From: Ferdinand M. <kii...@gm...> - 2012-09-07 19:59:35
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The line antialiasing seems to depend on GL_LINE_SMOOTH. This feature is supported on some GPUs/drivers and not supported on others - for instance on my system (Radeon 6770) it doesn't work, so I get the same result with Stellarium 0.11.3 and current. GL_LINE_SMOOTH is currently enabled in GL1 backend, but it makes no difference on my system. From some googling, it sometimes requires particular blend mode settings and this might vary between GPUs. TLDR - antialiasing lines through GL_LINE_SMOOTH is not portable. You could do manual AA with lines-as-triangle-strips with lower alpha at edges - I use it in my game project - but it'd be too slow with the amount of lines Stellarium draws (and regenerates each frame). MSAA would probably work, but I don't think there's enough benefit for cost (FPS) - and not sure how to go about it with Qt (needs specific video mode IIRC). You can try forcing MSAA in your driver if it supports it to see if there's a difference. One quick hack I can do now is to round line coordinates passed to drawLine() to integers. I'll try that but not sure if it will mess up something. Text antialiasing has nothing to do with GL - that's done by Qt (the text bug wasn't lack of antialiasing either - it was wrong alpha/color values - aliased text looks different) On 9/7/12, Ferdinand Majerech <kii...@gm...> wrote: > Text drawing has been fixed (pushed to glexperiment). > > On 9/7/12, Ferdinand Majerech <kii...@gm...> wrote: >> About the smallest lines vanishing: This is a rasterization issue >> (when they are smaller than one pixel, they aren't drawn), and it >> happens in pre-merge Stellarium as well. It might be possible to >> decrease it by using antialiasing, but it can't be completely >> eliminated. >> >> On 9/7/12, Ferdinand Majerech <kii...@gm...> wrote: >>> Could you send me a link to the landscape you're using? >>> >>> It seems the problems are much more clearly visible there. >>> >>> I'll look at text drawing, it might be due to different font >>> parameters, not sure. >>> >>> On 9/7/12, Georg Zotti <geo...@un...> wrote: >>>> >>>> On Fr, 7.09.2012, 04:07, Ferdinand Majerech wrote: >>>>> The warning spam seems to be caused by the Windows release build >>>>> workaround. >>>>> >>>>> The compilation error is weird; AFAIK clock_t is standard C++. >>>>> >>>>> Maybe it could be fixed by removing std:: and including <time.h> (C >>>>> include) >>>>> instead. >>>> >>>> Yes, indeed all that is needed under Windows/MinGW is in >>>> StelUtils.cpp: >>>> line 1067: #include <time.h> >>>> and >>>> line 1086: clock_t cpuTime = clock(); >>>> >>>> >>>> OK, the texturing issue in perspective mode is solved. Stereographic >>>> mode >>>> is also much cleaner now, the big zigzags are mostly gone, but still >>>> the >>>> older solution has "rounder" distortion. Also the shortest lines in the >>>> compass marks plugin appear to vanish sometimes at max fov, and its red >>>> text is less clear than in the older version (aliasing?). >>>> >>>> In order to not only test stereographic, in these images: >>>> https://dl.dropbox.com/u/30092392/stellarium-STG-cyl_11.4.png >>>> https://dl.dropbox.com/u/30092392/stellarium-STG-cyl_glexperiment5623.png >>>> >>>> you see a cylindrical view. The vertical pillars mark north and south, >>>> on >>>> the north pillar (stretching into the image at top left) there is a >>>> circular disk with a hole marking the north celestial pole. I tried to >>>> get >>>> the same view in both versions. The tesselation of the landscape is >>>> still >>>> coarser or maybe the previous mapping did more than linear >>>> interpolation, >>>> but in the glexperiment image the distortion of pillar and disk appear >>>> to >>>> be stronger, and the text from the compass marks grainier (a bit >>>> aliased). >>>> >>>> Concerning text rendition: The object info at top left seems OK, but >>>> star >>>> and constellation labels are also aliased. >>>> >>>> Kind regards, >>>> Georg >>>> >>>> >>>> ------------------------------------------------------------------------------ >>>> Live Security Virtual Conference >>>> Exclusive live event will cover all the ways today's security and >>>> threat landscape has changed and how IT managers can respond. >>>> Discussions >>>> will include endpoint security, mobile security and the latest in >>>> malware >>>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>>> _______________________________________________ >>>> Stellarium-pubdevel mailing list >>>> Ste...@li... >>>> https://lists.sourceforge.net/lists/listinfo/stellarium-pubdevel >>>> >>> >> > |