Killing four bugs with one PR? (#144)

* Killing four bugs with one fix?

* Revert unneeded changes

* Add comments

* Update CSharpMath.Forms.Example.UWP.csproj

Author: Happypig375

CSharpMath.Forms.Example/CSharpMath.Forms.Example.Android/Resources/Resource.designer.cs

@@ -171,9 +171,7 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="Xamarin.Forms" Version="4.3.0.908675" />
-    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform">
-      <Version>6.2.8</Version>
-    </PackageReference>
+    <PackageReference Include="Microsoft.NETCore.UniversalWindowsPlatform" Version="6.2.10" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\..\CSharpMath.Editor\CSharpMath.Editor.csproj">
@@ -212,4 +210,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
+</Project>

CSharpMath.Forms.Example/CSharpMath.Forms.Example.UWP/CSharpMath.Forms.Example.UWP.csproj

@@ -11,9 +11,9 @@ public SelectPage() {
       InitializeComponent();
       App.AllMathViews.Add(View);
       Size.ItemsSource = TryPage.FontSizes;
+      Size.SelectedItem = View.FontSize;
       Size.SelectedIndexChanged += (sender, e) =>
         View.FontSize = (float)Size.SelectedItem;
-      Size.SelectedItem = 96f;
       Picker.ItemsSource = Rendering.Tests.TestRenderingMathData.AllConstants.Keys.ToList();
       Picker.SelectedIndexChanged += (sender, e) =>
         View.LaTeX = Label.Text = Rendering.Tests.TestRenderingMathData.AllConstants[(string)Picker.SelectedItem];

CSharpMath.Forms.Example/CSharpMath.Forms.Example/SelectPage.xaml.cs

@@ -16,7 +16,8 @@ public BaseButton() {
           var latex = c.Painter.LaTeX;
           // Appropriate positioning for non-full characters, e.g. prime, degree
           // Also acts as spacing between MathButtons next to each other
-          c.Painter.LaTeX = @"{\color{#0000}|}" + latex + @"{\color{#0000}|}";
+          // TODO: Implement and use \phantom
+          c.Painter.LaTeX = @"{\color{#00000000}|}" + latex + @"{\color{#00000000}|}";
           var stream = c.Painter.DrawAsStream();
           c.Painter.LaTeX = latex;
           return stream;

CSharpMath.Forms/Buttons.cs

@@ -6,7 +6,7 @@ public class MathInputButton : MathButton {
     public MathInputButton() => Command = new Command(() => Keyboard?.KeyPress(Input));
     public static readonly BindableProperty KeyboardProperty =
       BindableProperty.Create(nameof(Keyboard), typeof(MathKeyboard), typeof(MathInputButton));
-    public MathKeyboard Keyboard { get => (MathKeyboard)GetValue(KeyboardProperty); set => SetValue(KeyboardProperty, value); }
+    public MathKeyboard? Keyboard { get => (MathKeyboard?)GetValue(KeyboardProperty); set => SetValue(KeyboardProperty, value); }
     static string InputToLaTeX(MathKeyboardInput input) {
       switch (input) {
         case MathKeyboardInput.Left: return "\u25C0";

