We will also need GL_ARB_color_buffer_float anyway and it shouldn't infringe anything. This issue of the spec nails it: <pre>>22. Should this extension require a floating-point color buffer > or texture? > > RESOLVED: No. This extension provides the ability to pass an > unclamped color between vertex and fragment programs/shaders, > which may be useful. This was possible prior to this extension, > by passing the color data as texture coordinates or named > varying variables (for vertex/fragment shaders). </pre> Yes, the color varyings between vertex and fragment shaders should be clamped by default (see also piglit/glsl-clamp-vertex-color). And concerning fragment color clamping, we should provide a way for a user to be able to write and read unclamped color values once we have GL_EXT_texture_snorm, the subset of which is already implemented in Mesa. Marek <div class="gmail_quote">On Fri, Dec 24, 2010 at 3:58 AM, Eric Anholt <<a href="mailto:eric@anholt.net">eric@anholt.net</a>> wrote: <blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;"> <div><div></div><div class="h5">On Wed, 22 Dec 2010 22:12:18 +0100, Marek Olšák <<a href="mailto:maraeo@gmail.com">maraeo@gmail.com</a>> wrote: > Hi, > > in case anyone is interested, I have implemented the floating-point formats > from GL_ARB_texture_rg, namely R16F, RG16F, R32F, RG32F, for both core Mesa > and st/mesa. The commits are here: > > <a href="http://cgit.freedesktop.org/%7Emareko/mesa/commit/?h=floating2&id=a68e9890451140f493d09f1dd2dd8dfc77ed29de" target="_blank">http://cgit.freedesktop.org/~mareko/mesa/commit/?h=floating2&id=a68e9890451140f493d09f1dd2dd8dfc77ed29de</a> > <a href="http://cgit.freedesktop.org/%7Emareko/mesa/commit/?h=floating2&id=7216311b553bcc9331492d4d03a25d36348567d5" target="_blank">http://cgit.freedesktop.org/~mareko/mesa/commit/?h=floating2&id=7216311b553bcc9331492d4d03a25d36348567d5</a> > > FWIW there is also experimental support of floating-point rendering for > r300g in that 'floating2' branch, and trivial support of > GL_ATI_texture_float. It's based on Luca's 'floating' branch. > > BTW, is there any progress on the floating-point patent matter? We should > probably also take into account non-US Linux distributions like some > variants of Mint, because they don't have to care about software patents and > they already freely distribute patented stuff like some multimedia codecs. I > think they would use whatever Mesa has to offer, patented or not. </div></div>We should just put enabling patented extensions under --enable configure flags and call it good. </blockquote></div>