fix: text wrapping logic with leading empty space

alibaba · Aug 31, 2023 · 436ee47 · 436ee47
1 parent abb4115
commit 436ee47
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Showing 3 changed files with 29 additions and 7 deletions.
diff --git a/Cargo.toml b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "fontkit"
-version = "0.4.1"
+version = "0.4.4"
 edition = "2021"
 authors = ["Zimon Dai <daizhuoxian@gmail.com>"]
 description = "A simple library for font loading and indexing"

diff --git a/package.json b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "fontkit-rs",
-  "version": "0.0.5",
+  "version": "0.0.6",
   "description": "Toolkit used to load, match, measure, and render texts",
   "main": "pkg/bundler/index.js",
   "directories": {

diff --git a/src/metrics/compose.rs b/src/metrics/compose.rs
@@ -55,6 +55,9 @@ pub struct Span<T> {
 
 impl<T> Span<T> {
     fn width(&self) -> f32 {
+        if self.metrics.positions.is_empty() {
+            return 0.0;
+        }
         let mut width = self.metrics.width(self.size, self.letter_spacing);
         if self.swallow_leading_space && self.metrics.positions[0].metrics.c == ' ' {
             let c = &self.metrics.positions[0];
@@ -291,7 +294,7 @@ where
                     let mut current_real_index = real_index;
                     while span.metrics.positions()[current_real_index].metrics.c == ' '
                         && span_values
-                            .get(current_real_index)
+                            .get(current_real_index - real_index)
                             .map(|c| *c != ' ')
                             .unwrap_or(true)
                     {
@@ -303,9 +306,9 @@ where
                     }
                     let factor = span.size / span.metrics.units() as f32;
                     let range = if rtl {
-                        (current_real_index + 1 - count)..total_count
+                        (current_real_index + 1 - count)..current_real_index
                     } else {
-                        0..(current_real_index + count)
+                        current_real_index..(current_real_index + count)
                     };
                     let acc_seg_width = range
                         .map(|index| span.metrics.positions.get(index).unwrap())
@@ -315,20 +318,39 @@ where
                                 + p.metrics.advanced_x as f32 * factor
                                 + span.letter_spacing
                         });
-                    if current_line_width + acc_seg_width <= width {
+                    let acc_seg_width_with_space = if current_real_index == real_index {
+                        acc_seg_width
+                    } else {
+                        let range = if rtl {
+                            (current_real_index + 1 - count)..real_index
+                        } else {
+                            real_index..(current_real_index + count)
+                        };
+                        range
+                            .map(|index| span.metrics.positions.get(index).unwrap())
+                            .fold(0.0, |current, p| {
+                                current
+                                    + p.kerning as f32 * factor
+                                    + p.metrics.advanced_x as f32 * factor
+                                    + span.letter_spacing
+                            })
+                    };
+                    if current_line_width + acc_seg_width_with_space <= width {
                         if rtl {
                             real_index = current_real_index - count;
                         } else {
                             real_index = current_real_index + count;
                         }
+                        current_line_width += acc_seg_width;
                     } else {
+                        real_index = current_real_index;
                         break;
                     }
                 }
                 if (real_index == 0 && !rtl)
                     || (rtl && real_index == span.metrics.positions.len() - 1)
                 {
-                    real_index = naive_break_index
+                    real_index = naive_break_index;
                 }
 
                 // Split here, create a new span