Microsoft Visual TrueType Version 6.32 release [October, 2019]

Viktor Rubenko

@Paul Linnerud
I think that undo/redo buffer is not working correctly.
I added 2 anchors, pressed 2 ctrl+z and vttTalk was erased:

Piotr Grochowski

So it's better not to use Undo and not to use Redo in this case. No wonder it is disabled in the stable release. So in this case, instead of doing Undo, the better option is to grab the points back and select the no round option. Because instructions are not undone or redone, they are added or removed.

This is how hinting an open source glyph looks like:



No Undo involved and no Redo involved.

Piotr Grochowski

delete

Piotr Grochowski

Viktor Rubenko said:

@Paul Linnerud
I think that undo/redo buffer is not working correctly.
I added 2 anchors, pressed 2 ctrl+z and vttTalk was erased:

I'm pretty sure that is an entirely deliberate feature, where double pressing undo will undo every single instruction.

Viktor Rubenko

Piotr Grochowski said:

Viktor Rubenko said:

@Paul Linnerud
I think that undo/redo buffer is not working correctly.
I added 2 anchors, pressed 2 ctrl+z and vttTalk was erased:

I'm pretty sure that is an entirely deliberate feature, where double pressing undo will undo every single instruction.

It's not double pressing. Autohinted vtt talk is not saved in a buffer. 

Piotr Grochowski

Viktor Rubenko said:

Piotr Grochowski said:

Viktor Rubenko said:

@Paul Linnerud
I think that undo/redo buffer is not working correctly.
I added 2 anchors, pressed 2 ctrl+z and vttTalk was erased:

I'm pretty sure that is an entirely deliberate feature, where double pressing undo will undo every single instruction.

It's not double pressing. Autohinted vtt talk is not saved in a buffer. 

So it means it will undo the autohint as well, which is deliberate. In general in VTT it is the better option to not undo or redo whatsoever. Instead perform the reverse operation. So instead of trying to undo anchors, go back to the points and unround them. Adding and removing instructions, not undoing and redoing.

Viktor Rubenko

Looks like VTT 'variation CVT' is broken. After some point it stops affect on real cvt values. 

Mike Duggan

hey Viktor, just curious if you could expand more and give some example of what you meant by > After some point it stops affect on real cvt values. 

Viktor Rubenko

For example:
cvt value for default master

150: 130

I change it for some other master to 80 in 'Variation CVT' window

150: 80 (-50)

then compile it, but it won't affect the outlines in the preview
and also if open this font throught ttx the value will be still 130

Paul Linnerud

The Variation CVT interface in VTT does not change the real CVT values. You can edit the real CVT values of the default instance in the Control Program. The Variation CVT interface establishes or modifies the cvar variation table to effectively adjust the real CVT value by applying a delta that is computed by the rendering code based on the current point in variation space and the cvar table. 

Viktor Rubenko

Paul Linnerud said:

The Variation CVT interface in VTT does not change the real CVT values. You can edit the real CVT values of the default instance in the Control Program. The Variation CVT interface establishes or modifies the cvar variation table to effectively adjust the real CVT value by applying a delta that is computed by the rendering code based on the current point in variation space and the cvar table. 

Yeah, sorry, by real cvt I mean a delta value in the cvar table. Anyway, it doesn't work.

Example:

98: 81 (-52)
150: 133

I set
150: 81 (-52)
but it's value is 129 (133-4) as ttx show and it's visiable on preview render.
If I manually change the delta value to -52 via ttx the cvar becomes normal, but if I open the font via VTT and compile it, the cvar brokes again

Paul Linnerud

Do you have a specific test case I can look at? 
VTT uses a C++ port of the fonttools variation model code to compute the cvar deltas. The model takes as input the desired outcome and the deltas are computed. You can't rely on looking at the raw values from the cvar for an entry because the final result of interpolation based on contributions from other parts of the model. 

Viktor Rubenko

I have noticed, that only first 63 "Edited CVTs" values work, any others don't.

Paul Linnerud

Thanks, I think I can repro it now. 

Viktor Rubenko

I faced another problem. I already had something similar, but with the help of Mike Duggan it was fixed. Latin-autohint brokes VTT, while East Asian works fine.
Sent font files in PM. I have found that glyph with id 183 causes crash.

Viktor Rubenko

Where does VTT store settings? I clicked something and VTT window stopped showing. 

Paul Linnerud

Using Registry Editor, delete HKEY_CURRENT_USER\SOFTWARE\Microsoft\VisualTrueType to return to default settings.