PassTextBlobPtr Font::buildTextBlob(const GlyphBuffer& glyphBuffer, float initialAdvance, const FloatRect& bounds) const
{
SkTextBlobBuilder builder;
SkScalar advance = SkFloatToScalar(initialAdvance);
bool success = glyphBuffer.hasOffsets() ?
buildTextBlobInternal<true>(glyphBuffer, advance, builder) :
buildTextBlobInternal<false>(glyphBuffer, advance, builder);
return success ? adoptRef(builder.build()) : nullptr;
}
void Font::drawGlyphs(GraphicsContext* gc, const SimpleFontData* font,
const GlyphBuffer& glyphBuffer, unsigned from, unsigned numGlyphs,
const FloatPoint& point, const FloatRect& textRect) const
{
SkScalar x = SkFloatToScalar(point.x());
SkScalar y = SkFloatToScalar(point.y());
const OpenTypeVerticalData* verticalData = font->verticalData();
if (font->platformData().orientation() == Vertical && verticalData) {
SkAutoSTMalloc<32, SkPoint> storage(numGlyphs);
SkPoint* pos = storage.get();
AffineTransform savedMatrix = gc->getCTM();
gc->concatCTM(AffineTransform(0, -1, 1, 0, point.x(), point.y()));
gc->concatCTM(AffineTransform(1, 0, 0, 1, -point.x(), -point.y()));
const unsigned kMaxBufferLength = 256;
Vector<FloatPoint, kMaxBufferLength> translations;
const FontMetrics& metrics = font->fontMetrics();
SkScalar verticalOriginX = SkFloatToScalar(point.x() + metrics.floatAscent() - metrics.floatAscent(IdeographicBaseline));
float horizontalOffset = point.x();
unsigned glyphIndex = 0;
while (glyphIndex < numGlyphs) {
unsigned chunkLength = std::min(kMaxBufferLength, numGlyphs - glyphIndex);
const Glyph* glyphs = glyphBuffer.glyphs(from + glyphIndex);
translations.resize(chunkLength);
verticalData->getVerticalTranslationsForGlyphs(font, &glyphs[0], chunkLength, reinterpret_cast<float*>(&translations[0]));
x = verticalOriginX;
y = SkFloatToScalar(point.y() + horizontalOffset - point.x());
float currentWidth = 0;
for (unsigned i = 0; i < chunkLength; ++i, ++glyphIndex) {
pos[i].set(
x + SkIntToScalar(lroundf(translations[i].x())),
y + -SkIntToScalar(-lroundf(currentWidth - translations[i].y())));
currentWidth += glyphBuffer.advanceAt(from + glyphIndex);
}
horizontalOffset += currentWidth;
paintGlyphs(gc, font, glyphs, chunkLength, pos, textRect);
}
gc->setCTM(savedMatrix);
return;
}
if (!glyphBuffer.hasOffsets()) {
SkAutoSTMalloc<64, SkScalar> storage(numGlyphs);
SkScalar* xpos = storage.get();
const float* adv = glyphBuffer.advances(from);
for (unsigned i = 0; i < numGlyphs; i++) {
xpos[i] = x;
x += SkFloatToScalar(adv[i]);
}
const Glyph* glyphs = glyphBuffer.glyphs(from);
paintGlyphsHorizontal(gc, font, glyphs, numGlyphs, xpos, SkFloatToScalar(y), textRect);
return;
}
// FIXME: text rendering speed:
// Android has code in their WebCore fork to special case when the
// GlyphBuffer has no advances other than the defaults. In that case the
// text drawing can proceed faster. However, it's unclear when those
// patches may be upstreamed to WebKit so we always use the slower path
// here.
SkAutoSTMalloc<32, SkPoint> storage(numGlyphs);
SkPoint* pos = storage.get();
const FloatSize* offsets = glyphBuffer.offsets(from);
const float* advances = glyphBuffer.advances(from);
SkScalar advanceSoFar = SkFloatToScalar(0);
for (unsigned i = 0; i < numGlyphs; i++) {
pos[i].set(
x + SkFloatToScalar(offsets[i].width()) + advanceSoFar,
y + SkFloatToScalar(offsets[i].height()));
advanceSoFar += SkFloatToScalar(advances[i]);
}
const Glyph* glyphs = glyphBuffer.glyphs(from);
paintGlyphs(gc, font, glyphs, numGlyphs, pos, textRect);
}