Add support for \cancel, \bcancel and \xcancel.

ForNeVeR · May 22, 2023 · 620cd87 · 620cd87
1 parent 93ce3c7
commit 620cd87
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Showing 15 changed files with 240 additions and 27 deletions.
diff --git a/src/AvaloniaMath/Rendering/AvaloniaBrush.cs b/src/AvaloniaMath/Rendering/AvaloniaBrush.cs
@@ -1,4 +1,3 @@
-using System.Diagnostics.CodeAnalysis;
 using Avalonia.Media;
 using XamlMath.Colors;
 using XamlMath.Rendering;
@@ -18,16 +17,6 @@ public static AvaloniaBrush FromColor(RgbaColor value) =>
                 Color.FromArgb(value.A, value.R, value.G, value.B)));
 }
 
-public static class AvaloniaBrushExtensions
-{
-    public static Avalonia.Media.IBrush? ToAvalonia(this IBrush? brush) =>
-        ((AvaloniaBrush?)brush)?.Value;
-
-    [return: NotNullIfNotNull(nameof(brush))]
-    public static IBrush? ToPlatform(this Brush? brush) =>
-        brush == null ? null : AvaloniaBrush.FromBrush(brush);
-}
-
 public class AvaloniaBrushFactory : IBrushFactory
 {
     private AvaloniaBrushFactory() { }

diff --git a/src/AvaloniaMath/Rendering/AvaloniaElementRenderer.cs b/src/AvaloniaMath/Rendering/AvaloniaElementRenderer.cs
@@ -9,6 +9,7 @@
 using XamlMath.Rendering;
 using XamlMath.Rendering.Transformations;
 using IBrush = XamlMath.Rendering.IBrush;
+using Point = XamlMath.Rendering.Point;
 
 namespace AvaloniaMath.Rendering;
 
@@ -32,6 +33,14 @@ public void RenderElement(Box box, double x, double y)
         box.RenderTo(this, x, y);
     }
 
+    public void RenderLine(Point point0, Point point1, IBrush? foreground)
+    {
+        point0 = GeometryHelper.ScalePoint(_scale, point0);
+        point1 = GeometryHelper.ScalePoint(_scale, point1);
+        var pen = new Pen(foreground.ToAvalonia() ?? DefaultForegroundBrush);
+        _foregroundContext.DrawLine(pen, point0.ToAvalonia(), point1.ToAvalonia());
+    }
+
     public void RenderCharacter(CharInfo info, double x, double y, IBrush? foreground)
     {
         var glyph = info.GetGlyphRun(x, y, _scale);

diff --git a/src/AvaloniaMath/Rendering/AvaloniaExtensions.cs b/src/AvaloniaMath/Rendering/AvaloniaExtensions.cs
@@ -0,0 +1,18 @@
+using System.Diagnostics.CodeAnalysis;
+using Avalonia.Media;
+using XamlMath.Rendering;
+using IBrush = XamlMath.Rendering.IBrush;
+
+namespace AvaloniaMath.Rendering
+{
+    public static class AvaloniaExtensions
+    {
+        [return: NotNullIfNotNull(nameof(brush))]
+        public static IBrush? ToPlatform(this Brush? brush) => brush == null ? null : AvaloniaBrush.FromBrush(brush);
+
+        [return: NotNullIfNotNull(nameof(brush))]
+        public static Avalonia.Media.IBrush? ToAvalonia(this IBrush? brush) => ((AvaloniaBrush?)brush)?.Value;
+
+        public static Avalonia.Point ToAvalonia(this Point point) => new(point.X, point.Y);
+    }
+}
diff --git a/src/AvaloniaMath/Rendering/GeometryElementRenderer.cs b/src/AvaloniaMath/Rendering/GeometryElementRenderer.cs
@@ -24,6 +24,14 @@ public GeometryElementRenderer(GeometryGroup geometry, double scale)
 
     public void RenderElement(Box box, double x, double y) => box.RenderTo(this, x, y);
 
