From: Marius Predut <marius.pre...@intel.com> 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.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=82668 Signed-off-by: Marius Predut <marius.pre...@intel.com> --- src/mesa/drivers/dri/i965/gen6_sf_state.c | 12 +++++++++--- 1 file changed, 9 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..1bed444 100644 --- a/src/mesa/drivers/dri/i965/gen6_sf_state.c +++ b/src/mesa/drivers/dri/i965/gen6_sf_state.c @@ -367,9 +367,15 @@ 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; + + if (!(multisampled_fbo && ctx->Multisample.Enabled)) { + if (ctx->Line.SmoothFlag && ctx->Line.Width <=1) + line_width_u3_7 = 0; + } else { + if (line_width_u3_7 == 0) + line_width_u3_7 = 1; + } + dw3 |= line_width_u3_7 << GEN6_SF_LINE_WIDTH_SHIFT; } if (ctx->Line.SmoothFlag) { -- 1.7.9.5 _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
