blinking text is now eased between bg and fg color

config/src/config.rs

@@ -1,5 +1,5 @@
 use crate::background::Gradient;
-use crate::bell::{AudibleBell, VisualBell};
+use crate::bell::{AudibleBell, EasingFunction, VisualBell};
 use crate::color::{ColorSchemeFile, HsbTransform, Palette, TabBarStyle, WindowFrameConfig};
 use crate::daemon::DaemonOptions;
 use crate::font::{
@@ -451,6 +451,10 @@ pub struct Config {
     /// interval specified with some degree of slop.
     #[serde(default = "default_text_blink_rate")]
     pub text_blink_rate: u64,
+    #[serde(default)]
+    pub text_blink_ease_in: EasingFunction,
+    #[serde(default)]
+    pub text_blink_ease_out: EasingFunction,
 
     /// Specifies how often blinking text (rapid speed) transitions
     /// between visible and invisible, expressed in milliseconds.
@@ -460,6 +464,10 @@ pub struct Config {
     /// interval specified with some degree of slop.
     #[serde(default = "default_text_blink_rate_rapid")]
     pub text_blink_rate_rapid: u64,
+    #[serde(default)]
+    pub text_blink_rapid_ease_in: EasingFunction,
+    #[serde(default)]
+    pub text_blink_rapid_ease_out: EasingFunction,
 
     /// If non-zero, specifies the period (in seconds) at which various
     /// statistics are logged.  Note that there is a minimum period of

docs/changelog.md

@@ -37,6 +37,7 @@ As features stabilize some brief notes about them will accumulate here.
 * [ScrollByPage](config/lua/keyassignment/ScrollByPage.md) now accepts fractional numbers like `0.5` to scroll by half a page at time. Thanks to [@hahuang65](https://github.com/hahuang65)! [#1534](https://github.com/wez/wezterm/pull/1534)
 * [use_ime](config/lua/config/use_ime.md) now defaults to `true` on all platforms; previously it was not enabled by default on macOS.
 * [canonicalize_pasted_newlines](config/lua/config/canonicalize_pasted_newlines.md) default has changed to be more compatible for `nano` users, and now provides more control over the text format that is pasted. [#1575](https://github.com/wez/wezterm/issues/1575)
+* Blinking text is now eased rather than binary-blinked. See [text_blink_ease_in](config/lua/config/text_blink_ease_in.md) and [text_blink_ease_out](config/lua/config/text_blink_ease_out.md), [text_blink_rapid_ease_in](config/lua/config/text_blink_rapid_ease_in.md) and [text_blink_rapid_ease_out](config/lua/config/text_blink_rapid_ease_out.md) for more information.
 
 #### Updated and Improved
 

docs/config/lua/config/text_blink_ease_in.md

@@ -0,0 +1,12 @@
+# text_blink_ease_in = "Ease"
+
+*Since: nightly builds only*
+
+Specifies the *easing function* to use when computing the color
+for text that has the blinking attribute in the fading-in
+phase--when the text is fading from the background color to the
+foreground color.
+
+See [visual_bell](visual_bell.md) for more information about
+easing functions.
+

docs/config/lua/config/text_blink_ease_out.md

@@ -0,0 +1,13 @@
+# text_blink_ease_out = "Ease"
+
+*Since: nightly builds only*
+
+Specifies the *easing function* to use when computing the color
+for text that has the blinking attribute in the fading-out
+phase--when the text is fading from the foreground color to the
+background color.
+
+See [visual_bell](visual_bell.md) for more information about
+easing functions.
+
+

docs/config/lua/config/text_blink_rapid_ease_in.md

@@ -0,0 +1,11 @@
+# text_blink_rapid_ease_in = "Ease"
+
+*Since: nightly builds only*
+
+Specifies the *easing function* to use when computing the color
+for text that has the rapid blinking attribute in the fading-in
+phase--when the text is fading from the background color to the
+foreground color.
+
+See [visual_bell](visual_bell.md) for more information about
+easing functions.

