[LAU] Need some programming help.

[Tito Latini]

On Sun, Mar 02, 2014 at 11:18:30PM +0000, Will Godfrey wrote:
> What is even stranger is that if I compile and run the synth on an old
> version of debian there is no problem. However *exactly* the same image run on
> the same machine but with debian upgraded shows the fault.
> 
> A possibly significant difference is the change from FLTK V1.1 to V1.3 but
> looking on their website I can find nothing that would give a clue.

Now I'm using gcc-4.8.2 and I can reproduce the problem.

Only a rapid glance: with

/* From Fl_Valuator.cxx */
void Fl_Valuator::step(double s) {
  if (s < 0) s = -s;
  A = rint(s);
  B = 1;
  while (fabs(s-A/B) > epsilon && B<=(0x7fffffff/10)) {B *= 10; A = rint(s*B);}
}

there is a roundoff error but if we use the simplest

/* From Fl_Valuator.H */
void step(double a, int b) {A = a; B = b;}

the problem disappears

--- yoshimi-1.1.0~/src/UI/ADnoteUI.fl	2013-05-08 09:47:45.000000000 +0200
+++ yoshimi-1.1.0/src/UI/ADnoteUI.fl	2014-03-03 14:41:58.054425629 +0100
@@ -89,8 +89,9 @@
         } {}
         Fl_Value_Output detunevalueoutput {
           callback {o->value(getDetune((pars->VoicePar[nvoice].PDetuneType == 0) ? (pars->GlobalPar.PDetuneType) : (pars->VoicePar[nvoice].PDetuneType), 0, pars->VoicePar[nvoice].PDetune) * pars->getBandwidthDetuneMultiplier());}
-          xywh {265 5 45 20} labelsize 10 align 5 minimum -5000 maximum 5000 step 0.01 textfont 1 textsize 10
-          code0 {o->value(getDetune(pars->VoicePar[nvoice].PDetuneType, 0, pars->VoicePar[nvoice].PDetune) * pars->getBandwidthDetuneMultiplier());}
+          xywh {265 5 45 20} labelsize 10 align 5 minimum -5000 maximum 5000 textfont 1 textsize 10
+          code0 {o->step(0.01, 1);}
+          code1 {o->value(getDetune(pars->VoicePar[nvoice].PDetuneType, 0, pars->VoicePar[nvoice].PDetune) * pars->getBandwidthDetuneMultiplier());}
         }

[ ... censored for avoiding noise in LAU; the complete patch is in a private msg ]

Tito Latini