Hi, On Friday, December 30, 2011 00:09:20 Csaba Halász wrote: > I wonder if there is an open standard counterpart that can do the same > as the dds compression? Or is the whole idea patented? (Eww, too broad > software patents are the work of the devil).
No, Sadly. It is all about an OpenGL extension that could be exposed or not. If it is exposed you are allowed to provide texture images in the precompressed format. If this is not exposed you are not allowed and the implementation may behave undefined. This is perfectly legal for an OpenGL implementation - the usual extension behaviour. By providing these precompressed data blobs without checking for this extension is an applications fault. Ok, what to do if we detect that we cannot feed the implementation with these blobs? We could try to decompress the blobs? ---> No, patent infringement!!! Just feed the blobs? ---> No, the driver may behave undefined - at least it does not work as expected. So, what can we do? I can see several approaches: * Just do not use the patented compression stuff. The precomputed mipmaps could probably do the job of avoiding the hangs (hopefully? to be checked?). May be we could lower disk space usage by providing a dds.gz or similar wrapper? * If it's just the mipmaps. May be we can precompute the mipmaps using the cpu in the database loader thread. This would help all textures not only the ones that could be converted. May be this is the most generic solution. * Implement some kind of image lookup order that knows if the compressed files could be handled or not. On loading an image in case of available compression first try to find a dds file with the same name of the original one. That involves some 'magic' which often leads to problems but that could at least work. Other ideas? Also may be creative ones? Next step is to make sure that compression is not required to avoid the hangs. My favorite bet would be that then the new configure option regarding texture compression needs to be set to none. Greetings Mathias ------------------------------------------------------------------------------ Ridiculously easy VDI. With Citrix VDI-in-a-Box, you don't need a complex infrastructure or vast IT resources to deliver seamless, secure access to virtual desktops. With this all-in-one solution, easily deploy virtual desktops for less than the cost of PCs and save 60% on VDI infrastructure costs. Try it free! http://p.sf.net/sfu/Citrix-VDIinabox _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
