On 03/19/2015 01:23 PM, Marius Predut wrote: > On SNB and IVB hw, for 1 pixel line thickness or less, > the general anti-aliasing algorithm give up - garbage line is generated. > Setting a Line Width of 0.0 specifies the rasterization of > the “thinnest” (one-pixel-wide), non-antialiased lines. > Lines rendered with zero Line Width are rasterized using > Grid Intersection Quantization rules as specified > by bspec section 6.3.12.1 Zero-Width (Cosmetic) Line Rasterization. > > v2: Daniel Stone: Fix = used instead of == in an if-statement. > v3: Ian Romanick: Use "._Enabled" flag insteed ".Enabled". > Add code comments. re-word wrap the commit message. > Add a complete bugzillia list. > Improve the hardcoded values to produce better results. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=28832 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=9951 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=27007 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=60797 > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=15006 > > Signed-off-by: Marius Predut <marius.pre...@intel.com> > --- > src/mesa/drivers/dri/i965/gen6_sf_state.c | 22 +++++++++++++++++++--- > 1 file changed, 19 insertions(+), 3 deletions(-) > > diff --git a/src/mesa/drivers/dri/i965/gen6_sf_state.c > b/src/mesa/drivers/dri/i965/gen6_sf_state.c > index f9d8d27..91b46d9 100644 > --- a/src/mesa/drivers/dri/i965/gen6_sf_state.c > +++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c > @@ -367,9 +367,25 @@ upload_sf_state(struct brw_context *brw) > float line_width = > roundf(CLAMP(ctx->Line.Width, 0.0, ctx->Const.MaxLineWidth)); > uint32_t line_width_u3_7 = U_FIXED(line_width, 7); > - /* TODO: line width of 0 is not allowed when MSAA enabled */ > - if (line_width_u3_7 == 0) > - line_width_u3_7 = 1; > + > + /* Line width of 0 is not allowed when MSAA enabled */ > + if (ctx->Multisample._Enabled) { > + if (line_width_u3_7 == 0) > + line_width_u3_7 = 1; > + } else if (ctx->Line.SmoothFlag && ctx->Line.Width <= 1.49) { ^^^^ Based on the previous version of the patch, isn't that supposed to be 1.0? Does this really not cause any piglit regressions?
> + /* For lines less than 1 pixel thick, the general > + * anti-aliasing algorithm gives up, and a garbage line is > + * generated. Setting a Line Width of 0.0 specifies the > + * rasterization of the "thinnest" (one-pixel-wide), > + * non-antialiased lines. > + * > + * Lines rendered with zero Line Width are rasterized using > + * Grid Intersection Quantization rules as specified by > + * bspec section 6.3.12.1 Zero-Width (Cosmetic) Line > + * Rasterization. > + */ > + line_width_u3_7 = 0; > + } > dw3 |= line_width_u3_7 << GEN6_SF_LINE_WIDTH_SHIFT; > } > if (ctx->Line.SmoothFlag) { > _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev