Function to get the named style used by a variable font instance

kitty/core_text.m

@@ -939,6 +939,12 @@ get_best_name(CTFace *self, PyObject *nameid) {
     return get_best_name_from_name_table(self->name_lookup_table, nameid);
 }
 
+static PyObject*
+get_variation(CTFace *self) {
+    RAII_CoreFoundation(CFDictionaryRef, src, CTFontCopyVariation(self->ct_font));
+    return variation_to_python(src);
+}
+
 static PyObject*
 get_variable_data(CTFace *self) {
     if (!ensure_name_table(self)) return NULL;
@@ -982,6 +988,7 @@ static PyMethodDef methods[] = {
     METHODB(display_name, METH_NOARGS),
     METHODB(postscript_name, METH_NOARGS),
     METHODB(get_variable_data, METH_NOARGS),
+    METHODB(get_variation, METH_NOARGS),
     METHODB(identify_for_debug, METH_NOARGS),
     METHODB(set_size, METH_VARARGS),
     METHODB(render_sample_text, METH_VARARGS),

kitty/fast_data_types.pyi

@@ -429,6 +429,7 @@ class Face:
     def postscript_name(self) -> str: ...
     def set_size(self, sz_in_pts: float, dpi_x: float, dpi_y: float) -> None: ...
     def render_sample_text(self, text: str, width: int, height: int, fg_color: int = 0xffffff) -> bytes: ...
+    def get_variation(self) -> Optional[Dict[str, float]]: ...
 
 
 class CoreTextFont(TypedDict):
@@ -461,6 +462,7 @@ class CTFace:
     def postscript_name(self) -> str: ...
     def set_size(self, sz_in_pts: float, dpi_x: float, dpi_y: float) -> None: ...
     def render_sample_text(self, text: str, width: int, height: int, fg_color: int = 0xffffff) -> bytes: ...
+    def get_variation(self) -> Optional[Dict[str, float]]: ...
 
 
 def coretext_all_fonts(monospaced_only: bool) -> Tuple[CoreTextFont, ...]:

kitty/fonts/common.py

@@ -4,7 +4,7 @@
 from typing import TYPE_CHECKING, Any, Dict, List, Literal, Optional, Sequence, Tuple, TypedDict, Union
 
 from kitty.constants import is_macos
-from kitty.fonts import Descriptor, DesignAxis, FontSpec, Scorer, VariableData, family_name_to_key
+from kitty.fonts import Descriptor, DesignAxis, FontSpec, NamedStyle, Scorer, VariableData, family_name_to_key
 from kitty.options.types import Options
 
 if TYPE_CHECKING:
@@ -289,5 +289,16 @@ def develop(family: str = '') -> None:
     print('Bold-Italic:', s(ff['bi']))
 
 
+def get_named_style(face: Face) -> Optional[NamedStyle]:
+    axis_map = face.get_variation()
+    if axis_map is None:
+        return None
+    vd = face.get_variable_data()
+    for ns in vd['named_styles']:
+        if ns['axis_values'] == axis_map:
+            return ns
+    return None
+
+
 if __name__ == '__main__':
     develop()

kitty/freetype.c

@@ -820,6 +820,28 @@ convert_axis_to_python(Face *face, const FT_Var_Axis *src, FT_UInt flags) {
     );
 }
 
+static PyObject*
+get_variation(Face *self, PyObject *a UNUSED) {
+    RAII_FTMMVar(mm);
+    FT_Error err;
+    if ((err = FT_Get_MM_Var(self->face, &mm))) { Py_RETURN_NONE; }
+    RAII_ALLOC(FT_Fixed, coords, malloc(mm->num_axis * sizeof(FT_Fixed)));
+    if (!coords) return PyErr_NoMemory();
+    if ((err = FT_Get_Var_Design_Coordinates(self->face, mm->num_axis, coords))) {
+        set_freetype_error("Failed to load the variation data from font with error:", err); return NULL;
+    }
+    RAII_PyObject(ans, PyDict_New()); if (!ans) return NULL;
+    uint8_t tag[5];
+    for (FT_UInt i = 0; i < mm->num_axis; i++) {
+        double val = coords[i] / 65536.0;
+        tag_to_string(mm->axis[i].tag, tag);
+        RAII_PyObject(pval, PyFloat_FromDouble(val));
+        if (!pval) return NULL;
+        if (PyDict_SetItemString(ans, (const char*)tag, pval) != 0) return NULL;
+    }
+    Py_INCREF(ans); return ans;
+}
+
 static PyObject*
 get_variable_data(Face *self, PyObject *a UNUSED) {
     if (!ensure_name_table(self)) return NULL;
@@ -969,6 +991,7 @@ static PyMethodDef methods[] = {
     METHODB(identify_for_debug, METH_NOARGS),
     METHODB(extra_data, METH_NOARGS),
     METHODB(get_variable_data, METH_NOARGS),
+    METHODB(get_variation, METH_NOARGS),
     METHODB(get_best_name, METH_O),
     METHODB(set_size, METH_VARARGS),
     METHODB(render_sample_text, METH_VARARGS),