On 24.10.2012 18:45, Albert Astals Cid wrote: > El Dimarts, 23 d'octubre de 2012, a les 06:51:20, Adam Reichold va escriure: > Hello, > > On 23.10.2012 00:56, Albert Astals Cid wrote: >>>> El Dissabte, 20 d'octubre de 2012, a les 17:36:22, Thomas Freitag >>>> >>>> va escriure: >>>>> On 16.10.2012 22:57, Albert Astals Cid wrote: >>>>>> El Dilluns, 15 d'octubre de 2012, a les 07:15:51, Thomas >>>>>> Freitag va >>>> >>>> escriure: >>>>>>> On 14.10.2012 22:58, Albert Astals Cid wrote: >>>>>>>> El Diumenge, 14 d'octubre de 2012, a les 19:41:26, Thomas >>>>>>>> Freitag va >>>>>> >>>>>> escriure: >>>>>>>>> On 14.10.2012 17:21, Albert Astals Cid wrote: >>>>>>>>>> El Diumenge, 14 d'octubre de 2012, a les 13:47:29, >>>>>>>>>> Thomas Freitag va >>>>>>>> >>>>>>>> escriure: >>>>>>>>>>> Hi folks! >>>>>>>>>>> >>>>>>>>>>> Is there anybody in the community who wants the >>>>>>>>>>> possibility to simulate overprint in qt library? With >>>>>>>>>>> the implementation of DeviceN support in splash this >>>>>>>>>>> is quite easy now, so I can upload a patch. >>>>>>>>>> >>>>>>>>>> Sure, why not? Let's see the patch :-) >>>>>>>>> >>>>>>>>> Okay, here it is. >>>>>>>> >>>>>>>> The two new methods are missing @since markers (and also i >>>>>>>> think the documentation of the two methods could be a bit >>>>>>>> more explanatory) >>>>>>> >>>>>>> @since: I thought that You insert it when You commit it. If I >>>>>>> would insert 0.22.0 You have to change it if You will not >>>>>>> have the time to commit it :-) or I need to change it and >>>>>>> have to upload a new patch if You will not have the time :-( >>>>>> >>>>>> Well, if you do it, it's less work i have to do and thus it's >>>>>> easier i'll have time ;-) >>>>> >>>>> Because I removed these two new methods now there is no need to >>>>> comment them anymore :-) But I introduced a new (static) method >>>>> "okToUseOverprint" which just proofs if poppler is compiled with >>>>> SPLASH_CMYK, and there I add the @since comment now. >>>>> >>>>>>> Explanatory: Okay, but this will be hard. For those who know >>>>>>> what overprint is the documentation is self-explanatory, for >>>>>>> others I need to write reams. What's about to insert the link >>>>>>> to http://en.wikipedia.org/wiki/Overprinting? >>>>>> >>>>>> To be honest doesn't seem to make things much clearer to me :D >>>>> >>>>> Okay, let me try to explain it in my own words: First of all, in >>>>> the normal behaviour, if something is painted everything >>>>> previously painted at this place is knocked out. This is rather >>>>> simplified, because we ignore functionality like transparency, >>>>> blending modes etc. Now let us have a look at the printing >>>>> process with 4 different colour plates Cyan, Magenta, Yellow and >>>>> Black. Without setting the overprint mode, the behaviour is the >>>>> same: if something is painted everything previously painted on >>>>> every plate is knocked out. But when overprint mode is enabled, >>>>> and i.e. in a DeviceN colorspace with only one process colour, >>>>> let us assume Cyan, the Magenta, Yellow and Black plates kept >>>>> untouched and only previously painted objects on the Cyan plate >>>>> at this position are knocked out. But when You paint in >>>>> DeviceCMYK, the behaviour remains the same (all is knocked out) >>>>> even with overprint on, unless You set overprint mode to true in >>>>> addition. With overprint mode true You need to look at the colour >>>>> components You use for painting: if the a component is 0 the >>>>> corresponding colour plate is left untouched again, if it is not >>>>> 0 it will be knocked out again on this colour plate. If there is >>>>> a additional spot colour plate, it is similar: overprint false: >>>>> everything is knocked out, overprint true: if You paint with >>>>> process colours only this spot colour plate is left untouched, if >>>>> You paint with this spot colour, the process colour plates remain >>>>> untouched but on this spot colour plate previously painted >>>>> objects are knocked out. As I said, this is rather simplified, >>>>> there are special rules for images, blending modes and so on and >>>>> so on. A complete explanation can be found in the PDF >>>>> specification. As overprint just works on colour plates, You'll >>>>> see no effects when You print in RGB as on a monitor, therefore >>>>> You have to simulate the effects (overprint preview :-) ) if You >>>>> want to see them on a monitor. >>>>> >>>>>> Ok, let's leave the docu as it is >>>>>> >>>>>>>> Also why are you calling it "overprint preview"? How is it >>>>>>>> a preview? >>>>>>> >>>>>>> To be honest, I haven't really thought about that. Probably I >>>>>>> choose that name because it is also introduced in >>>>>>> GlobalParams with that name. But also in the acrobat reader >>>>>>> preferences it is called "Use overprint preview". And because >>>>>>> not all RIPs support it (i.e. RGB printers) it is indeed >>>>>>> something like a preview (for RIPs which support it). >>>>>> >>>>>> Ok, let's leave it with that name (but maybe make it a >>>>>> RenderingHint as Adam suggests?). >>>>> >>>>> I tried to understand what You meant with RenderingHint and made >>>>> it, hopefully it is what You meant. I attach the changed patches >>>>> (poppler and