void RenderCombineText::combineText()
{
if (!m_needsFontUpdate)
return;
m_isCombined = false;
m_needsFontUpdate = false;
// CSS3 spec says text-combine works only in vertical writing mode.
if (style().isHorizontalWritingMode())
return;
auto description = originalFont().fontDescription();
float emWidth = description.computedSize() * textCombineMargin;
bool shouldUpdateFont = false;
description.setOrientation(Horizontal); // We are going to draw combined text horizontally.
GlyphOverflow glyphOverflow;
glyphOverflow.computeBounds = true;
float combinedTextWidth = width(0, textLength(), originalFont(), 0, nullptr, &glyphOverflow);
m_isCombined = combinedTextWidth <= emWidth;
FontSelector* fontSelector = style().fontCascade().fontSelector();
if (m_isCombined)
shouldUpdateFont = m_combineFontStyle->setFontDescription(description); // Need to change font orientation to horizontal.
else {
// Need to try compressed glyphs.
static const FontWidthVariant widthVariants[] = { HalfWidth, ThirdWidth, QuarterWidth };
for (size_t i = 0 ; i < WTF_ARRAY_LENGTH(widthVariants) ; ++i) {
description.setWidthVariant(widthVariants[i]); // When modifying this, make sure to keep it in sync with FontPlatformData::isForTextCombine()!
FontCascade compressedFont(description, style().fontCascade().letterSpacing(), style().fontCascade().wordSpacing());
compressedFont.update(fontSelector);
float runWidth = RenderText::width(0, textLength(), compressedFont, 0, nullptr, &glyphOverflow);
if (runWidth <= emWidth) {
combinedTextWidth = runWidth;
m_isCombined = true;
// Replace my font with the new one.
shouldUpdateFont = m_combineFontStyle->setFontDescription(description);
break;
}
}
}
if (!m_isCombined)
shouldUpdateFont = m_combineFontStyle->setFontDescription(originalFont().fontDescription());
if (shouldUpdateFont)
m_combineFontStyle->fontCascade().update(fontSelector);
if (m_isCombined) {
DEPRECATED_DEFINE_STATIC_LOCAL(String, objectReplacementCharacterString, (&objectReplacementCharacter, 1));
RenderText::setRenderedText(objectReplacementCharacterString.impl());
m_combinedTextSize = FloatSize(combinedTextWidth, glyphOverflow.bottom + glyphOverflow.top);
}
}
void RenderCombineText::combineText()
{
if (!m_needsFontUpdate)
return;
// An ancestor element may trigger us to lay out again, even when we're already combined.
if (m_isCombined)
RenderText::setRenderedText(originalText());
m_isCombined = false;
m_needsFontUpdate = false;
// CSS3 spec says text-combine works only in vertical writing mode.
if (style().isHorizontalWritingMode())
return;
auto description = originalFont().fontDescription();
float emWidth = description.computedSize() * textCombineMargin;
bool shouldUpdateFont = false;
description.setOrientation(Horizontal); // We are going to draw combined text horizontally.
GlyphOverflow glyphOverflow;
glyphOverflow.computeBounds = true;
float combinedTextWidth = width(0, textLength(), originalFont(), 0, nullptr, &glyphOverflow);
float bestFitDelta = combinedTextWidth - emWidth;
auto bestFitDescription = description;
m_isCombined = combinedTextWidth <= emWidth;
FontSelector* fontSelector = style().fontCascade().fontSelector();
if (m_isCombined)
shouldUpdateFont = m_combineFontStyle->setFontDescription(description); // Need to change font orientation to horizontal.
else {
// Need to try compressed glyphs.
static const FontWidthVariant widthVariants[] = { HalfWidth, ThirdWidth, QuarterWidth };
for (size_t i = 0 ; i < WTF_ARRAY_LENGTH(widthVariants) ; ++i) {
description.setWidthVariant(widthVariants[i]); // When modifying this, make sure to keep it in sync with FontPlatformData::isForTextCombine()!
FontCascade compressedFont(description, style().fontCascade().letterSpacing(), style().fontCascade().wordSpacing());
compressedFont.update(fontSelector);
glyphOverflow.left = glyphOverflow.top = glyphOverflow.right = glyphOverflow.bottom = 0;
float runWidth = RenderText::width(0, textLength(), compressedFont, 0, nullptr, &glyphOverflow);
if (runWidth <= emWidth) {
combinedTextWidth = runWidth;
m_isCombined = true;
// Replace my font with the new one.
shouldUpdateFont = m_combineFontStyle->setFontDescription(description);
break;
}
float widthDelta = runWidth - emWidth;
if (widthDelta < bestFitDelta) {
bestFitDelta = widthDelta;
bestFitDescription = description;
}
}
}
if (!m_isCombined) {
float scaleFactor = std::max(0.4f, emWidth / (emWidth + bestFitDelta));
float originalSize = bestFitDescription.computedSize();
do {
float computedSize = originalSize * scaleFactor;
bestFitDescription.setComputedSize(computedSize);
shouldUpdateFont = m_combineFontStyle->setFontDescription(bestFitDescription);
FontCascade compressedFont(bestFitDescription, style().fontCascade().letterSpacing(), style().fontCascade().wordSpacing());
compressedFont.update(fontSelector);
glyphOverflow.left = glyphOverflow.top = glyphOverflow.right = glyphOverflow.bottom = 0;
float runWidth = RenderText::width(0, textLength(), compressedFont, 0, nullptr, &glyphOverflow);
if (runWidth <= emWidth) {
combinedTextWidth = runWidth;
m_isCombined = true;
break;
}
scaleFactor -= 0.05f;
} while (scaleFactor >= 0.4f);
}
if (shouldUpdateFont)
m_combineFontStyle->fontCascade().update(fontSelector);
if (m_isCombined) {
static NeverDestroyed<String> objectReplacementCharacterString(&objectReplacementCharacter, 1);
RenderText::setRenderedText(objectReplacementCharacterString.get());
m_combinedTextWidth = combinedTextWidth;
m_combinedTextAscent = glyphOverflow.top;
m_combinedTextDescent = glyphOverflow.bottom;
}
}
