Kenneth Graunke <kenn...@whitecape.org> writes: > The original Broadwater and Crestline platforms computed antialiased > line distances using "manhattan" distance, aka a + b = c. Eaglelake > and Cantiga added "true" distance, aka a^2 + b^2 = c^2, which is > obviously superior. >
The hardware docs are incredibly optimistic calling the improved AA line distance mode "true", in reality the strips and fans unit does something along the lines of 'max(a, b) + min(a, b) / 4' in "true" distance mode in order to avoid calculating the square root. At any rate, it's still better than manhattan. Series is: Reviewed-by: Francisco Jerez <curroje...@riseup.net> > The G45 documentation indicates that the old manhattan distance setting > is "only for debug purposes" and should never be used. The Ironlake > documentation no longer mentions AALINEDISTANCE_MANHATTAN, though it > does still contain the narrative about the feature. > > At any rate, we should use it. > > Cc: rafael.antogno...@intel.com > --- > src/mesa/drivers/dri/i965/brw_sf_state.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/src/mesa/drivers/dri/i965/brw_sf_state.c > b/src/mesa/drivers/dri/i965/brw_sf_state.c > index e919f5d14b4..d50ceb12133 100644 > --- a/src/mesa/drivers/dri/i965/brw_sf_state.c > +++ b/src/mesa/drivers/dri/i965/brw_sf_state.c > @@ -265,7 +265,7 @@ static void upload_sf_unit( struct brw_context *brw ) > /* _NEW_PROGRAM | _NEW_POINT */ > sf->sf7.use_point_size_state = !(ctx->VertexProgram.PointSizeEnabled || > ctx->Point._Attenuated); > - sf->sf7.aa_line_distance_mode = 0; > + sf->sf7.aa_line_distance_mode = brw->is_g4x || brw->gen == 5; > > /* might be BRW_NEW_PRIMITIVE if we have to adjust pv for polygons: > * _NEW_LIGHT > -- > 2.12.2 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/mesa-dev
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