Hi Phil, > Verify your ARGB values that are uploaded are what you expect > and in the correct order required. > If they are then maybe its something in the xrender usage. Thanks a lot for looking into this, you were right of course and the values were in wrong order. It seems to be BGRA, however the Xrender-docs mention the data has to be in the format of a ZPIXMAP, so I guess I am doing it wrong anyway, and I should be using an XImage for uploading instead of self-allocated buffers. I guess I am just doing manual byte-swapping here ;)
It now looks quite ok: http://picasaweb.google.com/linuxhippy/Subpixel , but there is a difference, maybe because of the gamma adjustments. > The LUTs are used as pre and post conversions on the components > of the destination. They apply an inverse gamma adjustment on > the component that is read from the device, and a gamma adjustment > on the results before they are written back. > If Xrender does something like this at all, then it should have > some way for you to specify the gamma value. If it doesn't then > you'll either have to accept what it does, or if the results aren't > ideal, then Xrender can't be used at all for this case. > The effect of this is to increase or decrease the contrast, and > JDK needs this to be compatible with Windows behaviours. > So if you don't or can't apply it then the text rendered will be different > in contrast between the xrender and the other pipelines, but has > no bearing on the bigger problems you are seeing. Well maybe there are some tricks to get it done right, but the XRender-Api does not (at least not explicitly) mention anything like contrast or gamma, I'll ask on the xorg-list maybe there are other ways. I may have misunderstood the blog here (http://anholt.livejournal.com/32058.html), but if they optimize subpixel-text with just two composition operations, is there even any room for gamma adjustment? Thanks a lot, Clemens
