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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// #define VERBOSE_DEBUG
#define LOG_TAG "Minikin"
#include <cutils/log.h>
#include "MinikinInternal.h"
#include <minikin/CmapCoverage.h>
#include <minikin/FontCollection.h>
using std::vector;
namespace android {
template <typename T>
static inline T max(T a, T b) {
return a>b ? a : b;
}
uint32_t FontCollection::sNextId = 0;
FontCollection::FontCollection(const vector<FontFamily*>& typefaces) :
mMaxChar(0) {
AutoMutex _l(gMinikinLock);
mId = sNextId++;
vector<uint32_t> lastChar;
size_t nTypefaces = typefaces.size();
#ifdef VERBOSE_DEBUG
ALOGD("nTypefaces = %d\n", nTypefaces);
#endif
const FontStyle defaultStyle;
for (size_t i = 0; i < nTypefaces; i++) {
FontFamily* family = typefaces[i];
MinikinFont* typeface = family->getClosestMatch(defaultStyle).font;
if (typeface == NULL) {
ALOGE("FontCollection: closest match was null");
// TODO: we shouldn't hit this, as there should be more robust
// checks upstream to prevent empty/invalid FontFamily objects
continue;
}
family->RefLocked();
FontInstance dummy;
mInstances.push_back(dummy); // emplace_back would be better
FontInstance* instance = &mInstances.back();
instance->mFamily = family;
instance->mCoverage = new SparseBitSet;
#ifdef VERBOSE_DEBUG
ALOGD("closest match = %p, family size = %d\n", typeface, family->getNumFonts());
#endif
const uint32_t cmapTag = MinikinFont::MakeTag('c', 'm', 'a', 'p');
size_t cmapSize = 0;
bool ok = typeface->GetTable(cmapTag, NULL, &cmapSize);
UniquePtr<uint8_t[]> cmapData(new uint8_t[cmapSize]);
ok = typeface->GetTable(cmapTag, cmapData.get(), &cmapSize);
CmapCoverage::getCoverage(*instance->mCoverage, cmapData.get(), cmapSize);
#ifdef VERBOSE_DEBUG
ALOGD("font coverage length=%d, first ch=%x\n", instance->mCoverage->length(),
instance->mCoverage->nextSetBit(0));
#endif
mMaxChar = max(mMaxChar, instance->mCoverage->length());
lastChar.push_back(instance->mCoverage->nextSetBit(0));
}
nTypefaces = mInstances.size();
size_t nPages = (mMaxChar + kPageMask) >> kLogCharsPerPage;
size_t offset = 0;
for (size_t i = 0; i < nPages; i++) {
Range dummy;
mRanges.push_back(dummy);
Range* range = &mRanges.back();
#ifdef VERBOSE_DEBUG
ALOGD("i=%d: range start = %d\n", i, offset);
#endif
range->start = offset;
for (size_t j = 0; j < nTypefaces; j++) {
if (lastChar[j] < (i + 1) << kLogCharsPerPage) {
const FontInstance* instance = &mInstances[j];
mInstanceVec.push_back(instance);
offset++;
uint32_t nextChar = instance->mCoverage->nextSetBit((i + 1) << kLogCharsPerPage);
#ifdef VERBOSE_DEBUG
ALOGD("nextChar = %d (j = %d)\n", nextChar, j);
#endif
lastChar[j] = nextChar;
}
}
range->end = offset;
}
}
FontCollection::~FontCollection() {
for (size_t i = 0; i < mInstances.size(); i++) {
delete mInstances[i].mCoverage;
mInstances[i].mFamily->UnrefLocked();
}
}
// Implement heuristic for choosing best-match font. Here are the rules:
// 1. If first font in the collection has the character, it wins.
// 2. If a font matches both language and script, it gets a score of 4.
// 3. If a font matches just language, it gets a score of 2.
// 4. Matching the "compact" or "elegant" variant adds one to the score.
// 5. Highest score wins, with ties resolved to the first font.
const FontCollection::FontInstance* FontCollection::getInstanceForChar(uint32_t ch,
FontLanguage lang, int variant) const {
if (ch >= mMaxChar) {
return NULL;
}
const Range& range = mRanges[ch >> kLogCharsPerPage];
#ifdef VERBOSE_DEBUG
ALOGD("querying range %d:%d\n", range.start, range.end);
#endif
const FontInstance* bestInstance = NULL;
int bestScore = -1;
for (size_t i = range.start; i < range.end; i++) {
const FontInstance* instance = mInstanceVec[i];
if (instance->mCoverage->get(ch)) {
FontFamily* family = instance->mFamily;
// First font family in collection always matches
if (mInstances[0].mFamily == family) {
return instance;
}
int score = lang.match(family->lang()) * 2;
if (variant != 0 && variant == family->variant()) {
score++;
}
if (score > bestScore) {
bestScore = score;
bestInstance = instance;
}
}
}
return bestInstance;
}
const uint32_t NBSP = 0xa0;
const uint32_t ZWJ = 0x200c;
const uint32_t ZWNJ = 0x200d;
// Characters where we want to continue using existing font run instead of
// recomputing the best match in the fallback list.
static const uint32_t stickyWhitelist[] = { '!', ',', '.', ':', ';', '?', NBSP, ZWJ, ZWNJ };
static bool isStickyWhitelisted(uint32_t c) {
for (size_t i = 0; i < sizeof(stickyWhitelist) / sizeof(stickyWhitelist[0]); i++) {
if (stickyWhitelist[i] == c) return true;
}
return false;
}
void FontCollection::itemize(const uint16_t *string, size_t string_size, FontStyle style,
vector<Run>* result) const {
FontLanguage lang = style.getLanguage();
int variant = style.getVariant();
const FontInstance* lastInstance = NULL;
Run* run = NULL;
int nShorts;
for (size_t i = 0; i < string_size; i += nShorts) {
nShorts = 1;
uint32_t ch = string[i];
// sigh, decode UTF-16 by hand here
if ((ch & 0xfc00) == 0xd800) {
if ((i + 1) < string_size) {
ch = 0x10000 + ((ch & 0x3ff) << 10) + (string[i + 1] & 0x3ff);
nShorts = 2;
}
}
// Continue using existing font as long as it has coverage and is whitelisted
if (lastInstance == NULL
|| !(isStickyWhitelisted(ch) && lastInstance->mCoverage->get(ch))) {
const FontInstance* instance = getInstanceForChar(ch, lang, variant);
if (i == 0 || instance != lastInstance) {
Run dummy;
result->push_back(dummy);
run = &result->back();
if (instance == NULL) {
run->fakedFont.font = NULL;
} else {
run->fakedFont = instance->mFamily->getClosestMatch(style);
}
lastInstance = instance;
run->start = i;
}
}
run->end = i + nShorts;
}
}
MinikinFont* FontCollection::baseFont(FontStyle style) {
return baseFontFaked(style).font;
}
FakedFont FontCollection::baseFontFaked(FontStyle style) {
if (mInstances.empty()) {
return FakedFont();
}
return mInstances[0].mFamily->getClosestMatch(style);
}
uint32_t FontCollection::getId() const {
return mId;
}
} // namespace android
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