/// <summary>
/// Create a new instance of the <see cref="Font" /> for the named font family.
/// </summary>
/// <param name="size">The size of the font in PT units.</param>
/// <param name="style">The font style.</param>
/// <returns>The new <see cref="Font" />.</returns>
public Font CreateFont(float size, FontStyle style)
{
if (this == default)
{
FontsThrowHelper.ThrowDefaultInstance();
}
return(new Font(this, size, style));
}
/// <summary>
/// Gets the specified font metrics matching the given font style.
/// </summary>
/// <param name="style">The font style to use when searching for a match.</param>
/// <param name="metrics">
/// When this method returns, contains the metrics associated with the specified name,
/// if the name is found; otherwise, the default value for the type of the metrics parameter.
/// This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <see langword="true"/> if the <see cref="FontFamily"/> contains font metrics
/// with the specified name; otherwise, <see langword="false"/>.
/// </returns>
internal bool TryGetMetrics(FontStyle style, [NotNullWhen(true)] out FontMetrics?metrics)
{
if (this == default)
{
FontsThrowHelper.ThrowDefaultInstance();
}
return(this.collection.TryGetMetrics(this.Name, this.Culture, style, out metrics));
}
/// <summary>
/// Gets the collection of <see cref="FontStyle" /> that are currently available.
/// </summary>
/// <returns>The <see cref="IEnumerable{T}" />.</returns>
public IEnumerable <FontStyle> GetAvailableStyles()
{
if (this == default)
{
FontsThrowHelper.ThrowDefaultInstance();
}
return(this.collection.GetAllStyles(this.Name, this.Culture));
}
/// <summary>
/// Gets the filesystem path to the font family source.
/// </summary>
/// <param name="path">
/// When this method returns, contains the filesystem path to the font family source,
/// if the path exists; otherwise, the default value for the type of the path parameter.
/// This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <see langword="true" /> if the <see cref="Font" /> was created via a filesystem path; otherwise, <see langword="false" />.
/// </returns>
public bool TryGetPath([NotNullWhen(true)] out string?path)
{
if (this == default)
{
FontsThrowHelper.ThrowDefaultInstance();
}
if (this.FontMetrics is FileFontMetrics fileMetrics)
{
path = fileMetrics.Path;
return(true);
}
path = null;
return(false);
}
/// <summary>
/// Gets the collection of filesystem paths to the font family sources.
/// </summary>
/// <param name="paths">
/// When this method returns, contains the filesystem paths to the font family sources,
/// if the path exists; otherwise, an empty value for the type of the paths parameter.
/// This parameter is passed uninitialized.
/// </param>
/// <returns>
/// <see langword="true" /> if the <see cref="FontFamily" /> was created via filesystem paths; otherwise, <see langword="false" />.
/// </returns>
public bool TryGetPaths(out IEnumerable <string> paths)
{
if (this == default)
{
FontsThrowHelper.ThrowDefaultInstance();
}
var filePaths = new List <string>();
foreach (FontStyle style in this.GetAvailableStyles())
{
if (this.collection.TryGetMetrics(this.Name, this.Culture, style, out FontMetrics? metrics) &&
metrics is FileFontMetrics fileMetrics)
{
filePaths.Add(fileMetrics.Path);
}
}
paths = filePaths;
return(filePaths.Count > 0);
}
/// <summary>
/// Generates the layout.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="options">The style.</param>
/// <returns>A collection of layout that describe all thats needed to measure or render a series of glyphs.</returns>
public IReadOnlyList <GlyphLayout> GenerateLayout(ReadOnlySpan <char> text, RendererOptions options)
{
if (text.IsEmpty)
{
return(Array.Empty <GlyphLayout>());
}
var dpi = new Vector2(options.DpiX, options.DpiY);
Vector2 origin = options.Origin / dpi;
float maxWidth = float.MaxValue;
float originX = 0;
if (options.WrappingWidth > 0)
{
// trim trailing white spaces from the text
text = text.TrimEnd(null);
maxWidth = options.WrappingWidth / options.DpiX;
}
// lets convert the text into codepoints
Memory <int> codePointsMemory = LineBreaker.ToUtf32(text);
if (codePointsMemory.IsEmpty)
{
return(Array.Empty <GlyphLayout>());
}
Span <int> codepoints = codePointsMemory.Span;
var lineBreaker = new LineBreaker();
lineBreaker.Reset(codePointsMemory);
AppliedFontStyle spanStyle = options.GetStyle(0, codepoints.Length);
var layout = new List <GlyphLayout>(codepoints.Length);
float unscaledLineHeight = 0f;
float lineHeight = 0f;
float unscaledLineMaxAscender = 0f;
float unscaledLineMaxDescender = 0f;
float lineMaxAscender = 0f;
float lineMaxDescender = 0f;
Vector2 location = Vector2.Zero;
float lineHeightOfFirstLine = 0;
// Remember where the top of the layouted text is for accurate vertical alignment.
