unsigned WidthIterator::advance(int offset, GlyphBuffer* glyphBuffer)
{
int length = m_run.length();
if (offset > length)
offset = length;
if (m_currentCharacter >= static_cast<unsigned>(offset))
return 0;
if (m_run.is8Bit()) {
Latin1TextIterator textIterator(m_run.data8(m_currentCharacter), m_currentCharacter, offset, length);
return advanceInternal(textIterator, glyphBuffer);
}
SurrogatePairAwareTextIterator textIterator(m_run.data16(m_currentCharacter), m_currentCharacter, offset, length);
return advanceInternal(textIterator, glyphBuffer);
}
unsigned SimpleShaper::advance(unsigned offset, GlyphBuffer* glyphBuffer)
{
unsigned length = m_run.length();
if (offset > length)
offset = length;
if (m_currentCharacter >= offset)
return 0;
if (m_run.is8Bit()) {
Latin1TextIterator textIterator(m_run.data8(m_currentCharacter), m_currentCharacter, offset, length);
return advanceInternal(textIterator, glyphBuffer);
}
SurrogatePairAwareTextIterator textIterator(m_run.data16(m_currentCharacter), m_currentCharacter, offset, length);
return advanceInternal(textIterator, glyphBuffer);
}
unsigned SimpleShaper::advance(int offset, GlyphBuffer* glyphBuffer)
{
int length = m_textRun.length();
if (offset > length)
offset = length;
if (m_currentCharacter >= static_cast<unsigned>(offset))
return 0;
if (m_textRun.is8Bit()) {
Latin1TextIterator textIterator(m_textRun.data8(m_currentCharacter), m_currentCharacter, offset);
return advanceInternal(textIterator, glyphBuffer);
}
UTF16TextIterator textIterator(m_textRun.data16(m_currentCharacter), m_currentCharacter, offset, length);
return advanceInternal(textIterator, glyphBuffer);
}
unsigned WidthIterator::advance(int offset, GlyphBuffer* glyphBuffer)
{
if (offset > m_run.length())
offset = m_run.length();
if (int(m_currentCharacter) >= offset)
return 0;
bool rtl = m_run.rtl();
bool hasExtraSpacing = (m_font->letterSpacing() || m_font->wordSpacing() || m_expansion) && !m_run.spacingDisabled();
float widthSinceLastRounding = m_runWidthSoFar;
m_runWidthSoFar = floorf(m_runWidthSoFar);
widthSinceLastRounding -= m_runWidthSoFar;
float lastRoundingWidth = m_finalRoundingWidth;
FloatRect bounds;
const SimpleFontData* primaryFont = m_font->primaryFont();
const SimpleFontData* lastFontData = primaryFont;
UChar32 character = 0;
unsigned clusterLength = 0;
SurrogatePairAwareTextIterator textIterator(m_run.data(m_currentCharacter), m_currentCharacter, offset, m_run.length());
while (textIterator.consume(character, clusterLength)) {
unsigned advanceLength = clusterLength;
const GlyphData& glyphData = glyphDataForCharacter(character, rtl, textIterator.currentCharacter(), advanceLength);
Glyph glyph = glyphData.glyph;
const SimpleFontData* fontData = glyphData.fontData;
ASSERT(fontData);
// Now that we have a glyph and font data, get its width.
float width;
if (character == '\t' && m_run.allowTabs()) {
float tabWidth = m_font->tabWidth(*fontData);
width = tabWidth - fmodf(m_run.xPos() + m_runWidthSoFar + widthSinceLastRounding, tabWidth);
} else {
width = fontData->widthForGlyph(glyph);
#if ENABLE(SVG)
// SVG uses horizontalGlyphStretch(), when textLength is used to stretch/squeeze text.
width *= m_run.horizontalGlyphStretch();
#endif
// We special case spaces in two ways when applying word rounding.
// First, we round spaces to an adjusted width in all fonts.
// Second, in fixed-pitch fonts we ensure that all characters that
// match the width of the space character have the same width as the space character.
if (m_run.applyWordRounding() && width == fontData->spaceWidth() && (fontData->pitch() == FixedPitch || glyph == fontData->spaceGlyph()))
width = fontData->adjustedSpaceWidth();
}
if (fontData != lastFontData && width) {
lastFontData = fontData;
if (m_fallbackFonts && fontData != primaryFont) {
// FIXME: This does a little extra work that could be avoided if
// glyphDataForCharacter() returned whether it chose to use a small caps font.
