expose cursor_trail options

kitty/child-monitor.c

@@ -751,7 +751,7 @@ prepare_to_render_os_window(OSWindow *os_window, monotonic_t now, unsigned int *
                 WD.screen->cursor_render_info.is_focused = os_window->is_focused;
                 set_os_window_title_from_window(w, os_window);
                 *active_window_bg = window_bg;
-                if (true && update_cursor_trail(&tab->cursor_trail, w, now, os_window)) needs_render = true;
+                if (OPT(enable_cursor_trail) && update_cursor_trail(&tab->cursor_trail, w, now, os_window)) needs_render = true;
             } else {
                 if (WD.screen->cursor_render_info.render_even_when_unfocused) {
                     if (collect_cursor_info(&WD.screen->cursor_render_info, w, now, os_window)) needs_render = true;
@@ -809,7 +809,7 @@ render_prepared_os_window(OSWindow *os_window, unsigned int active_window_id, co
             w->cursor_opacity_at_last_render = WD.screen->cursor_render_info.opacity; w->last_cursor_shape = WD.screen->cursor_render_info.shape;
         }
     }
-    if (true && tab->cursor_trail.needs_render) draw_cursor_trail(&tab->cursor_trail);
+    if (OPT(enable_cursor_trail) && tab->cursor_trail.needs_render) draw_cursor_trail(&tab->cursor_trail);
     if (os_window->live_resize.in_progress) draw_resizing_text(os_window);
     swap_window_buffers(os_window);
     os_window->last_active_tab = os_window->active_tab; os_window->last_num_tabs = os_window->num_tabs; os_window->last_active_window_id = active_window_id;

kitty/cursor_trail.c

@@ -45,10 +45,9 @@ update_cursor_trail(CursorTrail *ct, Window *w, monotonic_t now, OSWindow *os_wi
         return needs_render_prev;
     }
 
-    // todo - make these configurable
     // the decay time for the trail to reach 1/1024 of its distance from the cursor corner
-    float decay_fast = 0.10f;
+    float decay_fast = OPT(cursor_trail_decay_fast);
-    float decay_slow = 0.30f;
+    float decay_slow = OPT(cursor_trail_decay_slow);
 
     if (os_window->live_resize.in_progress) {
         for (int i = 0; i < 4; ++i) {

kitty/options/definition.py

@@ -350,6 +350,28 @@ inactivity. Set to zero to never stop blinking.
 '''
     )
 
+opt('enable_cursor_trail', 'no',
+    option_type='to_bool', ctype='bool',
+    long_text='''
+Enables or disables the cursor trail effect. When set to `yes`, a trailing
+effect is rendered behind the cursor as it moves, creating a motion trail.
+'''
+    )
+
+opt('cursor_trail_decay', '0.1 0.3',
+    option_type='cursor_trail_decay',
+    ctype='!cursor_trail_decay',
+    long_text='''
+Controls the decay times for the cursor trail effect when  :code:`enable_cursor_trail`
+is set to  :code:`yes`. This option accepts two positive float values specifying the
+fastest and slowest decay times in seconds. The first value corresponds to the
+fastest decay time (minimum), and the second value corresponds to the slowest
+decay time (maximum). The second value must be equal to or greater than the
+first value. Smaller values result in a faster decay of the cursor trail.
+Adjust these values to control how quickly the cursor trail fades away.
+''',
+    )
+
 egr()  # }}}
 
 

kitty/options/parse.py

@@ -10,7 +10,7 @@ from kitty.options.utils import (
     action_alias, active_tab_title_template, allow_hyperlinks, bell_on_tab, box_drawing_scale,
     clear_all_mouse_actions, clear_all_shortcuts, clipboard_control, clone_source_strategies,
     config_or_absolute_path, copy_on_select, cursor_blink_interval, cursor_text_color,
-    deprecated_adjust_line_height, deprecated_hide_window_decorations_aliases,
+    cursor_trail_decay, deprecated_adjust_line_height, deprecated_hide_window_decorations_aliases,
     deprecated_macos_show_window_title_in_menubar_alias, deprecated_send_text, disable_ligatures,
     edge_width, env, filter_notification, font_features, hide_window_decorations, macos_option_as_alt,
     macos_titlebar_color, menu_map, modify_font, narrow_symbols, notify_on_cmd_finish,
@@ -931,6 +931,9 @@ class Parser:
     def cursor_text_color(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['cursor_text_color'] = cursor_text_color(val)
 
+    def cursor_trail_decay(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
+        ans['cursor_trail_decay'] = cursor_trail_decay(val)
+
     def cursor_underline_thickness(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['cursor_underline_thickness'] = positive_float(val)
 
@@ -963,6 +966,9 @@ class Parser:
     def enable_audio_bell(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['enable_audio_bell'] = to_bool(val)
 
+    def enable_cursor_trail(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
+        ans['enable_cursor_trail'] = to_bool(val)
+
     def enabled_layouts(self, val: str, ans: typing.Dict[str, typing.Any]) -> None:
         ans['enabled_layouts'] = to_layout_names(val)
 

kitty/options/to-c-generated.h

@@ -161,6 +161,32 @@ convert_from_opts_cursor_stop_blinking_after(PyObject *py_opts, Options *opts) {
     Py_DECREF(ret);
 }
 
