Christian Buchner wrote: > Hi, > > I've been looking into using 32 bit floating point textures as render > targets ( for example by creating an FBO with a 32 bit RGBA texture ). > On further research I found that the extension "ARB_texture_float" is > not currently provided by Mesa. I do run Mesa HEAD using a GEM enabled > Linux kernel and the latest i915 XOrg and DRM drivers (all HEAD > releases). > > Are there any plans to support floating point textures in Mesa in the > future? These are really important for GPGPU (general purpose > computing) because in combination with fragment shaders these can be > used to perform single precision floating point arithmetics. > > After enabling the extension I found that the i915 DRI driver was not > yet able to map floating point texture types to a hardware ID. I know > that the Intel 950GMA core is well capable of using floating point > textures, as for example on an Intel Mac Mini running MAC OS X Leopard > I am successfully running fragment shaders on these textures. > > So I am having two issues that I would like to resolve > > a) the fact that Mesa doesn't currently support the GL_RGBA32F_ARB > internalFormat when creating textures (and frame buffer objects) > > b) the i915 driver (and probably all other Mesa DRI drivers for that > matter) do not yet handle GL_RGBA32F_ARB the texture format. > > I`ve partially solved the first problem by patching Mesa accordingly > but now I've hit a snag with the DRI driver. > > Looking into the i915_reg.h header file I find references to page > numbers in some hardware manual, however it is not clearly stated > which manual was used. There are unfortunately no defines for hardware > IDs matching floating point textures defined in this header file. > > So I downloaded the 915G and 945GM chipset manuals from the Intel > developer site, but the page numbers given in the header files do not > match those I looked up in these Intel documents. Would anyone here > know which developer manual describes the graphics registers of the > 950GMA graphics core - in particular for the texture stages? If I can > get hold of that manual I might try to add the missing texture > capabilities myself (being a fearless hacker...) > > Is there a separate mailing list for the Intel 3D drivers in Mesa?
If you read the "IP Status" section of the GL_ARB_texture_float spec (http://www.opengl.org/registry/specs/ARB/texture_float.txt) you'll see the reason why Mesa doesn't support this extension yet. Perhaps a work-around similar to what's done for s3tc texture compression would be the way forward... -Brian ------------------------------------------------------------------------------ This SF.net email is sponsored by: SourcForge Community SourceForge wants to tell your story. http://p.sf.net/sfu/sf-spreadtheword _______________________________________________ Mesa3d-dev mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mesa3d-dev