okular). >>>> >>>> Looks good, I've made some changes (to try to make the roundtrip >>>> faster if you agree to them) >>>> >>>> Rename Document::okToUseOverprint to isOverprintPreviewSupported >>>> like we had for the cms stuff > > This seems a better way to name it as the old one would suggest it is > a per-document property which it is not. > >>>> Put back the thing that creates the splashoutputdev and do the same >>>> we do with antialias in the hint changes but for overprint (I don't >>>> really see why we need this code shuffling around, so i'm trying to >>>> minimize the diff size which hopefully minimizes the impact for >>>> other features than this one) > > While the change is not strictly necessary, the new > Document::setRenderHints, Document::getOuputDev and also > DocumentData::setPaperColor show why it makes things much simpler. > (Looking at the patch: If we add "delete m_outputDev;" to the end of > the latter shouldn't there be a "m_outputDev = NULL;" as well?) > >> Yes, there is a = NULL missing, i'll add it when i find some time, note i'm >> on >> a business travel until Nov 1st so my time is ultra limited until then. > > > I also think that there should not be any fallout from this change > since the member "DocumentData::m_outputDev" is gone afterwards, hence > any code that still relies on a pre-created output device would have > been spotted by the compiler. > >> I'm not oposing to that change, it's just a separate change, not needed for >> this feature, let's keep features/fixes/cleanups in separate commits :-) > >> Cheers, >> Albert
Sorry, I misunderstood you there. The policy sounds very reasonable. Thanks for a lot of work with limited resources! Regards, Adam. > (And there is also Thomas' threading patch which would also introduce > those changes to the output device creation.) > >>>> Do not set the overprint hint if isOverprintPreviewSupported is >>>> false > > Makes sense. > >>>> Rename the getXBGRPtr to convertToXBGRPtr since it does a lot more >>>> than what you'd expect a getter to do > > I agree. > > Best regards, Adam. > >>>> What do you think? >>>> >>>> Cheers, Albert >>>> >>>>> Cheers, Thomas >>>>> >>>>>> Cheers, >>>>>> >>>>>> Albert >>>>>> >>>>>>>> Given that overprint only works if defined(SPLASH_CMYK) you >>>>>>>> should make the setter return a boolean that says if the >>>>>>>> set worked or not (i.e. make it fail if >>>>>>>> !defined(SPLASH_CMYK)) >>>>>>> >>>>>>> Gotcha. I thought about that and disable / enable the option >>>>>>> in okular if the format generator doesn't support it. But >>>>>>> because I'm not familiar enough with okular I defered it and >>>>>>> then forgot it... I'll insert it in QT when I get answers to >>>>>>> the other points. >>>>>>> >>>>>>> Cheers, Thomas >>>>>>> >>>>>>>> Cheers, >>>>>>>> >>>>>>>> Albert >>>>>>>> >>>>>>>>> In a few places it has already a similar implementation >>>>>>>>> than in bug 50992 (thread safe), because changing the >>>>>>>>> overprint option also meant that we need a different >>>>>>>>> SplashOutputDev instance. But You probably also want to >>>>>>>>> test it in okular? Even if we are here not on an okular >>>>>>>>> list, I attach the okular patch here, too. Also here, it >>>>>>>>> has already the changes from bug 50992. But because >>>>>>>>> POPPLER_QT_THREADSAFE is not defined here, it doesn't >>>>>>>>> make any difference, so I let these changes as they are. >>>>>>>>> BTW, I'm not really familiar with qt programming, so most >>>>>>>>> changes in okular are more or less a (hopefully) best >>>>>>>>> guess. >>>>>>>>> >>>>>>>>> Cheers, Thomas >>>>>>>>> >>>>>>>>>> Cheers, >>>>>>>>>> >>>>>>>>>> Albert >>>>>>>>>> >>>>>>>>>>> For everybody who doesn't know anything about >>>>>>>>>>> overprint I attach three screenshots which shows the >>>>>>>>>>> implementation in okular. (This is not fake, I made a >>>>>>>>>>> small apprentice piece today morning :-) ) >>>>>>>>>>> >>>>>>>>>>> Cheers, Thomas >>>>>>>>>> >>>>>>>>>> _______________________________________________ poppler >>>>>>>>>> mailing list [email protected] >>>>>>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>>>>>>> >>>>>>>>>> . >>>>>>>> >>>>>>>> _______________________________________________ poppler >>>>>>>> mailing list [email protected] >>>>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>>>>> >>>>>>>> . >>>>>>> >>>>>>> _______________________________________________ poppler >>>>>>> mailing list [email protected] >>>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>>> >>>>>> _______________________________________________ poppler mailing >>>>>> list [email protected] >>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler >>>>>> >>>>>> . >>>>>> >>>>>> >>>>>> _______________________________________________ poppler mailing >>>>>> list [email protected] >>>>>> http://lists.freedesktop.org/mailman/listinfo/poppler > >> _______________________________________________ >> poppler mailing list >> [email protected] >> http://lists.freedesktop.org/mailman/listinfo/poppler > _______________________________________________ > poppler mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/poppler > _______________________________________________ poppler mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/poppler