// This is important because there is considerable space between the lineHeight at the glyph's ascender.
float top = 0;
bool firstLine = true;
GlyphInstance?previousGlyph = null;
float scale = 0;
int lastWrappableLocation = -1;
int nextWrappableLocation = codepoints.Length;
bool nextWrappableRequired = false;
bool startOfLine = true;
float totalHeight = 0;
int graphemeIndex = 0;
if (lineBreaker.TryGetNextBreak(out LineBreak b))
{
nextWrappableLocation = b.PositionWrap - 1;
nextWrappableRequired = b.Required;
}
for (int i = 0; i < codepoints.Length; i++)
{
if (spanStyle.End < i)
{
spanStyle = options.GetStyle(i, codepoints.Length);
previousGlyph = null;
}
int codePoint = codepoints[i];
GlyphInstance[] glyphs = spanStyle.GetGlyphLayers(codePoint, options.ColorFontSupport);
if (glyphs.Length == 0)
{
return(FontsThrowHelper.ThrowGlyphMissingException <IReadOnlyList <GlyphLayout> >(codePoint));
}
GlyphInstance?glyph = glyphs[0];
float fontHeight = glyph.Font.LineHeight * options.LineSpacing;
if (fontHeight > unscaledLineHeight)
{
// get the larget lineheight thus far
unscaledLineHeight = fontHeight;
scale = glyph.Font.EmSize * 72;
lineHeight = unscaledLineHeight * spanStyle.PointSize / scale;
}
if (glyph.Font.Ascender > unscaledLineMaxAscender)
{
unscaledLineMaxAscender = glyph.Font.Ascender;
scale = glyph.Font.EmSize * 72;
lineMaxAscender = unscaledLineMaxAscender * spanStyle.PointSize / scale;
}
if (Math.Abs(glyph.Font.Descender) > unscaledLineMaxDescender)
{
unscaledLineMaxDescender = Math.Abs(glyph.Font.Descender);
scale = glyph.Font.EmSize * 72;
lineMaxDescender = unscaledLineMaxDescender * spanStyle.PointSize / scale;
}
if (firstLine)
{
// Reset the line height for the first line to prevent initial lead.
float unspacedLineHeight = lineHeight / options.LineSpacing;
if (unspacedLineHeight > lineHeightOfFirstLine)
{
lineHeightOfFirstLine = unspacedLineHeight;
}
switch (options.VerticalAlignment)
{
case VerticalAlignment.Top:
top = lineMaxAscender;
break;
case VerticalAlignment.Center:
top = (lineMaxAscender / 2F) - (lineMaxDescender / 2F);
break;
case VerticalAlignment.Bottom:
top = -lineMaxDescender;
break;
}
}
if ((options.WrappingWidth > 0 && nextWrappableLocation == i) || nextWrappableRequired)
{
// keep a record of where to wrap text and ensure that no line starts with white space
for (int j = layout.Count - 1; j >= 0; j--)
{
if (!layout[j].IsWhiteSpace)
{
lastWrappableLocation = j + 1;
break;
}
}
}
if (nextWrappableLocation == i)
{
if (lineBreaker.TryGetNextBreak(out b))
{
nextWrappableLocation = b.PositionWrap - 1;
nextWrappableRequired = b.Required;
}
}
float glyphWidth = glyph.AdvanceWidth * spanStyle.PointSize / scale;
float glyphHeight = glyph.Height * spanStyle.PointSize / scale;
if (codepoints[i] != '\r' && codepoints[i] != '\n' && codepoints[i] != '\t' && codepoints[i] != ' ')
{
Vector2 glyphLocation = location;
if (spanStyle.ApplyKerning && previousGlyph != null)
{
// if there is special instructions for this glyph pair use that width
Vector2 scaledOffset = spanStyle.GetOffset(glyph, previousGlyph) * spanStyle.PointSize / scale;
glyphLocation += scaledOffset;
// only fix the 'X' of the current tracked location but use the actual 'X'/'Y' of the offset
location.X = glyphLocation.X;
}
foreach (GlyphInstance?g in glyphs)
{
float w = g.AdvanceWidth * spanStyle.PointSize / scale;
float h = g.Height * spanStyle.PointSize / scale;
layout.Add(new GlyphLayout(graphemeIndex, codePoint, new Glyph(g, spanStyle.PointSize), glyphLocation, w, h, lineHeight, startOfLine, false, false));
if (w > glyphWidth)
{
glyphWidth = w;
}
}
// Increment the index to signify we have moved on the a new cluster.
