Re: mvwprintw

[Bob Rossi]

On Mon, Apr 03, 2006 at 02:24:01PM -0400, Thomas Dickey wrote:
> On Mon, 3 Apr 2006, Bob Rossi wrote:
> 
> >>>Hi Thomas,
> >>>
> >>>Sorry I haven't got to the bottom of this yet. Hopefully I'll find the
> >>>problem today. Since the debug doesn't seem to be helping to much here,
> >>>what's the lowest level function I should be debugging to determine why
> >>>my screen is getting corrupted?
> >>
> >>hmm - go back to my last explanation.  The screen is being corrupted
> >>because either ncurses or some other code is writing bad data.  If it is
> >>ncurses, you should be able to see it by tracing the low-level function
> >>PutAttrChar(), which is actually doing the output to the screen.  The
> >>trace you sent should have showed PutAttrChar(), but did not.
> >>
> >>I'd see why it did not, and fix that (perhaps I misread the trace-level).
> >>Then see if PutAttrChar() is getting bad data, or making it bad - there's
> >>one call to PUTC() in tty_update.c which is doing the work.
> >
> >OK, I'll do that. As a side note, is ncurses smart enough to only output
> >to the terminal the info that has changed, instead of the whole screen?
> 
> that's what it tries to do - it has an array curscr which records what it 
> last put on the screen, makes a newscr (the changed screen) from stdscr 
> and other windows.  But if another program - or another function - writes 
> to the screen, it can be confused.

I've also verified via a breakpoint that tty_update.c
 269  PUTC(CHDEREF(ch), SP->_ofp);    /* macro's fastest... */
does get called for normal char's like 'a', but not for arrow movements.

Bob Rossi