void Canvas::drawText(const uint16_t* text, int start, int count, int contextCount,
float x, float y, int bidiFlags, const Paint& origPaint, Typeface* typeface) {
// minikin may modify the original paint
Paint paint(origPaint);
Layout layout;
MinikinUtils::doLayout(&layout, &paint, bidiFlags, typeface, text, start, count, contextCount);
size_t nGlyphs = layout.nGlyphs();
std::unique_ptr<uint16_t[]> glyphs(new uint16_t[nGlyphs]);
std::unique_ptr<float[]> pos(new float[nGlyphs * 2]);
x += MinikinUtils::xOffsetForTextAlign(&paint, layout);
MinikinRect bounds;
layout.getBounds(&bounds);
if (!drawTextAbsolutePos()) {
bounds.offset(x, y);
}
// Set align to left for drawing, as we don't want individual
// glyphs centered or right-aligned; the offset above takes
// care of all alignment.
paint.setTextAlign(Paint::kLeft_Align);
DrawTextFunctor f(layout, this, glyphs.get(), pos.get(),
paint, x, y, bounds, layout.getAdvance());
MinikinUtils::forFontRun(layout, &paint, f);
}
void MinikinRect::join(const MinikinRect& r) {
if (isEmpty()) {
set(r);
} else if (!r.isEmpty()) {
mLeft = std::min(mLeft, r.mLeft);
mTop = std::min(mTop, r.mTop);
mRight = std::max(mRight, r.mRight);
mBottom = std::max(mBottom, r.mBottom);
}
}
void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
bool isRtl, LayoutContext* ctx) {
hb_buffer_t* buffer = LayoutEngine::getInstance().hbBuffer;
vector<FontCollection::Run> items;
mCollection->itemize(buf + start, count, ctx->style, &items);
if (isRtl) {
std::reverse(items.begin(), items.end());
}
vector<hb_feature_t> features;
// Disable default-on non-required ligature features if letter-spacing
// See http://dev.w3.org/csswg/css-text-3/#letter-spacing-property
// "When the effective spacing between two characters is not zero (due to
// either justification or a non-zero value of letter-spacing), user agents
// should not apply optional ligatures."
if (fabs(ctx->paint.letterSpacing) > 0.03)
{
static const hb_feature_t no_liga = { HB_TAG('l', 'i', 'g', 'a'), 0, 0, ~0u };
static const hb_feature_t no_clig = { HB_TAG('c', 'l', 'i', 'g'), 0, 0, ~0u };
features.push_back(no_liga);
features.push_back(no_clig);
}
addFeatures(ctx->paint.fontFeatureSettings, &features);
double size = ctx->paint.size;
double scaleX = ctx->paint.scaleX;
double letterSpace = ctx->paint.letterSpacing * size * scaleX;
double letterSpaceHalfLeft;
if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
letterSpace = round(letterSpace);
letterSpaceHalfLeft = floor(letterSpace * 0.5);
} else {
letterSpaceHalfLeft = letterSpace * 0.5;
}
double letterSpaceHalfRight = letterSpace - letterSpaceHalfLeft;
float x = mAdvance;
float y = 0;
for (size_t run_ix = 0; run_ix < items.size(); run_ix++) {
FontCollection::Run &run = items[run_ix];
if (run.fakedFont.font == NULL) {
ALOGE("no font for run starting u+%04x length %d", buf[run.start], run.end - run.start);
continue;
}
int font_ix = findFace(run.fakedFont, ctx);
ctx->paint.font = mFaces[font_ix].font;
ctx->paint.fakery = mFaces[font_ix].fakery;
hb_font_t* hbFont = ctx->hbFonts[font_ix];
#ifdef VERBOSE
std::cout << "Run " << run_ix << ", font " << font_ix <<
" [" << run.start << ":" << run.end << "]" << std::endl;
#endif
hb_font_set_ppem(hbFont, size * scaleX, size);
hb_font_set_scale(hbFont, HBFloatToFixed(size * scaleX), HBFloatToFixed(size));
// TODO: if there are multiple scripts within a font in an RTL run,
// we need to reorder those runs. This is unlikely with our current
// font stack, but should be done for correctness.
ssize_t srunend;
for (ssize_t srunstart = run.start; srunstart < run.end; srunstart = srunend) {
srunend = srunstart;
hb_script_t script = getScriptRun(buf + start, run.end, &srunend);
hb_buffer_reset(buffer);
hb_buffer_set_script(buffer, script);
hb_buffer_set_direction(buffer, isRtl? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
FontLanguage language = ctx->style.getLanguage();
if (language) {
string lang = language.getString();
hb_buffer_set_language(buffer, hb_language_from_string(lang.c_str(), -1));
}
hb_buffer_add_utf16(buffer, buf, bufSize, srunstart + start, srunend - srunstart);
hb_shape(hbFont, buffer, features.empty() ? NULL : &features[0], features.size());
unsigned int numGlyphs;
hb_glyph_info_t* info = hb_buffer_get_glyph_infos(buffer, &numGlyphs);
hb_glyph_position_t* positions = hb_buffer_get_glyph_positions(buffer, NULL);
if (numGlyphs)
{
mAdvances[info[0].cluster - start] += letterSpaceHalfLeft;
x += letterSpaceHalfLeft;
}
for (unsigned int i = 0; i < numGlyphs; i++) {
#ifdef VERBOSE
std::cout << positions[i].x_advance << " " << positions[i].y_advance << " " << positions[i].x_offset << " " << positions[i].y_offset << std::endl; std::cout << "DoLayout " << info[i].codepoint <<
": " << HBFixedToFloat(positions[i].x_advance) << "; " << positions[i].x_offset << ", " << positions[i].y_offset << std::endl;
#endif
if (i > 0 && info[i - 1].cluster != info[i].cluster) {
mAdvances[info[i - 1].cluster - start] += letterSpaceHalfRight;
mAdvances[info[i].cluster - start] += letterSpaceHalfLeft;
x += letterSpace;
}
hb_codepoint_t glyph_ix = info[i].codepoint;
float xoff = HBFixedToFloat(positions[i].x_offset);
float yoff = -HBFixedToFloat(positions[i].y_offset);
xoff += yoff * ctx->paint.skewX;
LayoutGlyph glyph = {font_ix, glyph_ix, x + xoff, y + yoff};
mGlyphs.push_back(glyph);
float xAdvance = HBFixedToFloat(positions[i].x_advance);
if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
xAdvance = roundf(xAdvance);
}
MinikinRect glyphBounds;
ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
glyphBounds.offset(x + xoff, y + yoff);
mBounds.join(glyphBounds);
mAdvances[info[i].cluster - start] += xAdvance;
x += xAdvance;
}
if (numGlyphs)
{
mAdvances[info[numGlyphs - 1].cluster - start] += letterSpaceHalfRight;
x += letterSpaceHalfRight;
}
}
}
mAdvance = x;
}