602523 - Rendering artifacts when GLES acceleration enabled

Status: RESOLVED DUPLICATE of bug 609195

(Core :: Graphics, defect)

Description

[Oleg Romashin (:romaxa)]

With basic GL image rendering  or with optimized EGL Bind surface, we have strange rendering artifacts.

Probably we have bug in common GL code, and need to optimize common GL code for
GLES.

Comment 1

[Oleg Romashin (:romaxa)]

Attachment: screenshot

Comment 2

[Oleg Romashin (:romaxa)]

I have heard that it could be related to GL_REPEAT/CLAMP_TO_EDGE parameter... and wrong rendering in common GL code... but why then it works fine on GLX backend?

Comment 3

[Oleg Romashin (:romaxa)]

I'm using this patch:
https://bug597590.bugzilla.mozilla.org/attachment.cgi?id=481514
And starting Qt fennec with
MOZ_ACCELERATED=1 ./fennec -url about:license

...
It would be nice to check on android and confirm that it is common problem for all GLES implementations

Comment 4

[Oleg Romashin (:romaxa)]

Some comments about this issue:
********************
Based on the screenshots I can think of three possibilities:

1. You are doing copy scrolling and there is a synchronization problem that
somehow causes rows to be duplicated.

2. You are rendering very tall triangles, causing the accuracy of texture
coordinates to drop.

3. The vertical positioning of layers is somehow incorrect so that the full
surface contents are not filled in for every frame, causing things from
previous frames to show through. Note that we don't support EGL_SWAP_BEHAVIOR =
EGL_PRESERVED_SWAP, so a full frame must be rendered every time (until we
enable eglSwapBuffersRegionNOK() at least).


************
not sure, haven't really seen this before :/ is there a clear for the
background for each frame?
********************

Comment 5

[Oleg Romashin (:romaxa)]

ok, I found that problem appearing when TEXTURE rotation happen
also I asked our graphics people and they said:
**************************
> Not sure but we are using GL_REPEAT mode for texture and basically problem
> happen when we start uploading texture data in top and that supposed to be
> appeared in bottom...
> 
> Do we support GL_REPEATED mode correctly or any specific tricks possible with
> that?

NPOT textures and GL_REPEAT wrap mode are not supported by GLES2.0 spec
**********************

So I applied patch from bug 609195, and now I don't see this artifacts anymore!

Comment 6

[Oleg Romashin (:romaxa)]

this is not related to remote rendering

Comment 7

[Jeff Muizelaar [:jrmuizel]]

So is this a dup of 609195?

Comment 8

[Oleg Romashin (:romaxa)]

yes, it is dup