1 files changed, 75 insertions, 0 deletions
diff --git a/lib/scaled-num.c b/lib/scaled-num.c
new file mode 100644
index 0000000..cf4a18f
--- /dev/null
+++ b/lib/scaled-num.c
@@ -0,0 +1,75 @@
+/* scaled-num.c: conversions on ``scaled'' numbers, which are a 32-bit
+   word with 16 bits of fraction.
+
+Copyright (C) 1992 Free Software Foundation, Inc.
+
+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 2, 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, write to the Free Software
+Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
+
+#include "config.h"
+
+#include "scaled-num.h"
+
+
+#define SCALED_UNITY (1 << 16)	/* 2^16, represents 1.00000.  */
+
+
+/* This prints a scaled number, rounded to five digits.  */
+
+void
+print_scaled (scaled s)
+{
+  scaled delta;
+
+  if (s < 0)
+    {				/* Print sign, if negative. */
+      putchar ('-');
+      s = -s;
+    }
+
+  printf ("%u", s / SCALED_UNITY);   /* Print integer part. */
+  putchar ('.');
+
+  s = 10 * (s % SCALED_UNITY) + 5;
+  delta = 10;
+
+  do
+    {
+      if (delta > SCALED_UNITY)
+        s += 0100000 - (delta / 2);	/* Round the last digit. */
+
+      printf ("%c", '0' + (s / SCALED_UNITY));
+      s = 10 * (s % SCALED_UNITY);
+      delta *= 10;
+    }
+  while (s > delta);
+}
+
+
+const real
+scaled_to_real (scaled s)
+{
+  real r = (real) s / SCALED_UNITY;
+
+  return r;
+}
+
+
+const scaled
+real_to_scaled (real r)
+{
+  scaled s = r * SCALED_UNITY;
+
+  return s;
+}