CSharpMath.Forms/MathInputButton.cs

@@ -100,6 +100,33 @@ public void TextCenterInfiniteWidth(string file, string latex) =>
     [SkippableTheory, ClassData(typeof(TestRenderingTextData))]
     public void TextRightInfiniteWidth(string file, string latex) =>
       Run(file, latex, new TTextPainter(), TextAlignment.TopRight, textPainterCanvasWidth: float.PositiveInfinity);
+    public static TheoryData<float, TextAlignment> TextFontSizesData() {
+      var data = new TheoryData<float, TextAlignment>();
+      // TODO: Fix font sizes at 100 and 300
+      foreach (var fontSize in stackalloc[] { 20, 40, 60 })
+        foreach (var alignment in typeof(TextAlignment).GetEnumValues().Cast<TextAlignment>())
+          data.Add(fontSize, alignment); 
+      return data;
+    }
+    [SkippableTheory, MemberData(nameof(TextFontSizesData))]
+    public void TextFontSizes(float fontSize, TextAlignment alignment) =>
+      Run((fontSize, alignment).ToString(), @"Here are some text.
+This text is made to be long enough to have the TextPainter of CSharpMath add a line break to this text automatically.
+To demonstrate the capabilities of the TextPainter,
+here are some math content:
+First, a fraction in inline mode: $\frac34$
+Next, a summation in inline mode: $\sum_{i=0}^3i^i$
+Then, a summation in display mode: $$\sum_{i=0}^3i^i$$
+After that, an integral in display mode: $$\int^6_{-56}x\ dx$$
+Finally, an escaped dollar sign \$ that represents the start/end of math mode when it is unescaped.
+Colors can be achieved via \backslash color\textit{\{color\}\{content\}}, or \backslash \textit{color\{content\}},
+where \textit{color} stands for one of the LaTeX standard colors.
+\red{Colored text in text mode are able to automatically break up when spaces are inside the colored text, which the equivalent in math mode cannot do.}
+\textbf{Styled} \texttt{text} can be achieved via the LaTeX styling commands.
+The SkiaSharp version of this is located at CSharpMath.SkiaSharp.TextPainter;
+and the Xamarin.Forms version of this is located at CSharpMath.Forms.TextView.
+Was added in 0.1.0-pre4; working in 0.1.0-pre5; fully tested in 0.1.0-pre6. \[\frac{Display}{maths} \sqrt\text\mathtt{\ at\ the\ end}^\mathbf{are\ now\ incuded\ in\ Measure!} \]",
+        new TTextPainter { FontSize = fontSize }, alignment);
     protected void Run<TContent>(
       string inFile, string latex, Painter<TCanvas, TContent, TColor> painter, TextAlignment alignment = TextAlignment.TopLeft,
       float textPainterCanvasWidth = TextPainter<TCanvas, TColor>.DefaultCanvasWidth, [CallerMemberName] string folder = "") where TContent : class {
@@ -120,7 +147,7 @@ protected void Run<TContent>(
 
       var expectedFile = new FileInfo(System.IO.Path.Combine(folder, inFile + ".png"));
       if (!expectedFile.Exists) {
-        Skip.If(FileSizeTolerance != 0, "Baseline images may only be created by SkiaSharp.");
+        Skip.IfNot(FileSizeTolerance is 0, "Baseline images may only be created by SkiaSharp.");
         actualFile.CopyTo(expectedFile.FullName);
         expectedFile.Refresh();
       }

CSharpMath.Rendering.Tests/TestRendering.cs

@@ -64,6 +64,9 @@ private void DrawCore(TCanvas canvas, float? width, TextAlignment alignment,
           ? System.Math.Max(_relativeXCoordDisplay.Displays.CollectionWidth(),
             _absoluteXCoordDisplay.Displays.IsNonEmpty() ? _absoluteXCoordDisplay.Displays.Max(d => d.Width) : 0)
           : c.Width;
+        // https://github.com/verybadcat/CSharpMath/issues/123
+        // Take into account padding, offset etc. on both sides
+        adjustedCanvasWidth -= _relativeXCoordDisplay.Position.X * 2;
         float Δx = 0;
         var y = float.NegativeInfinity;
         var leftRightFlags = alignment & (TextAlignment.Left | TextAlignment.Right);

CSharpMath.Rendering.Tests/TextCenter/Accent.png

@@ -156,8 +156,12 @@ protected override void OnTouch(global::SkiaSharp.Views.Forms.SKTouchEventArgs e
     }
     protected sealed override void OnPaintSurface(global::SkiaSharp.Views.Forms.SKPaintSurfaceEventArgs e) {
       base.OnPaintSurface(e);
-      e.Surface.Canvas.Clear();
       var canvas = e.Surface.Canvas;
+      canvas.Clear();
+      // https://github.com/verybadcat/CSharpMath/issues/136 and https://github.com/verybadcat/CSharpMath/issues/137
+      // SkiaSharp deals with raw pixels as opposed to Xamarin.Forms's device-independent units.
+      // We should scale to occupy the full view size.
+      canvas.Scale(e.Info.Width / (float)Width);
 #endif
       Painter.Draw(canvas, TextAlignment, Padding, DisplacementX, DisplacementY);
     }

