Cleartype (forced) always enabled for CT now?

[Timur Born]

Hello,

since the other thread was closed I have to create a new one to report that the new "Cleartype (forced)" option now seems permanently enabled even when the standard Cleartype (LCD) option is used. All my former test-cases now display CT with both options.

[Paul - Tracker Supp]

Hi Timur,

it should be on, it doesn't show at high zoom levels as it is pointless and gets turned off.

See this screen shot of the attached PDF:

image.png

Do you see something different?

xform.pdf

[Timur Born]

Hi Paul,

I do see the difference in your example, but I don't see any more differences in my earlier examples, which kind of started the whole thing. So it seems that not only did you add the "forced" mode now, but you also changed something about the classic Cleartype mode.

I am not complaining, but wondered if this might have been an unintentional change and whether there are any differences at all anymore. Your example demonstrated that some difference still exist.

[Lzcat - Tracker Supp]

Hi, Timur Born

No, "Cleartype (forced)" is not always enabled because it can have artifacts in many cases in PDFs (depending on the PDF content, of course). The previous/default settings were not changed, we just changed the algorithm which decides whether to use Cleartype or Antialiasing. Cleartype requires that text background should be used during rendering text, while the PDF specification requires rendering some objects as though there was no background at all and only then compose with it. Previous versions were using a simplified algorithm, which was often disabling Cleartype even when it was possible to use it.
Below is test file, and some screenshots, illustrating the changes.

image.png

Here we turned on regular Cleartype, and it works properly. As you can see middle line of text ("Text on isolated XForm") is rendered using Antialiasing, because it was placed in an isolated XForm object it must not be rendered on the background. Previous version of the Editor just turned off Cleartype for the entire page, even when an isolated XForm does not contain any text.

image1.png

And here "Cleartype (forced)" is used. As you can see Cleartype is used for all text lines, but if text background is not white you can see some rendering artifacts on the middle line of text (you may need to save screenshots and open it in another program which does not blur them when scaling, as my browser does).
As you can see, the new algorithm enables Cleartype for many files (or their parts) where it was disabled in previous version, so it is used much more often.
"Cleartype (forced)" in addition, the new algorithm is forcing the use of Cleartype for cases when it is not permitted because of possible artifacts. If your pdf files have a white text background you may use it without any restrictions - there will be no artifacts.
And of course we disable Cleartype even when "Cleartype (forced)" is set when text is rendered using any blend mode except Normal.

xform3.pdf

Kind regards,
Lzcat - Tracker Supp

[Timur Born]

we just changed the algorithm which decides whether to use Cleartype or Antialiasing.

This would be the improvement to the old Cleartype mechanism then. All my examples where Editor did *not* use Cleartype in the past now show as Cleartype even when (forced) is *not* used. So improvements on all fronts.

[TrackerSupp-Daniel]