+    public void RenderLine(Point point0, Point point1, IBrush? foreground)
+    {
+        point0 = GeometryHelper.ScalePoint(_scale, point0);
+        point1 = GeometryHelper.ScalePoint(_scale, point1);
+        var lineGeometry = new LineGeometry(point0.ToAvalonia(), point1.ToAvalonia());
+        _geometry.Children.Add(lineGeometry);
+    }
+
     public void RenderCharacter(CharInfo info, double x, double y, IBrush? foreground)
     {
         /*TODO[#357]       var glyph = scaledGlyphFactory(_scale);

diff --git a/src/WpfMath.Example/MainViewModel.cs b/src/WpfMath.Example/MainViewModel.cs
@@ -33,6 +33,7 @@ public MainViewModel()
             new ("Integral 3", @"L = \int_a^\infty \sqrt[4]{ \left\vert \sum_{i,j=1}^ng_{ij}\left\(\gamma(t)\right\) \left\[\frac{d}{dt}x^i\circ\gamma(t) \right\] \left\{\frac{d}{dt}x^j\circ\gamma(t) \right\} \right\|} \, dt"),
             new ("Number matrix", @"\matrix{4&78&3 \\ 5 & 9  & 82 }"),
             new ("Nested matrix", @"\matrix{4&78&3\\ 57 & {\matrix{78 \\ 12}}  & 20782 }"),
+            new ("Cancel",@"\cancel{Q} \\ \xcancel{69} \\ \frac{a\bcancel{b}}{\bcancel{b}}"),
             new ("Cases", @"f(x) = \cases{1/3 & \mathrm{if} \thinspace 0\le x\le 1;\cr 2/3 & \mathrm{if} \thinspace 3\le x \le 4; \cr 0 & \mathrm{elsewhere.}\cr}"),
             new ("Matrix and new lines", @"v \times w = \left( \matrix{v_2 w_3 - v_3 w_2 \\ v_3 w_1 - v_1 w_3 \\ v_1 w_2 - v_2 w_1} \right) \\ \matrix{\mathrm{where} & v= \left(\matrix{ v_1 \\ v_2 \\ v_3 }\right), \\ & w= \left( \matrix{w_1 \\ w_2  \\ w_3} \right)}"),
             new ("Big matrix", @"\Gamma_{\mu \rho} ^{\sigma}= \pmatrix{\pmatrix{0 & 0 & 0 \\ 0 & -r & 0 \\ 0 & 0 & -r \sin^2(\theta)} \\ \pmatrix{0 & \frac{1}{r} & 0 \\ \frac{1}{r} & 0 & 0 \\ 0 & 0 & -\sin(\theta) \cos(\theta)} \\ \pmatrix{0 & 0 & \frac{1}{r} \\ 0 & 0 & \frac{1}{\tan(\theta)} \\ \frac{1}{r} & \frac{1}{\tan(\theta)} & 0 }}"),

diff --git a/src/WpfMath/Converters/SVGConverter.cs b/src/WpfMath/Converters/SVGConverter.cs
@@ -38,6 +38,11 @@ private void AddGeometry(StringBuilder svgString, GeometryGroup group)
                     GeometryGroup childGroup = (GeometryGroup)geometry;
                     AddGeometry(svgString, childGroup);
                 }
+                else if (geometry is LineGeometry)
+                {
+                    LineGeometry lineGeometry = (LineGeometry)geometry;
+                    AddGeometry(svgString, lineGeometry);
+                }
                 else if (geometry is PathGeometry)
                 {
                     PathGeometry path = (PathGeometry)geometry;
@@ -62,6 +67,17 @@ private void AddGeometry(StringBuilder svgString, GeometryGroup group)
             m_nestedLevel--;
         }
 
