Re: FreeType INSTCTRL behavior (Po Lu) (Re: Freetype-devel Digest, Vol 217, Issue 8)

[Po Lu]

Alexei Podtelezhnikov <apodtele@gmail.com> writes:

> Sorry,
>> >   To establish a new default value for a graphics state variable, it is
>> >   necessary to change the value of that variable in the control value
>> >   program. Changes made in the control value program will apply to all
>> >   subsequently processed glyphs unless INSTCTRL[] is used to inhibit
>> >   these new values.
> You are looking at the outdated Apple's specifications. Please check
> with OpenType 1.9 instead:
> https://learn.microsoft.com/en-us/typography/opentype/spec/tt_instructions#instruction-execution-control
>
> Specifically, "INSTCTRL[ ] can only be executed in the CVT program."
> There are further clarifications
> https://learn.microsoft.com/en-us/typography/cleartype/truetypecleartype#instctrl
>
> Best,
> Alexei

I don't see anything there that contradicts the behavior of my
interpreter, though.

The control value program executes _NO_ INSTCTRL[] instructions
whatsoever, yet the reference points and the freedom vector are reset
after execution.