Add option to apply opacity to all background colors

In some cases it could be desired to apply 'background_opacity'
to all background colors instead of just 'colors.primary.background',
thus adding an 'colors.opaque_background_colors' option to control that.

Fixes #741.

CHANGELOG.md

@@ -7,9 +7,14 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## 0.10.0-dev
 
+### Added
+
+- Option `colors.transparent_background_colors` to allow applying opacity to all background colors
+
 ### Changed
 
 - `ExpandSelection` is now a configurable mouse binding action
+- Config option `background_opacity`, you should use `window.opacity` instead
 
 ## 0.9.0
 

alacritty.yml

@@ -63,6 +63,12 @@
   #     - buttonless: Title bar, transparent background and no title bar buttons
   #decorations: full
 
+  # Background opacity
+  #
+  # Window opacity as a floating point number from `0.0` to `1.0`.
+  # The value `0.0` is completely transparent and `1.0` is opaque.
+  #opacity: 1.0
+
   # Startup Mode (changes require restart)
   #
   # Values for `startup_mode`:
@@ -312,6 +318,13 @@
   #
   #indexed_colors: []
 
+  # Transparent cell backgrounds
+  #
+  # Whether or not `window.opacity` applies to all cell backgrounds or only to
+  # the default background. When set to `true` all cells will be transparent
+  # regardless of their background color.
+  #transparent_background_colors: false
+
 # Bell
 #
 # The bell is rung every time the BEL control character is received.
@@ -353,12 +366,6 @@
   #
   #command: None
 
-# Background opacity
-#
-# Window opacity as a floating point number from `0.0` to `1.0`.
-# The value `0.0` is completely transparent and `1.0` is opaque.
-#background_opacity: 1.0
-
 #selection:
   # This string contains all characters that are used as separators for
   # "semantic words" in Alacritty.

alacritty/res/text.f.glsl

@@ -18,7 +18,7 @@ void main() {
         }
 
         alphaMask = vec4(1.0);
-        color = vec4(bg.rgb, 1.0);
+        color = vec4(bg.rgb, bg.a);
     } else if ((int(fg.a) & COLORED) != 0) {
         // Color glyphs, like emojis.
         vec4 glyphColor = texture(mask, TexCoords);

alacritty/res/text.v.glsl

@@ -65,6 +65,6 @@ void main() {
         TexCoords = uvOffset + position * uvSize;
     }
 
-    bg = vec4(backgroundColor.rgb / 255.0, backgroundColor.a);
+    bg = backgroundColor / 255.0;
     fg = vec4(textColor.rgb / 255.0, textColor.a);
 }

alacritty/src/config/color.rs

@@ -17,6 +17,7 @@ pub struct Colors {
     pub search: SearchColors,
     pub line_indicator: LineIndicatorColors,
     pub hints: HintColors,
+    pub transparent_background_colors: bool,
 }
 
 impl Colors {

alacritty/src/config/ui_config.rs

@@ -69,7 +69,8 @@ pub struct UiConfig {
     mouse_bindings: MouseBindings,
 
     /// Background opacity from 0.0 to 1.0.
-    background_opacity: Percentage,
+    #[config(deprecated = "use window.opacity instead")]
+    window_opacity: Option<Percentage>,
 }
 
 impl Default for UiConfig {
@@ -84,7 +85,7 @@ impl Default for UiConfig {
             config_paths: Default::default(),
             key_bindings: Default::default(),
             mouse_bindings: Default::default(),
-            background_opacity: Default::default(),
+            window_opacity: Default::default(),
             bell: Default::default(),
             colors: Default::default(),
             draw_bold_text_with_bright_colors: Default::default(),
@@ -115,8 +116,8 @@ impl UiConfig {
     }
 
     #[inline]
-    pub fn background_opacity(&self) -> f32 {
-        self.background_opacity.as_f32()
+    pub fn window_opacity(&self) -> f32 {
+        self.window_opacity.unwrap_or(self.window.opacity).as_f32()
     }
 