CSharpMath.Rendering.Tests/TextCenter/Alphabets.png

@@ -168,7 +168,7 @@ private void CreateDisplayAtoms(List<MathAtom> preprocessedAtoms) {
           case Variable _:
           case UnaryOperator _:
             throw new InvalidCodePathException
-              ($"Type {atom.GetType()} should have been removed by preprocessing");
+              ($"Type {atom.TypeName} should have been removed by preprocessing");
           case Space space:
             AddDisplayLine(false);
             _currentPosition.X += space.ActualLength(_mathTable, _font);
@@ -232,7 +232,7 @@ private void CreateDisplayAtoms(List<MathAtom> preprocessedAtoms) {
             AddInterElementSpace(prevAtom, inner);
             IDisplay<TFont, TGlyph> innerDisplay;
             if (inner.LeftBoundary != Boundary.Empty || inner.RightBoundary != Boundary.Empty) {
-              innerDisplay = _MakeInner(inner, atom.IndexRange);
+              innerDisplay = MakeInner(inner, atom.IndexRange);
             } else {
               innerDisplay = CreateLine(inner.InnerList, _font, _context, _style, _cramped);
             }
@@ -522,6 +522,20 @@ private void AddInterElementSpace(MathAtom? prev, MathAtom current) =>
       return null;
     }
     private RadicalDisplay<TFont, TGlyph> MakeRadical(MathList radicand, Range range) {
+      IGlyphDisplay<TFont, TGlyph> _GetRadicalGlyph(float radicalHeight) {
+        // TODO: something related to GlyphFinder.FindGlyph
+        var radicalGlyph = _context.GlyphFinder.FindGlyphForCharacterAtIndex(_font, 0, "\u221A");
+        var glyph = FindGlyph(radicalGlyph, radicalHeight,
+          out float glyphAscent, out float glyphDescent, out float glyphWidth);
+
+        return
+          glyphAscent + glyphDescent < radicalHeight
+          // the glyphs are not big enough, so we construct one using extenders
+          && ConstructGlyph(radicalGlyph, radicalHeight) is IGlyphDisplay<TFont, TGlyph> constructed
+          ? constructed
+          : new GlyphDisplay<TFont, TGlyph>
+            (glyph, Range.NotFound, _styleFont, glyphAscent, glyphDescent, glyphWidth);
+      }
       var innerDisplay = CreateLine(radicand, _font, _context, _style, true);
       var radicalVerticalGap =
         _style == LineStyle.Display
@@ -562,46 +576,43 @@ private RadicalDisplay<TFont, TGlyph> MakeRadical(MathList radicand, Range range
       };
     }
 
