Merge pull request #692 from AvaloniaUI/relative-path-fixes

Fix relative points in paths.

samples/ControlCatalog/Pages/CanvasPage.xaml

@@ -13,7 +13,7 @@
           </LinearGradientBrush>
         </Rectangle.OpacityMask>      </Rectangle>
       <Ellipse Fill="Green" Width="58" Height="58" Canvas.Left="88" Canvas.Top="100"/>
-      <Path Fill="Orange" Data="M 0,0 c 50,0 50,-50 c 50,0 50,50 h -50 v 50 l -50,-50 Z" Canvas.Left="30" Canvas.Top="250"/>
+      <Path Fill="Orange" Data="M 0,0 c 0,0 50,0 50,-50 c 0,0 50,0 50,50 h -50 v 50 l -50,-50 Z" Canvas.Left="30" Canvas.Top="250"/>
       <Path Fill="OrangeRed" Canvas.Left="180" Canvas.Top="250">
         <Path.Data>
           <PathGeometry>

src/Avalonia.SceneGraph/Media/PathMarkupParser.cs

@@ -17,21 +17,13 @@ namespace Avalonia.Media
         private static readonly Dictionary<char, Command> Commands = new Dictionary<char, Command>
         {
             { 'F', Command.FillRule },
-            { 'f', Command.FillRule },
             { 'M', Command.Move },
-            { 'm', Command.MoveRelative },
             { 'L', Command.Line },
-            { 'l', Command.LineRelative },
             { 'H', Command.HorizontalLine },
-            { 'h', Command.HorizontalLineRelative },
             { 'V', Command.VerticalLine },
-            { 'v', Command.VerticalLineRelative },
             { 'C', Command.CubicBezierCurve },
-            { 'c', Command.CubicBezierCurveRelative },
             { 'A', Command.Arc },
-            { 'a', Command.Arc },
             { 'Z', Command.Close },
-            { 'z', Command.Close },
         };
 
         private static readonly Dictionary<char, FillRule> FillRules = new Dictionary<char, FillRule>
@@ -63,18 +55,12 @@ namespace Avalonia.Media
             None,
             FillRule,
             Move,
-            MoveRelative,
             Line,
-            LineRelative,
             HorizontalLine,
-            HorizontalLineRelative,
             VerticalLine,
-            VerticalLineRelative,
             CubicBezierCurve,
-            CubicBezierCurveRelative,
             Arc,
             Close,
-            Eof,
         }
 
         /// <summary>
@@ -87,11 +73,11 @@ namespace Avalonia.Media
 
             using (StringReader reader = new StringReader(s))
             {
-                Command lastCommand = Command.None;
-                Command command;
+                Command command = Command.None;
                 Point point = new Point();
+                bool relative = false;
 
-                while ((command = ReadCommand(reader, lastCommand)) != Command.Eof)
+                while (ReadCommand(reader, ref command, ref relative))
                 {
                     switch (command)
                     {
@@ -100,72 +86,58 @@ namespace Avalonia.Media
                             break;
 
                         case Command.Move:
-                        case Command.MoveRelative:
                             if (openFigure)
                             {
                                 _context.EndFigure(false);
                             }
 
-                            point = command == Command.Move ?
-                                ReadPoint(reader) :
-                                ReadRelativePoint(reader, point);
-
+                            point = ReadPoint(reader, point, relative);
                             _context.BeginFigure(point, true);
                             openFigure = true;
                             break;
 
                         case Command.Line:
-                            point = ReadPoint(reader);
-                            _context.LineTo(point);
-                            break;
-
-                        case Command.LineRelative:
-                            point = ReadRelativePoint(reader, point);
+                            point = ReadPoint(reader, point, relative);
                             _context.LineTo(point);
                             break;
 
                         case Command.HorizontalLine:
-                            point = point.WithX(ReadDouble(reader));
-                            _context.LineTo(point);
-                            break;
+                            if (!relative)
+                            {
+                                point = point.WithX(ReadDouble(reader));
+                            }
+                            else
+                            {
+                                point = new Point(point.X + ReadDouble(reader), point.Y);
+                            }
 
-                        case Command.HorizontalLineRelative:
-                            point = new Point(point.X + ReadDouble(reader), point.Y);
                             _context.LineTo(point);
                             break;
 
                         case Command.VerticalLine:
-                            point = point.WithY(ReadDouble(reader));
-                            _context.LineTo(point);
-                            break;
+                            if (!relative)
+                            {
+                                point = point.WithY(ReadDouble(reader));
+                            }
+                            else
+                            {
+                                point = new Point(point.X, point.Y + ReadDouble(reader));
+                            }
 
-                        case Command.VerticalLineRelative:
-                            point = new Point(point.X, point.Y + ReadDouble(reader));
                             _context.LineTo(point);
                             break;
 
                         case Command.CubicBezierCurve:
                             {
-                                Point point1 = ReadPoint(reader);
-                                Point point2 = ReadPoint(reader);
-                                point = ReadPoint(reader);
+                                Point point1 = ReadPoint(reader, point, relative);
+                                Point point2 = ReadPoint(reader, point, relative);
+                                point = ReadPoint(reader, point, relative);
                                 _context.CubicBezierTo(point1, point2, point);
                                 break;
                             }
 
