Re: FreeType INSTCTRL behavior (Po Lu)

[Alexei Podtelezhnikov]

>     /* UNDOCUMENTED!  The MS rasterizer doesn't allow the following */
>     /* graphics state variables to be modified by the CVT program.  */

On Mon, Feb 13, 2023 at 3:50 PM Hin-Tak Leung
<htl10@users.sourceforge.net> wrote:
> I think it is probably mis-documented - the projection vector and rp1 are not 
> even per-glyph/contour parameter, but per contour fragment....

It does say that "Some [not all] state variables can be reset in the
CVT Program." (1)
Then it says that "instructions intended to move points within a
particular glyph outline cannot be used in the CV Program." (2)
I suppose you can figure out that projection vectors and references
are *intended to move points*. It could be clarified.

(1) https://learn.microsoft.com/en-us/typography/opentype/spec/tt_graphics_state
(2) https://learn.microsoft.com/en-us/typography/opentype/spec/prep