public.postscript.hints confusion

[yarmola]

I have few questions on the subject.

1 . Spec says:

Each stem string starts with either ‘hstem” or “vstem” and is a followed by a series of white-space delimited stem coordinate values. A stem coordinate value is an absolute coordinate.

while following sample obviously has hint delta stored as relative value:

<string>hstem 11 -21</string>
<string>vstem 30 207</string>

(It references x coordinate of 327 which is a valid coordinate in the contour above)

What option is correct?

2 . Sample references point tags hintSet0000 and hintSet0004 which aren't defined in the contour. Is it just a error or there is a way to encode point index in the hint set tag?

3 . id key — is it required? Building it basically requires to store another copy of the contour which I'd like to avoid. What will happen if there is no id?

[yarmola]

4 . Can pointTag be avoided if there is only one hintSetList? That could mean that there is no hint replacement. Generally it would be very nice to assume that first hintSetList is applied from the first point in the current glyph/layer, if not specified otherwise by pointTag.

[yarmola]

opened this issue in a more appropriate place:
unified-font-object/ufo-spec#149