Dear Oliver,
I don’t agree. It is true that the white lines are only present in Preview when the smoothing is enabled and that they are not present in Adobe Acrobat, but this does not mean that we can’t do anything.
Ferhue showed in this post [url]Test other language
that the lines are gone in Preview if one produces a pdf from the canvas saved in tex format.
He also showed that there is a difference in the xml code of both the pdf produced directly from root and the one from tex.
The last one is rendered perfectly in Preview while the first one isn’t.
That means that something can be done with the attributes of the fill areas (the bins) when creating the pdf from the canvas. Something that produces an output compatible with the Preview rendering.
I guess that we would just need to change some defaults in root code when printing colored areas in a pdf.
Perhaps, changing this will solve the problem in Preview while not affecting the behavior in other viewers.
I have been exploring in TPDF.cxx, but I couldn’t find anything…
Would you tell me which class is the responsible of actually drawing the 2D histograms with col option into a pdf?
I need to fix this because one can’t use Preview without the smoothing: Everything becomes ugly!
I have also noticed that there are no white lines when one draws the histogram with the “cont” option.
In any case I’ll be glad if you can tell me where to look in the ROOT code to try to fix it.
Cheers