graphemeIndex++;
startOfLine = false;
// move forward the actual width of the glyph, we are retaining the baseline
location.X += glyphWidth;
// if the word extended pass the end of the box, wrap it
if (location.X >= maxWidth && lastWrappableLocation > 0)
{
if (lastWrappableLocation < layout.Count)
{
float wrappingOffset = layout[lastWrappableLocation].Location.X;
startOfLine = true;
// move the characters to the next line
for (int j = lastWrappableLocation; j < layout.Count; j++)
{
if (layout[j].IsWhiteSpace)
{
wrappingOffset += layout[j].Width;
layout.RemoveAt(j);
j--;
continue;
}
Vector2 current = layout[j].Location;
layout[j] = new GlyphLayout(layout[j].GraphemeIndex, layout[j].CodePoint, layout[j].Glyph, new Vector2(current.X - wrappingOffset, current.Y + lineHeight), layout[j].Width, layout[j].Height, layout[j].LineHeight, startOfLine, layout[j].IsWhiteSpace, layout[j].IsControlCharacter);
startOfLine = false;
location.X = layout[j].Location.X + layout[j].Width;
}
location.Y += lineHeight;
totalHeight += lineHeight;
firstLine = false;
lastWrappableLocation = -1;
}
}
previousGlyph = glyph;
}
else if (codepoints[i] == '\r')
{
// carriage return resets the XX coordinate to 0
location.X = 0;
previousGlyph = null;
startOfLine = true;
layout.Add(new GlyphLayout(-1, codePoint, new Glyph(glyph, spanStyle.PointSize), location, 0, glyphHeight, lineHeight, startOfLine, true, true));
startOfLine = false;
}
else if (codepoints[i] == '\n')
{
// carriage return resets the XX coordinate to 0
layout.Add(new GlyphLayout(-1, codePoint, new Glyph(glyph, spanStyle.PointSize), location, 0, glyphHeight, lineHeight, startOfLine, true, true));
location.X = 0;
location.Y += lineHeight;
totalHeight += lineHeight;
unscaledLineHeight = 0;
unscaledLineMaxAscender = 0;
previousGlyph = null;
firstLine = false;
lastWrappableLocation = -1;
startOfLine = true;
}
else if (codepoints[i] == '\t')
{
float tabStop = glyphWidth * spanStyle.TabWidth;
float finalWidth = 0;
if (tabStop > 0)
{
finalWidth = tabStop - (location.X % tabStop);
}
if (finalWidth < glyphWidth)
{
// if we are not going to tab atleast a glyph width add another tabstop to it ???