-    private float _NumeratorShiftUp(bool hasRule) =>
-      (hasRule, _style) switch
-      {
-        (true, LineStyle.Display) => _mathTable.FractionNumeratorDisplayStyleShiftUp(_styleFont),
-        (true, _) => _mathTable.FractionNumeratorShiftUp(_styleFont),
-        (false, LineStyle.Display) => _mathTable.StackTopDisplayStyleShiftUp(_styleFont),
-        (false, _) => _mathTable.StackTopShiftUp(_styleFont)
-      };
-    private float _NumeratorGapMin =>
-      _style == LineStyle.Display
-      ? _mathTable.FractionNumDisplayStyleGapMin(_styleFont)
-      : _mathTable.FractionNumeratorGapMin(_styleFont);
-
-    private float _DenominatorShiftDown(bool hasRule) =>
-      (hasRule, _style) switch
-      {
-        (true, LineStyle.Display) => _mathTable.FractionDenominatorDisplayStyleShiftDown(_styleFont),
-        (true, _) => _mathTable.FractionDenominatorShiftDown(_styleFont),
-        (false, LineStyle.Display) => _mathTable.StackBottomDisplayStyleShiftDown(_styleFont),
-        (false, _) => _mathTable.StackBottomShiftDown(_styleFont)
-      };
-
-    private float _DenominatorGapMin =>
-      _style == LineStyle.Display
-      ? _mathTable.FractionDenomDisplayStyleGapMin(_styleFont)
-      : _mathTable.FractionDenominatorGapMin(_styleFont);
-
-    private float _StackGapMin =>
-      _style == LineStyle.Display
-      ? _mathTable.StackDisplayStyleGapMin(_styleFont)
-      : _mathTable.StackGapMin(_styleFont);
-
-    private float _FractionDelimiterHeight =>
-      _style == LineStyle.Display
-      ? _mathTable.FractionDelimiterDisplayStyleSize(_styleFont)
-      : _mathTable.FractionDelimiterSize(_styleFont);
-
     private IDisplay<TFont, TGlyph> MakeFraction(Fraction fraction) {
+      float _NumeratorShiftUp(bool hasRule) =>
+        (hasRule, _style) switch
+        {
+          (true, LineStyle.Display) => _mathTable.FractionNumeratorDisplayStyleShiftUp(_styleFont),
+          (true, _) => _mathTable.FractionNumeratorShiftUp(_styleFont),
+          (false, LineStyle.Display) => _mathTable.StackTopDisplayStyleShiftUp(_styleFont),
+          (false, _) => _mathTable.StackTopShiftUp(_styleFont)
+        };
+      float _NumeratorGapMin() =>
+        _style == LineStyle.Display
+        ? _mathTable.FractionNumDisplayStyleGapMin(_styleFont)
+        : _mathTable.FractionNumeratorGapMin(_styleFont);
+
+      float _DenominatorShiftDown(bool hasRule) =>
+        (hasRule, _style) switch
+        {
+          (true, LineStyle.Display) => _mathTable.FractionDenominatorDisplayStyleShiftDown(_styleFont),
+          (true, _) => _mathTable.FractionDenominatorShiftDown(_styleFont),
+          (false, LineStyle.Display) => _mathTable.StackBottomDisplayStyleShiftDown(_styleFont),
+          (false, _) => _mathTable.StackBottomShiftDown(_styleFont)
+        };
+      float _DenominatorGapMin() =>
+        _style == LineStyle.Display
+        ? _mathTable.FractionDenomDisplayStyleGapMin(_styleFont)
+        : _mathTable.FractionDenominatorGapMin(_styleFont);
+      float _StackGapMin() =>
+        _style == LineStyle.Display
+        ? _mathTable.StackDisplayStyleGapMin(_styleFont)
+        : _mathTable.StackGapMin(_styleFont);
+      float _FractionDelimiterHeight() =>
+          _style == LineStyle.Display
+          ? _mathTable.FractionDelimiterDisplayStyleSize(_styleFont)
+          : _mathTable.FractionDelimiterSize(_styleFont);
+
       var numeratorDisplay =
-        CreateLine(fraction.Numerator, _font, _context, _fractionStyle, false);
+          CreateLine(fraction.Numerator, _font, _context, _fractionStyle, false);
       var denominatorDisplay =
         CreateLine(fraction.Denominator, _font, _context, _fractionStyle, true);
 
