(#63) TexFormula: move to the Shared assembly

src/WpfMath.Example/MainWindow.xaml.cs

@@ -7,6 +7,7 @@
 using System.Windows.Media.Imaging;
 using Microsoft.Win32;
 using WpfMath.Converters;
+using WpfMath.Rendering;
 
 namespace WpfMath.Example;
 
@@ -68,15 +69,16 @@ private void saveButton_Click(object sender, RoutedEventArgs e)
         // Create formula object from input text.
         var formula = ParseFormula(InputTextBox.Text);
         if (formula == null) return;
-        var renderer = formula.GetRenderer(TexStyle.Display, Formula.Scale, "Arial");
+        var scale = Formula.Scale;
+        var environment = WpfTeXEnvironment.Create(scale: scale);
 
         // Open stream
         var filename = saveFileDialog.FileName;
         using var stream = new FileStream(filename, FileMode.Create);
         switch (saveFileDialog.FilterIndex)
         {
             case 1:
-                var geometry = renderer.RenderToGeometry(0, 0);
+                var geometry = formula.RenderToGeometry(environment, scale: scale);
                 var converter = new SVGConverter();
                 var svgPathText = converter.ConvertGeometry(geometry);
                 var svgText = AddSvgHeader(svgPathText);
@@ -85,7 +87,7 @@ private void saveButton_Click(object sender, RoutedEventArgs e)
                 break;
 
             case 2:
-                var bitmap = renderer.RenderToBitmap(0, 0, 300);
+                var bitmap = formula.RenderToBitmap(environment, scale, dpi: 300);
                 var encoder = new PngBitmapEncoder
                 {
                     Frames = { BitmapFrame.Create(bitmap) }

src/WpfMath/TexFormula.cs → src/WpfMath.Shared/TexFormula.cs

@@ -1,16 +1,13 @@
-using System;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
-using System.Windows.Media;
 using WpfMath.Atoms;
 using WpfMath.Boxes;
-using WpfMath.Fonts;
 using WpfMath.Rendering;
 
 namespace WpfMath
 {
-    // Represents mathematical formula that can be rendered.
+    /// <summary>Represents mathematical formula that can be rendered.</summary>
     public sealed class TexFormula
     {
         public string? TextStyle
@@ -27,18 +24,8 @@ internal Atom? RootAtom
 
         public SourceSpan? Source { get; set; }
 
-        [Obsolete("Use extension methods from WpfMath.Rendering.TeXFormulaExtensions and WpfMath.Rendering.WpfTeXFormulaExtensions instead.")]
-        public TexRenderer GetRenderer(TexStyle style, // TODO: Revise internal usages of this method.
-            double scale,
-            string? systemTextFontName,
-            Brush? background = null,
-            Brush? foreground = null)
-        {
-            var mathFont = new DefaultTexFont(WpfMathFontProvider.Instance, scale);
-            var textFont = systemTextFontName == null ? (ITeXFont)mathFont : GetSystemFont(systemTextFontName, scale);
-            var environment = new TexEnvironment(style, mathFont, textFont, WpfBrush.FromBrush(background), WpfBrush.FromBrush(foreground));
-            return new TexRenderer(CreateBox(environment), scale);
-        }
+        // TODO: Document the absence of TexFormula.GetRenderer method (that should be replaced with
+        // WpfMath.Rendering.TeXFormulaExtensions and WpfMath.Rendering.WpfTeXFormulaExtensions).
 
         public void Add(TexFormula formula, SourceSpan? source = null)
         {
@@ -74,43 +61,36 @@ internal void Add(Atom atom, SourceSpan? rowSource)
             }
         }
 
-        public void SetForeground(Brush brush)
+        public void SetForeground(IPlatformBrush brush)
         {
             if (this.RootAtom is StyledAtom sa)
             {
-                this.RootAtom = sa with { Foreground = brush.ToPlatform() };
+                this.RootAtom = sa with { Foreground = brush };
             }
             else
             {
-                RootAtom = new StyledAtom(RootAtom?.Source, RootAtom, null, brush.ToPlatform());
+                RootAtom = new StyledAtom(RootAtom?.Source, RootAtom, null, brush);
             }
         }
 
-        public void SetBackground(Brush brush)
+        public void SetBackground(IPlatformBrush brush)
         {
             if (this.RootAtom is StyledAtom sa)
             {
-                this.RootAtom = sa with { Background = brush.ToPlatform() };
+                this.RootAtom = sa with { Background = brush };
             }
             else
             {
-                this.RootAtom = new StyledAtom(this.RootAtom?.Source, this.RootAtom, brush.ToPlatform(), null);
+                this.RootAtom = new StyledAtom(this.RootAtom?.Source, this.RootAtom, brush, null);
             }
         }
 
