Merge pull request #5 from JetBrains/fix-ligatures-cursor

Fix cursor position in ligatures

.github/workflows/build.yml

@@ -14,7 +14,7 @@ on:
         default: 'false'
 
 env:
-  version: m99-f85ab491eb
+  version: m99-f85ab491eb-2
 
 jobs:
   macos:

README.md

@@ -13,15 +13,15 @@ Update `version` in [.github/workflows/build.yml](https://github.com/JetBrains/s
 ## Building locally
 
 ```sh
-python3 script/checkout.py --version m99-f85ab491eb
+python3 script/checkout.py --version m99-f85ab491eb-2
 python3 script/build.py
 python3 script/archive.py
 ```
 
 To build a debug build:
 
 ```sh
-python3 script/checkout.py --version m99-f85ab491eb
+python3 script/checkout.py --version m99-f85ab491eb-2
 python3 script/build.py --build-type Debug
 python3 script/archive.py --build-type Debug
 ```

patches/Fix_glyph_position_and_rects_for_chars_inside_ligatures.patch

@@ -0,0 +1,55 @@
+Index: modules/skparagraph/src/TextLine.cpp
+IDEA additional info:
+Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
+<+>UTF-8
+===================================================================
+diff --git a/modules/skparagraph/src/TextLine.cpp b/modules/skparagraph/src/TextLine.cpp
+--- a/modules/skparagraph/src/TextLine.cpp	(revision f85ab491eb97b54d0bfeac19fed27feb499b8912)
++++ b/modules/skparagraph/src/TextLine.cpp	(date 1646928189139)
+@@ -615,6 +615,7 @@
+         }
+         return result;
+     }
++    TextRange origTextRange = textRange;
+     // Find [start:end] clusters for the text
+     Cluster* start = nullptr;
+     Cluster* end = nullptr;
+@@ -688,8 +689,8 @@
+     // TODO: This is where we get smart about selecting a part of a cluster
+     //  by shaping each grapheme separately and then use the result sizes
+     //  to calculate the proportions
+-    auto leftCorrection = start->sizeToChar(textRange.start);
+-    auto rightCorrection = end->sizeFromChar(textRange.end - 1);
++    auto leftCorrection = start->sizeToChar(origTextRange.start);
++    auto rightCorrection = end->sizeFromChar(origTextRange.end - 1);
+     result.clip.fLeft += leftCorrection;
+     result.clip.fRight -= rightCorrection;
+     result.clippingNeeded = leftCorrection != 0 || rightCorrection != 0;
+@@ -1248,6 +1249,27 @@
+                 auto clusterIndex8 = context.run->globalClusterIndex(found);
+                 auto clusterEnd8 = context.run->globalClusterIndex(found + 1);
+
++                size_t charsInCluster = 0;
++                for (auto i = clusterIndex8; i < clusterEnd8; i++) {
++                    i = run->owner()->findNextGraphemeBoundary(i);
++                    if (i < clusterEnd8) charsInCluster++;
++                }
++
++                // Calculate offset for a character inside a ligature (e.g. ff or ffi)
++                // Considering all characters in the ligature have equal width
++                if (glyphemePosWidth > 0 && charsInCluster > 1) {
++                    glyphemePosWidth /= charsInCluster;
++                    size_t charIndexInCluster = std::floor((dx - glyphemePosLeft) / glyphemePosWidth);
++                    if (!context.run->leftToRight()) {
++                        charIndexInCluster = charsInCluster - charIndexInCluster;
++                    }
++                    glyphemePosLeft += charIndexInCluster * glyphemePosWidth;
++                    for (size_t i = 0; i < charIndexInCluster; i++) {
++                        clusterIndex8 = run->owner()->findNextGraphemeBoundary(clusterIndex8 + 1);
++                    }
++                    clusterEnd8 = run->owner()->findNextGraphemeBoundary(clusterIndex8 + 1);
++                }
++
+                 SkScalar center = glyphemePosLeft + glyphemePosWidth / 2;
+                 if ((dx < center) == context.run->leftToRight()) {
+                     size_t utf16Index = context.run->leftToRight()

script/update_version.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 ROOT="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"/..
-OLDVER=m99-51988d0bc1
-NEWVER=m99-f85ab491eb
+OLDVER=m99-f85ab491eb
+NEWVER=m99-f85ab491eb-2
 find -E $ROOT/script *.md .github  -regex '.*\.(py|md|yml)' -exec sed -i '' -e "s/$OLDVER/$NEWVER/g" {} \;