Make Galleys share Rows and store their offsets

crates/egui/src/text_selection/accesskit_text.rs

@@ -39,11 +39,11 @@ pub fn update_accesskit_for_text_widget(
     };
 
     ctx.with_accessibility_parent(parent_id, || {
-        for (row_index, row) in galley.rows.iter().enumerate() {
+        for (row_index, (row, offset)) in galley.rows.iter().enumerate() {
             let row_id = parent_id.with(row_index);
             ctx.accesskit_node_builder(row_id, |builder| {
                 builder.set_role(accesskit::Role::TextRun);
-                let rect = row.rect.translate(galley_pos.to_vec2());
+                let rect = row.rect.translate(offset.to_vec2() + galley_pos.to_vec2());
                 builder.set_bounds(accesskit::Rect {
                     x0: rect.min.x.into(),
                     y0: rect.min.y.into(),

crates/egui/src/text_selection/cursor_range.rs

@@ -284,7 +284,7 @@ fn ccursor_from_accesskit_text_position(
     position: &accesskit::TextPosition,
 ) -> Option<CCursor> {
     let mut total_length = 0usize;
-    for (i, row) in galley.rows.iter().enumerate() {
+    for (i, (row, _)) in galley.rows.iter().enumerate() {
         let row_id = id.with(i);
         if row_id.accesskit_id() == position.node {
             return Some(CCursor {

crates/egui/src/text_selection/label_text_selection.rs

@@ -179,7 +179,10 @@ impl LabelSelectionState {
                                 if let epaint::Shape::Text(text_shape) = &mut shape.shape {
                                     let galley = Arc::make_mut(&mut text_shape.galley);
                                     for row_selection in row_selections {
-                                        if let Some(row) = galley.rows.get_mut(row_selection.row) {
+                                        if let Some((row, _)) =
+                                            galley.rows.get_mut(row_selection.row)
+                                        {
+                                            let row = Arc::make_mut(row);
                                             for vertex_index in row_selection.vertex_indices {
                                                 if let Some(vertex) = row
                                                     .visuals
@@ -659,7 +662,7 @@ fn selected_text(galley: &Galley, cursor_range: &CursorRange) -> String {
 }
 
 fn estimate_row_height(galley: &Galley) -> f32 {
-    if let Some(row) = galley.rows.first() {
+    if let Some((row, _)) = galley.rows.first() {
         row.rect.height()
     } else {
         galley.size().y

crates/egui/src/text_selection/visuals.rs

@@ -31,7 +31,9 @@ pub fn paint_text_selection(
     let max = max.rcursor;
 
     for ri in min.row..=max.row {
-        let row = &mut galley.rows[ri];
+        let (row, _) = &mut galley.rows[ri];
+        let row = Arc::make_mut(row);
+
         let left = if ri == min.row {
             row.x_offset(min.column)
         } else {

crates/egui/src/widget_text.rs

@@ -640,7 +640,7 @@ impl WidgetText {
             Self::RichText(text) => text.font_height(fonts, style),
             Self::LayoutJob(job) => job.font_height(fonts),
             Self::Galley(galley) => {
-                if let Some(row) = galley.rows.first() {
+                if let Some((row, _)) = galley.rows.first() {
                     row.height()
                 } else {
                     galley.size().y

crates/egui/src/widgets/label.rs

@@ -1,8 +1,8 @@
 use std::sync::Arc;
 
 use crate::{
-    epaint, pos2, text_selection, vec2, Align, Direction, FontSelection, Galley, Pos2, Response,
-    Sense, Stroke, TextWrapMode, Ui, Widget, WidgetInfo, WidgetText, WidgetType,
+    epaint, pos2, text_selection, Align, Direction, FontSelection, Galley, Pos2, Response, Sense,
+    Stroke, TextWrapMode, Ui, Widget, WidgetInfo, WidgetText, WidgetType,
 };
 
 use self::text_selection::LabelSelectionState;
@@ -194,10 +194,13 @@ impl Label {
             let pos = pos2(ui.max_rect().left(), ui.cursor().top());
             assert!(!galley.rows.is_empty(), "Galleys are never empty");
             // collect a response from many rows:
-            let rect = galley.rows[0].rect.translate(vec2(pos.x, pos.y));
+            let rect = galley.rows[0]
+                .0
+                .rect
+                .translate(galley.rows[0].1.to_vec2() + pos.to_vec2());
             let mut response = ui.allocate_rect(rect, sense);
-            for row in galley.rows.iter().skip(1) {
-                let rect = row.rect.translate(vec2(pos.x, pos.y));
+            for (row, offset) in galley.rows.iter().skip(1) {
+                let rect = row.rect.translate(offset.to_vec2() + pos.to_vec2());
                 response |= ui.allocate_rect(rect, sense);
             }
             (pos, galley, response)

