Fix visual bell rendering mode

Fixes #2911.

CHANGELOG.md

@@ -73,6 +73,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Crash when trying to start on X11 with a Wayland compositor running
 - Crash with a virtual display connected on X11
 - Use `\` instead of `\\` as path separators on Windows for logging config file location
+- Underline/strikeout drawn above visual bell
+- Terminal going transparent during visual bell
 
 ### Removed
 

alacritty/src/display.rs

@@ -400,27 +400,33 @@ impl Display {
 
         let mut rects = lines.into_rects(&metrics, &size_info);
 
+        // Push visual bell after underline/strikeout rects
+        if visual_bell_intensity != 0. {
+            let visual_bell_rect = RenderRect::new(
+                0.,
+                0.,
+                size_info.width,
+                size_info.height,
+                config.visual_bell.color,
+                visual_bell_intensity as f32,
+            );
+            rects.push(visual_bell_rect);
+        }
+
         if let Some(message) = message_buffer.message() {
             let text = message.text(&size_info);
 
             // Create a new rectangle for the background
             let start_line = size_info.lines().0 - text.len();
             let y = size_info.padding_y + size_info.cell_height * start_line as f32;
-            rects.push(RenderRect::new(
-                0.,
-                y,
-                size_info.width,
-                size_info.height - y,
-                message.color(),
-            ));
+            let message_bar_rect =
+                RenderRect::new(0., y, size_info.width, size_info.height - y, message.color(), 1.);
 
-            // Draw rectangles including the new background
-            self.renderer.draw_rects(
-                &size_info,
-                config.visual_bell.color,
-                visual_bell_intensity,
-                rects,
-            );
+            // Push message_bar in the end, so it'll be above all other content
+            rects.push(message_bar_rect);
+
+            // Draw rectangles
+            self.renderer.draw_rects(&size_info, rects);
 
             // Relay messages to the user
             let mut offset = 1;
@@ -437,12 +443,7 @@ impl Display {
             }
         } else {
             // Draw rectangles
-            self.renderer.draw_rects(
-                &size_info,
-                config.visual_bell.color,
-                visual_bell_intensity,
-                rects,
-            );
+            self.renderer.draw_rects(&size_info, rects);
         }
 
         // Draw render timer

alacritty_terminal/src/renderer/mod.rs

@@ -713,13 +713,7 @@ impl QuadRenderer {
     }
 
     // Draw all rectangles simultaneously to prevent excessive program swaps
-    pub fn draw_rects(
-        &mut self,
-        props: &term::SizeInfo,
-        visual_bell_color: Rgb,
-        visual_bell_intensity: f64,
-        cell_line_rects: Vec<RenderRect>,
-    ) {
+    pub fn draw_rects(&mut self, props: &term::SizeInfo, rects: Vec<RenderRect>) {
         // Swap to rectangle rendering program
         unsafe {
             // Swap program
@@ -729,7 +723,7 @@ impl QuadRenderer {
             gl::Viewport(0, 0, props.width as i32, props.height as i32);
 
             // Change blending strategy
-            gl::BlendFunc(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
+            gl::BlendFuncSeparate(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA, gl::SRC_ALPHA, gl::ONE);
 
             // Setup data and buffers
             gl::BindVertexArray(self.rect_vao);
@@ -747,13 +741,9 @@ impl QuadRenderer {
             gl::EnableVertexAttribArray(0);
         }
 
-        // Draw visual bell
-        let rect = RenderRect::new(0., 0., props.width, props.height, visual_bell_color);
-        self.render_rect(&rect, visual_bell_intensity as f32, props);
-
-        // Draw underlines and strikeouts
-        for cell_line_rect in cell_line_rects {
-            self.render_rect(&cell_line_rect, 255., props);
+        // Draw all the rects
+        for rect in rects {
+            self.render_rect(&rect, props);
         }
 
         // Deactivate rectangle program again
@@ -881,9 +871,9 @@ impl QuadRenderer {
     // Render a rectangle
     //
     // This requires the rectangle program to be activated
-    fn render_rect(&mut self, rect: &RenderRect, alpha: f32, size: &term::SizeInfo) {
+    fn render_rect(&mut self, rect: &RenderRect, size: &term::SizeInfo) {
         // Do nothing when alpha is fully transparent
-        if alpha == 0. {
+        if rect.alpha == 0. {
             return;
         }
 
@@ -908,7 +898,7 @@ impl QuadRenderer {
             );
 
             // Color
-            self.rect_program.set_color(rect.color, alpha);
+            self.rect_program.set_color(rect.color, rect.alpha);
 
             // Draw the rectangle
             gl::DrawElements(gl::TRIANGLES, 6, gl::UNSIGNED_INT, ptr::null());

alacritty_terminal/src/renderer/rects.rs

@@ -27,11 +27,12 @@ pub struct RenderRect {
     pub width: f32,
     pub height: f32,
     pub color: Rgb,
+    pub alpha: f32,
 }
 
 impl RenderRect {
-    pub fn new(x: f32, y: f32, width: f32, height: f32, color: Rgb) -> Self {
-        RenderRect { x, y, width, height, color }
+    pub fn new(x: f32, y: f32, width: f32, height: f32, color: Rgb, alpha: f32) -> Self {
+        RenderRect { x, y, width, height, color, alpha }
     }
 }
 
@@ -65,7 +66,7 @@ impl RenderLine {
             y = max_y;
         }
 
-        RenderRect::new(start_x + size.padding_x, y + size.padding_y, width, height, self.color)
+        RenderRect::new(start_x + size.padding_x, y + size.padding_y, width, height, self.color, 1.)
     }
 }