docs/config/lua/config/text_blink_rapid_ease_out.md

@@ -0,0 +1,12 @@
+# text_blink_rapid_ease_out = "Ease"
+
+*Since: nightly builds only*
+
+Specifies the *easing function* to use when computing the color
+for text that has the rapid blinking attribute in the fading-out
+phase--when the text is fading from the foreground color to the
+background color.
+
+See [visual_bell](visual_bell.md) for more information about
+easing functions.
+

docs/config/lua/config/text_blink_rate.md

@@ -13,3 +13,11 @@ return {
   text_blink_rate = 500
 }
 ```
+
+*Since: nightly builds only*
+
+Blinking is no longer a binary blink, but interpolates between invisible and
+visible text using an easing function.  See
+[text_blink_ease_in](text_blink_ease_in.md) and
+[text_blink_ease_out](text_blink_ease_out.md) for more information.
+

docs/config/lua/config/text_blink_rate_rapid.md

@@ -14,3 +14,10 @@ return {
 }
 ```
 
+*Since: nightly builds only*
+
+Blinking is no longer a binary blink, but interpolates between invisible and
+visible text using an easing function.  See
+[text_blink_rapid_ease_in](text_blink_rapid_ease_in.md) and
+[text_blink_rapid_ease_out](text_blink_rapid_ease_out.md) for more information.
+

wezterm-gui/src/termwindow/mod.rs

@@ -2,6 +2,7 @@
 use super::renderstate::*;
 use super::utilsprites::RenderMetrics;
 use crate::cache::LruCache;
+use crate::colorease::ColorEase;
 use crate::frontend::front_end;
 use crate::glium::texture::SrgbTexture2d;
 use crate::overlay::{
@@ -333,8 +334,8 @@ pub struct TermWindow {
 
     next_blink_paint: RefCell<Instant>,
     last_status_call: Instant,
-    last_text_blink_paint: RefCell<Instant>,
-    last_text_blink_paint_rapid: RefCell<Instant>,
+    blink_state: RefCell<ColorEase>,
+    rapid_blink_state: RefCell<ColorEase>,
 
     palette: Option<ColorPalette>,
 
@@ -725,8 +726,20 @@ impl TermWindow {
             )),
             next_blink_paint: RefCell::new(Instant::now()),
             last_status_call: Instant::now(),
-            last_text_blink_paint: RefCell::new(Instant::now()),
-            last_text_blink_paint_rapid: RefCell::new(Instant::now()),
+            blink_state: RefCell::new(ColorEase::new(
+                config.text_blink_rate,
+                config.text_blink_ease_in,
+                config.text_blink_rate,
+                config.text_blink_ease_out,
+                None,
+            )),
+            rapid_blink_state: RefCell::new(ColorEase::new(
+                config.text_blink_rate_rapid,
+                config.text_blink_rapid_ease_in,
+                config.text_blink_rate_rapid,
+                config.text_blink_rapid_ease_out,
+                None,
+            )),
             event_states: HashMap::new(),
             has_animation: RefCell::new(None),
             scheduled_animation: RefCell::new(None),
@@ -1361,6 +1374,20 @@ impl TermWindow {
         } else {
             self.show_tab_bar = config.enable_tab_bar;
         }
+        *self.blink_state.borrow_mut() = ColorEase::new(
+            config.text_blink_rate,
+            config.text_blink_ease_in,
+            config.text_blink_rate,
+            config.text_blink_ease_out,
+            None,
+        );
+        *self.rapid_blink_state.borrow_mut() = ColorEase::new(
+            config.text_blink_rate_rapid,
+            config.text_blink_rapid_ease_in,
+            config.text_blink_rate_rapid,
+            config.text_blink_rapid_ease_out,
+            None,
+        );
 
         self.show_scroll_bar = config.enable_scroll_bar;
         self.shape_cache.borrow_mut().clear();