+        private void AddGeometry(StringBuilder svgString, LineGeometry line)
+        {
+            var x1 = line.StartPoint.X.ToString(CultureInfo.InvariantCulture);
+            var y1 = line.StartPoint.Y.ToString(CultureInfo.InvariantCulture);
+
+            var x2 = line.EndPoint.X.ToString(CultureInfo.InvariantCulture);
+            var y2 = line.EndPoint.Y.ToString(CultureInfo.InvariantCulture);
+
+            svgString.AppendLine(@$"<line x1=""{x1}"" y1=""{y1}"" x2=""{x2}"" y2=""{y2}"" style=""stroke:black;stroke-width:1"" />");
+        }
+
         private void AddGeometry(StringBuilder svgString, PathGeometry path)
         {
             svgString.Append("<path d=\"");

diff --git a/src/WpfMath/Rendering/GeometryElementRenderer.cs b/src/WpfMath/Rendering/GeometryElementRenderer.cs
@@ -23,6 +23,13 @@ public GeometryElementRenderer(GeometryGroup geometry, double scale)
         }
 
         public void RenderElement(Box box, double x, double y) => box.RenderTo(this, x, y);
+        public void RenderLine(Point point0, Point point1, IBrush? foreground)
+        {
+            point0 = GeometryHelper.ScalePoint(_scale, point0);
+            point1 = GeometryHelper.ScalePoint(_scale, point1);
+            var lineGeometry = new LineGeometry(point0.ToWpf(), point1.ToWpf());
+            _geometry.Children.Add(lineGeometry);
+        }
 
         public void RenderCharacter(CharInfo info, double x, double y, IBrush? foreground)
         {

diff --git a/src/WpfMath/Rendering/WpfElementRenderer.cs b/src/WpfMath/Rendering/WpfElementRenderer.cs
@@ -1,13 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Windows;
 using System.Windows.Media;
 using WpfMath.Fonts;
 using XamlMath;
 using XamlMath.Boxes;
 using XamlMath.Rendering;
 using XamlMath.Rendering.Transformations;
+using WpfRect = System.Windows.Rect;
 
 namespace WpfMath.Rendering
 {
@@ -48,6 +48,14 @@ public void RenderElement(Box box, double x, double y)
             _foregroundContext.Pop();
         }
 
+        public void RenderLine(Point point0, Point point1, IBrush? foreground)
+        {
+            point0 = GeometryHelper.ScalePoint(_scale, point0);
+            point1 = GeometryHelper.ScalePoint(_scale, point1);
+            var pen = new Pen(foreground.ToWpf() ?? DefaultForegroundBrush, 1.0);
+            _foregroundContext.DrawLine(pen, point0.ToWpf(), point1.ToWpf());
+        }
+
         public void RenderCharacter(CharInfo info, double x, double y, IBrush? foreground)
         {
             var glyphRun = info.GetGlyphRun(x, y, _scale);
@@ -89,12 +97,8 @@ private void RenderBackground(Box box, double x, double y)
         {
             if (box.Background != null)
             {
-                _targetContext.DrawRectangle(
-                    box.Background.ToWpf(),
-                    null,
-                    new Rect(_scale * x, _scale * (y - box.Height),
-                        _scale * box.TotalWidth,
-                        _scale * box.TotalHeight));
+                var rectangle = new WpfRect(_scale * x, _scale * (y - box.Height), _scale * box.TotalWidth, _scale * box.TotalHeight);
+                _targetContext.DrawRectangle(box.Background.ToWpf(), null, rectangle);
             }
         }
 

diff --git a/src/WpfMath/Rendering/WpfBrushExtensions.cs → src/WpfMath/Rendering/WpfExtensions.cs b/src/WpfMath/Rendering/WpfBrushExtensions.cs → src/WpfMath/Rendering/WpfExtensions.cs
@@ -1,12 +1,17 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Windows.Media;
 using XamlMath.Rendering;
+using WpfPoint = System.Windows.Point;
 
 namespace WpfMath.Rendering;
 
