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bbdd73ec07
This CL contains the following changes: - Add a variation selector argument into getFamilyForChar to be able to select fonts which support variation selector. - In case no fonts support the codepoint and variation selector pair, add a fallback rule which selects font family with ignoring variation selector. - Change FontCollection::itemize to not change the font family immediately preceding a variation selector. - Introduce unit tests for variation selectors. With this CL, TextView can render the variation selectors correctly. Bug: 11256006 Change-Id: I22ce0e9eadc941f84e3a9b23462f194e51dd7180
277 lines
9.2 KiB
C++
277 lines
9.2 KiB
C++
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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// #define VERBOSE_DEBUG
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#define LOG_TAG "Minikin"
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#include <cutils/log.h>
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#include "unicode/unistr.h"
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#include "unicode/unorm2.h"
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#include "MinikinInternal.h"
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#include <minikin/FontCollection.h>
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using std::vector;
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namespace android {
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template <typename T>
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static inline T max(T a, T b) {
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return a>b ? a : b;
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}
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uint32_t FontCollection::sNextId = 0;
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FontCollection::FontCollection(const vector<FontFamily*>& typefaces) :
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mMaxChar(0) {
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AutoMutex _l(gMinikinLock);
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mId = sNextId++;
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vector<uint32_t> lastChar;
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size_t nTypefaces = typefaces.size();
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#ifdef VERBOSE_DEBUG
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ALOGD("nTypefaces = %d\n", nTypefaces);
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#endif
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const FontStyle defaultStyle;
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for (size_t i = 0; i < nTypefaces; i++) {
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FontFamily* family = typefaces[i];
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MinikinFont* typeface = family->getClosestMatch(defaultStyle).font;
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if (typeface == NULL) {
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continue;
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}
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family->RefLocked();
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const SparseBitSet* coverage = family->getCoverage();
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if (coverage == nullptr) {
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family->UnrefLocked();
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continue;
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}
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mFamilies.push_back(family); // emplace_back would be better
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mMaxChar = max(mMaxChar, coverage->length());
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lastChar.push_back(coverage->nextSetBit(0));
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}
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nTypefaces = mFamilies.size();
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LOG_ALWAYS_FATAL_IF(nTypefaces == 0,
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"Font collection must have at least one valid typeface");
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size_t nPages = (mMaxChar + kPageMask) >> kLogCharsPerPage;
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size_t offset = 0;
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for (size_t i = 0; i < nPages; i++) {
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Range dummy;
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mRanges.push_back(dummy);
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Range* range = &mRanges.back();
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#ifdef VERBOSE_DEBUG
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ALOGD("i=%d: range start = %d\n", i, offset);
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#endif
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range->start = offset;
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for (size_t j = 0; j < nTypefaces; j++) {
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if (lastChar[j] < (i + 1) << kLogCharsPerPage) {
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FontFamily* family = mFamilies[j];
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mFamilyVec.push_back(family);
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offset++;
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uint32_t nextChar = family->getCoverage()->nextSetBit((i + 1) << kLogCharsPerPage);
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#ifdef VERBOSE_DEBUG
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ALOGD("nextChar = %d (j = %d)\n", nextChar, j);
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#endif
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lastChar[j] = nextChar;
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}
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}
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range->end = offset;
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}
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}
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FontCollection::~FontCollection() {
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for (size_t i = 0; i < mFamilies.size(); i++) {
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mFamilies[i]->UnrefLocked();
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}
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}
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// Implement heuristic for choosing best-match font. Here are the rules:
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// 1. If first font in the collection has the character, it wins.
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// 2. If a font matches both language and script, it gets a score of 4.
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// 3. If a font matches just language, it gets a score of 2.
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// 4. Matching the "compact" or "elegant" variant adds one to the score.
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// 5. Highest score wins, with ties resolved to the first font.
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FontFamily* FontCollection::getFamilyForChar(uint32_t ch, uint32_t vs,
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FontLanguage lang, int variant) const {
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if (ch >= mMaxChar) {
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return NULL;
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}
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const Range& range = mRanges[ch >> kLogCharsPerPage];
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#ifdef VERBOSE_DEBUG
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ALOGD("querying range %d:%d\n", range.start, range.end);
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#endif
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FontFamily* bestFamily = nullptr;
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int bestScore = -1;
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for (size_t i = range.start; i < range.end; i++) {
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FontFamily* family = mFamilyVec[i];
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if (vs == 0 ? family->getCoverage()->get(ch) : family->hasVariationSelector(ch, vs)) {
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// First font family in collection always matches
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if (mFamilies[0] == family) {
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return family;
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}
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int score = lang.match(family->lang()) * 2;
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if (family->variant() == 0 || family->variant() == variant) {
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score++;
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}
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if (score > bestScore) {
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bestScore = score;
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bestFamily = family;
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}
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}
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}
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if (bestFamily == nullptr && vs != 0) {
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// If no fonts support the codepoint and variation selector pair,
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// fallback to select a font family that supports just the base
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// character, ignoring the variation selector.