wezterm-gui/src/termwindow/render.rs

@@ -30,7 +30,7 @@ use mux::tab::{PositionedPane, PositionedSplit, SplitDirection};
 use smol::Timer;
 use std::ops::Range;
 use std::rc::Rc;
-use std::time::{Duration, Instant, SystemTime, UNIX_EPOCH};
+use std::time::{Duration, Instant};
 use termwiz::cell::{unicode_column_width, Blink};
 use termwiz::cellcluster::CellCluster;
 use termwiz::surface::{CursorShape, CursorVisibility};
@@ -1578,6 +1578,8 @@ impl super::TermWindow {
                 let bg_color = params.palette.resolve_bg(attrs.background());
 
                 let fg_color = resolve_fg_color_attr(&attrs, attrs.foreground(), &params, style);
+                let fg_color = rgbcolor_to_window_color(fg_color);
+                let bg_color = rgbcolor_to_window_color(bg_color);
 
                 let (fg_color, bg_color, bg_is_default) = {
                     let mut fg = fg_color;
@@ -1596,49 +1598,48 @@ impl super::TermWindow {
                     // features.
                     let blink_rate = match attrs.blink() {
                         Blink::None => None,
-                        Blink::Slow => Some((
-                            params.config.text_blink_rate,
-                            self.last_text_blink_paint.borrow_mut(),
-                        )),
+                        Blink::Slow => {
+                            Some((params.config.text_blink_rate, self.blink_state.borrow_mut()))
+                        }
                         Blink::Rapid => Some((
                             params.config.text_blink_rate_rapid,
-                            self.last_text_blink_paint_rapid.borrow_mut(),
+                            self.rapid_blink_state.borrow_mut(),
                         )),
                     };
-                    if let Some((blink_rate, mut last_time)) = blink_rate {
+                    if let Some((blink_rate, mut colorease)) = blink_rate {
                         if blink_rate != 0 {
-                            let milli_uptime = SystemTime::now()
-                                .duration_since(UNIX_EPOCH)
-                                .unwrap()
-                                .as_millis();
+                            let intensity = colorease.intensity_continuous();
 
-                            let ticks = milli_uptime / blink_rate as u128;
-                            if (ticks & 1) == 0 {
-                                fg = bg;
-                            }
+                            let (r1, g1, b1, a) = bg.tuple();
+                            let (r, g, b, _a) = fg.tuple();
+                            fg = LinearRgba::with_components(
+                                r1 + (r - r1) * intensity,
+                                g1 + (g - g1) * intensity,
+                                b1 + (b - b1) * intensity,
+                                a,
+                            );
 
-                            let interval = Duration::from_millis(blink_rate);
-                            if last_time.elapsed() >= interval {
-                                *last_time = Instant::now();
-                            }
-                            let due = *last_time + interval;
-
-                            self.update_next_frame_time(Some(due));
+                            self.update_next_frame_time(Some(
+                                Instant::now()
+                                    + Duration::from_millis(1000 / self.config.max_fps as u64),
+                            ));
                         }
                     }
 
                     (fg, bg, bg_default)
                 };
 
-                let glyph_color = rgbcolor_to_window_color(fg_color);
+                let glyph_color = fg_color;
                 let underline_color = match attrs.underline_color() {
                     ColorAttribute::Default => fg_color,
-                    c => resolve_fg_color_attr(&attrs, c, &params, style),
+                    c => rgbcolor_to_window_color(resolve_fg_color_attr(&attrs, c, &params, style)),
                 };
-                let underline_color = rgbcolor_to_window_color(underline_color);
 
-                let bg_color = rgbcolor_alpha_to_window_color(
-                    bg_color,
+                let (bg_r, bg_g, bg_b, _) = bg_color.tuple();
+                let bg_color = LinearRgba::with_components(
+                    bg_r,
+                    bg_g,
+                    bg_b,
                     if params.window_is_transparent && bg_is_default {
                         0.0
                     } else {