1439136 - Broken subpixel blending on Amazon with WebRender enabled

Status: RESOLVED WORKSFORME

(Core :: Graphics: WebRender, defect, P2)

Description

[Clemens Eisserer]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180217100053

Steps to reproduce:

1. Logged into my amazon.de account


Actual results:

2. the text of the product recommendations (but not elsewhere) was rendered with broken subpixel blending.


Expected results:

results consistent with the "traditional" opengl backend

Comment 1

[Clemens Eisserer]

Attachment: amazon_opengl.png

Comment 2

[Clemens Eisserer]

Attachment: amazon_webrender.png

Comment 3

[Clemens Eisserer]

System: Fedora 27, Mesa-17.2.4, AMD Kaveri APU 7650k (radeonsi driver):

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD KAVERI (DRM 2.50.0 / 4.15.3-300.fc27.x86_64, LLVM 5.0.0) (0x1313)
    Version: 17.2.4
    Accelerated: yes
    Video memory: 2048MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1
Memory info (GL_ATI_meminfo):
    VBO free memory - total: 2047 MB, largest block: 2047 MB
    VBO free aux. memory - total: 2043 MB, largest block: 2043 MB
    Texture free memory - total: 2047 MB, largest block: 2047 MB
    Texture free aux. memory - total: 2043 MB, largest block: 2043 MB
    Renderbuffer free memory - total: 2047 MB, largest block: 2047 MB

Comment 4

[Jeff Muizelaar [:jrmuizel]]

Weird. Any chance you can reproduce this Lee?

Comment 5

[Lee Salzman [:lsalzman]]

Not able to reproduce this. But the screenshots are bizarre, like the subpixel layout has gone totally bonkers, almost like an endian-swap or other swizzle. Jonathan, ever seen something like elsewhere?

Comment 6

[Jonathan Kew [:jfkthame]]

No, that doesn't look quite like anything I recognize. It seems kinda like the text has been overpainted multiple times, maybe with the alpha channel mishandled in some way.... dunno really. Yes, maybe somehow subpixels have been scrambled, though it doesn't quite look like a straightforward endian swap to me.

What's really odd, though, is that it only messes with certain text; the heading in the screenshots looks unaffected. I don't see anything in the styling there that seems particularly weird.

Comment 7

[Clemens Eisserer]

I can still reproduce it with the current nightly version on my system - which in the meantime has been updated to:
Linux 4.15.7

Extended renderer info (GLX_MESA_query_renderer):
    Vendor: X.Org (0x1002)
    Device: AMD KAVERI (DRM 2.50.0 / 4.15.7-300.fc27.x86_64, LLVM 5.0.1) (0x1313)
    Version: 17.3.6
    Accelerated: yes
    Video memory: 1024MB
    Unified memory: no
    Preferred profile: core (0x1)
    Max core profile version: 4.5
    Max compat profile version: 3.0
    Max GLES1 profile version: 1.1
    Max GLES[23] profile version: 3.1

Comment 8

[Clemens Eisserer]

Attachment: same issue with updated mesa stack on 4k monitor

Comment 9

[Clemens Eisserer]

to me it seems almost like reading the destiontion pixels when blending fails.
The edges of the glyphs are blended against a black destination surface, while it actually is white.

Comment 10

[Glenn Watson [:gw] | PTO until 29th April]

Appears to be getting correct subpixel rendering for me now.