anchor.diff:  , libvdpau
   , enableTextureFloats ? false # Texture floats are patented, see docs/patents.txt
   , enableR600LlvmCompiler ? true, libelf
  -, enableExtraFeatures ? false # add ~15 MB to mesa_drivers; some problems building currently
  +, enableExtraFeatures ? false # not maintained
   }:
   
   if ! stdenv.lib.lists.elem stdenv.system stdenv.lib.platforms.mesaPlatforms then
  
positive.code:       $out/lib/vdpau \
        $out/lib/libxatracker*
  
    '' + /* now fix references in .la files */ ''
      sed "/^libdir=/s,$out,$drivers," -i \
    '' + optionalString enableExtraFeatures ''
        `#$drivers/lib/libXvMC*.la` \
        $drivers/lib/libOSMesa*.la \
        $drivers/lib/gallium-pipe/*.la \
    '' + ''
        $drivers/lib/libgallium.la \
  
negative.code:     "--enable-xa" # used in vmware driver
      "--enable-gles1" "--enable-gles2"
      "--enable-vdpau"
      "--enable-osmesa" # used by wine
  
      "--with-dri-drivers=i965,r200,radeon"
      ("--with-gallium-drivers=i915,nouveau,r300,r600,svga,swrast"
  