-        internal Box CreateBox(TexEnvironment environment)
+        public Box CreateBox(TexEnvironment environment)
         {
             if (this.RootAtom == null)
                 return StrutBox.Empty;
             else
                 return this.RootAtom.CreateBox(environment);
         }
-
-        internal static SystemFont GetSystemFont(string fontName, double size)
-        {
-            var fontFamily = System.Windows.Media.Fonts.SystemFontFamilies.First(
-                ff => ff.ToString() == fontName || ff.FamilyNames.Values?.Contains(fontName) == true);
-            return new SystemFont(size, fontFamily);
-        }
     }
 }

src/WpfMath.Tests/BoxTests.fs

@@ -8,7 +8,7 @@ open Xunit
 open WpfMath
 open WpfMath.Atoms
 open WpfMath.Boxes
-open WpfMath.Fonts
+open WpfMath.Rendering
 open WpfMath.Tests.ApprovalTestUtils
 
 let private parse(text: string) =
@@ -18,10 +18,7 @@ let private parse(text: string) =
 
 let private src (string: string) (start: int) (len: int) = SourceSpan("User input", string, start, len)
 
-let private environment =
-    let mathFont = DefaultTexFont(WpfMathFontProvider.Instance, 20.0)
-    let textFont = TexFormula.GetSystemFont("Arial", 20.0)
-    TexEnvironment(TexStyle.Display, mathFont, textFont)
+let private environment = WpfTeXEnvironment.Create()
 
 [<Fact>]
 let ``AccentedAtom should have a skew according to the char``() =

src/WpfMath.Tests/CharBoxTests.fs

@@ -19,10 +19,7 @@ type CharBoxTests() =
         let result = parser.Parse text
         result.RootAtom
 
-    let environment =
-        let mathFont = DefaultTexFont(WpfMathFontProvider.Instance, 20.0)
-        let textFont = TexFormula.GetSystemFont("Arial", 20.0)
-        TexEnvironment(TexStyle.Display, mathFont, textFont)
+    let environment = WpfTeXEnvironment.Create()
 
     [<Fact>]
     member _.``CharBox rendering calls to RenderCharacter``() =

src/WpfMath.Tests/TexRendererTests.fs → src/WpfMath.Tests/RenderingTests.fs

@@ -1,24 +1,26 @@
-module WpfMath.Tests.TexRendererTests
+module WpfMath.Tests.RenderingTests
 
-open WpfMath
 open Xunit
 
+open WpfMath
+open WpfMath.Rendering
+
 [<Fact>]
 let ``TexRenderer.RenderToBitmap should create an image of proper size``() =
     let parser = TexFormulaParser()
     let formula = parser.Parse "2+2=2"
-    let renderer = formula.GetRenderer(TexStyle.Display, 20.0, "Arial")
-    let bitmap = renderer.RenderToBitmap(0.0, 0.0)
+    let environment = WpfTeXEnvironment.Create()
+    let bitmap = formula.RenderToBitmap environment
     Assert.Equal(82, bitmap.PixelWidth)
     Assert.Equal(17, bitmap.PixelHeight)
 
 [<Fact>]
 let ``TexRenderer.RenderToBitmap should create an image of proper size with offset``() =
     let parser = TexFormulaParser()
     let formula = parser.Parse "2+2=2"
-    let renderer = formula.GetRenderer(TexStyle.Display, 20.0, "Arial")
+    let environment = WpfTeXEnvironment.Create()
     let margin = 50
-    let bitmap = renderer.RenderToBitmap(float(margin), float(margin))
+    let bitmap = formula.RenderToBitmap(environment, x = float margin, y = float margin)
 
     let formulaWidth = 82
     let formulaHeight = 16
@@ -29,8 +31,8 @@ let ``TexRenderer.RenderToBitmap should create an image of proper size with offs
 let ``TexRenderer.RenderToBitmap should work with different DPI``() =
     let parser = TexFormulaParser()
     let formula = parser.Parse "2+2=2"
-    let renderer = formula.GetRenderer(TexStyle.Display, 20.0, "Arial")
-    let bitmap = renderer.RenderToBitmap(0.0, 0.0, 192.0)
+    let environment = WpfTeXEnvironment.Create()
+    let bitmap = formula.RenderToBitmap(environment, dpi = 192.0)
     Assert.Equal(163, bitmap.PixelWidth)
     Assert.Equal(34, bitmap.PixelHeight)
     Assert.Equal(192.0, bitmap.DpiX)

src/WpfMath.Tests/WpfMath.Tests.fsproj

@@ -39,7 +39,7 @@
         <Compile Include="OverUnderBoxTests.fs" />
         <Compile Include="ParserTests.fs" />
         <Compile Include="ParserExceptionTests.fs" />
-        <Compile Include="TexRendererTests.fs" />
+        <Compile Include="RenderingTests.fs" />
         <Compile Include="TransformationTests.fs" />
         <Compile Include="VerticalBoxTests.fs" />
         <Compile Include="WpfRendererTests.fs" />

src/WpfMath/Controls/FormulaControl.xaml.cs

@@ -15,7 +15,7 @@ namespace WpfMath.Controls
     /// </summary>
     public partial class FormulaControl : UserControl
     {
-        private static TexFormulaParser formulaParser = new TexFormulaParser();
+        private static TexFormulaParser _formulaParser = new();
         private TexFormula? texFormula;
 
         public string Formula
@@ -136,15 +136,20 @@ private void Render()
             // Render formula to visual.
             var visual = new DrawingVisual();
 
