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HyphenEdit in support of hyphenation

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Adds a "HyphenEdit" field to the Minikin Paint object, which represents
an edit to the text to add a hyphen (and, in the future, other edits to
support nonstandard hyphenation).

Change-Id: Ib4ee690b0fe2137e1d1e2c9251e5526b274ec3a7
This commit is contained in:
Raph Levien 2015-01-29 16:28:37 -08:00
parent 4c4af7f4dc
commit aa1337a41a
2 changed files with 32 additions and 2 deletions
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16
engine/src/flutter/include/minikin/MinikinFont.h
View File

@ -27,6 +27,18 @@
namespace android {
// The hyphen edit represents an edit to the string when a word is
// hyphenated. The most common hyphen edit is adding a "-" at the end
// of a syllable, but nonstandard hyphenation allows for more choices.
class HyphenEdit {
public:
HyphenEdit() : hyphen(0) { }
HyphenEdit(uint32_t hyphenInt) : hyphen(hyphenInt) { }
bool hasHyphen() const { return hyphen != 0; }
private:
uint32_t hyphen;
};
class MinikinFont;
// Possibly move into own .h file?
@ -36,7 +48,8 @@ struct MinikinPaint {
fakery(), fontFeatureSettings() { }
bool skipCache() const {
return !fontFeatureSettings.empty();
// TODO: add hyphen to cache
return !fontFeatureSettings.empty() || hyphenEdit.hasHyphen();
}
MinikinFont *font;
@ -46,6 +59,7 @@ struct MinikinPaint {
float letterSpacing;
uint32_t paintFlags;
FontFakery fakery;
HyphenEdit hyphenEdit;
std::string fontFeatureSettings;
};

18
engine/src/flutter/libs/minikin/Layout.cpp
View File

@ -594,12 +594,15 @@ void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bu
void Layout::doLayoutRunCached(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
bool isRtl, LayoutContext* ctx, size_t dstStart) {
HyphenEdit hyphen = ctx->paint.hyphenEdit;
if (!isRtl) {
// left to right
size_t wordstart = start == bufSize ? start : getPrevWordBreak(buf, start + 1);
size_t wordend;
for (size_t iter = start; iter < start + count; iter = wordend) {
wordend = getNextWordBreak(buf, iter, bufSize);
// Only apply hyphen to the last word in the string.
ctx->paint.hyphenEdit = wordend >= start + count ? hyphen : HyphenEdit();
size_t wordcount = std::min(start + count, wordend) - iter;
doLayoutWord(buf + wordstart, iter - wordstart, wordcount, wordend - wordstart,
isRtl, ctx, iter - dstStart);
@ -612,6 +615,8 @@ void Layout::doLayoutRunCached(const uint16_t* buf, size_t start, size_t count,
size_t wordend = end == 0 ? 0 : getNextWordBreak(buf, end - 1, bufSize);
for (size_t iter = end; iter > start; iter = wordstart) {
wordstart = getPrevWordBreak(buf, iter);
// Only apply hyphen to the last (leftmost) word in the string.
ctx->paint.hyphenEdit = iter == end ? hyphen : HyphenEdit();
size_t bufStart = std::max(start, wordstart);
doLayoutWord(buf + wordstart, bufStart - wordstart, iter - bufStart,
wordend - wordstart, isRtl, ctx, bufStart - dstStart);
@ -729,6 +734,12 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t
hb_buffer_set_language(buffer, hb_language_from_string(lang.c_str(), -1));
}
hb_buffer_add_utf16(buffer, buf, bufSize, srunstart + start, srunend - srunstart);
if (ctx->paint.hyphenEdit.hasHyphen() && srunend > srunstart) {
// TODO: check whether this is really the desired semantics. It could have the
// effect of assigning the hyphen width to a nonspacing mark
unsigned int lastCluster = srunend - 1;
hb_buffer_add(buffer, 0x2010, lastCluster);
}
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);
@ -763,7 +774,12 @@ void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t
ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
glyphBounds.offset(x + xoff, y + yoff);
mBounds.join(glyphBounds);
mAdvances[info[i].cluster - start] += xAdvance;
if (info[i].cluster - start < count) {
mAdvances[info[i].cluster - start] += xAdvance;
} else {
ALOGE("cluster %d (start %d) out of bounds of count %d",
info[i].cluster - start, start, count);
}
x += xAdvance;
}
if (numGlyphs)