"accu-timer": some changes to repeat_timeout that seem to make it accurate

on Unix and Win32 at speeds up to 500000 timeouts/second (and 700000 on
Linux), and within about .001% as accurate as the system clock.

Fix to Fl_Valuator::step() by Guillermo Andrade.


git-svn-id: file:///fltk/svn/fltk/branches/branch-1.0@1354 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

2 files changed, 19 insertions, 10 deletions

diff --git a/src/Fl.cxx b/src/Fl.cxx
index b0275a939..2296e0c74 100644
--- a/src/Fl.cxx
+++ b/src/Fl.cxx
@@ -1,5 +1,5 @@
 //
-// "$Id: Fl.cxx,v 1.24.2.37 2001/01/15 23:51:37 spitzak Exp $"
+// "$Id: Fl.cxx,v 1.24.2.38 2001/01/21 06:00:58 spitzak Exp $"
 //
 // Main event handling code for the Fast Light Tool Kit (FLTK).
 //
@@ -57,13 +57,15 @@ int		Fl::e_length;
 //
 
 int Fl::event_inside(int x,int y,int w,int h) /*const*/ {
-  int mx = event_x() - x;
-  int my = event_y() - y;
+  int mx = e_x - x;
+  int my = e_y - y;
   return (mx >= 0 && mx < w && my >= 0 && my < h);
 }
 
 int Fl::event_inside(const Fl_Widget *o) /*const*/ {
-  return event_inside(o->x(),o->y(),o->w(),o->h());
+  int mx = e_x - o->x();
+  int my = e_y - o->y();
+  return (mx >= 0 && mx < o->w() && my >= 0 && my < o->h());
 }
 
 ////////////////////////////////////////////////////////////////
@@ -110,13 +112,19 @@ static void elapse_timeouts() {
   }
 }
 
+// Continuously-adjusted error value, this is a number <= 0 for how late
+// we were at calling the last timeout. This appears to make repeat_timeout
+// very accurate even when processing takes a significant portion of the
+// time interval:
+static double missed_timeout_by;
+
 void Fl::add_timeout(double time, Fl_Timeout_Handler cb, void *arg) {
   elapse_timeouts();
   repeat_timeout(time, cb, arg);
 }
 
 void Fl::repeat_timeout(double time, Fl_Timeout_Handler cb, void *arg) {
-  elapse_timeouts();
+  time += missed_timeout_by; if (time < -.05) time = 0;
   Timeout* t = free_timeout;
   if (t) free_timeout = t->next;
   else t = new Timeout;
@@ -207,6 +215,7 @@ double Fl::wait(double time_to_wait) {
     while ((t = first_timeout)) {
       if (t->time > 0) break;
       // The first timeout in the array has expired.
+      missed_timeout_by = t->time;
       // We must remove timeout from array before doing the callback:
       void (*cb)(void*) = t->cb;
       void *arg = t->arg;
@@ -772,5 +781,5 @@ void Fl_Window::flush() {
 }
 
 //
-// End of "$Id: Fl.cxx,v 1.24.2.37 2001/01/15 23:51:37 spitzak Exp $".
+// End of "$Id: Fl.cxx,v 1.24.2.38 2001/01/21 06:00:58 spitzak Exp $".
 //
diff --git a/src/Fl_Valuator.cxx b/src/Fl_Valuator.cxx
index b066514b4..eaea57c2a 100644
--- a/src/Fl_Valuator.cxx
+++ b/src/Fl_Valuator.cxx
@@ -1,5 +1,5 @@
 //
-// "$Id: Fl_Valuator.cxx,v 1.5.2.2 2000/06/05 21:20:58 mike Exp $"
+// "$Id: Fl_Valuator.cxx,v 1.5.2.3 2001/01/21 06:00:59 spitzak Exp $"
 //
 // Valuator widget for the Fast Light Tool Kit (FLTK).
 //
@@ -41,13 +41,13 @@ Fl_Valuator::Fl_Valuator(int X, int Y, int W, int H, const char* L)
   B = 1;
 }
 
-const double epsilon = 1e-12 ;
+const double epsilon = 4.66e-10;
 
 void Fl_Valuator::step(double s) {
   if (s < 0) s = -s;
   A = rint(s);
   B = 1;
-  while (fabs(s-A/B) > epsilon) {B *= 10; A = rint(s*B);}
+  while (fabs(s-A/B) > epsilon && B<=(0x7fffffff/10)) {B *= 10; A = rint(s*B);}
 }
 
 void Fl_Valuator::precision(int p) {
@@ -123,5 +123,5 @@ int Fl_Valuator::format(char* buffer) {
 }
 
 //
-// End of "$Id: Fl_Valuator.cxx,v 1.5.2.2 2000/06/05 21:20:58 mike Exp $".
+// End of "$Id: Fl_Valuator.cxx,v 1.5.2.3 2001/01/21 06:00:59 spitzak Exp $".
 //