// should I be doing this?
finalWidth += tabStop;
}
layout.Add(new GlyphLayout(-1, codePoint, new Glyph(glyph, spanStyle.PointSize), location, finalWidth, glyphHeight, lineHeight, startOfLine, true, false));
startOfLine = false;
// advance to a position > width away that
location.X += finalWidth;
previousGlyph = null;
}
else if (codepoints[i] == ' ')
{
layout.Add(new GlyphLayout(-1, codePoint, new Glyph(glyph, spanStyle.PointSize), location, glyphWidth, glyphHeight, lineHeight, startOfLine, true, false));
startOfLine = false;
location.X += glyphWidth;
previousGlyph = null;
}
}
var offsetY = new Vector2(0, top);
switch (options.VerticalAlignment)
{
case VerticalAlignment.Center:
offsetY += new Vector2(0, -(totalHeight / 2F));
break;
case VerticalAlignment.Bottom:
offsetY += new Vector2(0, -totalHeight);
break;
}
Vector2 offsetX = Vector2.Zero;
for (int i = 0; i < layout.Count; i++)
{
GlyphLayout glyphLayout = layout[i];
graphemeIndex = glyphLayout.GraphemeIndex;
// Scan ahead getting the width.
if (glyphLayout.StartOfLine)
{
float width = 0;
for (int j = i; j < layout.Count; j++)
{
GlyphLayout current = layout[j];
int currentGraphemeIndex = current.GraphemeIndex;
if (current.StartOfLine && (currentGraphemeIndex != graphemeIndex))
{
// Leading graphemes are made up of multiple glyphs all marked as 'StartOfLine so we only
// break when we are sure we have entered a new cluster or previously defined break.
break;
}
width = current.Location.X + current.Width;
}
switch (options.HorizontalAlignment)
{
case HorizontalAlignment.Left:
offsetX = new Vector2(originX, 0) + offsetY;
break;
case HorizontalAlignment.Right:
offsetX = new Vector2(originX - width, 0) + offsetY;
break;
case HorizontalAlignment.Center:
offsetX = new Vector2(originX - (width / 2F), 0) + offsetY;
break;
}
}
// TODO calculate an offset from the 'origin' based on TextAlignment for each line
layout[i] = new GlyphLayout(
glyphLayout.GraphemeIndex,
glyphLayout.CodePoint,
glyphLayout.Glyph,
glyphLayout.Location + offsetX + origin,
glyphLayout.Width,
glyphLayout.Height,
glyphLayout.LineHeight,
glyphLayout.StartOfLine,
glyphLayout.IsWhiteSpace,
glyphLayout.IsControlCharacter);
}
return(layout);
}
/// <summary>
/// Generates the layout.
/// </summary>
/// <param name="text">The text.</param>
/// <param name="options">The style.</param>
/// <returns>A collection of layout that describe all thats needed to measure or render a series of glyphs.</returns>
public IReadOnlyList <GlyphLayout> GenerateLayout(ReadOnlySpan <char> text, RendererOptions options)
{
var dpi = new Vector2(options.DpiX, options.DpiY);
Vector2 origin = (Vector2)options.Origin / dpi;
float maxWidth = float.MaxValue;
float originX = 0;
if (options.WrappingWidth > 0)
{
// trim trailing white spaces from the text
text = text.TrimEnd(null);
maxWidth = options.WrappingWidth / options.DpiX;
switch (options.HorizontalAlignment)
{
case HorizontalAlignment.Right:
originX = maxWidth;
break;
case HorizontalAlignment.Center:
originX = 0.5f * maxWidth;
break;
case HorizontalAlignment.Left:
default:
originX = 0;
break;
}
}
AppliedFontStyle spanStyle = options.GetStyle(0, text.Length);
var layout = new List <GlyphLayout>(text.Length);
float unscaledLineHeight = 0f;
float lineHeight = 0f;
float unscaledLineMaxAscender = 0f;
float unscaledLineMaxDescender = 0f;
float lineMaxAscender = 0f;
float lineMaxDescender = 0f;
Vector2 location = Vector2.Zero;
float lineHeightOfFirstLine = 0;
// Remember where the top of the layouted text is for accurate vertical alignment.
