RE: stupid (?) C question

[Neil Brown]

Hi Pete,

Why not pass a pointer to the midX part of the structure and pass that to a
routine that sets the values as per your code fragment.

{
...

        case midi1:

                Function(&prefs.mid1, &save, &handle, &prefs);
                break;

...

        case midiX:

                Function(&prefs.midX, &save, &handle, &prefs);
                break;

...
}

void Function(ptrMidX, ptrSave, ptrHandle, ptrPrefs)
{
        if (ptrSave)
        {
                ptrMidX->chan       = ptrPrefs->chan;
                ptrMidX->instrument = ptrPrefs->instrument;
                ptrMidX->vel        = ptrPrefs->vel;
                ptrMidX->pitch      = ptrPrefs->pitch;
                ptrMidX->range      = ptrPrefs->range;

                ptrSave = false;
        }
        else
        {
                SetFieldInt(instrumentlbl, ptrMidX->instrument + 1);
                SetFieldInt(pitchlbl,      ptrMidX->pitch + 1);
                SetFieldInt(vellbl,        ptrMidX->vel + 1);
                SetFieldInt(rangelbl,      ptrMidX->range + 1);
                SetFieldInt(chanlbl,       ptrMidX->chan + 1);
        }

        ptrHandled = true;

        return;
}

Neil D. Brown
Software Manager
Applied Interactive Ltd.
Phone: +44 (0)1234 756049/50
Fax  : +44 (0)1234 756138

-----Original Message-----
From: pete moss [mailto:[EMAIL PROTECTED]]
Sent: 01 July 1999 06:31
To: [EMAIL PROTECTED]
Subject: stupid (?) C question


i am not the best C programmer, so this might be a stupid question but:

in my app, i have 16 presets.  here is the code for one of the preset
button handlers:

case midi1:
if (save)
        {
        prefs.mid1.chan=prefs.chan;
        prefs.mid1.instrument=prefs.instrument;
        prefs.mid1.vel=prefs.vel;
        prefs.mid1.pitch=prefs.pitch;
        prefs.mid1.range=prefs.range;
        save = false;
        }
else
        {
        SetFieldInt(instrumentlbl, prefs.mid1.instrument+1);
        SetFieldInt(pitchlbl, prefs.mid1.pitch+1);
        SetFieldInt(vellbl, prefs.mid1.vel+1);
        SetFieldInt(rangelbl, prefs.mid1.range+1);
        SetFieldInt(chanlbl, prefs.mid1.chan+1);
        }
handled = true;
break;

it either sets the fields with a saved value or saves the current values
into a preset.  i have sixteen version of this (16 presets), with mid1,
mid2, mid3, mid4, etc, so my code is quite huge.  is there a
way to do this in a function where i could pass prefs.midX instead of
having 16 copies of nearly the same code?

i seem to remember someone recently saying that one shouldnt pass
structs in function parameters.  if that is bad, then how can i take 16
code segments with nearly the same code and make 1 code segment with the
ability to fill in the changing part?

any ptrs?

:P