Brian Paul wrote: > 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...
Reading through the various Gallium drivers, I take it that we will support floating-point textures and surfaces, but *not* the relevant GL extensions. Actually, while we're on the subject, have we gotten any new permission for S3TC? ~ C. ------------------------------------------------------------------------------ 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
