After scroll pull-down, font becomes thin for 2-3 seconds.. Maybe anti aliasing issue.

VERIFIED FIXED in mozilla6



6 years ago
4 years ago


(Reporter: Alice0775 White, Assigned: roc)



Windows 7

Firefox Tracking Flags

(Not tracked)



(2 attachments)



6 years ago
Created attachment 529924 [details]

Build Identifier:
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0.2pre) Gecko/20110501 Firefox/4.0.2pre ID:20110501030621
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20110413 Firefox/5.0a2 ID:20110503042003
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0.2pre) Gecko/20110501 Firefox/4.0.2pre ID:20110501030621

After scroll pull-down, font becomes thin for 2-3 seconds..
Maybe anti aliasing issue.

Reproducible: Always

Steps to Reproduce:
1. Start Firefox with new profile
2. Open ( ex. )
4. Page Zoom-In Ctrl++ repeats 5 times (In order to make easy to verify the bug)
5. Open pull-down "Timezone used to display dates and times"
6. Scroll the pull-down and watch the font for a while

Actual Results:
 After scroll pull-down, font becomes thin for 2-3 seconds.

Expected Results:
 Font appearance should be same .
Probably something with layers going active/inactive. Not sure if this is a bug.

Comment 2

6 years ago
layers.acceleration.disabled=true does not fix.
But, gfx.direct2d.disabled=true helps.

Default preferences:
  Adapter Description: ATI Radeon HD 4300/4500 Series
  Vendor ID: 1002
  Device ID: 954f
  Adapter RAM: 512
  Adapter Drivers: aticfx64 aticfx64 aticfx32 aticfx32 atiumd64 atidxx64 atiumdag atidxx32 atiumdva atiumd6a atitmm64
  Driver Version: 8.841.0.0
  Driver Date: 4-5-2011
  Direct2D Enabled: true
  DirectWrite Enabled: true (6.1.7601.17563, font cache n/a)
  WebGL Renderer: Google Inc. -- ANGLE -- OpenGL ES 2.0 (ANGLE
  GPU Accelerated Windows: 1/1 Direct3D 10
Severity: normal → minor

Comment 3

6 years ago
Regression window(cached m-c hourly):
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b13pre) Gecko/20110222 Firefox/4.0b13pre ID:20110222201727
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0b13pre) Gecko/20110222 Firefox/4.0b13pre ID:20110222214147

b8194445b364	Robert O'Callahan — Bug 630835. Make BuildLayer responsible for setting a visible region on the layer, and let FrameLayerBuilder only reduce it. r=tnikkel,a=blocking This avoids problems with FrameLayerBuilder making the visible region bigger than we expected, invalidating CONTENT_OPAQUE flags set on the layer. In particular, we had been using TransformBounds to compute the new visible region, and for non-axis-aligned transforms this gives us a visible region which contains areas not actually painted by the layer contents.


6 years ago
Blocks: 630835
Keywords: regression
Manual antialiasing due to us deciding that some layer is transparent, probably...
Is there a bug for fixing the gamma correction issues there?
Created attachment 529932 [details] [diff] [review]

Eh, I can just fix this.

The reason we have this problem is that the nsDisplaySolidColor at the root of the select has a fractional pixel width. So the ThebesLayer it goes into gets a visible region that's the rounded-out width, but the nsDisplaySolidColor only opaquely covers the rounded-in width.

This patch fixes the problem by making nsDisplaySolidColor::GetBounds return the snapped bounds when appropriate, like nsDisplayBackground does.
Assignee: nobody → roc
Attachment #529932 - Flags: review?(tnikkel)
Attachment #529932 - Flags: review?(tnikkel) → review+
Whiteboard: [needs landing]
Last Resolved: 6 years ago
Resolution: --- → FIXED
Whiteboard: [needs landing]
Target Milestone: --- → mozilla6
Comment on attachment 529932 [details] [diff] [review]

Ugly regression in Firefox 4, fairly safe fix.
Attachment #529932 - Flags: approval-mozilla-aurora?

Comment 9

6 years ago
How widespread is this likely to be on the Web and how likely is this to be obvious to users without the 5x zooming. I realize that the steps to reproduce are in order to exaggerate the problem to make it easier to identify, but what I don't understand is whether or not this is a big problem for users in the wild who aren't zooming in 5x.

I'm leaning towards a no on taking this into Beta. (Would we have taken this into Firefox 4 RC?)
Zooming doesn't affect it, for me; I can see it without zooming. It looks ugly. It's probably less important than my other approval requests though :-).
Comment on attachment 529932 [details] [diff] [review]

Not taking this in the Fx5 beta period.
Attachment #529932 - Flags: approval-mozilla-aurora? → approval-mozilla-beta-

Comment 12

6 years ago
Setting resolution to Verified Fixed on Mozilla/5.0 (Windows NT 6.1; rv:6.0) Gecko/20100101 Firefox/6.0

Comment 13

6 years ago
Machine: Win7 Pro 32bit, Ati Mobility Radeon x1400 (10.2 legacy driver)

This problem still appears on some pages. A sample page where i encounter it: There is Mibbit IRC chat. If I scroll or the chat has a new entry then everything becomes thin for a few seconds, when undisturbed it returns to normal. Problem with FF4 to FF6.

About:support says "Direct2D Enabled (Blocked for your graphics driver version. Try updating your graphics driver to version 10.6 or newer.)"
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