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Merge "Do BiDi algorithm for text layout" into lmp-preview-dev

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This commit is contained in:
Raph Levien 2014-05-27 15:36:36 +00:00 committed by Android (Google) Code Review
commit d973b3926b
3 changed files with 85 additions and 10 deletions
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4
include/minikin/Layout.h
View File

@ -94,6 +94,10 @@ private:
// Find a face in the mFaces vector, or create a new entry
int findFace(MinikinFont* face, MinikinPaint* paint);
// Lay out a single bidi run
void doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
bool isRtl, FontStyle style, MinikinPaint& paint);
CssProperties mProps; // TODO: want spans
std::vector<LayoutGlyph> mGlyphs;
std::vector<float> mAdvances;

3
libs/minikin/Android.mk
View File

@ -43,6 +43,7 @@ LOCAL_SHARED_LIBRARIES := \
liblog \
libpng \
libz \
libstlport
libstlport \
libicuuc
include $(BUILD_SHARED_LIBRARY)

88
libs/minikin/Layout.cpp
View File

@ -39,6 +39,21 @@ namespace android {
// TODO: globals are not cool, move to a factory-ish object
hb_buffer_t* buffer = 0;
// TODO: these should move into the header file, but for now we don't want
// to cause namespace collisions with TextLayout.h
enum {
kBidi_LTR = 0,
kBidi_RTL = 1,
kBidi_Default_LTR = 2,
kBidi_Default_RTL = 3,
kBidi_Force_LTR = 4,
kBidi_Force_RTL = 5,
kBidi_Mask = 0x7
};
const int kDirection_Mask = 0x1;
Bitmap::Bitmap(int width, int height) : width(width), height(height) {
buf = new uint8_t[width * height]();
}
@ -291,18 +306,14 @@ void Layout::doLayout(const uint16_t* buf, size_t nchars) {
}
FT_Error error;
vector<FontCollection::Run> items;
FontStyle style = styleFromCss(mProps);
mCollection->itemize(buf, nchars, style, &items);
MinikinPaint paint;
double size = mProps.value(fontSize).getFloatValue();
paint.size = size;
int bidiFlags = mProps.hasTag(minikinBidi) ? mProps.value(minikinBidi).getIntValue() : 0;
bool isRtl = (bidiFlags & 1) != 0; // TODO: do real bidi algo
if (isRtl) {
std::reverse(items.begin(), items.end());
}
bool isRtl = (bidiFlags & kDirection_Mask) != 0;
bool doSingleRun = true;
mGlyphs.clear();
mFaces.clear();
@ -310,7 +321,65 @@ void Layout::doLayout(const uint16_t* buf, size_t nchars) {
mBounds.setEmpty();
mAdvances.clear();
mAdvances.resize(nchars, 0);
float x = 0;
mAdvance = 0;
if (!(bidiFlags == kBidi_Force_LTR || bidiFlags == kBidi_Force_RTL)) {
UBiDi* bidi = ubidi_open();
if (bidi) {
UErrorCode status = U_ZERO_ERROR;
UBiDiLevel bidiReq = bidiFlags;
if (bidiFlags == kBidi_Default_LTR) {
bidiReq = UBIDI_DEFAULT_LTR;
} else if (bidiFlags == kBidi_Default_RTL) {
bidiReq = UBIDI_DEFAULT_RTL;
}
ubidi_setPara(bidi, buf, nchars, bidiReq, NULL, &status);
if (U_SUCCESS(status)) {
int paraDir = ubidi_getParaLevel(bidi) & kDirection_Mask;
ssize_t rc = ubidi_countRuns(bidi, &status);
if (!U_SUCCESS(status) || rc < 1) {
ALOGD("error counting bidi runs, status = %d", status);
}
if (!U_SUCCESS(status) || rc <= 1) {
isRtl = (paraDir == kBidi_RTL);
} else {
doSingleRun = false;
// iterate through runs
for (ssize_t i = 0; i < (ssize_t)rc; i++) {
int32_t startRun = -1;
int32_t lengthRun = -1;
UBiDiDirection runDir = ubidi_getVisualRun(bidi, i, &startRun, &lengthRun);
if (startRun == -1 || lengthRun == -1) {
ALOGE("invalid visual run");
// Note: this case will lose text; can it ever actually happen?
break;
}
isRtl = (runDir == UBIDI_RTL);
// TODO: min/max with context
doLayoutRun(buf, startRun, lengthRun, nchars, isRtl, style, paint);
}
}
} else {
ALOGE("error calling ubidi_setPara, status = %d", status);
}
ubidi_close(bidi);
} else {
ALOGE("error creating bidi object");
}
}
if (doSingleRun) {
doLayoutRun(buf, 0, nchars, nchars, isRtl, style, paint);
}
}
void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
bool isRtl, FontStyle style, MinikinPaint& paint) {
vector<FontCollection::Run> items;
mCollection->itemize(buf + start, count, style, &items);
if (isRtl) {
std::reverse(items.begin(), items.end());
}
float x = mAdvance;
float y = 0;
for (size_t run_ix = 0; run_ix < items.size(); run_ix++) {
FontCollection::Run &run = items[run_ix];
@ -325,6 +394,7 @@ void Layout::doLayout(const uint16_t* buf, size_t nchars) {
std::cout << "Run " << run_ix << ", font " << font_ix <<
" [" << run.start << ":" << run.end << "]" << std::endl;
#endif
double size = paint.size;
hb_font_set_ppem(hbFont, size, size);
hb_font_set_scale(hbFont, HBFloatToFixed(size), HBFloatToFixed(size));
@ -334,12 +404,12 @@ void Layout::doLayout(const uint16_t* buf, size_t nchars) {
ssize_t srunend;
for (ssize_t srunstart = run.start; srunstart < run.end; srunstart = srunend) {
srunend = srunstart;
hb_script_t script = getScriptRun(buf, run.end, &srunend);
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);
hb_buffer_add_utf16(buffer, buf, nchars, srunstart, srunend - srunstart);
hb_buffer_add_utf16(buffer, buf, bufSize, srunstart + start, srunend - srunstart);
hb_shape(hbFont, buffer, NULL, 0);
unsigned int numGlyphs;
hb_glyph_info_t *info = hb_buffer_get_glyph_infos(buffer, &numGlyphs);