On Dec 29, 2016 4:58 PM, "Kenneth Graunke" <kenn...@whitecape.org> wrote:
On Thursday, December 29, 2016 1:25:57 PM PST Chad Versace wrote: > Fixes tests 'dEQP-GLES3.functional.texture.mipmap.*.generate.rgba5551*' on > Intel Broadwell 0x1616. > > The GL 4.5 spec describes the algorithm of glGenerateMipmap as: > > The contents of the derived images are computed by repeated, filtered > reduction of the level base image. [...] No particular filter algorithm is > required, though a box filter is recommended as the default filter. > > Consider a texture for which all pixels are identical at level 0. > From the spec's description above, one may reasonably assume that the "filtered > reduction" of level 0 produces a new miplevel for which again all pixels are > identical. For any 2x2 subspan of identical pixels, it is difficult to see how > the "filtered reduction" of that subspan can produce a pixel that differs from > the source pixels. > > Dithering during _mesa_meta_GenerateMipmap() violated that reasonable > assumption. > > Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99210 > Cc: mesa-sta...@lists.freedesktop.org > --- > src/mesa/drivers/common/meta_generate_mipmap.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/src/mesa/drivers/common/meta_generate_mipmap.c b/src/mesa/drivers/common/meta_generate_mipmap.c > index bbe9d6d886..55093e9553 100644 > --- a/src/mesa/drivers/common/meta_generate_mipmap.c > +++ b/src/mesa/drivers/common/meta_generate_mipmap.c > @@ -182,6 +182,7 @@ _mesa_meta_GenerateMipmap(struct gl_context *ctx, GLenum target, > > _mesa_meta_begin(ctx, MESA_META_ALL & ~MESA_META_DRAW_BUFFERS); > _mesa_ColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); > + _mesa_Disable(GL_DITHER); > > /* Choose between glsl version and fixed function version of > * GenerateMipmap function. > Good catch! That makes sense. I verified that the meta begin flags will restore the dither mode at the end. Die meta! Die! Reviewed-by: Kenneth Graunke <kenn...@whitecape.org> _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/mesa-dev
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