render more symbol/icon/emoji at double width by default

Default `allow_square_glyphs_to_overflow_width="WhenFollowedBySpace"`,
and expand its meaning from mostly square glyphs to glyphs that are
also wider than they are tall.

refs: https://github.com/wez/wezterm/issues/565

config/src/font.rs

@@ -354,7 +354,7 @@ pub enum AllowSquareGlyphOverflow {
 
 impl Default for AllowSquareGlyphOverflow {
     fn default() -> Self {
-        Self::Never
+        Self::WhenFollowedBySpace
     }
 }
 

docs/changelog.md

@@ -20,6 +20,7 @@ brief notes about them may accumulate here.
 * Fixed: panic when dismissing the tab navigator [#542](https://github.com/wez/wezterm/issues/542)
 * Fixed: font fallback on macOS returns unresolvable `.AppleSymbolsFB` rather than `Apple Symbols`, leading to slowdowns when rendering symbols [#506](https://github.com/wez/wezterm/issues/506)
 * Fixed: laggy repaints for large windows particularly on Windows, but applicable to all systems.  Tuned and triple-buffered vertex buffer updates. [#546](https://github.com/wez/wezterm/issues/546)
+* Changed: [allow_square_glyphs_to_overflow_width](config/lua/config/allow_square_glyphs_to_overflow_width.md) now defaults to `WhenFollowedBySpace` and applies to more symbol glyphs. [#565](https://github.com/wez/wezterm/issues/565)
 
 ### 20210314-114017-04b7cedd
 

docs/config/lua/config/allow_square_glyphs_to_overflow_width.md

@@ -9,3 +9,11 @@ Configures how square symbol glyph's cell is rendered:
 * "Always" - overflow the cell regardless of the next cell
   being a space.
 * "Never" (the default) - strictly respect the cell width.
+
+*Since: nightly builds*
+
+This setting now applies to any glyph with an aspect ratio
+larger than 0.9, which covers more symbol glyphs than in
+earlier releases.
+
+The default value for this setting has changed to `WhenFollowedBySpace`.

wezterm-gui/src/glyphcache.rs

@@ -440,9 +440,9 @@ impl<T: Texture2d> GlyphCache<T> {
             base_metrics.cell_width.get() / (idx_metrics.cell_width.get() / info.num_cells as f64);
 
         let aspect = (idx_metrics.cell_height / idx_metrics.cell_width).get();
-        let is_square = aspect >= 0.9 && aspect <= 1.1;
+        let is_square_or_wide = aspect >= 0.9;
 
-        let allow_width_overflow = if is_square {
+        let allow_width_overflow = if is_square_or_wide {
             match configuration().allow_square_glyphs_to_overflow_width {
                 AllowSquareGlyphOverflow::Never => false,
                 AllowSquareGlyphOverflow::Always => true,
@@ -489,13 +489,14 @@ impl<T: Texture2d> GlyphCache<T> {
 
             let (scale, raw_im) = if scale != 1.0 {
                 log::trace!(
-                    "physically scaling {:?} by {} bcos {}x{} > {:?}x{:?}",
+                    "physically scaling {:?} by {} bcos {}x{} > {:?}x{:?}. aspect={}",
                     info,
                     scale,
                     glyph.width,
                     glyph.height,
                     cell_width,
-                    cell_height
+                    cell_height,
+                    aspect,
                 );
                 (1.0, raw_im.scale_by(scale))
             } else {