@@ -616,20 +627,20 @@ private IDisplay<TFont, TGlyph> MakeFraction(Fraction fraction) {
         var distanceFromNumeratorToBar =
           numeratorShiftUp - numeratorDisplay.Descent - (barLocation + barThickness / 2);
         // The distance should be at least displayGap
-        if (distanceFromNumeratorToBar < _NumeratorGapMin) {
-          numeratorShiftUp += (_NumeratorGapMin - distanceFromNumeratorToBar);
+        if (distanceFromNumeratorToBar < _NumeratorGapMin()) {
+          numeratorShiftUp += (_NumeratorGapMin() - distanceFromNumeratorToBar);
         }
         // now, do the same for the denominator
         var distanceFromDenominatorToBar =
           barLocation - barThickness / 2 - (denominatorDisplay.Ascent - denominatorShiftDown);
-        if (distanceFromDenominatorToBar < _DenominatorGapMin) {
-          denominatorShiftDown += _DenominatorGapMin - distanceFromDenominatorToBar;
+        if (distanceFromDenominatorToBar < _DenominatorGapMin()) {
+          denominatorShiftDown += _DenominatorGapMin() - distanceFromDenominatorToBar;
         }
       } else {
         float clearance =
           numeratorShiftUp - numeratorDisplay.Descent
           - (denominatorDisplay.Ascent - denominatorShiftDown);
-        float minClearance = _StackGapMin;
+        float minClearance = _StackGapMin();
         if (clearance < minClearance) {
           numeratorShiftUp += (minClearance - clearance / 2);
           denominatorShiftDown += (minClearance - clearance) / 2;
@@ -649,11 +660,11 @@ private IDisplay<TFont, TGlyph> MakeFraction(Fraction fraction) {
 
       if (fraction.LeftDelimiter is null && fraction.RightDelimiter is null)
         return display;
-      var glyphHeight = _FractionDelimiterHeight;
+      var glyphHeight = _FractionDelimiterHeight();
       var position = new PointF();
       var innerGlyphs = new List<IDisplay<TFont, TGlyph>>();
       if (fraction.LeftDelimiter?.Length > 0) {
-        var leftGlyph = _FindGlyphForBoundary(fraction.LeftDelimiter, glyphHeight);
+        var leftGlyph = FindGlyphForBoundary(fraction.LeftDelimiter, glyphHeight);
         leftGlyph.Position = position;
         innerGlyphs.Add(leftGlyph);
         position.X += leftGlyph.Width;
@@ -662,7 +673,7 @@ private IDisplay<TFont, TGlyph> MakeFraction(Fraction fraction) {
       position.X += display.Width;
       innerGlyphs.Add(display);
       if (fraction.RightDelimiter?.Length > 0) {
-        var rightGlyph = _FindGlyphForBoundary(fraction.RightDelimiter, glyphHeight);
+        var rightGlyph = FindGlyphForBoundary(fraction.RightDelimiter, glyphHeight);
         rightGlyph.Position = position;
         innerGlyphs.Add(rightGlyph);
         position.X += rightGlyph.Width;
@@ -672,7 +683,7 @@ private IDisplay<TFont, TGlyph> MakeFraction(Fraction fraction) {
       };
     }
 
-    private InnerDisplay<TFont, TGlyph> _MakeInner(Inner inner, Range range) {
+    private InnerDisplay<TFont, TGlyph> MakeInner(Inner inner, Range range) {
       if (inner.LeftBoundary == Boundary.Empty && inner.RightBoundary == Boundary.Empty) {
         throw new InvalidCodePathException("Inner should have a boundary to call this function.");
       }
@@ -689,24 +700,24 @@ private InnerDisplay<TFont, TGlyph> _MakeInner(Inner inner, Range range) {
 
       var leftGlyph =
         inner.LeftBoundary is Boundary { Nucleus: var left } && left.Length > 0
-        ? _FindGlyphForBoundary(left, glyphHeight)
+        ? FindGlyphForBoundary(left, glyphHeight)
         : null;
 
       var rightGlyph =
         inner.RightBoundary is Boundary { Nucleus: var right } && right.Length > 0
-        ? _FindGlyphForBoundary(right, glyphHeight)
+        ? FindGlyphForBoundary(right, glyphHeight)
         : null;
       return new InnerDisplay<TFont, TGlyph>(innerListDisplay, leftGlyph, rightGlyph, range);
     }
 
