The FreeType Project - Bugs: bug #59413, Big fat glitch in TrueType...
You are not allowed to post comments on this tracker with your current authentication level.
bug #59413: Big fat glitch in TrueType interpreter v40
Submitter: | Alexei Podtelezhnikov <podtelez> | ||
Submitted: | Wed 04 Nov 2020 03:18:31 AM UTC | ||
Severity: | 3 - Normal | Item Group: | None |
Status: | Confirmed | Privacy: | Public |
Assigned to: | morksig | Open/Closed: | Open |
Planned Release: | None |
Wed 04 Nov 2020 05:15:13 PM UTC, comment #3: |
Werner LEMBERG <wl> |
Wed 04 Nov 2020 02:19:24 PM UTC, comment #2: Are you saying that x-component of the freedom vector is unreliable, given that we x-moves might be quite different? We can try to ignore small Δx altogether and use (0, 47). |
Alexei Podtelezhnikov <podtelez> |
Wed 04 Nov 2020 01:46:14 PM UTC, comment #1: This is a hard one, AFAICS. The problem seems to be opcode SFVTL, which eventually resolves to a call to `Ins_SxVTL`. The points used for it are 128 and 127, respectively.
|
Werner LEMBERG <wl> |
Wed 04 Nov 2020 03:18:31 AM UTC, original submission:
$ ftgrid -f628 20 Windows/Fonts/pala.ttf
|
Alexei Podtelezhnikov <podtelez> |
Depends on the following items: None found
Items that depend on this one: None found
There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.
Follow 3 latest changes.
Date | Changed by | Updated Field | Previous Value | => | Replaced by |
---|---|---|---|---|---|
2020-11-04 | wl | Status | None | Confirmed | |
2020-11-04 | podtelez | Attached File | - | Added ftgrid.png, #50203 | |
Carbon-Copy | - | Added morksig |
Powered by Savane 3.13-d3ae.
Corresponding source code
Yes, the x component is unreliable, since it usually varies by ±1 pixels in comparison to the hinted outlines. However, in almost all cases it works quite nicely – you are the first who shows an example where the current v40 algorithm fails miserably, because the distance used for setting up the freedom vector is so ridiculously short.
I'm not sure whether your suggestion works: The difference in direction between (0,47) and (-11,47) is quite large...