Support default font_features from fontconfig

Author: Diaoul

kitty/config.py

@@ -21,6 +21,7 @@
 )
 from .config_data import all_options, parse_mods, type_convert
 from .constants import cache_dir, defconf, is_macos
+from .fonts import FontFeature
 from .key_names import get_key_name_lookup, key_name_aliases
 from .options_stub import Options as OptionsStub
 from .typing import TypedDict
@@ -524,14 +525,6 @@ def handle_symbol_map(key: str, val: str, ans: Dict[str, Any]) -> None:
     ans['symbol_map'].update(parse_symbol_map(val))
 
 
-class FontFeature(str):
-
-    def __new__(cls, name: str, parsed: bytes) -> 'FontFeature':
-        ans: FontFeature = str.__new__(cls, name)  # type: ignore
-        ans.parsed = parsed  # type: ignore
-        return ans
-
-
 @special_handler
 def handle_font_features(key: str, val: str, ans: Dict[str, Any]) -> None:
     if val != 'none':

kitty/fast_data_types.pyi

@@ -410,6 +410,7 @@ class FontConfigPattern(TypedDict):
     postscript_name: str
     style: str
     spacing: str
+    fontfeatures: str
     weight: int
     width: int
     slant: int
@@ -441,6 +442,12 @@ def fc_match(
     pass
 
 
+def fc_match_postscript_name(
+    postscript_name: str
+) -> FontConfigPattern:
+    pass
+
+
 class CoreTextFont(TypedDict):
     path: str
     postscript_name: str

kitty/fontconfig.c

@@ -46,6 +46,7 @@ pattern_as_dict(FcPattern *pat) {
     S(FC_STYLE, style);
     S(FC_FULLNAME, full_name);
     S(FC_POSTSCRIPT_NAME, postscript_name);
+    S(FC_FONT_FEATURES, fontfeatures);
     I(FC_WEIGHT, weight);
     I(FC_WIDTH, width)
     I(FC_SLANT, slant);
@@ -179,6 +180,26 @@ fc_match(PyObject UNUSED *self, PyObject *args) {
     return ans;
 }
 
+static PyObject*
+fc_match_postscript_name(PyObject UNUSED *self, PyObject *args) {
+    char *postscript_name = NULL;
+    FcPattern *pat = NULL;
+    PyObject *ans = NULL;
+
+    if (!PyArg_ParseTuple(args, "|z", &postscript_name)) return NULL;
+    pat = FcPatternCreate();
+    if (pat == NULL) return PyErr_NoMemory();
+    if (!postscript_name || strlen(postscript_name) == 0) return NULL;
+
+    AP(FcPatternAddString, FC_POSTSCRIPT_NAME, (const FcChar8*)postscript_name, "postscript_name");
+
+    ans = _fc_match(pat);
+
+end:
+    if (pat != NULL) FcPatternDestroy(pat);
+    return ans;
+}
+
 PyObject*
 specialize_font_descriptor(PyObject *base_descriptor, FONTS_DATA_HANDLE fg) {
     PyObject *p = PyDict_GetItemString(base_descriptor, "path"), *ans = NULL;
@@ -224,6 +245,7 @@ create_fallback_face(PyObject UNUSED *base_face, CPUCell* cell, bool bold, bool
 static PyMethodDef module_methods[] = {
     METHODB(fc_list, METH_VARARGS),
     METHODB(fc_match, METH_VARARGS),
+    METHODB(fc_match_postscript_name, METH_VARARGS),
     {NULL, NULL, 0, NULL}        /* Sentinel */
 };
 

kitty/fonts/__init__.py

@@ -9,3 +9,11 @@ class ListedFont(TypedDict):
     full_name: str
     postscript_name: str
     is_monospace: bool
+
+
+class FontFeature(str):
+
+    def __new__(cls, name: str, parsed: bytes) -> 'FontFeature':
+        ans: FontFeature = str.__new__(cls, name)  # type: ignore
+        ans.parsed = parsed  # type: ignore
+        return ans

kitty/fonts/core_text.py

@@ -50,6 +50,11 @@ def list_fonts() -> Generator[ListedFont, None, None]:
             yield {'family': f, 'full_name': fn, 'postscript_name': fd['postscript_name'] or '', 'is_monospace': is_mono}
 
