On 16 February 2013 10:58, Brian Paul <bri...@vmware.com> wrote: > This fixes a regression from ab74fee5e1a3fc3323b7238278637b232c2d0d95. > When we use the clip coordinate to compute the screen-space interpolation > factor, we need to first apply the divide-by-zero step to the clip > coordinate. >
I think you mean "divide-by-W" :) > > Fixes http://bugs.freedesktop.org/show_bug.cgi?id=60938 > > Note: This is a candidate for the 9.1 branch. > --- > src/gallium/auxiliary/draw/draw_pipe_clip.c | 11 ++++++++--- > 1 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/src/gallium/auxiliary/draw/draw_pipe_clip.c > b/src/gallium/auxiliary/draw/draw_pipe_clip.c > index 7b879c4..3110809 100644 > --- a/src/gallium/auxiliary/draw/draw_pipe_clip.c > +++ b/src/gallium/auxiliary/draw/draw_pipe_clip.c > @@ -167,12 +167,17 @@ static void interp( const struct clip_stage *clip, > { > int k; > t_nopersp = t; > - for (k = 0; k < 2; k++) > + /* find either in.x != out.x or in.y != out.y */ > + for (k = 0; k < 2; k++) { > if (in->clip[k] != out->clip[k]) { > - t_nopersp = (dst->clip[k] - out->clip[k]) / > - (in->clip[k] - out->clip[k]); > + /* do divide by W, then compute linear interpolation factor */ > + float in_coord = in->clip[k] / in->clip[3]; > + float out_coord = out->clip[k] / out->clip[3]; > + float dst_coord = dst->clip[k] / dst->clip[3]; > + t_nopersp = (dst_coord - out_coord) / (in_coord - out_coord); > break; > } > + } > } > > /* Other attributes > -- > 1.7.3.4 > > _______________________________________________ > mesa-dev mailing list > mesa-dev@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/mesa-dev >
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