From e080e0d5de727f4c152492653ec627d0feb9e825 Mon Sep 17 00:00:00 2001
From: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>
Date: Sat, 28 Mar 2026 15:31:06 +0100
Subject: [PATCH] Remove the old pair_kerning path

---
 Cargo.lock                            |  8 -----
 crates/epaint/src/text/font.rs        | 46 +--------------------------
 crates/epaint/src/text/text_layout.rs | 27 +++-------------
 3 files changed, 5 insertions(+), 76 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ed2c5f46f..47fd9501d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4096,14 +4096,6 @@ dependencies = [
  "log",
 ]
 
-[[package]]
-name = "shaping_demo"
-version = "0.1.0"
-dependencies = [
- "eframe",
- "env_logger",
-]
-
 [[package]]
 name = "shlex"
 version = "1.3.0"
diff --git a/crates/epaint/src/text/font.rs b/crates/epaint/src/text/font.rs
index e3ae9f840..a0e3c965d 100644
--- a/crates/epaint/src/text/font.rs
+++ b/crates/epaint/src/text/font.rs
@@ -2,10 +2,7 @@
 
 use emath::{GuiRounding as _, OrderedFloat, Vec2, vec2};
 use self_cell::self_cell;
-use skrifa::{
-    MetadataProvider as _,
-    raw::{TableProvider as _, tables::kern::SubtableKind},
-};
+use skrifa::MetadataProvider as _;
 use std::collections::BTreeMap;
 use vello_cpu::{color, kurbo};
 
@@ -44,8 +41,6 @@ impl UvRect {
 
 #[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
 pub struct GlyphInfo {
-    /// Used for pair-kerning.
-    ///
     /// Doesn't need to be unique.
     ///
     /// Is `None` for a special "invisible" glyph.
@@ -126,12 +121,6 @@ impl SubpixelBin {
 
 #[derive(Clone, Copy, Debug, PartialEq, Default)]
 pub struct GlyphAllocation {
-    /// The glyph ID in the font face that produced this allocation.
-    ///
-    /// Used for legacy `kern` table lookup when positioning the overflow
-    /// character (e.g. `…`) during text truncation.
-    pub(crate) id: skrifa::GlyphId,
-
     /// Unit: screen pixels.
     pub advance_width_px: f32,
 
@@ -289,7 +278,6 @@ impl FontCell {
         };
 
         Some(GlyphAllocation {
-            id: glyph_id,
             advance_width_px: glyph_info.advance_width_unscaled.0 * metrics.px_scale_factor,
             uv_rect,
         })
@@ -504,38 +492,6 @@ impl FontFace {
         Some(glyph_info)
     }
 
-    #[inline]
-    pub(super) fn pair_kerning_pixels(
-        &self,
-        metrics: &StyledMetrics,
-        last_glyph_id: skrifa::GlyphId,
-        glyph_id: skrifa::GlyphId,
-    ) -> f32 {
-        let skrifa_font = &self.font.borrow_dependent().skrifa;
-        let Ok(kern) = skrifa_font.kern() else {
-            return 0.0;
-        };
-        kern.subtables()
-            .find_map(|st| match st.ok()?.kind().ok()? {
-                SubtableKind::Format0(table_ref) => table_ref.kerning(last_glyph_id, glyph_id),
-                SubtableKind::Format1(_) => None,
-                SubtableKind::Format2(subtable2) => subtable2.kerning(last_glyph_id, glyph_id),
-                SubtableKind::Format3(table_ref) => table_ref.kerning(last_glyph_id, glyph_id),
-            })
-            .unwrap_or_default() as f32
-            * metrics.px_scale_factor
-    }
-
-    #[inline]
-    pub fn pair_kerning(
-        &self,
-        metrics: &StyledMetrics,
-        last_glyph_id: skrifa::GlyphId,
-        glyph_id: skrifa::GlyphId,
-    ) -> f32 {
-        self.pair_kerning_pixels(metrics, last_glyph_id, glyph_id) / metrics.pixels_per_point
-    }
-
     #[inline(always)]
     pub fn styled_metrics(
         &self,
diff --git a/crates/epaint/src/text/text_layout.rs b/crates/epaint/src/text/text_layout.rs
index ca7d27e1c..9077f33fc 100644
--- a/crates/epaint/src/text/text_layout.rs
+++ b/crates/epaint/src/text/text_layout.rs
@@ -664,33 +664,14 @@ fn replace_last_glyph_with_overflow_character(
             .unwrap_or_default();
 
         let overflow_glyph_x = if let Some(prev_glyph) = row.glyphs.last() {
-            // Kern the overflow character properly
-            let pair_kerning = font_face
-                .as_mut()
-                .map(|font_face| {
-                    if let (Some(prev_glyph_id), Some(overflow_glyph_id)) = (
-                        font_face.glyph_info(prev_glyph.chr).and_then(|g| g.id),
-                        font_face.glyph_info(overflow_character).and_then(|g| g.id),
-                    ) {
-                        font_face.pair_kerning(&font_face_metrics, prev_glyph_id, overflow_glyph_id)
-                    } else {
-                        0.0
-                    }
-                })
-                .unwrap_or_default();
-
-            prev_glyph.max_x() + extra_letter_spacing + pair_kerning
+            prev_glyph.max_x() + extra_letter_spacing
         } else {
             0.0 // TODO(emilk): heed paragraph leading_space 😬
         };
 
-        let replacement_glyph_width = font_face
-            .as_mut()
-            .and_then(|f| f.glyph_info(overflow_character))
-            .map(|i| {
-                i.advance_width_unscaled.0 * font_face_metrics.px_scale_factor / pixels_per_point
-            })
-            .unwrap_or_default();
+        let replacement_glyph_width = glyph_info.advance_width_unscaled.0
+            * font_face_metrics.px_scale_factor
+            / pixels_per_point;
 
         // Check if we're within width budget:
         if overflow_glyph_x + replacement_glyph_width <= job.effective_wrap_width()