 
+def find_font_features(postscript_name: str) -> Tuple[str, ...]:
+    """Not Implemented"""
+    return tuple()
+
+
 def find_best_match(family: str, bold: bool = False, italic: bool = False) -> CoreTextFont:
     q = re.sub(r'\s+', ' ', family.lower())
     font_map = all_fonts_map()

kitty/fonts/fontconfig.py

@@ -8,12 +8,14 @@
 
 from kitty.fast_data_types import (
     FC_DUAL, FC_MONO, FC_SLANT_ITALIC, FC_SLANT_ROMAN, FC_WEIGHT_BOLD,
-    FC_WEIGHT_REGULAR, FC_WIDTH_NORMAL, fc_list, fc_match as fc_match_impl
+    FC_WEIGHT_REGULAR, FC_WIDTH_NORMAL, fc_list, fc_match as fc_match_impl,
+    fc_match_postscript_name, parse_font_feature
 )
 from kitty.options_stub import Options
 from kitty.typing import FontConfigPattern
+from kitty.utils import log_error
 
-from . import ListedFont
+from . import ListedFont, FontFeature
 
 attr_map = {(False, False): 'font_family',
             (True, False): 'bold_font',
@@ -69,6 +71,24 @@ def fc_match(family: str, bold: bool, italic: bool, spacing: int = FC_MONO) -> F
     return fc_match_impl(family, bold, italic, spacing)
 
 
+def find_font_features(postscript_name: str) -> Tuple[str, ...]:
+    pat = fc_match_postscript_name(postscript_name)
+
+    if 'postscript_name' not in pat or pat['postscript_name'] != postscript_name or 'fontfeatures' not in pat:
+        return tuple()
+
+    features = []
+    for feat in pat['fontfeatures'].split():
+        try:
+            parsed = parse_font_feature(feat)
+        except ValueError:
+            log_error('Ignoring invalid font feature: {}'.format(feat))
+        else:
+            features.append(FontFeature(feat, parsed))
+
+    return tuple(features)
+
+
 def find_best_match(family: str, bold: bool = False, italic: bool = False, monospaced: bool = True) -> FontConfigPattern:
     q = family_name_to_key(family)
     font_map = all_fonts_map(monospaced)

kitty/fonts/render.py

@@ -25,9 +25,9 @@
 from kitty.utils import log_error
 
 if is_macos:
-    from .core_text import get_font_files as get_font_files_coretext, font_for_family as font_for_family_macos
+    from .core_text import get_font_files as get_font_files_coretext, font_for_family as font_for_family_macos, find_font_features
 else:
-    from .fontconfig import get_font_files as get_font_files_fontconfig, font_for_family as font_for_family_fontconfig
+    from .fontconfig import get_font_files as get_font_files_fontconfig, font_for_family as font_for_family_fontconfig, find_font_features
 
 FontObject = Union[CoreTextFont, FontConfigPattern]
 current_faces: List[Tuple[FontObject, bool, bool]] = []
@@ -189,12 +189,16 @@ def set_font_family(opts: Optional[OptionsStub] = None, override_font_size: Opti
     before = len(current_faces)
     sm = create_symbol_map(opts)
     num_symbol_fonts = len(current_faces) - before
+    font_features = {}
+    for face, _, _ in current_faces:
+        font_features[face['postscript_name']] = find_font_features(face['postscript_name'])
+    font_features.update(opts.font_features)
     if debug_font_matching:
         dump_faces(ftypes, indices)
     set_font_data(
         render_box_drawing, prerender_function, descriptor_for_idx,
         indices['bold'], indices['italic'], indices['bi'], num_symbol_fonts,
-        sm, sz, opts.font_features
+        sm, sz, font_features
     )