700088 - Enhanced_contrast effect disappears and reappears

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Fanolian]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:10.0a1) Gecko/20111105 Firefox/10.0a1
Build ID: 20111105031111

Steps to reproduce:

1. Set gfx.font_rendering.cleartype_params.rendering_mode to 5, and gfx.font_rendering.cleartype_params.enhanced_contrast to 1000. Text should be very dark at the moment;
2. Log in to Google Reader. On the left pane select "All items" or any subscription that has enough feeds so that you can see the scrollbar;
3. Slowly scroll down from the top.


Actual results:

All the text in the feed pane suddenly become very light at some places when scrolling down, as if gfx.font_rendering.cleartype_params.enhanced_contrast has not been set. However, the text is dark again after a second or so. You can repeat it by scrolling up and down around that region.


Expected results:

Text contrast should be consistent at all times.


In addition, I have a customised text shadow in userContent.css that disappears and reappears at the same time as the contrast. The CSS I use is
* {
    text-shadow: 1px 1px 0px rgba(0,0,0,0.2);
}

Comment 1

[Alice0775 White]

Font rendering is became thinner/thicker when scroll down. 

#1 Regression window,
Works:
http://hg.mozilla.org/mozilla-central/rev/9c32afba1189
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110115 Firefox/4.0b10pre ID:20110115123545
Fails, become slightly darker and 'MS PGothic' bitmap font disappears:
http://hg.mozilla.org/mozilla-central/rev/aa14a8d4c97b
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110115 Firefox/4.0b10pre ID:20110115183417
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=9c32afba1189&tochange=aa14a8d4c97b
Triggered by:
Bug 622482 - Support subpixel-AA when drawing to transparent surfaces with DirectWrite


#2 Regression window(partially fixed disappearing bitmap font),
Fails, become slightly darker and MS PGothic font disappear:
http://hg.mozilla.org/mozilla-central/rev/0b2511671608
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110117 Firefox/4.0b10pre ID:20110117094038
Fails, become slightly darker (partially fixed disappearing bitmap font):
http://hg.mozilla.org/mozilla-central/rev/a66254dfa588
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b10pre) Gecko/20110117 Firefox/4.0b10pre ID:20110117095114
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0b2511671608&tochange=a66254dfa588
66254dfa588	Jonathan Kew — bug 626299 - fix disappearing text when D2D manual subpixel-AA codepath tries to use a bitmap font size. r=bas a=blocking-betaN


#3 Regression window,
Fails, become slightly darker:
http://hg.mozilla.org/mozilla-central/rev/0c3bd5909e79
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a1) Gecko/20110420 Firefox/6.0a1 ID:20110420170520
Fails, become Lighter:
http://hg.mozilla.org/mozilla-central/rev/46fdf12082d4
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:6.0a1) Gecko/20110421 Firefox/6.0a1 ID:20110421030547
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=0c3bd5909e79&tochange=46fdf12082d4
Triggered by:
Bug 642589 - expose prefs for tweaking DirectWrite/D2D antialiasing behavior

Comment 2

[Fanolian]

Another example is hovering on most of the image results in Google Image Search.

Comment 3

[Gary [:streetwolf52]]

Another example is at https://docs.google.com/document/d/1kll86bDn_MgWoo6Ja7oHo_yvI0SCqggEvNWwPWIcrHY/preview?pli=1&sle=true



Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20120425 Firefox/15.0a1

Comment 4

[Fanolian]

Thanks for the new example as I cannot reproduce it in Google Reader nor Google Image Search anymore.

(In reply to Gary [:streetwolf] from comment #3)
> Another example is at
> https://docs.google.com/document/d/
> 1kll86bDn_MgWoo6Ja7oHo_yvI0SCqggEvNWwPWIcrHY/preview?pli=1&sle=true
> 
> 
> 
> Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20120425 Firefox/15.0a1

Comment 5

[Gary [:streetwolf52]]

This problem seems like it was corrected by https://bugzilla.mozilla.org/show_bug.cgi?id=743590

Comment 6

[Fanolian]

(In reply to Gary [:streetwolf] from comment #5)
> This problem seems like it was corrected by
> https://bugzilla.mozilla.org/show_bug.cgi?id=743590

Only if Azure-Thebes Wrapper is on. I can still reproduce the bug in a vanilla profile in Nightly. It is better to leave this opened before the wrapper is enabled by default.

Comment 7

[Alice0775 White]

Attachment: reduced html

Comment 8

[Fanolian]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20.0 Firefox/20.0
Build ID: 20121120030739

I cannot produce it anymore in latest Nightly. Mark it as WORKSFORME similar to Bug 758862.

Comment 9

[Fanolian]

The bug is returning to Google Reader, but only with display density set to "compact".

Steps to reproduce:

1. Set gfx.font_rendering.cleartype_params.rendering_mode to 5, and gfx.font_rendering.cleartype_params.enhanced_contrast to 1000. Text should be very dark at the moment;
2. Log in to Google Reader. Set the display density to "Compact" from the gear icon near the top right corner. You may have to widen the browser so the display density settings does make a difference. 
3. On the left pane of Google Reader, select "All items" or any subscription that has enough feeds so that you can see the scrollbar;
4. Slowly scroll down from the top.

Actual results:
All the text in the feed pane suddenly become very light at some places when scrolling down, as if gfx.font_rendering.cleartype_params.enhanced_contrast has not been set. However, the text is dark again after a second or so. You can repeat it by scrolling up and down around that region.

In addition to the text problem, if you have smooth scrolling enabled, the first scroll from the top is always noticeably more sluggish than other scrolls that does not initiate at the top. 

Last good nightly: 2012-12-06
First bad nightly: 2012-12-07
Pushlog: http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=3c81e1c0d252&tochange=739f20de3c1e

Comment 10

[u279076]

Is this still reproducible in the current Firefox Nightly?

Comment 11

[Fanolian]

I think I haven't seen it for quite a while.