-            // Pass transparent background, since the control background will be effectively used anyway.
-            var renderer = texFormula.GetRenderer(TexStyle.Display, Scale, SystemTextFontName, Brushes.Transparent, Foreground);
+            // Omit passing the background, since the control background will be effectively used anyway.
+            var environment = WpfTeXEnvironment.Create(
+                scale: Scale,
+                systemTextFontName: SystemTextFontName,
+                foreground: Foreground);
+
             var formulaSource = texFormula.Source;
+            var formulaBox = texFormula.CreateBox(environment);
             if (formulaSource != null)
             {
                 var selectionBrush = SelectionBrush;
                 if (selectionBrush != null)
                 {
-                    var allBoxes = new List<Box>(renderer.Box.Children);
+                    var allBoxes = new List<Box>(formulaBox.Children);
                     var selectionStart = SelectionStart;
                     var selectionEnd = selectionStart + SelectionLength;
                     for (var idx = 0; idx < allBoxes.Count; idx++)
@@ -168,7 +173,7 @@ private void Render()
 
             using (var drawingContext = visual.RenderOpen())
             {
-                renderer.Render(drawingContext, 0, 0);
+                texFormula.RenderTo(drawingContext, environment, Scale, 0, 0);
             }
             formulaContainerElement.Visual = visual;
         }
@@ -181,7 +186,7 @@ private static object CoerceFormula(DependencyObject d, object baseValue)
             {
                 control.HasError = false;
                 control.Errors.Clear();
-                control.texFormula = formulaParser.Parse(formula);
+                control.texFormula = _formulaParser.Parse(formula);
                 return baseValue;
             }
             catch (TexException e)

src/WpfMath/Extensions.cs

@@ -1,5 +1,6 @@
 using System.IO;
 using System.Windows.Media.Imaging;
+using WpfMath.Rendering;
 
 namespace WpfMath
 {
@@ -11,8 +12,8 @@ public static byte[] RenderToPng(this TexFormula texForm,
             double y,
             string systemTextFontName)
         {
-            var trnder = texForm.GetRenderer(TexStyle.Display, scale, systemTextFontName);
-            BitmapSource image = trnder.RenderToBitmap(x, y);
+            var environment = WpfTeXEnvironment.Create();
+            BitmapSource image = texForm.RenderToBitmap(environment, scale, x, y);
 
             PngBitmapEncoder encoder = new PngBitmapEncoder();
             encoder.Frames.Add(BitmapFrame.Create(image));

src/WpfMath/Rendering/WpfTeXEnvironment.cs

@@ -0,0 +1,39 @@
+using System.Linq;
+using System.Windows.Media;
+using WpfMath.Fonts;
+
+namespace WpfMath.Rendering;
+
+public static class WpfTeXEnvironment
+{
+    /// <summary>Creates an instance of <see cref="TexEnvironment"/> for a WPF program.</summary>
+    /// <param name="style">Initial style for the formula content.</param>
+    /// <param name="scale">Formula font size.</param>
+    /// <param name="systemTextFontName">Name of the system font to use for the <code>\text</code> blocks.</param>
+    /// <param name="foreground">Foreground color. Black if not specified.</param>
+    /// <param name="background">Background color.</param>
+    public static TexEnvironment Create(
+        TexStyle style = TexStyle.Display,
+        double scale = 20.0,
+        string systemTextFontName = "Arial",
+        Brush? foreground = null,
+        Brush? background = null)
+    {
+        var mathFont = new DefaultTexFont(WpfMathFontProvider.Instance, scale);
+        var textFont = GetSystemFont(systemTextFontName, scale);
+
+        return new TexEnvironment(
+            style,
+            mathFont,
+            textFont,
+            background.ToPlatform(),
+            foreground.ToPlatform());
+    }
+
+    private static SystemFont GetSystemFont(string fontName, double size)
+    {
+        var fontFamily = System.Windows.Media.Fonts.SystemFontFamilies.First(
+            ff => ff.ToString() == fontName || ff.FamilyNames.Values?.Contains(fontName) == true);
+        return new SystemFont(size, fontFamily);
+    }
+}

src/WpfMath/Rendering/WpfTeXFormulaExtensions.cs

@@ -12,7 +12,7 @@ public static class WpfTeXFormulaExtensions
     public static Geometry RenderToGeometry( // TODO: Tests for this method.
         this TexFormula formula,
         TexEnvironment environment,
-        double scale, // TODO: Get rid of this; it is already encoded in the renderer anyway.
+        double scale = 20.0,
         double x = 0.0,
         double y = 0.0)
     {
@@ -25,9 +25,9 @@ public static class WpfTeXFormulaExtensions
     public static BitmapSource RenderToBitmap( // TODO: Tests for this method.
         this TexFormula formula,
         TexEnvironment environment,
-        double scale, // TODO: Get rid of this; it is already encoded in the renderer anyway.
-        double x,
-        double y,
+        double scale = 20.0,
+        double x = 0,
+        double y = 0,
         double dpi = DefaultDpi)
     {
         var visual = new DrawingVisual();