[scribus-dev] Scribus CTL

Khaled Hosny khaledhosny at eglug.org
Tue Mar 22 19:23:37 UTC 2016

On Tue, Mar 22, 2016 at 07:36:08PM +0100, Craig Bradney wrote:
> >> 
> >> Some rendering comparisons:
> >> 
> >> We need to do this side by side comparison of trunk vs host/boxes.
> >> 3 issues to note at first:
> >> - character positioning is higher in the frame in boxes
> >> - Not as many characters fit in the frames in boxes
> > 
> > We couldn’t see such differences in the file you sent, see the diff
> > images in Dawood’s reply.
> At lower zoom levels I can see them, at higher ones, no. 

I can check again, but if it depends on zoom level so it might be
related to the different font rasterisation strategy we are using.

> > 
> >> - The right aligned paragraphs have the top line missing a character/aren’t aligned
> > 
> > It was indeed that the last glyph in the line was always remove, should
> > be fixed now.
> Now thats better.
> We need some more complex tests apart from the file I created. Ideas
> on how we can do this?

We have a collection of files we use for testing here, not complex but
they try to test different features. I’ll try to collect and send them.

> Also, what about any ideas on rendering speed comparisons?

I have no idea how to measure that, but I worked on optimizing the rendering
(after profiling was callgrind) fearing that ours was too slow, to
discover that we are actually feel much faster than trunk (text
selection, for example is snappier and does not lag behind as the cursor

Currently (on my HiDPI machine) most of the rendering time (~30% of the
all application profile) is spent in QPainter::drawPixmap(). I believe
rewriting ScPainter on top of QPainter can make it much faster, instead
of the current code which redraws the whole canvas as a pixmap on each
draw event. But that is a small project of its own.


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