On 16.03.2009 14:03, Keith Whitwell wrote: > >> The only hardware that can support this extension that doesn't already >> have support for ARB_fragment_shader is G400 and R100. Convince me that >> we really want to clutter Mesa with shit extensions to add functionality >> to support 10 year old hardware. you forgot to mention the R200 - not that it makes much difference, and I wouldn't know exactly how to implement this on these chips, though it probably wouldn't be too difficult. There's also potentially other chips (GeForce3 comes to mind - nvidia used to expose this functionality through NV_texture_shader, which is a way more complicated extension).
> > Roland can probably give a much better technical dissection of the > alternatives, but I'll make a stab at it. > > I think the real value in the extension is the signed texture format it > exposes. Right now, applications which want to use that type of texture > are already checking for this extension. If we want to support such > applications, the most straight-forward way to do that is implement this > extension. > > Additionally, signed texture formats are available and heavily used in > other graphics API's, so porting such apps to linux and GL or supporting > them through translation layers is simplified if similar functionality > is available in the local version of GL. > > While it would be possible to advertise this extension but only > implement it partially - ie just provide the texture format support but > not implement the entrypoints, etc., I'd consider that pretty poor > practice and wouldn't be inclined to support such an approach. The extension isn't ideal for only exposing the texture format since by definition a texture lookup doesn't really deliver rgba results and it cannot be really used with fragment shaders. But it is necessary if you want to use d3d-style bump mapping without translating everything to use shaders. We're working on a new extension for supporting a signed texture format (which will only be useful with shaders). Roland ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
