Fix GetTextBounds for mixed runs

src/Avalonia.Base/Media/TextFormatting/TextLineImpl.cs

@@ -536,6 +536,11 @@ namespace Avalonia.Media.TextFormatting
                                 endX += currentRun.Size.Width;
                             }
 
+                            if(currentPosition < firstTextSourceCharacterIndex)
+                            {
+                                startX += currentRun.Size.Width;
+                            }
+
                             currentPosition += currentRun.TextSourceLength;
 
                             break;
@@ -590,10 +595,10 @@ namespace Avalonia.Media.TextFormatting
 
         public TextLineImpl FinalizeLine()
         {
-            BidiReorder();
-
             _textLineMetrics = CreateLineMetrics();
 
+            BidiReorder();
+
             return this;
         }
 
@@ -1068,41 +1073,11 @@ namespace Avalonia.Media.TextFormatting
                                 }
                             }
 
-                            switch (_paragraphProperties.FlowDirection)
+                            if (index == _textRuns.Count - 1)
                             {
-                                case FlowDirection.LeftToRight:
-                                    {
-                                        if (index == _textRuns.Count - 1)
-                                        {
-                                            width = widthIncludingWhitespace + textRun.GlyphRun.Metrics.Width;
-                                            trailingWhitespaceLength = textRun.GlyphRun.Metrics.TrailingWhitespaceLength;
-                                            newLineLength = textRun.GlyphRun.Metrics.NewlineLength;
-                                        }
-
-                                        break;
-                                    }
-
-                                case FlowDirection.RightToLeft:
-                                    {
-                                        if (index == _textRuns.Count - 1)
-                                        {
-                                            var firstRun = _textRuns[0];
-
-                                            if (firstRun is ShapedTextCharacters shapedTextCharacters)
-                                            {
-                                                var offset = shapedTextCharacters.GlyphRun.Metrics.WidthIncludingTrailingWhitespace -
-                                                             shapedTextCharacters.GlyphRun.Metrics.Width;
-
-                                                width = widthIncludingWhitespace +
-                                                    textRun.GlyphRun.Metrics.WidthIncludingTrailingWhitespace - offset;
-
-                                                trailingWhitespaceLength = shapedTextCharacters.GlyphRun.Metrics.TrailingWhitespaceLength;
-                                                newLineLength = shapedTextCharacters.GlyphRun.Metrics.NewlineLength;
-                                            }
-                                        }
-
-                                        break;
-                                    }
+                                width = widthIncludingWhitespace + textRun.GlyphRun.Metrics.Width;
+                                trailingWhitespaceLength = textRun.GlyphRun.Metrics.TrailingWhitespaceLength;
+                                newLineLength = textRun.GlyphRun.Metrics.NewlineLength;
                             }
 
                             widthIncludingWhitespace += textRun.GlyphRun.Metrics.WidthIncludingTrailingWhitespace;

src/Skia/Avalonia.Skia/TextShaperImpl.cs

@@ -27,7 +27,7 @@ namespace Avalonia.Skia
                 
                 buffer.GuessSegmentProperties();
 
-                buffer.Direction = (bidiLevel & 1) == 0 ? Direction.LeftToRight : Direction.RightToLeft;
+                buffer.Direction = Direction.LeftToRight; //Always shape LeftToRight
 
                 buffer.Language = new Language(culture ?? CultureInfo.CurrentCulture);              
 
@@ -35,11 +35,6 @@ namespace Avalonia.Skia
 
                 font.Shape(buffer);
 
-                if (buffer.Direction == Direction.RightToLeft)
-                {
-                    buffer.Reverse();
-                }
-
                 font.GetScale(out var scaleX, out _);
 
                 var textScale = fontRenderingEmSize / scaleX;

src/Windows/Avalonia.Direct2D1/Media/TextShaperImpl.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Globalization;
-using Avalonia.Media;
 using Avalonia.Media.TextFormatting;
 using Avalonia.Media.TextFormatting.Unicode;
 using Avalonia.Platform;
@@ -11,8 +10,7 @@ using GlyphInfo = HarfBuzzSharp.GlyphInfo;
 
 namespace Avalonia.Direct2D1.Media
 {
-
-internal class TextShaperImpl : ITextShaperImpl
+    internal class TextShaperImpl : ITextShaperImpl
     {
         public ShapedBuffer ShapeText(ReadOnlySlice<char> text, TextShaperOptions options)
         {
@@ -23,25 +21,20 @@ internal class TextShaperImpl : ITextShaperImpl
 
             using (var buffer = new Buffer())
             {
-                buffer.AddUtf16(text.Buffer.Span, text.Start, text.Length);
+                buffer.AddUtf16(text.Buffer.Span, text.BufferOffset, text.Length);
 
