Hi Damon I think I found the reason. I thought I had made sure that the pixbufs were placed exactly at a pixel boundary (converting position in canvas coordinate to pixel, rounding the pixel, then back to canvas coordinates).
they werent all of them. Now that I fix that it seems to have solved problem. Sorry for the noise, and thanks for your help, --daniel On Wed, Oct 16, 2013 at 10:16 AM, D M German <d...@uvic.ca> wrote: > > Hi Damon, > > Damon> On Tue, 2013-10-15 at 23:27 -0700, dmg wrote: > >> I forgot to add. I have been fixing our code to make sure the pixbuf > >> is always placed in a pixel boundary, with respect to the top,corner > >> of the canvas. > >> > >> My hypothesis for the blurring is that the scrolling seems to place > >> it in an offset of the visible canvas that is a subpixel coordinate, > >> making it blurry. > >> > >> what would you recommend is a way to fix this? > > Damon> I think GooCanvas only scrolls by integer numbers of pixels - it moves > Damon> around a child GdkWindow to do the scrolling, and that can only be > done > Damon> in pixels. > > Damon> So I'm not sure what is causing your problem. Both pictures look a bit > Damon> blurry to me. Maybe the image is being scaled a tiny bit accidentally? > > I thought so originally, so I exported the pixbuf and compared it > against what is on the screen. > > Look at these files: > > http://turingmachine.org/~dmg/temp/goocanvas/ > > original is the pixbuf that is to be rendered. > > before is the goocanvas with that pixbuf when it looks "blurry". > > after is the goocanvas with the pibxuf when it looks good. > > I made crops that show it more (see directory crops). The difference is > subtle. > > The only difference between "before" and "after" is pressing the down key > twice. I am almost certain we don't do anything when the down key is > pressed. > > thanks again for any insight into this, > > --daniel > > > Damon> Damon > > > > -- > Daniel M. German "A coin symbolizes our free will" > El ZahÃr, Jorge Luis Borges > http://turingmachine.org/ > http://silvernegative.com/ > dmg (at) uvic (dot) ca > replace (at) with @ and (dot) with . > > -- --dmg --- Daniel M. German http://turingmachine.org ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60135031&iu=/4140/ostg.clktrk _______________________________________________ Xournal-devel mailing list Xournal-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xournal-devel
