<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW --- - [Steam] Implement GLSL 1.30 on Ironlake Mobile/HM 55 (Gen5)" href="https://bugs.freedesktop.org/show_bug.cgi?id=59187#c5">Comment # 5</a> on <a class="bz_bug_link bz_status_NEW " title="NEW --- - [Steam] Implement GLSL 1.30 on Ironlake Mobile/HM 55 (Gen5)" href="https://bugs.freedesktop.org/show_bug.cgi?id=59187">bug 59187</a> from <a class="email" href="mailto:stereotype441@gmail.com" title="Paul Berry <stereotype441@gmail.com>"> Paul Berry</a> <pre>(In reply to <a href="show_bug.cgi?id=59187#c4">comment #4</a>) > (In reply to <a href="show_bug.cgi?id=59187#c3">comment #3</a>) > > In #60481 Ian Romanick said Source-Games would depend on GL3.. > > I demonstrated that the Source-Games don't need full GL3, but just depend on > > GLSL 1.30 [0]. I run CS:S using Mesa-9.0's softpipe driver (OpenGL 2.1 & > > GLSL 1.30). So there is probably just some GLSL 1.30 functionallity missing, > > which could be implemented as a software fallback or using the graphics > > hardware (if supported). > > > > Where would we have to implement those missing GLSL 1.30 functions? > > > > [0] > > <a href="https://github.com/ValveSoftware/Source-1-Games/issues/19#issuecomment">https://github.com/ValveSoftware/Source-1-Games/issues/19#issuecomment</a>- > > 13801640 > > I can't speak to whether Source games require GL 3.0 or not, but here's a > rough list of what would need to be added to the i965 driver in order to > support GLSL 1.30 on Ironlake (this is based on section 1.2.1 "Summary of > Functionality differences from version 1.2" of the GLSL 1.30 spec): > > - Texture size queries* > - Texture arrays* > - Texture offsetting* > - Explicit LOD and derivative controls* > - "noperspective" and "flat" interpolation qualifiers > - gl_VertexID > > *Some of these may already work on IronLake--I'm not terribly familiar with > the texturing code. Argh, sorry. I hit submit before I was finished. One more item: - gl_ClipDistance Of all of these items, the trickiest one is gl_ClipDistance, since it requires modifying the Gen4/5-specific "clip" program (brw_clip.c) to perform clipping in a manner more like what happens in Gen6+ (using clip distances provided by the vertex shader rather than performing dot products in the clip program). This is not a project for the faint of heart--the brw_clip.c code isn't terribly well tested, and has a lot of tricky corner cases in it. Once those things are done, we would of course want to run the driver through a pretty thorough round of piglit testing to make sure we hadn't missed any small details.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>