PDF viewer font rendering inconsistent spacing




3 years ago
3 years ago


(Reporter: raysatiro, Unassigned)


38 Branch

Firefox Tracking Flags

(Not tracked)


(Whiteboard: [pdfjs-c-rendering])


(4 attachments)



3 years ago
Created attachment 8715984 [details]

User Agent: Mozilla/5.0 (Windows NT 6.1; rv:38.0) Gecko/20100101 Firefox/38.0
Build ID: 20100101

Steps to reproduce:

I'm trying to read that document in Firefox's PDF viewer:


The spacing is all wrong. I am using ESR 38 at the moment but I also tried in Nightly and the results were the same.

Actual results:

The spacing between letters is inconsistent. For example look at the word 'Abstract' which reads more like 'A bst r act'.

Expected results:

The spacing should be consistent.


3 years ago
Component: Untriaged → PDF Viewer

Comment 1

3 years ago
Do you have HWA enabled?

Comment 2

3 years ago
(In reply to Loic from comment #1)
> Do you have HWA enabled?

No, but I enabled it in Nightly and restarted and it doesn't seem to make any difference in the rendering of that document.
Could you try opening the PDF with a clean profile? It is showing up fine for me on windows 7 with hardware acceleration off.

Flags: needinfo?(raysatiro)
Priority: -- → P3
Whiteboard: [pdfjs-c-rendering]

Comment 4

3 years ago
Created attachment 8717215 [details]
PDF in Aurora 20160207004019.PNG

In Nightly there is no difference. As I said I have tried with both HWA enabled and disabled.
Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0

I just tried in Aurora now and it looks better when HWA is enabled but kind of grainy (see attachment). When HWA is disabled it looks like Nightly.
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:46.0) Gecko/20100101 Firefox/46.0
Flags: needinfo?(raysatiro)
Toggling the HWA preference is different than starting with a clean profile. See https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

Testing with a clean profile will let us know whether your operating system is rejecting the font or if there's some add-on/setting in your profile that is causing issues.
Flags: needinfo?(raysatiro)

Comment 6

3 years ago
Sorry I should have been more specific. I did use clean profiles for the results I disclosed in my last reply. I made a clean profile for Aurora, tested with HWA checked then disabled HWA restarted and tested again. I did the same thing for Nightly. Note Cleartype is disabled on this computer, if that helps. Normally I have no problem viewing PDFs though.
Flags: needinfo?(raysatiro)

Comment 7

3 years ago
Created attachment 8732471 [details]

Comment 8

3 years ago
Created attachment 8732472 [details]

I just uploaded two attachments, VSDebuggerPDF-FF38ESR.PNG and VSDebuggerPDF-FF47.0a2.PNG that show another PDF file with weird font spacing. It seems to be a particular type of font because in other parts of the PDF with other fonts it looks fine. Also peculiar - in 47.0a2 (Aurora) the bad font looks kind of fuzzy compared to 38ESR where it's crisp. Hardware acceleration is disabled in both.


Comment 9

3 years ago
Does it work better if you enable ClearType?
You need to log in before you can comment on or make changes to this bug.