AnchorsFactory

A module for working with the rules for placing anchors in a font. The rule describes the position of one or several anchors at once. Several rules can be applied to one glyph at once. The rules are stored in a separate text file, for example anchors-list.txt

General recording format:

@Label1=Anchor:Alignment:VertPosition
@Label2=..
# a comment
GlyphName=@Label1,@Label2,..

General rules syntax

@Label=Anchor:Alignment:VertPosition, ...

@Label - the name of the rule label, always starting with @

Anchor - the name of the anchor, in names to indicate anchors in accents you must use the _ sign

Alignment - horizontal alignment of the anchor. If a numeric value is specified, this will be the horizontal position of the anchor. left/center/right - anchor position on the left/right border of the glyph (glyph.bounds) or in the middle of the glyph glyph.width/2; centerpos - in the middle glyph.bounds

leftinter/rightinter - position is calculated by intersection with the glyph outline at the height specified after $.. (intersection)

VertPosition - anchor height. Numeric value, or the height of the glyph indicated by $.. after $GlyphName you can write the fractional value of the anchor height using the * sign 1/2 - in the middle in height, 1/3 - in the first lower third of the height, 2/3 - in the upper third of the height

For example:

@bar=bar:center:$H*2/3 - @bar label, bar anchor, aligned to the center of the character width, height - 2/3 of the H glyph height

@back=back:left:700 - @back label, back anchor, on the left border of the glyph, at height 700

If the glyph name ends with _ the height is calculated by its lower bound glyph.bounds, can be used for multi-story accents

Example:

@_grave=_grave:center:$gravecomb_ the _grave anchor will be centered, but at the height of the bottom border of the gravecomb glyph

One rule can have several anchors; they are listed with a comma

@=top:center:700,bottom:center:0

If there are alternatives in the font, they can be indicated via a label @SFXLIST=alt,alt01 in this case, alternatives with suffixes *.alt, *.alt01 will be found for all glyphs listed in the file and the same anchor rules will be applied as for the base character