Added tng_compress trajectory compression algorithms

1 files changed, 73 insertions, 0 deletions

diff --git a/src/compression/vals16.c b/src/compression/vals16.c
new file mode 100644
index 0000000..6a8e7e7
--- /dev/null
+++ b/src/compression/vals16.c
@@ -0,0 +1,73 @@
+/* This code is part of the tng compression routines.
+ *
+ * Written by Daniel Spangberg
+ * Copyright (c) 2010, 2013, The GROMACS development team.
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the License, or (at your option) any later version.
+ */
+
+
+#include "vals16.h"
+
+/* Coding 32 bit ints in sequences of 16 bit ints. Worst case
+   the output is 3*nvals long. */
+void Ptngc_comp_conv_to_vals16(unsigned int *vals,int nvals,
+			 unsigned int *vals16, int *nvals16)
+{
+  int i;
+  int j=0;
+  for (i=0; i<nvals; i++)
+    {
+      if (vals[i]<=0x7FFFU)
+	vals16[j++]=vals[i];
+      else
+	{
+	  unsigned int lo=(vals[i]&0x7FFFU)|0x8000U;
+	  unsigned int hi=vals[i]>>15;
+	  vals16[j++]=lo;
+	  if (hi<=0x7FFFU)
+	    vals16[j++]=hi;
+	  else
+	    {
+	      unsigned int lohi=(hi&0x7FFFU)|0x8000U;
+	      unsigned int hihi=hi>>15;
+	      vals16[j++]=lohi;
+	      vals16[j++]=hihi;
+	    }
+	}
+    }
+#if 0
+  /* Test that things that detect that this is bad really works. */
+  vals16[0]=0;
+#endif
+  *nvals16=j;
+}
+
+void Ptngc_comp_conv_from_vals16(unsigned int *vals16,int nvals16,
+			   unsigned int *vals, int *nvals)
+{
+  int i=0;
+  int j=0;
+  while (i<nvals16)
+    {
+      if (vals16[i]<=0x7FFFU)
+	vals[j++]=vals16[i++];
+      else
+	{
+	  unsigned int lo=vals16[i++];
+	  unsigned int hi=vals16[i++];
+	  if (hi<=0x7FFFU)
+	    vals[j++]=(lo&0x7FFFU)|(hi<<15);
+	  else
+	    {
+	      unsigned int hihi=vals16[i++];
+	      vals[j++]=(lo&0x7FFFU)|((hi&0x7FFFU)<<15)|(hihi<<30);
+	    }
+	}
+    }
+  *nvals=j;
+}