if (!m_font->isSmallCaps() || character == toUpper(character))
m_fallbackFonts->add(fontData);
else {
const GlyphData& uppercaseGlyphData = m_font->glyphDataForCharacter(toUpper(character), rtl);
if (uppercaseGlyphData.fontData != primaryFont)
m_fallbackFonts->add(uppercaseGlyphData.fontData);
}
}
}
if (hasExtraSpacing) {
// Account for letter-spacing.
if (width && m_font->letterSpacing())
width += m_font->letterSpacing();
static bool expandAroundIdeographs = Font::canExpandAroundIdeographsInComplexText();
bool treatAsSpace = Font::treatAsSpace(character);
if (treatAsSpace || (expandAroundIdeographs && Font::isCJKIdeographOrSymbol(character))) {
// Distribute the run's total expansion evenly over all expansion opportunities in the run.
if (m_expansion) {
float previousExpansion = m_expansion;
if (!treatAsSpace && !m_isAfterExpansion) {
// Take the expansion opportunity before this ideograph.
m_expansion -= m_expansionPerOpportunity;
float expansionAtThisOpportunity = !m_run.applyWordRounding() ? m_expansionPerOpportunity : roundf(previousExpansion) - roundf(m_expansion);
m_runWidthSoFar += expansionAtThisOpportunity;
if (glyphBuffer) {
if (glyphBuffer->isEmpty())
glyphBuffer->add(fontData->spaceGlyph(), fontData, expansionAtThisOpportunity);
else
glyphBuffer->expandLastAdvance(expansionAtThisOpportunity);
}
previousExpansion = m_expansion;
}
if (m_run.allowsTrailingExpansion() || (m_run.ltr() && textIterator.currentCharacter() + advanceLength < static_cast<size_t>(m_run.length()))
|| (m_run.rtl() && textIterator.currentCharacter())) {
m_expansion -= m_expansionPerOpportunity;
width += !m_run.applyWordRounding() ? m_expansionPerOpportunity : roundf(previousExpansion) - roundf(m_expansion);
m_isAfterExpansion = true;
}
} else
m_isAfterExpansion = false;
// Account for word spacing.
// We apply additional space between "words" by adding width to the space character.
if (treatAsSpace && textIterator.currentCharacter() && !Font::treatAsSpace(textIterator.characters()[-1]) && m_font->wordSpacing())
width += m_font->wordSpacing();
} else
m_isAfterExpansion = false;
}
if (m_accountForGlyphBounds) {
bounds = fontData->boundsForGlyph(glyph);
if (!textIterator.currentCharacter())
m_firstGlyphOverflow = max<float>(0, -bounds.x());
}
if (m_forTextEmphasis && !Font::canReceiveTextEmphasis(character))
glyph = 0;
// Advance past the character we just dealt with.
textIterator.advance(advanceLength);
float oldWidth = width;
// Force characters that are used to determine word boundaries for the rounding hack
// to be integer width, so following words will start on an integer boundary.
if (m_run.applyWordRounding() && Font::isRoundingHackCharacter(character)) {
width = ceilf(width);
// Since widthSinceLastRounding can lose precision if we include measurements for
// preceding whitespace, we bypass it here.
m_runWidthSoFar += width;
// Since this is a rounding hack character, we should have reset this sum on the previous
// iteration.
ASSERT(!widthSinceLastRounding);
} else {
// Check to see if the next character is a "rounding hack character", if so, adjust
// width so that the total run width will be on an integer boundary.
if ((m_run.applyWordRounding() && textIterator.currentCharacter() < m_run.length() && Font::isRoundingHackCharacter(*(textIterator.characters())))
|| (m_run.applyRunRounding() && textIterator.currentCharacter() >= m_run.length())) {
float totalWidth = widthSinceLastRounding + width;
widthSinceLastRounding = ceilf(totalWidth);
width += widthSinceLastRounding - totalWidth;
m_runWidthSoFar += widthSinceLastRounding;
widthSinceLastRounding = 0;
} else
widthSinceLastRounding += width;
}
if (glyphBuffer)
glyphBuffer->add(glyph, fontData, (rtl ? oldWidth + lastRoundingWidth : width));
lastRoundingWidth = width - oldWidth;
if (m_accountForGlyphBounds) {
m_maxGlyphBoundingBoxY = max(m_maxGlyphBoundingBoxY, bounds.maxY());
m_minGlyphBoundingBoxY = min(m_minGlyphBoundingBoxY, bounds.y());
m_lastGlyphOverflow = max<float>(0, bounds.maxX() - width);
}
}
unsigned consumedCharacters = textIterator.currentCharacter() - m_currentCharacter;
m_currentCharacter = textIterator.currentCharacter();
m_runWidthSoFar += widthSinceLastRounding;
m_finalRoundingWidth = lastRoundingWidth;
return consumedCharacters;
}