-public static class WpfBrushExtensions
+public static class WpfExtensions
 {
-    public static Brush? ToWpf(this IBrush? brush) => ((WpfBrush?)brush)?.Value;
     [return: NotNullIfNotNull(nameof(brush))]
     public static IBrush? ToPlatform(this Brush? brush) => brush == null ? null : WpfBrush.FromBrush(brush);
+
+    [return: NotNullIfNotNull(nameof(brush))]
+    public static Brush? ToWpf(this IBrush? brush) => ((WpfBrush?)brush)?.Value;
+
+    public static WpfPoint ToWpf(this Point point) => new(point.X, point.Y);
 }
diff --git a/src/XamlMath.Shared/Atoms/CancelAtom.cs b/src/XamlMath.Shared/Atoms/CancelAtom.cs
@@ -0,0 +1,33 @@
+using XamlMath.Boxes;
+
+namespace XamlMath.Atoms
+{
+    internal record CancelAtom : Atom
+    {
+        private readonly Atom? _contentAtom;
+        private readonly StrokeBoxMode _strokeBoxMode;
+
+        public CancelAtom(SourceSpan atomSource, Atom? contentAtom, StrokeBoxMode strokeBoxMode) : base(atomSource)
+        {
+            _contentAtom = contentAtom;
+            _strokeBoxMode = strokeBoxMode;
+        }
+
+        protected override Box CreateBoxCore(TexEnvironment environment)
+        {
+            var contentBox = _contentAtom is null ? StrutBox.Empty : _contentAtom.CreateBox(environment);
+            var lineBox = new StrokeBox(_strokeBoxMode)
+            {
+                Height = contentBox.Height,
+                Depth = contentBox.Depth,
+                Width = contentBox.Width
+            };
+
+            var box = new ZBox();
+            box.Add(contentBox);
+            box.Add(lineBox);
+
+            return box;
+        }
+    }
+}
diff --git a/src/XamlMath.Shared/Boxes/StrokeBox.cs b/src/XamlMath.Shared/Boxes/StrokeBox.cs
@@ -0,0 +1,44 @@
+using System;
+using XamlMath.Rendering;
+
+namespace XamlMath.Boxes;
+
+public class StrokeBox : Box
+{
+    private readonly StrokeBoxMode _mode;
+
+    public StrokeBox(StrokeBoxMode mode)
+    {
+        _mode = mode;
+    }
+
+    public override void RenderTo(IElementRenderer renderer, double x, double y)
+    {
+        if (_mode.HasFlag(StrokeBoxMode.Normal))
+            renderer.RenderLine(new Point(x, y + Depth), new Point(x + Width, y - Height), Foreground);
+
+        if (_mode.HasFlag(StrokeBoxMode.Back))
+            renderer.RenderLine(new Point(x, y - Height), new Point(x + Width, y + Depth), Foreground);
+    }
+
+    public override int GetLastFontId()
+    {
+        var fontId = TexFontUtilities.NoFontId;
+        foreach (var child in Children)
+        {
+            fontId = child.GetLastFontId();
+            if (fontId == TexFontUtilities.NoFontId)
+                break;
+        }
+        return fontId;
+    }
+}
+
+[Flags]
+public enum StrokeBoxMode
+{
+    None = 0,
+    Normal = 1,
+    Back = 2,
+    Both = 3
+}
diff --git a/src/XamlMath.Shared/Boxes/ZBox.cs b/src/XamlMath.Shared/Boxes/ZBox.cs
@@ -0,0 +1,38 @@
+using System.Linq;
+using XamlMath.Rendering;
+
+namespace XamlMath.Boxes
+{
+    public class ZBox : Box
+    {
+        public override void Add(Box box)
+        {
+            base.Add(box);
+
+            Width = Children.Select(c => c.Width).DefaultIfEmpty(0).Max();
+            Height = Children.Select(c => c.Height - c.Shift).DefaultIfEmpty(double.NegativeInfinity).Max();
+            Depth = Children.Select(c => c.Depth + c.Shift).DefaultIfEmpty(double.NegativeInfinity).Max(); ;
+            Italic = Children.Select(c => c.Italic).DefaultIfEmpty(double.NegativeInfinity).Max(); ;
+        }
+
+        public override void RenderTo(IElementRenderer renderer, double x, double y)
+        {
+            foreach (var box in Children)
+            {
+                renderer.RenderElement(box, x, y + box.Shift);
+            }
+        }
+
+        public override int GetLastFontId()
+        {
+            var fontId = TexFontUtilities.NoFontId;
+            foreach (var child in Children)
+            {
+                fontId = child.GetLastFontId();
+                if (fontId == TexFontUtilities.NoFontId)
+                    break;
+            }
+            return fontId;
+        }
+    }
+}
diff --git a/src/XamlMath.Shared/Parsers/StandardCommands.cs b/src/XamlMath.Shared/Parsers/StandardCommands.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using XamlMath.Atoms;
+using XamlMath.Boxes;
 using XamlMath.Parsers.Matrices;
 
