test-mark.fea

# diacritics-minimal.fea
# Minimal GDEF + mark + mkmk for testing diacritic placement on "o"

# ----------------------------------------------------------
# 1. Language systems
# ----------------------------------------------------------
languagesystem DFLT dflt;
languagesystem latn dflt;

# ----------------------------------------------------------
# 2. Glyph classes for GDEF
#    Adjust/add bases and marks as needed.
# ----------------------------------------------------------

# Base glyphs: just "o" for this minimal test
@BASE_GLYPHS = [ o ];

# Ligature glyphs: none for this minimal test
@LIGATURES   = [ ];

# Mark glyphs: U+0300 COMBINING GRAVE ACCENT
# Make sure the name "gravecomb" exists in the font
@MARK_GLYPHS = [ gravecomb ];

# Components: typically empty
@COMPONENTS  = [ ];

# ----------------------------------------------------------
# 3. GDEF table
#    This is crucial so shaping engines will apply mark GPOS.
# ----------------------------------------------------------
table GDEF {
    GlyphClassDef
        @BASE_GLYPHS,
        @LIGATURES,
        @MARK_GLYPHS,
        @COMPONENTS;
} GDEF;

# ----------------------------------------------------------
# 4. Mark feature (mark-to-base)
#    Places gravecomb (U+0300) on "o".
# ----------------------------------------------------------

# For convenience, a mark class with our single mark glyph
@GRAVE_MARKS = [ gravecomb ];

feature mark {

    # markClass: define the anchor on the MARK (gravecomb)
    # anonymous anchor: <anchor x y>
    markClass gravecomb <anchor 0 500> @GRAVE_MARKS;

    # Base glyph "o": give it a crazy-high anchor so movement is obvious
    pos base o <anchor 0 1700> mark @GRAVE_MARKS;

} mark;

# ----------------------------------------------------------
# 5. mkmk feature (mark-to-mark)
#    Minimal stub: allows future stacking, but not essential for the test.
# ----------------------------------------------------------
feature mkmk {

    # Attach the mark to another mark (here just itself) at a second position
    # This is mostly to make the mkmk feature non-empty.
    pos mark gravecomb <anchor 0 550> mark @GRAVE_MARKS;

} mkmk;