-    private IGlyphDisplay<TFont, TGlyph> _FindGlyphForBoundary(
+    private IGlyphDisplay<TFont, TGlyph> FindGlyphForBoundary(
       string delimiter, float glyphHeight) {
       var leftGlyph = _context.GlyphFinder.FindGlyphForCharacterAtIndex(_font, 0, delimiter);
-      var glyph = _FindGlyph(leftGlyph, glyphHeight,
+      var glyph = FindGlyph(leftGlyph, glyphHeight,
         out float glyphAscent, out float glyphDescent, out float glyphWidth);
       var glyphDisplay =
         glyphAscent + glyphDescent < glyphHeight
-        && _ConstructGlyph(leftGlyph, glyphHeight) is IGlyphDisplay<TFont, TGlyph> constructed
+        && ConstructGlyph(leftGlyph, glyphHeight) is IGlyphDisplay<TFont, TGlyph> constructed
         ? constructed
         : new GlyphDisplay<TFont, TGlyph>
           (glyph, Range.NotFound, _styleFont, glyphAscent, glyphDescent, glyphWidth);
@@ -718,35 +729,21 @@ private IGlyphDisplay<TFont, TGlyph> _FindGlyphForBoundary(
       return glyphDisplay;
     }
 
-    private IGlyphDisplay<TFont, TGlyph> _GetRadicalGlyph(float radicalHeight) {
-      // TODO: something related to GlyphFinder.FindGlyph
-      var radicalGlyph = _context.GlyphFinder.FindGlyphForCharacterAtIndex(_font, 0, "\u221A");
-      var glyph = _FindGlyph(radicalGlyph, radicalHeight,
-        out float glyphAscent, out float glyphDescent, out float glyphWidth);
-
-      return
-        glyphAscent + glyphDescent < radicalHeight
-        // the glyphs are not big enough, so we construct one using extenders
-        && _ConstructGlyph(radicalGlyph, radicalHeight) is IGlyphDisplay<TFont, TGlyph> constructed
-        ? constructed
-        : new GlyphDisplay<TFont, TGlyph>
-          (glyph, Range.NotFound, _styleFont, glyphAscent, glyphDescent, glyphWidth);
-    }
 
-    private GlyphConstructionDisplay<TFont, TGlyph>? _ConstructGlyph(TGlyph glyph, float glyphHeight) {
+    private GlyphConstructionDisplay<TFont, TGlyph>? ConstructGlyph(TGlyph glyph, float glyphHeight) {
       var parts = _mathTable.GetVerticalGlyphAssembly(glyph, _styleFont);
       if (parts is null) return null;
       var glyphs = new List<TGlyph>();
       var offsets = new List<float>();
-      float height = _ConstructGlyphWithParts(parts, glyphHeight, glyphs, offsets);
+      float height = ConstructGlyphWithParts(parts, glyphHeight, glyphs, offsets);
       using var singleGlyph = new Structures.RentedArray<TGlyph>(glyphs[0]);
       // descent:0 because it's up to the rendering to adjust the display glyph up or down by setting ShiftDown
       return new GlyphConstructionDisplay<TFont, TGlyph>
         (glyphs, offsets, _styleFont, height, 0, _context.GlyphBoundsProvider
           .GetAdvancesForGlyphs(_styleFont, singleGlyph.Result, 1).Total);
     }
 
-    private float _ConstructGlyphWithParts(IEnumerable<GlyphPart<TGlyph>> parts,
+    private float ConstructGlyphWithParts(IEnumerable<GlyphPart<TGlyph>> parts,
       float glyphHeight, List<TGlyph> glyphs, List<float> offsets) {
       for (int nExtenders = 0; ; nExtenders++) {
         glyphs.Clear();
@@ -800,7 +797,7 @@ private float _ConstructGlyphWithParts(IEnumerable<GlyphPart<TGlyph>> parts,
       }
     }
 
-    private TGlyph _FindGlyph(TGlyph rawGlyph, float height,
+    private TGlyph FindGlyph(TGlyph rawGlyph, float height,
       out float glyphAscent, out float glyphDescent, out float glyphWidth) {
       // in iosMath.
       glyphAscent = glyphDescent = glyphWidth = float.NaN;