Add option adjust_baseline to adjust the baseline position on macOS

kitty/core_text.m

@@ -366,7 +366,7 @@ cell_metrics(PyObject *s, unsigned int* cell_width, unsigned int* cell_height, u
     CGRect bounds_without_leading = CTLineGetBoundsWithOptions(line, kCTLineBoundsExcludeTypographicLeading);
     CGFloat typographic_ascent, typographic_descent, typographic_leading;
     CTLineGetTypographicBounds(line, &typographic_ascent, &typographic_descent, &typographic_leading);
-    CGFloat bounds_ascent = bounds_without_leading.size.height + bounds_without_leading.origin.y;
+    CGFloat bounds_ascent = bounds_without_leading.size.height + bounds_without_leading.origin.y - OPT(adjust_baseline);
     *baseline = (unsigned int)floor(bounds_ascent + 0.5);
     *cell_height = MAX(4u, (unsigned int)ceilf(line_height));
     // Not sure if we should add this to bounds ascent and then round it or add

kitty/options/definition.py

@@ -94,6 +94,15 @@ opt('adjust_column_width', '0',
     option_type='adjust_line_height', ctype='!adjust_column_width',
     )
 
+opt('adjust_baseline', '0',
+    option_type='int', ctype='int',
+    add_to_default=False,
+    long_text='''
+Adjust the baseline position of each character (in pixels) on macOS. A positive
+number moves all characters up, and a negative number moves them down.
+'''
+    )
+
 opt('+symbol_map', 'U+E0A0-U+E0A3,U+E0C0-U+E0C7 PowerlineSymbols',
     option_type='symbol_map',
     add_to_default=False,

kitty/options/parse.py

@@ -37,6 +37,9 @@ class Parser:
     def active_tab_title_template(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['active_tab_title_template'] = active_tab_title_template(val)
 
+    def adjust_baseline(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
+        ans['adjust_baseline'] = int(val)
+
     def adjust_column_width(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['adjust_column_width'] = adjust_line_height(val)
 

kitty/options/to-c-generated.h

@@ -57,6 +57,19 @@ convert_from_opts_adjust_column_width(PyObject *py_opts, Options *opts) {
     Py_DECREF(ret);
 }
 
+static void
+convert_from_python_adjust_baseline(PyObject *val, Options *opts) {
+    opts->adjust_baseline = PyLong_AsLong(val);
+}
+
+static void
+convert_from_opts_adjust_baseline(PyObject *py_opts, Options *opts) {
+    PyObject *ret = PyObject_GetAttrString(py_opts, "adjust_baseline");
+    if (ret == NULL) return;
+    convert_from_python_adjust_baseline(ret, opts);
+    Py_DECREF(ret);
+}
+
 static void
 convert_from_python_disable_ligatures(PyObject *val, Options *opts) {
     opts->disable_ligatures = PyLong_AsLong(val);
@@ -886,6 +899,8 @@ convert_opts_from_python_opts(PyObject *py_opts, Options *opts) {
     if (PyErr_Occurred()) return false;
     convert_from_opts_adjust_column_width(py_opts, opts);
     if (PyErr_Occurred()) return false;
+    convert_from_opts_adjust_baseline(py_opts, opts);
+    if (PyErr_Occurred()) return false;
     convert_from_opts_disable_ligatures(py_opts, opts);
     if (PyErr_Occurred()) return false;
     convert_from_opts_cursor_shape(py_opts, opts);

kitty/options/types.py

@@ -45,6 +45,7 @@ option_names = (  # {{{
  'active_tab_font_style',
  'active_tab_foreground',
  'active_tab_title_template',
+ 'adjust_baseline',
  'adjust_column_width',
  'adjust_line_height',
  'allow_hyperlinks',
@@ -435,6 +436,7 @@ class Options:
     active_tab_font_style: typing.Tuple[bool, bool] = (True, True)
     active_tab_foreground: Color = Color(red=0, green=0, blue=0)
     active_tab_title_template: typing.Optional[str] = None
+    adjust_baseline: int = 0
     adjust_column_width: typing.Union[int, float] = 0
     adjust_line_height: typing.Union[int, float] = 0
     allow_hyperlinks: int = 1

kitty/state.h

@@ -42,6 +42,7 @@ typedef struct {
     WindowTitleIn macos_show_window_title_in;
     int adjust_line_height_px, adjust_column_width_px;
     float adjust_line_height_frac, adjust_column_width_frac;
+    int adjust_baseline;
     float background_opacity, dim_opacity;
 
     char* background_image;