+static void
+convert_from_python_enable_cursor_trail(PyObject *val, Options *opts) {
+    opts->enable_cursor_trail = PyObject_IsTrue(val);
+}
+
+static void
+convert_from_opts_enable_cursor_trail(PyObject *py_opts, Options *opts) {
+    PyObject *ret = PyObject_GetAttrString(py_opts, "enable_cursor_trail");
+    if (ret == NULL) return;
+    convert_from_python_enable_cursor_trail(ret, opts);
+    Py_DECREF(ret);
+}
+
+static void
+convert_from_python_cursor_trail_decay(PyObject *val, Options *opts) {
+    cursor_trail_decay(val, opts);
+}
+
+static void
+convert_from_opts_cursor_trail_decay(PyObject *py_opts, Options *opts) {
+    PyObject *ret = PyObject_GetAttrString(py_opts, "cursor_trail_decay");
+    if (ret == NULL) return;
+    convert_from_python_cursor_trail_decay(ret, opts);
+    Py_DECREF(ret);
+}
+
 static void
 convert_from_python_scrollback_indicator_opacity(PyObject *val, Options *opts) {
     opts->scrollback_indicator_opacity = PyFloat_AsFloat(val);
@@ -1123,6 +1149,10 @@ convert_opts_from_python_opts(PyObject *py_opts, Options *opts) {
     if (PyErr_Occurred()) return false;
     convert_from_opts_cursor_stop_blinking_after(py_opts, opts);
     if (PyErr_Occurred()) return false;
+    convert_from_opts_enable_cursor_trail(py_opts, opts);
+    if (PyErr_Occurred()) return false;
+    convert_from_opts_cursor_trail_decay(py_opts, opts);
+    if (PyErr_Occurred()) return false;
     convert_from_opts_scrollback_indicator_opacity(py_opts, opts);
     if (PyErr_Occurred()) return false;
     convert_from_opts_scrollback_pager_history_size(py_opts, opts);

kitty/options/to-c.h

@@ -180,6 +180,11 @@ visual_bell_duration(PyObject *src, Options *opts) {
 
 #undef parse_animation
 
+static inline void
+cursor_trail_decay(PyObject *src, Options *opts) {
+    opts->cursor_trail_decay_fast = PyFloat_AsFloat(PyTuple_GET_ITEM(src, 0));
+    opts->cursor_trail_decay_slow = PyFloat_AsFloat(PyTuple_GET_ITEM(src, 1));
+}
 
 static void
 parse_font_mod_size(PyObject *val, float *sz, AdjustmentUnit *unit) {

kitty/options/types.py

@@ -334,6 +334,7 @@ option_names = (  # {{{
  'cursor_shape_unfocused',
  'cursor_stop_blinking_after',
  'cursor_text_color',
+ 'cursor_trail_decay',
  'cursor_underline_thickness',
  'default_pointer_shape',
  'detect_urls',
@@ -343,6 +344,7 @@ option_names = (  # {{{
  'dynamic_background_opacity',
  'editor',
  'enable_audio_bell',
+ 'enable_cursor_trail',
  'enabled_layouts',
  'env',
  'exe_search_path',
@@ -510,6 +512,7 @@ class Options:
     cursor_shape_unfocused: int = 4
     cursor_stop_blinking_after: float = 15.0
     cursor_text_color: typing.Optional[kitty.fast_data_types.Color] = Color(17, 17, 17)
+    cursor_trail_decay: typing.Tuple[float, float] = (0.1, 0.3)
     cursor_underline_thickness: float = 2.0
     default_pointer_shape: choices_for_default_pointer_shape = 'beam'
     detect_urls: bool = True
@@ -519,6 +522,7 @@ class Options:
     dynamic_background_opacity: bool = False
     editor: str = '.'
     enable_audio_bell: bool = True
+    enable_cursor_trail: bool = False
     enabled_layouts: typing.List[str] = ['fat', 'grid', 'horizontal', 'splits', 'stack', 'tall', 'vertical']
     file_transfer_confirmation_bypass: str = ''
     focus_follows_mouse: bool = False

kitty/options/utils.py

@@ -558,6 +558,11 @@ def to_cursor_unfocused_shape(x: str) -> int:
             )
         )
 
+def cursor_trail_decay(x: str) -> Tuple[float, float]:
+    fast, slow = map(positive_float, x.split())
+    slow = max(slow, fast)
+    return fast, slow
+
 
 def scrollback_lines(x: str) -> int:
     ans = int(x)

kitty/state.h

@@ -46,6 +46,9 @@ typedef struct {
     CursorShape cursor_shape, cursor_shape_unfocused;
     float cursor_beam_thickness;
     float cursor_underline_thickness;
+    bool enable_cursor_trail;
+    float cursor_trail_decay_fast;
+    float cursor_trail_decay_slow;
     unsigned int url_style;
     unsigned int scrollback_pager_history_size;
     bool scrollback_fill_enlarged_window;