// This is important because there is considerable space between the lineHeight at the glyph's ascender.
float top = 0;
bool firstLine = true;
GlyphInstance?previousGlyph = null;
float scale = 0;
int lastWrappableLocation = -1;
bool startOfLine = true;
float totalHeight = 0;
for (int i = 0; i < text.Length; i++)
{
// four-byte characters are processed on the first char
if (char.IsLowSurrogate(text[i]))
{
continue;
}
if (spanStyle.End < i)
{
spanStyle = options.GetStyle(i, text.Length);
previousGlyph = null;
}
bool hasFourBytes = char.IsHighSurrogate(text[i]);
int codePoint = hasFourBytes ? char.ConvertToUtf32(text[i], text[i + 1]) : text[i];
GlyphInstance[] glyphs = spanStyle.GetGlyphLayers(codePoint, options.ColorFontSupport);
if (glyphs.Length == 0)
{
return(FontsThrowHelper.ThrowGlyphMissingException <IReadOnlyList <GlyphLayout> >(codePoint));
}
var glyph = glyphs[0];
if (glyph.Font.LineHeight > unscaledLineHeight)
{
// get the larget lineheight thus far
unscaledLineHeight = glyph.Font.LineHeight;
scale = glyph.Font.EmSize * 72;
lineHeight = (unscaledLineHeight * spanStyle.PointSize) / scale;
}
if (glyph.Font.Ascender > unscaledLineMaxAscender)
{
unscaledLineMaxAscender = glyph.Font.Ascender;
scale = glyph.Font.EmSize * 72;
lineMaxAscender = (unscaledLineMaxAscender * spanStyle.PointSize) / scale;
}
if (glyph.Font.Descender > unscaledLineMaxDescender)
{
unscaledLineMaxDescender = glyph.Font.Descender;
scale = glyph.Font.EmSize * 72;
lineMaxDescender = (unscaledLineMaxDescender * spanStyle.PointSize) / scale;
}
if (firstLine)
{
if (lineHeight > lineHeightOfFirstLine)
{
lineHeightOfFirstLine = lineHeight;
}
var lineGap = lineHeightOfFirstLine - lineMaxAscender - lineMaxDescender;
top = lineHeightOfFirstLine - lineMaxAscender - (lineGap / 2);
}
if (options.WrappingWidth > 0 && char.IsWhiteSpace(text[i]))
{
// keep a record of where to wrap text and ensure that no line starts with white space
for (int j = layout.Count - 1; j >= 0; j--)
{
if (!layout[j].IsWhiteSpace)
{
lastWrappableLocation = j + 1;
break;
}
}
}
float glyphWidth = (glyph.AdvanceWidth * spanStyle.PointSize) / scale;
float glyphHeight = (glyph.Height * spanStyle.PointSize) / scale;
if (hasFourBytes || (text[i] != '\r' && text[i] != '\n' && text[i] != '\t' && text[i] != ' '))
{
Vector2 glyphLocation = location;
if (spanStyle.ApplyKerning && previousGlyph != null)
{
// if there is special instructions for this glyph pair use that width
Vector2 scaledOffset = (spanStyle.GetOffset(glyph, previousGlyph) * spanStyle.PointSize) / scale;
glyphLocation += scaledOffset;
// only fix the 'X' of the current tracked location but use the actual 'X'/'Y' of the offset
location.X = glyphLocation.X;
}
foreach (var g in glyphs)
{
var w = (g.AdvanceWidth * spanStyle.PointSize) / scale;
var h = (g.Height * spanStyle.PointSize) / scale;
layout.Add(new GlyphLayout(codePoint, new Glyph(g, spanStyle.PointSize), glyphLocation, w, h, lineHeight, startOfLine, false, false));
if (w > glyphWidth)
{
glyphWidth = w;
}
}
startOfLine = false;
// move forward the actual width of the glyph, we are retaining the baseline
location.X += glyphWidth;
// if the word extended pass the end of the box, wrap it
if (location.X >= maxWidth && lastWrappableLocation > 0)
{
if (lastWrappableLocation < layout.Count)
{
float wrappingOffset = layout[lastWrappableLocation].Location.X;
startOfLine = true;
// move the characters to the next line
for (int j = lastWrappableLocation; j < layout.Count; j++)
{
if (layout[j].IsWhiteSpace)
{
wrappingOffset += layout[j].Width;
