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Use HarfBuzz metric implementation for emoji font.

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To avoid lock contention in Skia, use HarfBuzz implementation
for retrieving boundary box and advance information from font.

Bug: 21705974
Test: Manually done

Change-Id: Ia88cb670ca9e0bb352bccef22c5ea3a789bcc1da
This commit is contained in:
Seigo Nonaka 2016-12-04 08:52:34 -08:00
parent 32c12c0ac8
commit 58ee6af0c3
2 changed files with 45 additions and 13 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

54
libs/minikin/Layout.cpp
View File

@ -294,16 +294,36 @@ static hb_bool_t harfbuzzGetGlyphHorizontalOrigin(hb_font_t* /* hbFont */, void*
return true;
}
hb_font_funcs_t* getHbFontFuncs() {
static hb_font_funcs_t* hbFontFuncs = 0;
hb_font_funcs_t* getHbFontFuncs(bool forColorBitmapFont) {
assertMinikinLocked();
if (hbFontFuncs == 0) {
hbFontFuncs = hb_font_funcs_create();
hb_font_funcs_set_glyph_h_advance_func(hbFontFuncs, harfbuzzGetGlyphHorizontalAdvance, 0, 0);
hb_font_funcs_set_glyph_h_origin_func(hbFontFuncs, harfbuzzGetGlyphHorizontalOrigin, 0, 0);
hb_font_funcs_make_immutable(hbFontFuncs);
static hb_font_funcs_t* hbFuncs = nullptr;
static hb_font_funcs_t* hbFuncsForColorBitmap = nullptr;
hb_font_funcs_t** funcs = forColorBitmapFont ? &hbFuncs : &hbFuncsForColorBitmap;
if (*funcs == nullptr) {
*funcs = hb_font_funcs_create();
if (forColorBitmapFont) {
// Override the h_advance function since we can't use HarfBuzz's implemenation. It may
// return the wrong value if the font uses hinting aggressively.
hb_font_funcs_set_glyph_h_advance_func(*funcs, harfbuzzGetGlyphHorizontalAdvance, 0, 0);
} else {
// Don't override the h_advance function since we use HarfBuzz's implementation for
// emoji for performance reasons.
// Note that it is technically possible for a TrueType font to have outline and embedded
// bitmap at the same time. We ignore modified advances of hinted outline glyphs in that
// case.
}
hb_font_funcs_set_glyph_h_origin_func(*funcs, harfbuzzGetGlyphHorizontalOrigin, 0, 0);
hb_font_funcs_make_immutable(*funcs);
}
return hbFontFuncs;
return *funcs;
}
static bool isColorBitmapFont(hb_font_t* font) {
hb_face_t* face = hb_font_get_face(font);
HbBlob cbdt(hb_face_reference_table(face, HB_TAG('C', 'B', 'D', 'T')));
return cbdt.size() > 0;
}
static float HBFixedToFloat(hb_position_t v)
@ -335,7 +355,7 @@ int Layout::findFace(FakedFont face, LayoutContext* ctx) {
// corresponding hb_font object.
if (ctx != NULL) {
hb_font_t* font = getHbFontLocked(face.font);
hb_font_set_funcs(font, getHbFontFuncs(), &ctx->paint, 0);
hb_font_set_funcs(font, getHbFontFuncs(isColorBitmapFont(font)), &ctx->paint, 0);
ctx->hbFonts.push_back(font);
}
return ix;
@ -753,6 +773,8 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t
hb_font_set_ppem(hbFont, size * scaleX, size);
hb_font_set_scale(hbFont, HBFloatToFixed(size * scaleX), HBFloatToFixed(size));
const bool is_color_bitmap_font = isColorBitmapFont(hbFont);
// 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.
@ -844,7 +866,19 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t
xAdvance = roundf(xAdvance);
}
MinikinRect glyphBounds;
ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
hb_glyph_extents_t extents = {};
if (is_color_bitmap_font && hb_font_get_glyph_extents(hbFont, glyph_ix, &extents)) {
// Note that it is technically possible for a TrueType font to have outline and
// embedded bitmap at the same time. We ignore modified bbox of hinted outline
// glyphs in that case.
glyphBounds.mLeft = roundf(HBFixedToFloat(extents.x_bearing));
glyphBounds.mTop = roundf(HBFixedToFloat(-extents.y_bearing));
glyphBounds.mRight = roundf(HBFixedToFloat(extents.x_bearing + extents.width));
glyphBounds.mBottom =
roundf(HBFixedToFloat(-extents.y_bearing - extents.height));
} else {
ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
}
glyphBounds.offset(x + xoff, y + yoff);
mBounds.join(glyphBounds);
if (info[i].cluster - start < count) {

4
libs/minikin/MinikinInternal.h
View File

@ -65,9 +65,7 @@ public:
}
size_t size() const {
unsigned int length = 0;
hb_blob_get_data(mBlob, &length);
return (size_t)length;
return (size_t)hb_blob_get_length(mBlob);
}
private: