/// <summary>
/// Compute unshaped glyph run object from the specified character-based info
/// </summary>
internal sealed override GlyphRun ComputeUnshapedGlyphRun(
Point origin,
char[] characterString,
IList <double> characterAdvances
)
{
bool nullFont;
GlyphTypeface glyphTypeface = GetGlyphTypeface(out nullFont);
Invariant.Assert(glyphTypeface != null);
return(glyphTypeface.ComputeUnshapedGlyphRun(
origin,
new CharacterBufferRange(
characterString,
0, // offsetToFirstChar
characterString.Length
),
characterAdvances,
_emSize,
(float)_properties.PixelsPerDip,
_properties.FontHintingEmSize,
nullFont,
CultureMapper.GetSpecificCulture(_properties.CultureInfo),
(_shapeTypeface == null || _shapeTypeface.DeviceFont == null) ? null : _shapeTypeface.DeviceFont.Name,
_textFormattingMode
));
}
/// <summary>
/// Compute a shaped glyph run object from specified glyph-based info
/// </summary>
internal sealed override GlyphRun ComputeShapedGlyphRun(
Point origin,
char[] characterString,
ushort[] clusterMap,
ushort[] glyphIndices,
IList <double> glyphAdvances,
IList <Point> glyphOffsets,
bool rightToLeft,
bool sideways
)
{
Invariant.Assert(_shapeTypeface != null);
Invariant.Assert(glyphIndices != null);
// Device fonts are only used through the LS non-glyphed code path. Only when a DigitCulture is set
// will a potential device font be ignored and come through shaping.
Invariant.Assert(_shapeTypeface.DeviceFont == null || _textItem.DigitCulture != null);
bool[] caretStops = null;
if (clusterMap != null &&
(HasExtendedCharacter || NeedsCaretInfo)
)
{
caretStops = new bool[clusterMap.Length + 1];
// caret stops at cluster boundaries, the first and the last entries are always set
caretStops[0] = true;
caretStops[clusterMap.Length] = true;
ushort lastGlyph = clusterMap[0];
for (int i = 1; i < clusterMap.Length; i++)
{
ushort glyph = clusterMap[i];
if (glyph != lastGlyph)
{
caretStops[i] = true;
lastGlyph = glyph;
}
}
}
return(GlyphRun.TryCreate(
_shapeTypeface.GlyphTypeface,
(rightToLeft ? 1 : 0),
sideways,
_emSize,
glyphIndices,
origin,
glyphAdvances,
glyphOffsets,
characterString,
null,
clusterMap,
caretStops,
XmlLanguage.GetLanguage(CultureMapper.GetSpecificCulture(_properties.CultureInfo).IetfLanguageTag),
_textFormattingMode
));
}
private static CultureInfo GetNumberCulture(TextRunProperties properties, out NumberSubstitutionMethod method, out bool ignoreUserOverride)
{
ignoreUserOverride = true;
NumberSubstitution sub = properties.NumberSubstitution;
if (sub == null)
{
method = NumberSubstitutionMethod.AsCulture;
return(CultureMapper.GetSpecificCulture(properties.CultureInfo));
}
method = sub.Substitution;
switch (sub.CultureSource)
{
case NumberCultureSource.Text:
return(CultureMapper.GetSpecificCulture(properties.CultureInfo));
case NumberCultureSource.User:
ignoreUserOverride = false;
return(CultureInfo.CurrentCulture);
case NumberCultureSource.Override:
return(sub.CultureOverride);
}
return(null);
}
/// <summary>
/// Get text immediately preceding cpLimit.
/// </summary>
internal TextSpan <CultureSpecificCharacterBufferRange> GetPrecedingText(TextSource textSource, int cpLimit)
{
if (cpLimit > 0)
{
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition);
if (textRunSpanRider.At(cpLimit - 1))
{
CharacterBufferRange charString = CharacterBufferRange.Empty;
CultureInfo culture = null;
TextRun run = textRunSpanRider.CurrentElement as TextRun;
if (run != null)
{
// Only TextRun containing text would have non-empty Character buffer range.
if (TextRunInfo.GetRunType(run) == Plsrun.Text &&
run.CharacterBufferReference.CharacterBuffer != null)
{
charString = new CharacterBufferRange(
run.CharacterBufferReference,
cpLimit - textRunSpanRider.CurrentSpanStart);
culture = CultureMapper.GetSpecificCulture(run.Properties.CultureInfo);
}
return(new TextSpan <CultureSpecificCharacterBufferRange>(
cpLimit - textRunSpanRider.CurrentSpanStart, // cp length
new CultureSpecificCharacterBufferRange(culture, charString)
));
}
}
}
// not in cache so call back to client
return(textSource.GetPrecedingText(cpLimit));
}
/// <summary>
/// Break a run of text into individually shape items.
/// Shape items are delimited by
/// Change of writing system
/// Change of glyph typeface
/// </summary>
IList <TextShapeableSymbols> ITextSymbols.GetTextShapeableSymbols(
GlyphingCache glyphingCache,
CharacterBufferReference characterBufferReference,
int length,
bool rightToLeft,
bool isRightToLeftParagraph,
CultureInfo digitCulture,
TextModifierScope textModifierScope,
TextFormattingMode textFormattingMode,
bool isSideways
)
{
if (characterBufferReference.CharacterBuffer == null)
{
throw new ArgumentNullException("characterBufferReference.CharacterBuffer");
}
int offsetToFirstChar = characterBufferReference.OffsetToFirstChar - _characterBufferReference.OffsetToFirstChar;
Debug.Assert(characterBufferReference.CharacterBuffer == _characterBufferReference.CharacterBuffer);
Debug.Assert(offsetToFirstChar >= 0 && offsetToFirstChar < _length);
if (length < 0 ||
offsetToFirstChar + length > _length)
{
length = _length - offsetToFirstChar;
}
// Get the actual text run properties in effect, after invoking any
// text modifiers that may be in scope.
TextRunProperties textRunProperties = _textRunProperties;
if (textModifierScope != null)
{
textRunProperties = textModifierScope.ModifyProperties(textRunProperties);
}
if (!rightToLeft)
{
// Fast loop early out for run with all non-complex characters
// which can be optimized by not going thru shaping engine.
int nominalLength;
if (textRunProperties.Typeface.CheckFastPathNominalGlyphs(
new CharacterBufferRange(characterBufferReference, length),
textRunProperties.FontRenderingEmSize,
(float)textRunProperties.PixelsPerDip,
1.0,
double.MaxValue, // widthMax
true, // keepAWord
digitCulture != null,
CultureMapper.GetSpecificCulture(textRunProperties.CultureInfo),
textFormattingMode,
isSideways,
false, //breakOnTabs
out nominalLength
) && length == nominalLength)
{
return(new TextShapeableCharacters[]
{
new TextShapeableCharacters(
new CharacterBufferRange(characterBufferReference, nominalLength),
textRunProperties,
textRunProperties.FontRenderingEmSize,
new MS.Internal.Text.TextInterface.ItemProps(),
null, // shapeTypeface (no shaping required)
false, // nullShape,
textFormattingMode,
isSideways
)
});
}
}
IList <TextShapeableSymbols> shapeables = new List <TextShapeableSymbols>(2);
glyphingCache.GetShapeableText(
textRunProperties.Typeface,
characterBufferReference,
length,
textRunProperties,
digitCulture,
isRightToLeftParagraph,
shapeables,
this as IShapeableTextCollector,
textFormattingMode
);
return(shapeables);
}
/// <summary>
/// Fetch cached textrun
/// </summary>
internal TextRun FetchTextRun(
FormatSettings settings,
int cpFetch,
int cpFirst,
out int offsetToFirstCp,
out int runLength
)
{
SpanRider textRunSpanRider = new SpanRider(_textRunVector, _latestPosition, cpFetch);
_latestPosition = textRunSpanRider.SpanPosition;
TextRun textRun = (TextRun)textRunSpanRider.CurrentElement;
if (textRun == null)
{
// run not already cached, fetch new run and cache it
textRun = settings.TextSource.GetTextRun(cpFetch);
if (textRun.Length < 1)
{
throw new ArgumentOutOfRangeException("textRun.Length", SR.Get(SRID.ParameterMustBeGreaterThanZero));
}
Plsrun plsrun = TextRunInfo.GetRunType(textRun);
if (plsrun == Plsrun.Text || plsrun == Plsrun.InlineObject)
{
TextRunProperties properties = textRun.Properties;
if (properties == null)
{
throw new ArgumentException(SR.Get(SRID.TextRunPropertiesCannotBeNull));
}
if (properties.FontRenderingEmSize <= 0)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassMustBeGreaterThanZero, "FontRenderingEmSize", "TextRunProperties"));
}
double realMaxFontRenderingEmSize = Constants.RealInfiniteWidth / Constants.GreatestMutiplierOfEm;
if (properties.FontRenderingEmSize > realMaxFontRenderingEmSize)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeGreaterThan, "FontRenderingEmSize", "TextRunProperties", realMaxFontRenderingEmSize));
}
CultureInfo culture = CultureMapper.GetSpecificCulture(properties.CultureInfo);
if (culture == null)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "CultureInfo", "TextRunProperties"));
}
if (properties.Typeface == null)
{
throw new ArgumentException(SR.Get(SRID.PropertyOfClassCannotBeNull, "Typeface", "TextRunProperties"));
}
}
//
// TextRun is specifial to SpanVector because TextRun also encodes position which needs to be
// consistent with the positions encoded by SpanVector. In run cache, the begining of a span
// should always correspond to the begining of a cached text run. If the end of the currently fetched
// run overlaps with the begining of an already cached run, the begining of the cached run needs to be
// adjusted as well as its span. Because we can't gurantee the correctness of the overlapped range
// so we'll simply remove the overlapped runs here.