 namespace XamlMath.Parsers
@@ -50,6 +51,35 @@ public CommandProcessingResult ProcessCommand(CommandContext context)
             }
         }
 
+        private class CancelCommand : ICommandParser
+        {
+            public static CancelCommand BCancel { get; } = new(StrokeBoxMode.Back);
+            public static CancelCommand Cancel { get; } = new(StrokeBoxMode.Normal);
+            public static CancelCommand XCancel { get; } = new(StrokeBoxMode.Both);
+
+            private CancelCommand(StrokeBoxMode strokeBoxMode)
+            {
+                _strokeBoxMode = strokeBoxMode;
+            }
+
+            private readonly StrokeBoxMode _strokeBoxMode;
+
+            public CommandProcessingResult ProcessCommand(CommandContext context)
+            {
+                var source = context.CommandSource;
+                var position = context.ArgumentsStartPosition;
+                var contentFormula = context.Parser.Parse(TexFormulaParser.ReadElement(source, ref position),
+                                                          context.Formula.TextStyle,
+                                                          context.Environment.CreateChildEnvironment());
+
+                var start = context.CommandNameStartPosition;
+                var atomSource = source.Segment(start, position - start);
+                var cancelAtom = new CancelAtom(atomSource, contentFormula.RootAtom, _strokeBoxMode);
+
+                return new CommandProcessingResult(cancelAtom, position);
+            }
+        }
+
         /// <summary>
         /// This command will parse the remaining part of an input string, and add it onto a new line of a formula. The
         /// new line is created as a <see cref="MatrixAtom"/>; the command will try to reuse existing atoms if possible.
@@ -100,6 +130,9 @@ public CommandProcessingResult ProcessCommand(CommandContext context)
             {
                 [@"\"] = new NewLineCommand(),
                 ["binom"] = new BinomCommand(),
+                ["cancel"] = CancelCommand.Cancel,
+                ["bcancel"] = CancelCommand.BCancel,
+                ["xcancel"] = CancelCommand.XCancel,
                 ["cases"] = MatrixCommandParser.Cases,
                 ["matrix"] = MatrixCommandParser.Matrix,
                 ["pmatrix"] = MatrixCommandParser.PMatrix,

diff --git a/src/XamlMath.Shared/Rendering/GeometryHelper.cs b/src/XamlMath.Shared/Rendering/GeometryHelper.cs
@@ -2,7 +2,7 @@ namespace XamlMath.Rendering
 {
     internal static class GeometryHelper
     {
-        public static Rectangle ScaleRectangle(double scale, Rectangle rectangle) =>
-            new(rectangle.X * scale, rectangle.Y * scale, rectangle.Width * scale, rectangle.Height * scale);
+        public static Point ScalePoint(double scale, Point point) => new(point.X * scale, point.Y * scale);
+        public static Rectangle ScaleRectangle(double scale, Rectangle rectangle) => new(rectangle.X * scale, rectangle.Y * scale, rectangle.Width * scale, rectangle.Height * scale);
     }
 }