-                        case Command.CubicBezierCurveRelative:
-                            {
-                                Point point1 = ReadRelativePoint(reader, point);
-                                Point point2 = ReadRelativePoint(reader, point);
-                                _context.CubicBezierTo(point, point1, point2);
-                                point = point2;
-                                break;
-                            }
-
                         case Command.Arc:
                             {
-                                //example: A10,10 0 0,0 10,20
-                                //format - size rotationAngle isLargeArcFlag sweepDirectionFlag endPoint
                                 Size size = ReadSize(reader);
                                 ReadSeparator(reader);
                                 double rotationAngle = ReadDouble(reader);
@@ -173,7 +145,7 @@ namespace Avalonia.Media
                                 bool isLargeArc = ReadBool(reader);
                                 ReadSeparator(reader);
                                 SweepDirection sweepDirection = ReadBool(reader) ? SweepDirection.Clockwise : SweepDirection.CounterClockwise;
-                                point = ReadPoint(reader);
+                                point = ReadPoint(reader, point, relative);
 
                                 _context.ArcTo(point, size, rotationAngle, isLargeArc, sweepDirection);
                                 break;
@@ -187,8 +159,6 @@ namespace Avalonia.Media
                         default:
                             throw new NotSupportedException("Unsupported command");
                     }
-
-                    lastCommand = command;
                 }
 
                 if (openFigure)
@@ -198,7 +168,10 @@ namespace Avalonia.Media
             }
         }
 
-        private static Command ReadCommand(StringReader reader, Command lastCommand)
+        private static bool ReadCommand(
+            StringReader reader,
+            ref Command command,
+            ref bool relative)
         {
             ReadWhitespace(reader);
 
@@ -206,19 +179,19 @@ namespace Avalonia.Media
 
             if (i == -1)
             {
-                return Command.Eof;
+                return false;
             }
             else
             {
                 char c = (char)i;
-                Command command = Command.None;
+                Command next = Command.None;
 
-                if (!Commands.TryGetValue(c, out command))
+                if (!Commands.TryGetValue(char.ToUpperInvariant(c), out next))
                 {
                     if ((char.IsDigit(c) || c == '.' || c == '+' || c == '-') &&
-                        (lastCommand != Command.None))
+                        (command != Command.None))
                     {
-                        return lastCommand;
+                        return true;
                     }
                     else
                     {
@@ -226,8 +199,10 @@ namespace Avalonia.Media
                     }
                 }
 
+                command = next;
+                relative = char.IsLower(c);
                 reader.Read();
-                return command;
+                return true;
             }
         }
 
@@ -297,12 +272,17 @@ namespace Avalonia.Media
             return double.Parse(b.ToString(), CultureInfo.InvariantCulture);
         }
 
-        private static Point ReadPoint(StringReader reader)
+        private static Point ReadPoint(StringReader reader, Point current, bool relative)
         {
+            if (!relative)
+            {
+                current = new Point();
+            }
+
             ReadWhitespace(reader);
-            double x = ReadDouble(reader);
+            double x = current.X + ReadDouble(reader);
             ReadSeparator(reader);
-            double y = ReadDouble(reader);
+            double y = current.Y + ReadDouble(reader);
             return new Point(x, y);
         }
 

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

@@ -6,6 +6,8 @@ using Avalonia.Platform;
 using SharpDX.Direct2D1;
 using SweepDirection = SharpDX.Direct2D1.SweepDirection;
 using D2D = SharpDX.Direct2D1;
+using Avalonia.Logging;
+using System;
 
 namespace Avalonia.Direct2D1.Media
 {
@@ -76,7 +78,20 @@ namespace Avalonia.Direct2D1.Media
 
         public void Dispose()
         {
-            _sink.Close();
+            // Put a catch around sink.Close as it may throw if there were an error e.g. parsing a path.
+            try
+            {
+                _sink.Close();
+            }
+            catch (Exception ex)
+            {
+                Logger.Error(
+                    LogArea.Visual,
+                    this,
+                    "GeometrySink.Close exception: {Exception}",
+                    ex);
+            }
+
             _sink.Dispose();
         }
     }

tests/Avalonia.RenderTests/Shapes/PathTests.cs

@@ -24,6 +24,260 @@ namespace Avalonia.Direct2D1.RenderTests.Shapes
         {
         }
 
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void Line_Absolute()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M 10,190 L 190,10 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void Line_Relative()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M10,190 l190,-190 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void HorizontalLine_Absolute()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,100 H10 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void HorizontalLine_Relative()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,100 h-180 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void VerticalLine_Absolute()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M100,190 V10 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void VerticalLine_Relative()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M100,190 V-180 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void CubicBezier_Absolute()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Fill = Brushes.Gray,
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,0 C10,10 190,190 10,190 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void CubicBezier_Relative()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Fill = Brushes.Gray,
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,0 c-180,10 0,190 -180,190 M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void Arc_Absolute()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Fill = Brushes.Gray,
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,100 A90,90 0 1,0 10,100  M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
+#if AVALONIA_CAIRO
+        [Fact(Skip = "Broken in Cairo: waiting for Skia")]
+#else
+        [Fact]
+#endif
+        public void Arc_Relative()
+        {
+            Decorator target = new Decorator
+            {
+                Width = 200,
+                Height = 200,
+                Child = new Path
+                {
+                    Fill = Brushes.Gray,
+                    Stroke = Brushes.Red,
+                    StrokeThickness = 1,
+                    HorizontalAlignment = HorizontalAlignment.Center,
+                    VerticalAlignment = VerticalAlignment.Center,
+                    Data = StreamGeometry.Parse("M190,100 a90,90 0 1,0 -180,0  M0,0M200,200"),
+                }
+            };
+
+            RenderToFile(target);
+            CompareImages();
+        }
+
         [Fact]
         public void Path_100px_Triangle_Centered()
         {