crates/epaint/src/shape.rs

@@ -433,7 +433,9 @@ impl Shape {
 
                 // Scale text:
                 let galley = Arc::make_mut(&mut text_shape.galley);
-                for row in &mut galley.rows {
+                for (row, offset) in &mut galley.rows {
+                    let row = Arc::make_mut(row);
+                    *offset = *offset * transform.scaling;
                     row.visuals.mesh_bounds = transform.scaling * row.visuals.mesh_bounds;
                     for v in &mut row.visuals.mesh.vertices {
                         v.pos = Pos2::new(transform.scaling * v.pos.x, transform.scaling * v.pos.y);

crates/epaint/src/shape_transform.rs

@@ -88,7 +88,8 @@ pub fn adjust_colors(
 
             if !galley.is_empty() {
                 let galley = std::sync::Arc::make_mut(galley);
-                for row in &mut galley.rows {
+                for (row, _) in &mut galley.rows {
+                    let row = Arc::make_mut(row);
                     for vertex in &mut row.visuals.mesh.vertices {
                         adjust_color(&mut vertex.color);
                     }

crates/epaint/src/stats.rs

@@ -88,7 +88,11 @@ impl AllocInfo {
     pub fn from_galley(galley: &Galley) -> Self {
         Self::from_slice(galley.text().as_bytes())
             + Self::from_slice(&galley.rows)
-            + galley.rows.iter().map(Self::from_galley_row).sum()
+            + galley
+                .rows
+                .iter()
+                .map(|(row, _)| Self::from_galley_row(row))
+                .sum()
     }
 
     fn from_galley_row(row: &crate::text::Row) -> Self {
@@ -213,8 +217,8 @@ impl PaintStats {
                 self.shape_text += AllocInfo::from_galley(&text_shape.galley);
 
                 for row in &text_shape.galley.rows {
-                    self.text_shape_indices += AllocInfo::from_slice(&row.visuals.mesh.indices);
-                    self.text_shape_vertices += AllocInfo::from_slice(&row.visuals.mesh.vertices);
+                    self.text_shape_indices += AllocInfo::from_slice(&row.0.visuals.mesh.indices);
+                    self.text_shape_vertices += AllocInfo::from_slice(&row.0.visuals.mesh.vertices);
                 }
             }
             Shape::Mesh(mesh) => {

crates/epaint/src/tessellator.rs

@@ -1778,16 +1778,18 @@ impl Tessellator {
 
         let rotator = Rot2::from_angle(*angle);
 
-        for row in &galley.rows {
+        for (row, row_pos) in &galley.rows {
             if row.visuals.mesh.is_empty() {
                 continue;
             }
 
+            let final_pos = galley_pos + row_pos.to_vec2();
+
             let mut row_rect = row.visuals.mesh_bounds;
             if *angle != 0.0 {
                 row_rect = row_rect.rotate_bb(rotator);
             }
-            row_rect = row_rect.translate(galley_pos.to_vec2());
+            row_rect = row_rect.translate(final_pos.to_vec2());
 
             if self.options.coarse_tessellation_culling && !self.clip_rect.intersects(row_rect) {
                 // culling individual lines of text is important, since a single `Shape::Text`
@@ -1836,7 +1838,7 @@ impl Tessellator {
                         };
 
                         Vertex {
-                            pos: galley_pos + offset,
+                            pos: final_pos + offset,
                             uv: (uv.to_vec2() * uv_normalizer).to_pos2(),
                             color,
                         }

crates/epaint/src/text/fonts.rs

@@ -832,34 +832,14 @@ impl GalleyCache {
 
                     for galley in galleys {
                         let current_offset = emath::vec2(0.0, merged_galley.rect.height());
-                        merged_galley.rows.extend(galley.rows.iter().map(|row| {
-                            super::Row {
-                                // FIXME: what is this???
-                                section_index_at_start: row.section_index_at_start,
-                                glyphs: row
-                                    .glyphs
-                                    .iter()
-                                    .cloned()
-                                    .map(|mut p| {
-                                        p.pos.y += current_offset.y;
-                                        p
-                                    })
-                                    .collect(),
-                                rect: row.rect.translate(current_offset),
-                                visuals: {
-                                    let mut visuals = row.visuals.clone();
-                                    for vertex in visuals.mesh.vertices.iter_mut() {
-                                        vertex.pos.y += current_offset.y;
-                                    }
-                                    visuals.mesh_bounds =
-                                        visuals.mesh_bounds.translate(current_offset);
-                                    merged_galley.mesh_bounds =
-                                        merged_galley.mesh_bounds.union(visuals.mesh_bounds);
-                                    visuals
-                                },
-                                ends_with_newline: row.ends_with_newline,
-                            }
-                        }));
+                        merged_galley
+                            .rows
+                            .extend(galley.rows.iter().map(|(row, prev_offset)| {
+                                merged_galley.mesh_bounds =
+                                    merged_galley.mesh_bounds.union(row.visuals.mesh_bounds);
+
+                                (row.clone(), *prev_offset + current_offset)
+                            }));
                         merged_galley.rect = merged_galley
                             .rect
                             .union(galley.rect.translate(current_offset));