On Wed, Nov 01, 2006 at 11:03:18AM +0100, Abdelrazak Younes wrote: > Martin Vermeer wrote: > >On Wed, 2006-11-01 at 08:26 +0100, Asger Ottar Alstrup wrote: > >>Abdelrazak Younes wrote: > >>>No, I was interested in the details of QLPainter::text(), especially the > >>>QPainter::drawText(). This info was not there. It is in your newer > >>>screenshot. > >>This profile matches what I found on Windows. > >> > >>>If we manage to speed-up Qt drawing operation, we will win. I can't > >>>imagine that there is nothing we can't do. There must be some Qt > >>>settings. > >>As I said before, I believe the best is to draw less. There is > >>absolutely no need for redrawing the entire screen on every key press. > > > >Yes, I notice this too. I did the work in rowpainter to draw only one > >row when needed (no paragraph break) or one paragraph when needed (when > >the paragraph's height didn't change). Now, all that has been messed up. > > > >Just run LyX with -dbg PAINTING and you'll see what I mean. It prints a > >"#" for every row re-painted, and a "." for every paragraph re-painted. > > > >It paints WAY too much now. I believe the code in rowpainter is still > >good... somehow updates are triggered unnecessarily elsewhere. > > The problem lies in the new Paint strategy. Andre eliminated the backing > pixmap. This means that all expose() calls are simply ignored.
No, this is not the explanation. See my other mail.
> The nice thing about it is that we draw directly on screen thus
> eliminating the transfer of the old backing pixmap onto the screen.
> On the other hand, the screen estate is not saved. This means that, if
> part of the WorkArea is masked, the widget will receive a paint Event
> and everything will be redrawn, not only the part that is not masked.
>
> I have some idea how to solve that problem.
I don't think it's on the critical path.
> >>I just added a debug statement to QLPainter.C:
> >>
> >> if (isDrawingEnabled()) {
> >> lyxerr << "draw " << std::string(str.toUtf8()) << "
> >> at " << x << "," << y << std::endl;
> >> drawText(x, y, str);
> >> }
> >>
> >>You should try this. On every cursor blink, we redraw the entire screen.
> >
> >I can confirm this. Not sure it's the entire screen though... sometimes
> >it appears to be even more :-(
>
> What do you mean by more? Could you elaborate?
It paints also up to one paragraph above and one below the screen. (No essential
difference)
> I will fix the cursor.
OK good
> >
> >>This might be a result of André's reorganisation of how we paint, or it
> >>may be an old bug. In any case, it is very wasteful.
> >>
> >>If I disable cursor blinking by adding a return in WorkArea::showCursor,
> >>the result is that we redraw exactly once per key press.
> >
> >Confirmed, sort of (there may be several redraws per keypress)
>
> Yes, the number of lyx-redraws depend now on the number of Qt
> paintEvent(). paintEvent() can be triggered by other thing than
> WorkArea::redraw().
>
> Abdel.
- Martin
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