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.
--
2.11.0
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
