config: allow using bright but not bold text when brightening text

In https://github.com/wez/wezterm/issues/2932 the user desired to have
brightened text without the boldness, as they were accustomed to that
behavior in a couple of other terminal emulators.

This commit changes the `bold_brightens_ansi_colors` from a simple
boolean to a tristate that allows for not changing the brightness,
changing the brightness, and changing the brightness while adjusting
the boldness down to normal levels.

boolean values are accepted for backwards compatibility.

config/src/config.rs

@@ -102,8 +102,8 @@ pub struct Config {
     /// When true (the default), PaletteIndex 0-7 are shifted to
     /// bright when the font intensity is bold.  The brightening
     /// doesn't apply to text that is the default color.
-    #[dynamic(default = "default_true")]
-    pub bold_brightens_ansi_colors: bool,
+    #[dynamic(default)]
+    pub bold_brightens_ansi_colors: BoldBrightening,
 
     /// The color palette
     pub colors: Option<Palette>,
@@ -1729,6 +1729,45 @@ fn default_line_to_ele_shape_cache_size() -> usize {
     1024
 }
 
+#[derive(Debug, ToDynamic, Clone, Copy, PartialEq, Eq)]
+pub enum BoldBrightening {
+    /// Bold doesn't influence palette selection
+    No,
+    /// Bold Shifts palette from 0-7 to 8-15 and preserves bold font
+    BrightAndBold,
+    /// Bold Shifts palette from 0-7 to 8-15 and removes bold intensity
+    BrightOnly,
+}
+
+impl FromDynamic for BoldBrightening {
+    fn from_dynamic(
+        value: &wezterm_dynamic::Value,
+        options: wezterm_dynamic::FromDynamicOptions,
+    ) -> Result<Self, wezterm_dynamic::Error> {
+        match String::from_dynamic(value, options) {
+            Ok(s) => match s.as_str() {
+                "No" => Ok(Self::No),
+                "BrightAndBold" => Ok(Self::BrightAndBold),
+                "BrightOnly" => Ok(Self::BrightOnly),
+                s => Err(wezterm_dynamic::Error::Message(format!(
+                    "`{s}` is not valid, use one of `None`, `BrightAndBold` or `BrightOnly`"
+                ))),
+            },
+            Err(err) => match bool::from_dynamic(value, options) {
+                Ok(true) => Ok(Self::BrightAndBold),
+                Ok(false) => Ok(Self::No),
+                Err(_) => Err(err),
+            },
+        }
+    }
+}
+
+impl Default for BoldBrightening {
+    fn default() -> Self {
+        BoldBrightening::BrightAndBold
+    }
+}
+
 #[derive(Debug, FromDynamic, ToDynamic, Clone, Copy, PartialEq, Eq)]
 pub enum ImePreeditRendering {
     /// IME preedit is rendered by WezTerm itself

docs/changelog.md

@@ -49,6 +49,9 @@ As features stabilize some brief notes about them will accumulate here.
   [@Abdiramen](https://github.com/Abdiramen)!
   [#2889](https://github.com/wez/wezterm/pull/2889)
   [#2782](https://github.com/wez/wezterm/issues/2782)
+* [bold_brightens_ansi_colors](config/lua/config/bold_brightens_ansi_colors.md)
+  now supports `"BrightOnly"` to use the bright color without selecting a bold
+  font. [#2932](https://github.com/wez/wezterm/issues/2932)
 
 #### Updated
 * Bundled harfbuzz updated to version 6.0.0

docs/config/lua/config/bold_brightens_ansi_colors.md

@@ -11,3 +11,15 @@ range of mature software; for instance, a lot of software
 assumes that Black+Bold renders as a Dark Grey which is
 legible on a Black background, but if this option is set to
 false, it would render as Black on Black.
+
+*Since: nightly builds only*
+
+This option can now have one of three values:
+
+* `"No"` - the bold attribute will not influence palette selection
+* `"BrightAndBold"` - the bold attribute will select a bright version of palette indices 0-7 and preserve the bold attribute on the text, using both a bold font and a brighter color
+* `"BrightOnly"` - the bold attribute will select a bright version of palette indices 0-7 but the intensity will be treated as normal and a non-bold font will be used for the text.
+
+You may use `true` or `false` for backwards compatibility.  `true` is
+equivalent to `"BrightAndBold"` and `false` is equivalent to `"No"`.
+

wezterm-font/src/lib.rs

@@ -5,8 +5,8 @@ use crate::rasterizer::{new_rasterizer, FontRasterizer};
 use crate::shaper::{new_shaper, FontShaper, PresentationWidth};
 use anyhow::{Context, Error};
 use config::{
-    configuration, ConfigHandle, FontAttributes, FontRasterizerSelection, FontStretch, FontStyle,
-    FontWeight, TextStyle,
+    configuration, BoldBrightening, ConfigHandle, FontAttributes, FontRasterizerSelection,
+    FontStretch, FontStyle, FontWeight, TextStyle,
 };
 use rangeset::RangeSet;
 use std::cell::RefCell;
@@ -19,7 +19,7 @@ use std::time::{Duration, Instant};
 use termwiz::cell::Presentation;
 use thiserror::Error;
 use wezterm_bidi::Direction;
-use wezterm_term::CellAttributes;
+use wezterm_term::{CellAttributes, Intensity};
 use wezterm_toast_notification::ToastNotification;
 
 mod hbwrap;
@@ -995,8 +995,27 @@ impl FontConfigInner {
             };
         }
 
+        let would_bright = match attrs.foreground() {
+            wezterm_term::color::ColorAttribute::PaletteIndex(idx) if idx < 8 => {
+                attrs.intensity() == Intensity::Bold
+            }
+            _ => false,
+        };
+
         for rule in &config.font_rules {
-            attr_match!(intensity, &rule);
+            if let Some(intensity) = rule.intensity {
+                let effective_intensity = match config.bold_brightens_ansi_colors {
+                    BoldBrightening::BrightOnly if would_bright => Intensity::Normal,
+                    BoldBrightening::No
+                    | BoldBrightening::BrightAndBold
+                    | BoldBrightening::BrightOnly => attrs.intensity(),
+                };
+                if intensity != effective_intensity {
+                    // Rule does not match
+                    continue;
+                }
+                // matches so far
+            }
             attr_match!(underline, &rule);
             attr_match!(italic, &rule);
             attr_match!(blink, &rule);

wezterm-gui/src/termwindow/render.rs

@@ -25,8 +25,8 @@ use ::window::glium::{BlendingFunction, LinearBlendingFactor, Surface};
 use ::window::{glium, DeadKeyStatus, PointF, RectF, SizeF, ULength, WindowOps};
 use anyhow::anyhow;
 use config::{
-    ConfigHandle, Dimension, DimensionContext, FreeTypeLoadTarget, HsbTransform, TabBarColors,
-    TextStyle, VisualBellTarget,
+    BoldBrightening, ConfigHandle, Dimension, DimensionContext, FreeTypeLoadTarget, HsbTransform,
+    TabBarColors, TextStyle, VisualBellTarget,
 };
 use euclid::num::Zero;
 use mux::pane::{Pane, PaneId, WithPaneLines};
@@ -3738,7 +3738,7 @@ fn resolve_fg_color_attr(
             }
         }
         wezterm_term::color::ColorAttribute::PaletteIndex(idx)
-            if idx < 8 && config.bold_brightens_ansi_colors =>
+            if idx < 8 && config.bold_brightens_ansi_colors != BoldBrightening::No =>
         {
             // For compatibility purposes, switch to a brighter version
             // of one of the standard ANSI colors when Bold is enabled.