STR #1013: yet another attempt at fixing the precision count in Fl_Valuator. Does this work for everyone?

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.1@4558 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

1 files changed, 15 insertions, 8 deletions

diff --git a/src/Fl_Valuator.cxx b/src/Fl_Valuator.cxx
index b6065a4c8..e8431f10b 100644
--- a/src/Fl_Valuator.cxx
+++ b/src/Fl_Valuator.cxx
@@ -124,16 +124,23 @@ int Fl_Valuator::format(char* buffer) {
 
   // Figure out how many digits are required to correctly format the
   // value.
-  int i;
-  char temp[255], *ptr;
-  snprintf(temp, sizeof(temp), "%g", A/B);
-  if ((ptr = strchr(temp, '.')) != NULL)
-    i = strlen(ptr + 1);
-  else
-    i = 0;
+  int i, c = 0;
+  char temp[32], *ptr;
+  // output a number with many digits after the decimal point. This
+  // seems to be needed to get high precission
+  snprintf(temp, sizeof(temp), "%.12f", A/B);
+  // strip all trailing 0's
+  for (i=strlen(temp)-1; i>0; i--) {
+    if (temp[i]!='0') break;
+  }
+  // count digits until we find the decimal point (or comma or whatever
+  // letter is set in the current locale)
+  for (; i>0; i--, c++) {
+    if (!isdigit(temp[i])) break;
+  }
 
   // MRS: THIS IS A HACK - RECOMMEND ADDING BUFFER SIZE ARGUMENT
-  return snprintf(buffer, 128, "%.*f", i, v);
+  return snprintf(buffer, 128, "%.*f", c, v);
 }
 
 //