1 files changed, 126 insertions, 0 deletions
diff --git a/nxcomp/Alpha.cpp b/nxcomp/Alpha.cpp
new file mode 100644
index 000000000..931101495
--- /dev/null
+++ b/nxcomp/Alpha.cpp
@@ -0,0 +1,126 @@
+/**************************************************************************/
+/*                                                                        */
+/* Copyright (c) 2001, 2010 NoMachine, http://www.nomachine.com/.         */
+/*                                                                        */
+/* NXCOMP, NX protocol compression and NX extensions to this software     */
+/* are copyright of NoMachine. Redistribution and use of the present      */
+/* software is allowed according to terms specified in the file LICENSE   */
+/* which comes in the source distribution.                                */
+/*                                                                        */
+/* Check http://www.nomachine.com/licensing.html for applicability.       */
+/*                                                                        */
+/* NX and NoMachine are trademarks of Medialogic S.p.A.                   */
+/*                                                                        */
+/* All rights reserved.                                                   */
+/*                                                                        */
+/**************************************************************************/
+
+#include "Misc.h"
+#include "Unpack.h"
+#include "Alpha.h"
+
+#define PANIC
+#define WARNING
+#undef  TEST
+#undef  DEBUG
+
+int UnpackAlpha(unsigned char method, unsigned char *src_data, int src_size,
+                    unsigned char *dst_data, int dst_size)
+{
+  if (*src_data == 0)
+  {
+    if (dst_size != src_size - 1)
+    {
+      #ifdef TEST
+      *logofs << "UnpackAlpha: PANIC! Invalid destination size "
+              << dst_size << " with source " << src_size
+              << ".\n" << logofs_flush;
+      #endif
+
+      return -1;
+    }
+
+    #ifdef TEST
+    *logofs << "UnpackAlpha: Expanding " << src_size - 1
+            << " bytes of plain alpha data.\n" << logofs_flush;
+    #endif
+
+    memcpy(dst_data, src_data + 1, src_size - 1);
+
+    return 1;
+  }
+
+  unsigned int check_size = dst_size;
+
+  int result = ZDecompress(&unpackStream, dst_data, &check_size,
+                               src_data + 1, src_size - 1);
+
+  if (result != Z_OK)
+  {
+    #ifdef PANIC
+    *logofs << "UnpackAlpha: PANIC! Failure decompressing alpha data. "
+            << "Error is '" << zError(result) << "'.\n"
+            << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Failure decompressing alpha data. "
+         << "Error is '" << zError(result) << "'.\n";
+
+    return -1;
+  }
+  else if (check_size != (unsigned int) dst_size)
+  {
+    #ifdef PANIC
+    *logofs << "UnpackAlpha: PANIC! Size mismatch in alpha data. "
+            << "Resulting size is " << check_size << " with "
+            << "expected size " << dst_size << ".\n"
+            << logofs_flush;
+    #endif
+
+    cerr << "Error" << ": Size mismatch in alpha data. "
+         << "Resulting size is " << check_size << " with "
+         << "expected size " << dst_size << ".\n";
+
+    return -1;
+  }
+
+  #ifdef TEST
+  *logofs << "UnpackAlpha: Decompressed " << src_size - 1
+          << " bytes to " << dst_size << " bytes of alpha data.\n"
+          << logofs_flush;
+  #endif
+
+  return 1;
+}
+
+int UnpackAlpha(T_alpha *alpha, unsigned char *dst_data,
+                    int dst_size, int big_endian)
+{
+  unsigned int count = dst_size >> 2;
+
+  unsigned int i;
+
+  int shift;
+
+  if (count != alpha -> entries)
+  {
+    #ifdef WARNING
+    *logofs << "UnpackAlpha: WARNING! Not applying the alpha with "
+            << count << " elements needed and " << alpha -> entries
+            << " available.\n" << logofs_flush;
+    #endif
+
+    return 0;
+  }
+
+  shift = (big_endian == 1 ? 0 : 3);
+  
+  for (i = 0; i < count; i++)
+  {
+    *(dst_data + shift) = *(alpha -> data + i);
+
+    dst_data += 4;
+  }
+
+  return 1;
+}