                 MergeBreakPair(buffer);
-                
+
                 buffer.GuessSegmentProperties();
 
-                buffer.Direction = (bidiLevel & 1) == 0 ? Direction.LeftToRight : Direction.RightToLeft;
+                buffer.Direction = Direction.LeftToRight; //Always shape LeftToRight
 
-                buffer.Language = new Language(culture ?? CultureInfo.CurrentCulture);              
+                buffer.Language = new Language(culture ?? CultureInfo.CurrentCulture);
 
                 var font = ((GlyphTypefaceImpl)typeface.PlatformImpl).Font;
 
                 font.Shape(buffer);
 
-                if (buffer.Direction == Direction.RightToLeft)
-                {
-                    buffer.Reverse();
-                }
-
                 font.GetScale(out var scaleX, out _);
 
                 var textScale = fontRenderingEmSize / scaleX;
@@ -60,13 +53,13 @@ internal class TextShaperImpl : ITextShaperImpl
 
                     var glyphIndex = (ushort)sourceInfo.Codepoint;
 
-                    var glyphCluster = (int)sourceInfo.Cluster;
+                    var glyphCluster = (int)(sourceInfo.Cluster);
 
                     var glyphAdvance = GetGlyphAdvance(glyphPositions, i, textScale);
 
                     var glyphOffset = GetGlyphOffset(glyphPositions, i, textScale);
 
-                    if (glyphIndex == 0 && text[glyphCluster] == '\t')
+                    if (glyphIndex == 0 && text.Buffer.Span[glyphCluster] == '\t')
                     {
                         glyphIndex = typeface.GetGlyph(' ');
 
@@ -75,9 +68,7 @@ internal class TextShaperImpl : ITextShaperImpl
                             4 * typeface.GetGlyphAdvance(glyphIndex) * textScale;
                     }
 
-                    var targetInfo =
-                        new Avalonia.Media.TextFormatting.GlyphInfo(glyphIndex, glyphCluster, glyphAdvance,
-                            glyphOffset);
+                    var targetInfo = new Avalonia.Media.TextFormatting.GlyphInfo(glyphIndex, glyphCluster, glyphAdvance, glyphOffset);
 
                     shapedBuffer[i] = targetInfo;
                 }
@@ -91,7 +82,7 @@ internal class TextShaperImpl : ITextShaperImpl
             var length = buffer.Length;
 
             var glyphInfos = buffer.GetGlyphInfoSpan();
-            
+
             var second = glyphInfos[length - 1];
 
             if (!new Codepoint((int)second.Codepoint).IsBreakChar)
@@ -102,7 +93,7 @@ internal class TextShaperImpl : ITextShaperImpl
             if (length > 1 && glyphInfos[length - 2].Codepoint == '\r' && second.Codepoint == '\n')
             {
                 var first = glyphInfos[length - 2];
-                
+
                 first.Codepoint = '\u200C';
                 second.Codepoint = '\u200C';
                 second.Cluster = first.Cluster;
@@ -113,7 +104,7 @@ internal class TextShaperImpl : ITextShaperImpl
                     {
                         *p = first;
                     }
-                
+
                     fixed (GlyphInfo* p = &glyphInfos[length - 1])
                     {
                         *p = second;
@@ -148,7 +139,7 @@ internal class TextShaperImpl : ITextShaperImpl
         private static double GetGlyphAdvance(ReadOnlySpan<GlyphPosition> glyphPositions, int index, double textScale)
         {
             // Depends on direction of layout
-            // advanceBuffer[index] = buffer.GlyphPositions[index].YAdvance * textScale;
+            // glyphPositions[index].YAdvance * textScale;
             return glyphPositions[index].XAdvance * textScale;
         }
     }