Re: Potential Bug with BIZ UDGothic Font

[Hin-Tak Leung]

The option to toggle hinting (switching it on an off) is just pressing "h" (lowercase "h"). "H" uppercase cycles through the hinting engines, which are v35/v40 [my own freetype installation has an additional v38]. pressing "f" (lowercase "f") toggle auto-hinting - I think that means ignore the font's own hinting instructions and use freetype's own.

I think you'll find that the drop-out is gone if you either switch off hinting (pressing "h"), or switch to auto-hinting (pressing "f") in ftview. the display on the side should simultaneously change to "hinting: off" , or at the top from "v40" to "auto".

For this sort of problems ("drop out"), you might find that using "v35" and/or also mono rendering (press "A") works better on ftview.

The auto-hinting "f" key toggle is equivalent to FT_LOAD_FORCE_AUTOHINT , which might be a better option to use than FT_LOAD_TARGET_LIGHT , in some situation.

I checked your screen shots again, it says v40/normal at the top, and the two screenshot differs by ppem 13 vs ppem 14. In current freetype, if you set FT_LOAD_TARGET_LIGHT, it automatically sets FT_LOAD_FORCE_AUTOHINT, which is probably the actual solution/work-around to your problem ("buggy hinting instructions in fonts"), rather than FT_LOAD_TARGET_LIGHT in itself.

If you are going to get a lot of fonts from this font vendor, FT_LOAD_FORCE_AUTOHINT (ignore the font's hinting instructions and doing freetype's own) might be a better choice than either FT_LOAD_TARGET_LIGHT (setting lighter hinting, also have the side-effect of setting FT_LOAD_FORCE_AUTOHINT) or FT_LOAD_NO_HINTING (don't do any hinting of any sort).

On Thursday 19 December 2024 at 17:02:32 GMT, Simon Tremblay <stremblay@innovmetric.com> wrote:

Hi,

Thank you for getting back to me! I will reach to the customer.

Simon

 

 

Simon

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From: Hin-Tak Leung <htl10@users.sourceforge.net>
Sent: Wednesday, December 18, 2024 9:17 PM
To: freetype-devel@nongnu.org; Simon Tremblay <stremblay@innovmetric.com>
Subject: Re: Potential Bug with BIZ UDGothic Font

 

Vous n’obtenez pas souvent d’e-mail à partir dehtl10@users.sourceforge.net.Pourquoi c’est important

That would not be a bug in FreeType, but a bug in the Font. You need to report it to where you got the font from . From the look of it, that would be the hinting instruction and/or drop-out control in the font. FreeType is showing the font as its hinting instructions tell FreeType to. The difference between LIGHT and NORMAL is that some hinting instructions (in the font) are processed differently in the two modes. Again, this is a problem with the hinting instructions within the font, and you should report it as such.

You'll find that if you switch off hinting (one of the options in ftview) , the problem is gone. This, shows that the bug is in the font, and specifically in its hinting instructions.

On Wednesday 18 December 2024 at 21:07:15 GMT, Simon Tremblay <stremblay@innovmetric.com> wrote:

 

 

Hi,

I believe there is a bug with the BIZ UDGothic font, specifically with the '–' character when using a small font size.

The issue was found in version 2.13.3.

I managed to work around the issue by using FT_LOAD_TARGET_LIGHT instead of the default parameters.

 

Additionally, I was able to reproduce the problem in ftview.exe.

No bug


With the bug:


Best regards,
Simon

If necessary, to install the font on windows:
Here are the steps to install the fonts associated with the Japanese language without adding the Japanese language itself to your language preferences:

1. Click the Start button.
2. In Settings, click System.
3. Click Apps & features.
4. Click on the link, Manage optional features.
5. If "Japanese Supplemental Fonts" is not listed among the installed features, click on the "+" icon next to Add a feature.
6. Scroll to find "Japanese Supplemental Fonts". Click on that item, then click on Install.
7. Click on the back arrow in the upper corner of the window.