp
@@ -0,0 +1,104 @@
+/*
+**  Xbox360 USB Gamepad Userspace Driver
+**  Copyright (C) 2011 Ingo Ruhnke <grumbel@gmx.de>
+**
+**  This program is free software: you can redistribute it and/or modify
+**  it under the terms of the GNU General Public License as published by
+**  the Free Software Foundation, either version 3 of the License, or
+**  (at your option) any later version.
+**
+**  This program is distributed in the hope that it will be useful,
+**  but WITHOUT ANY WARRANTY; without even the implied warranty of
+**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**  GNU General Public License for more details.
+**
+**  You should have received a copy of the GNU General Public License
+**  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef HEADER_XBOXDRV_ENDIAN_HPP
+#define HEADER_XBOXDRV_ENDIAN_HPP
+
+#include <stdint.h>
+
+namespace unpack {
+
+inline bool is_big_endian()
+{
+  union {
+    uint32_t i;
+    char c[4];
+  } bint = {0x01020304};
+
+  return bint.c[0] == 1;
+}
+
+inline uint16_t swap16(uint16_t v)
+{
+  return (v<<8) | (v>>8);
+}
+
+inline uint32_t swap32(uint32_t v)
+{
+  return (v<<24) | ((v<<8) & 0x00ff0000) | ((v>>8) & 0x0000ff00) | (v>>24);
+}
+
+
+inline int16_t int16le(uint8_t* data)
+{
+  if (is_big_endian()) return swap16(*reinterpret_cast<int16_t*>(data));
+  else                 return *reinterpret_cast<int16_t*>(data);
+}
+
+inline uint16_t uint16le(uint8_t* data)
+{
+  if (is_big_endian()) return swap16(*reinterpret_cast<uint16_t*>(data));
+  else                 return *reinterpret_cast<uint16_t*>(data);
+}
+
+
+inline int32_t int32le(uint8_t* data)
+{
+  if (is_big_endian()) return swap32(*reinterpret_cast<int32_t*>(data));
+  else                 return *reinterpret_cast<int32_t*>(data);
+}
+
+inline uint32_t uint32le(uint8_t* data)
+{
+  if (is_big_endian()) return swap32(*reinterpret_cast<uint32_t*>(data));
+  else                 return *reinterpret_cast<uint32_t*>(data);
+}
+
+
+
+inline int16_t int16be(uint8_t* data)
+{
+  if (!is_big_endian()) return swap16(*reinterpret_cast<int16_t*>(data));
+  else                  return *reinterpret_cast<int16_t*>(data);
+}
+
+inline uint16_t uint16be(uint8_t* data)
+{
+  if (!is_big_endian()) return swap16(*reinterpret_cast<uint16_t*>(data));
+  else                  return *reinterpret_cast<uint16_t*>(data);
+}
+
+
+inline int32_t int32be(uint8_t* data)
+{
+  if (!is_big_endian()) return swap32(*reinterpret_cast<int32_t*>(data));
+  else                  return *reinterpret_cast<int32_t*>(data);
+}
+
+inline uint32_t uint32be(uint8_t* data)
+{
+  if (!is_big_endian()) return swap32(*reinterpret_cast<uint32_t*>(data));
+  else                  return *reinterpret_cast<uint32_t*>(data);
+}
+
+
+} // namespace unpack
+
+#endif
+
+/* EOF */
diff --git a/test/unpack_test.cpp b/test/unpack_test.cpp
new file mode 100644
index 0000000..5c92230
--- /dev/null
+++ b/test/unpack_test.cpp
@@ -0,0 +1,37 @@
+/*
+**  Xbox360 USB Gamepad Userspace Driver
+**  Copyright (C) 2011 Ingo Ruhnke <grumbel@gmx.de>
+**
+**  This program is free software: you can redistribute it and/or modify
+**  it under the terms of the GNU General Public License as published by
+**  the Free Software Foundation, either version 3 of the License, or
+**  (at your option) any later version.
+**
+**  This program is distributed in the hope that it will be useful,
+**  but WITHOUT ANY WARRANTY; without even the implied warranty of
+**  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+**  GNU General Public License for more details.
+**
+**  You should have received a copy of the GNU General Public License
+**  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <iostream>
+
+#include "unpack.hpp"
+
+int main(int argc, char** argv)
+{
+  uint8_t data[] = { 0x04, 0x03, 0x02, 0x01 };
+
+  std::cout << std::hex;
+  std::cout << "uint16be: " << unpack::uint16be(data) << std::endl;
+  std::cout << "uint16le: " << unpack::uint16le(data) << std::endl;
+
+  std::cout << "uint32be: " << unpack::uint32be(data) << std::endl;
+  std::cout << "uint32le: " << unpack::uint32le(data) << std::endl;
+
+  return 0;
+}
+
+/* EOF */