//
// Move the rider to the end of the current run
textRunSpanRider.At(cpFetch + textRun.Length - 1);
_latestPosition = textRunSpanRider.SpanPosition;
if (textRunSpanRider.CurrentElement != _textRunVector.Default)
{
// The end overlaps with one or more cached runs, clear the range from the
// begining of the current fetched run to the end of the last overlapped cached run.
_latestPosition = _textRunVector.SetReference(
cpFetch,
textRunSpanRider.CurrentPosition + textRunSpanRider.Length - cpFetch,
_textRunVector.Default,
_latestPosition
);
}
_latestPosition = _textRunVector.SetReference(cpFetch, textRun.Length, textRun, _latestPosition);
// Refresh the rider's SpanPosition following previous SpanVector.SetReference calls
textRunSpanRider.At(_latestPosition, cpFetch);
}
// If the TextRun was obtained from the cache, make sure it has the right PixelsPerDip set on its properties.
if (textRun.Properties != null)
{
textRun.Properties.PixelsPerDip = settings.TextSource.PixelsPerDip;
}
offsetToFirstCp = textRunSpanRider.CurrentPosition - textRunSpanRider.CurrentSpanStart;
runLength = textRunSpanRider.Length;
Debug.Assert(textRun != null && runLength > 0, "Invalid run!");
bool isText = textRun is ITextSymbols;
if (isText)
{
// Chop text run to optimal length so we dont spend forever analysing
// them all at once.
int looseCharLength = TextStore.TypicalCharactersPerLine - cpFetch + cpFirst;
if (looseCharLength <= 0)
{
// this line already exceeds typical line length, incremental fetch goes
// about a quarter of the typical length.
looseCharLength = (int)Math.Round(TextStore.TypicalCharactersPerLine * 0.25);
}
if (runLength > looseCharLength)
{
if (TextRunInfo.GetRunType(textRun) == Plsrun.Text)
{
//
// When chopping the run at the typical line length,
// - don't chop in between of higher & lower surrogate
// - don't chop combining mark away from its base character
// - don't chop joiner from surrounding characters
//
// Starting from the initial chopping point, we look ahead to find a safe position. We stop at
// a limit in case the run consists of many combining mark & joiner. That is rare and doesn't make
// much sense in shaping already.
//
CharacterBufferReference charBufferRef = textRun.CharacterBufferReference;
// We look ahead by one more line at most. It is not normal to have
// so many combining mark or joiner characters in a row. It doesn't make sense to
// look further if so.
int lookAheadLimit = Math.Min(runLength, looseCharLength + TextStore.TypicalCharactersPerLine);
int sizeOfChar = 0;
int endOffset = 0;
bool canBreakAfterPrecedingChar = false;
for (endOffset = looseCharLength - 1; endOffset < lookAheadLimit; endOffset += sizeOfChar)
{
CharacterBufferRange charString = new CharacterBufferRange(
charBufferRef.CharacterBuffer,
charBufferRef.OffsetToFirstChar + offsetToFirstCp + endOffset,
runLength - endOffset
);
int ch = Classification.UnicodeScalar(charString, out sizeOfChar);
// We can only safely break if the preceding char is not a joiner character (i.e. can-break-after),
// and the current char is not combining or joiner (i.e. can-break-before).
if (canBreakAfterPrecedingChar && !Classification.IsCombining(ch) && !Classification.IsJoiner(ch))
{
break;
}
canBreakAfterPrecedingChar = !Classification.IsJoiner(ch);
}
looseCharLength = Math.Min(runLength, endOffset);
}
runLength = looseCharLength;
}
}
Debug.Assert(
// valid run found
runLength > 0
// non-text run always fetched at run start
&& (isText ||
textRunSpanRider.CurrentSpanStart - textRunSpanRider.CurrentPosition == 0)
// span rider of both text and format point to valid position
&& (textRunSpanRider.Length > 0 && textRunSpanRider.CurrentElement != null),
"Text run fetching error!"
);
return(textRun);
}