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return getFamilyForChar(ch, 0, lang, variant);
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}
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if (bestFamily == nullptr && !mFamilyVec.empty()) {
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UErrorCode errorCode = U_ZERO_ERROR;
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const UNormalizer2* normalizer = unorm2_getNFDInstance(&errorCode);
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if (U_SUCCESS(errorCode)) {
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UChar decomposed[4];
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int len = unorm2_getRawDecomposition(normalizer, ch, decomposed, 4, &errorCode);
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if (U_SUCCESS(errorCode) && len > 0) {
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int off = 0;
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U16_NEXT_UNSAFE(decomposed, off, ch);
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return getFamilyForChar(ch, vs, lang, variant);
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}
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}
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bestFamily = mFamilies[0];
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}
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return bestFamily;
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}
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const uint32_t NBSP = 0xa0;
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const uint32_t ZWJ = 0x200c;
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const uint32_t ZWNJ = 0x200d;
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const uint32_t KEYCAP = 0x20e3;
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const uint32_t HYPHEN = 0x2010;
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const uint32_t NB_HYPHEN = 0x2011;
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// Characters where we want to continue using existing font run instead of
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// recomputing the best match in the fallback list.
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static const uint32_t stickyWhitelist[] = { '!', ',', '-', '.', ':', ';', '?', NBSP, ZWJ, ZWNJ,
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KEYCAP, HYPHEN, NB_HYPHEN };
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static bool isStickyWhitelisted(uint32_t c) {
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for (size_t i = 0; i < sizeof(stickyWhitelist) / sizeof(stickyWhitelist[0]); i++) {
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if (stickyWhitelist[i] == c) return true;
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}
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return false;
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}
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static bool isVariationSelector(uint32_t c) {
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return (0xFE00 <= c && c <= 0xFE0F) || (0xE0100 <= c && c <= 0xE01EF);
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}
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void FontCollection::itemize(const uint16_t *string, size_t string_size, FontStyle style,
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vector<Run>* result) const {
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FontLanguage lang = style.getLanguage();
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int variant = style.getVariant();
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FontFamily* lastFamily = NULL;
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Run* run = NULL;
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if (string_size == 0) {
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return;
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}
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const uint32_t kEndOfString = 0xFFFFFFFF;
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uint32_t nextCh = 0;
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uint32_t prevCh = 0;
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size_t nextUtf16Pos = 0;
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size_t readLength = 0;
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U16_NEXT(string, readLength, string_size, nextCh);
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do {
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const uint32_t ch = nextCh;
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const size_t utf16Pos = nextUtf16Pos;
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nextUtf16Pos = readLength;
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if (readLength < string_size) {
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U16_NEXT(string, readLength, string_size, nextCh);
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} else {
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nextCh = kEndOfString;
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}
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bool shouldContinueRun = false;
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if (lastFamily != nullptr) {
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if (isStickyWhitelisted(ch)) {
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// Continue using existing font as long as it has coverage and is whitelisted
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shouldContinueRun = lastFamily->getCoverage()->get(ch);
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} else if (isVariationSelector(ch)) {
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// Always continue if the character is a variation selector.
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shouldContinueRun = true;
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}
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}
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if (!shouldContinueRun) {
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FontFamily* family =
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getFamilyForChar(ch, isVariationSelector(nextCh) ? nextCh : 0, lang, variant);
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if (utf16Pos == 0 || family != lastFamily) {
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size_t start = utf16Pos;
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// Workaround for Emoji keycap until we implement per-cluster font
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// selection: if keycap is found in a different font that also
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// supports previous char, attach previous char to the new run.
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// Only handles non-surrogate characters.
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// Bug 7557244.
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if (ch == KEYCAP && utf16Pos != 0 && family && family->getCoverage()->get(prevCh)) {
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run->end--;
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if (run->start == run->end) {
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result->pop_back();
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}
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start--;
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}
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Run dummy;
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result->push_back(dummy);
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run = &result->back();
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if (family == NULL) {
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run->fakedFont.font = NULL;
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} else {
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run->fakedFont = family->getClosestMatch(style);
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}
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lastFamily = family;
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run->start = start;
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}
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}
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prevCh = ch;
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run->end = nextUtf16Pos; // exclusive
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} while (nextCh != kEndOfString);
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}
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MinikinFont* FontCollection::baseFont(FontStyle style) {
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return baseFontFaked(style).font;
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}
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FakedFont FontCollection::baseFontFaked(FontStyle style) {
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if (mFamilies.empty()) {
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return FakedFont();
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}
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return mFamilies[0]->getClosestMatch(style);
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}
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uint32_t FontCollection::getId() const {
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return mId;
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}
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void FontCollection::purgeFontFamilyHbFontCache() const {
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assertMinikinLocked();
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for (size_t i = 0; i < mFamilies.size(); ++i) {
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mFamilies[i]->purgeHbFontCache();
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}
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}
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} // namespace android
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