Re: another theory

[Stefan <e tuli gmx de>]

some minutes ago I observed the bahaviour on drawing text with 
gdk_pixbuf_render_to_drawable_alpha() in diagdkrenderer.c:draw_string(). 
Supporting that, I used a fix alpha threshold in 'pixels[i*stride+j*4+3] 
= graybitmap[i*rowstride+j];', i.e. 128. And what I explored is, that in 
the situations the font is drawn ugly, now the intensity of the color 
incresed. So ... there are some regions are still drawn and are 
overdrawn by this method. The transparency then causes the uglyness and 
egdy font.

So the problem is actually a problem with uninvalidated, still present 
regions in renderer->pixmap which have to be cleared, before redrawing 
the text again. The update-area logic doesn't pay attention on this.

regards, Stefan Bolus

Tom Kast wrote:

> i believe that changing 2.0 to 0.1 in ddisplay_add_update_pixels()
> fixes the right-click error conditions that we have defined thus far. 
> hats off to you -- thanks!
>
> ...on to your second error condition, "creepy on movement"...  
>
> i have tried to reproduce it (with size_x/0.1) and i have not been
> able to.  any more detail?
>
> if i understand correctly, "creepy on movement" refers to:
>  
>
> > Now try this ... . Drag the third object slowly from the bottom of one of the other objects to it's top. Even 
> > if the third object is actually behind the other objects the font is badly redrawn. Seems like there's a bad 
> > offset anywhere.
> >    
>
> tk
>
> On Mar 31, 2005 8:48 AM, Stefan <e tuli gmx de> wrote:
>  
>
> > I could "isolate" the behaviour of the problem to app/display.c in
> > ddisplay_add_update_pixels(). To problem seems to be caused by the
> > size_x/y stuff. Making them bigger reduces the problem. i.e. using the
> > 0.1 instead 2.0 in the following lines. The font gets further on ugly,
> > but not in all previously counted situations. So I believe the problem
> > is interlocked with the second problem I showed up in my previous
> > messages, because now the font only gets ugly if the described situation
> > is given (font gets creepy on movement).
> >
> > I'm actually not a dia developer, so I don't think to have the knowledge
> > to find the problem. So I hope Tom is further on interested in. :)
> >
> > regards, Stefan Bolus
> > _______________________________________________
> > Dia-list mailing list
> > Dia-list gnome org
> > http://mail.gnome.org/mailman/listinfo/dia-list
> > FAQ at http://www.gnome.org/projects/dia/faq.html
> > Main page at http://www.gnome.org/projects/dia
> >
> >
> >    
> _______________________________________________
> Dia-list mailing list
> Dia-list gnome org
> http://mail.gnome.org/mailman/listinfo/dia-list
> FAQ at http://www.gnome.org/projects/dia/faq.html
> Main page at http://www.gnome.org/projects/dia
>
>
>