     #[inline]

alacritty/src/config/window.rs

@@ -7,7 +7,7 @@ use serde::de::{self, MapAccess, Visitor};
 use serde::{Deserialize, Deserializer};
 
 use alacritty_config_derive::ConfigDeserialize;
-use alacritty_terminal::config::LOG_TARGET_CONFIG;
+use alacritty_terminal::config::{Percentage, LOG_TARGET_CONFIG};
 use alacritty_terminal::index::Column;
 
 use crate::config::ui_config::Delta;
@@ -15,7 +15,7 @@ use crate::config::ui_config::Delta;
 /// Default Alacritty name, used for window title and class.
 pub const DEFAULT_NAME: &str = "Alacritty";
 
-#[derive(ConfigDeserialize, Debug, Clone, PartialEq, Eq)]
+#[derive(ConfigDeserialize, Debug, Clone, PartialEq)]
 pub struct WindowConfig {
     /// Initial position.
     pub position: Option<Delta<i32>>,
@@ -45,6 +45,9 @@ pub struct WindowConfig {
     /// Window class.
     pub class: Class,
 
+    /// Background opacity from 0.0 to 1.0.
+    pub opacity: Percentage,
+
     /// Pixel padding.
     padding: Delta<u8>,
 
@@ -64,6 +67,7 @@ impl Default for WindowConfig {
             gtk_theme_variant: Default::default(),
             dynamic_padding: Default::default(),
             class: Default::default(),
+            opacity: Default::default(),
             padding: Default::default(),
             dimensions: Default::default(),
         }

alacritty/src/display/content.rs

@@ -203,7 +203,7 @@ impl RenderableCell {
             mem::swap(&mut fg, &mut bg);
             1.0
         } else {
-            Self::compute_bg_alpha(cell.bg)
+            Self::compute_bg_alpha(&content.config.ui_config, cell.bg)
         };
 
         let is_selected = content.terminal_content.selection.map_or(false, |selection| {
@@ -350,9 +350,11 @@ impl RenderableCell {
     /// using the named input color, rather than checking the RGB of the background after its color
     /// is computed.
     #[inline]
-    fn compute_bg_alpha(bg: Color) -> f32 {
+    fn compute_bg_alpha(config: &UiConfig, bg: Color) -> f32 {
         if bg == Color::Named(NamedColor::Background) {
             0.
+        } else if config.colors.transparent_background_colors {
+            config.window_opacity()
         } else {
             1.
         }

alacritty/src/display/mod.rs

@@ -299,7 +299,7 @@ impl Display {
 
         // Disable shadows for transparent windows on macOS.
         #[cfg(target_os = "macos")]
-        window.set_has_shadow(config.ui_config.background_opacity() >= 1.0);
+        window.set_has_shadow(config.ui_config.window_opacity() >= 1.0);
 
         // On Wayland we can safely ignore this call, since the window isn't visible until you
         // actually draw something into it and commit those changes.

alacritty/src/event.rs

@@ -1436,7 +1436,7 @@ impl<N: Notify + OnResize> Processor<N> {
 
         // Disable shadows for transparent windows on macOS.
         #[cfg(target_os = "macos")]
-        processor.ctx.window().set_has_shadow(config.ui_config.background_opacity() >= 1.0);
+        processor.ctx.window().set_has_shadow(config.ui_config.window_opacity() >= 1.0);
 
         // Update hint keys.
         processor.ctx.display.hint_state.update_alphabet(config.ui_config.hints.alphabet());

alacritty/src/renderer/mod.rs

@@ -767,7 +767,7 @@ impl Drop for QuadRenderer {
 impl<'a> RenderApi<'a> {
     pub fn clear(&self, color: Rgb) {
         unsafe {
-            let alpha = self.config.background_opacity();
+            let alpha = self.config.window_opacity();
             gl::ClearColor(
                 (f32::from(color.r) / 255.0).min(1.0) * alpha,
                 (f32::from(color.g) / 255.0).min(1.0) * alpha,