layout.RemoveAt(j);
j--;
continue;
}
Vector2 current = layout[j].Location;
layout[j] = new GlyphLayout(layout[j].CodePoint, layout[j].Glyph, new Vector2(current.X - wrappingOffset, current.Y + lineHeight), layout[j].Width, layout[j].Height, layout[j].LineHeight, startOfLine, layout[j].IsWhiteSpace, layout[j].IsControlCharacter);
startOfLine = false;
location.X = layout[j].Location.X + layout[j].Width;
}
location.Y += lineHeight;
firstLine = false;
lastWrappableLocation = -1;
}
}
float bottom = location.Y + lineHeight;
if (bottom > totalHeight)
{
totalHeight = bottom;
}
previousGlyph = glyph;
}
else if (text[i] == '\r')
{
// carriage return resets the XX coordinate to 0
location.X = 0;
previousGlyph = null;
startOfLine = true;
layout.Add(new GlyphLayout(codePoint, new Glyph(glyph, spanStyle.PointSize), location, 0, glyphHeight, lineHeight, startOfLine, true, true));
startOfLine = false;
}
else if (text[i] == '\n')
{
// carriage return resets the XX coordinate to 0
layout.Add(new GlyphLayout(codePoint, new Glyph(glyph, spanStyle.PointSize), location, 0, glyphHeight, lineHeight, startOfLine, true, true));
location.X = 0;
location.Y += lineHeight;
unscaledLineHeight = 0;
unscaledLineMaxAscender = 0;
previousGlyph = null;
firstLine = false;
lastWrappableLocation = -1;
startOfLine = true;
}
else if (text[i] == '\t')
{
float tabStop = glyphWidth * spanStyle.TabWidth;
float finalWidth = 0;
if (tabStop > 0)
{
finalWidth = tabStop - (location.X % tabStop);
}
if (finalWidth < glyphWidth)
{
// if we are not going to tab atleast a glyph width add another tabstop to it ???
// should I be doing this?
finalWidth += tabStop;
}
layout.Add(new GlyphLayout(codePoint, new Glyph(glyph, spanStyle.PointSize), location, finalWidth, glyphHeight, lineHeight, startOfLine, true, false));
startOfLine = false;
// advance to a position > width away that
location.X += finalWidth;
previousGlyph = null;
}
else if (text[i] == ' ')
{
layout.Add(new GlyphLayout(codePoint, new Glyph(glyph, spanStyle.PointSize), location, glyphWidth, glyphHeight, lineHeight, startOfLine, true, false));
startOfLine = false;
location.X += glyphWidth;
previousGlyph = null;
}
}
totalHeight -= top;
var offset = new Vector2(0, lineHeightOfFirstLine - top);
switch (options.VerticalAlignment)
{
case VerticalAlignment.Center:
offset += new Vector2(0, -0.5f * totalHeight);
break;
case VerticalAlignment.Bottom:
offset += new Vector2(0, -totalHeight);
break;
case VerticalAlignment.Top:
default:
// no change
break;
}
Vector2 lineOffset = offset;
for (int i = 0; i < layout.Count; i++)
{
GlyphLayout glyphLayout = layout[i];
if (glyphLayout.StartOfLine)
{
lineOffset = offset;
// scan ahead measuring width
float width = glyphLayout.Width;
for (int j = i + 1; j < layout.Count; j++)
{
if (layout[j].StartOfLine)
{
break;
}
width = layout[j].Location.X + layout[j].Width; // rhs
}
switch (options.HorizontalAlignment)
{
case HorizontalAlignment.Right:
lineOffset = new Vector2(originX - width, 0) + offset;
break;
case HorizontalAlignment.Center:
lineOffset = new Vector2(originX - (width / 2f), 0) + offset;
break;
case HorizontalAlignment.Left:
default:
lineOffset = new Vector2(originX, 0) + offset;
break;
}
}
// TODO calculate an offset from the 'origin' based on TextAlignment for each line
layout[i] = new GlyphLayout(glyphLayout.CodePoint, glyphLayout.Glyph, glyphLayout.Location + lineOffset + origin, glyphLayout.Width, glyphLayout.Height, glyphLayout.LineHeight, glyphLayout.StartOfLine, glyphLayout.IsWhiteSpace, glyphLayout.IsControlCharacter);
}
return(layout);
}
