public override Box CreateBox(TexStyle style)
{
float lineHeight = lineThickness * TexUtility.SizeFactor(style);
// Create boxes for numerator and demoninator atoms, and make them of equal width.
var numeratorBox = numerator == null ? StrutBox.Empty :
numerator.CreateBox(TexUtility.GetNumeratorStyle(style));
var denominatorBox = denominator == null ? StrutBox.Empty :
denominator.CreateBox(TexUtility.GetDenominatorStyle(style));
float maxWidth = (numeratorBox.width < denominatorBox.width ? denominatorBox.width : numeratorBox.width) + TEXConfiguration.main.FractionMargin * TexUtility.SizeFactor(style);
numeratorBox = HorizontalBox.Get(numeratorBox, maxWidth, numeratorAlignment);
denominatorBox = HorizontalBox.Get(denominatorBox, maxWidth, denominatorAlignment);
// Calculate preliminary shift-up and shift-down amounts.
float shiftUp, shiftDown;
var styleFactor = TexUtility.SizeFactor(style);
if (style >= TexStyle.Text)
{
styleFactor *= TEXConfiguration.main.FractionNarrowFactor;
}
shiftUp = TEXConfiguration.main.NumeratorShift * styleFactor;
shiftDown = TEXConfiguration.main.DenominatorShift * styleFactor;
// Create result box.
var resultBox = VerticalBox.Get();
// add box for numerator.
resultBox.Add(numeratorBox);
// Calculate clearance and adjust shift amounts.
//var axis = TEXConfiguration.main.AxisHeight * TexUtility.SizeFactor(style);
// Calculate clearance amount.
float clearance = lineHeight > 0 ? TEXConfiguration.main.FractionGap : TEXConfiguration.main.FractionGapNoLine;
// Adjust shift amounts.
var kern1 = shiftUp - numeratorBox.depth;
var kern2 = shiftDown - denominatorBox.height;
var delta1 = clearance - kern1;
var delta2 = clearance - kern2;
if (delta1 > 0)
{
shiftUp += delta1;
kern1 += delta1;
}
if (delta2 > 0)
{
shiftDown += delta2;
kern2 += delta2;
}
if (lineHeight > 0)
{
// Draw fraction line.
resultBox.Add(StrutBox.Get(0, kern1, 0, 0));
resultBox.Add(HorizontalRule.Get(lineHeight, numeratorBox.width, 0));
resultBox.Add(StrutBox.Get(0, kern2, 0, 0));
}
else
{
// Do not draw fraction line.
var kern = kern1 + kern2;
resultBox.Add(StrutBox.Get(0, kern, 0, 0));
}
// add box for denominator.
resultBox.Add(denominatorBox);
// Adjust height and depth of result box.
resultBox.height = shiftUp + numeratorBox.height;
resultBox.depth = shiftDown + lineHeight + denominatorBox.depth;
TexUtility.CentreBox(resultBox, style);
return(resultBox);
}