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/*
* Copyright (C) 2015 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 LOG_TAG "Minikin"
#include "FontLanguage.h"
#include <hb.h>
#include <unicode/uloc.h>
namespace android {
#define SCRIPT_TAG(c1, c2, c3, c4) \
(((uint32_t)(c1)) << 24 | ((uint32_t)(c2)) << 16 | ((uint32_t)(c3)) << 8 | \
((uint32_t)(c4)))
// Parse BCP 47 language identifier into internal structure
FontLanguage::FontLanguage(const char* buf, size_t length) : FontLanguage() {
size_t i;
for (i = 0; i < length; i++) {
char c = buf[i];
if (c == '-' || c == '_') break;
}
if (i == 2 || i == 3) { // only accept two or three letter language code.
mLanguage = buf[0] | (buf[1] << 8) | ((i == 3) ? (buf[2] << 16) : 0);
} else {
// We don't understand anything other than two-letter or three-letter
// language codes, so we skip parsing the rest of the string.
mLanguage = 0ul;
return;
}
size_t next;
for (i++; i < length; i = next + 1) {
for (next = i; next < length; next++) {
char c = buf[next];
if (c == '-' || c == '_') break;
}
if (next - i == 4 && 'A' <= buf[i] && buf[i] <= 'Z') {
mScript = SCRIPT_TAG(buf[i], buf[i + 1], buf[i + 2], buf[i + 3]);
}
}
mSubScriptBits = scriptToSubScriptBits(mScript);
}
//static
uint8_t FontLanguage::scriptToSubScriptBits(uint32_t script) {
uint8_t subScriptBits = 0u;
switch (script) {
case SCRIPT_TAG('B', 'o', 'p', 'o'):
subScriptBits = kBopomofoFlag;
break;
case SCRIPT_TAG('H', 'a', 'n', 'g'):
subScriptBits = kHangulFlag;
break;
case SCRIPT_TAG('H', 'a', 'n', 'b'):
// Bopomofo is almost exclusively used in Taiwan.
subScriptBits = kHanFlag | kBopomofoFlag;
break;
case SCRIPT_TAG('H', 'a', 'n', 'i'):
subScriptBits = kHanFlag;
break;
case SCRIPT_TAG('H', 'a', 'n', 's'):
subScriptBits = kHanFlag | kSimplifiedChineseFlag;
break;
case SCRIPT_TAG('H', 'a', 'n', 't'):
subScriptBits = kHanFlag | kTraditionalChineseFlag;
break;
case SCRIPT_TAG('H', 'i', 'r', 'a'):
subScriptBits = kHiraganaFlag;
break;
case SCRIPT_TAG('H', 'r', 'k', 't'):
subScriptBits = kKatakanaFlag | kHiraganaFlag;
break;
case SCRIPT_TAG('J', 'p', 'a', 'n'):
subScriptBits = kHanFlag | kKatakanaFlag | kHiraganaFlag;
break;
case SCRIPT_TAG('K', 'a', 'n', 'a'):
subScriptBits = kKatakanaFlag;
break;
case SCRIPT_TAG('K', 'o', 'r', 'e'):
subScriptBits = kHanFlag | kHangulFlag;
break;
case SCRIPT_TAG('Z', 's', 'y', 'e'):
subScriptBits = kEmojiFlag;
break;
}
return subScriptBits;
}
std::string FontLanguage::getString() const {
if (mLanguage == 0ul) {
return "und";
}
char buf[16];
size_t i = 0;
buf[i++] = mLanguage & 0xFF ;
buf[i++] = (mLanguage >> 8) & 0xFF;
char third_letter = (mLanguage >> 16) & 0xFF;
if (third_letter != 0) buf[i++] = third_letter;
if (mScript != 0) {
buf[i++] = '-';
buf[i++] = (mScript >> 24) & 0xFFu;
buf[i++] = (mScript >> 16) & 0xFFu;
buf[i++] = (mScript >> 8) & 0xFFu;
buf[i++] = mScript & 0xFFu;
}
return std::string(buf, i);
}
bool FontLanguage::isEqualScript(const FontLanguage& other) const {
return other.mScript == mScript;
}
// static
bool FontLanguage::supportsScript(uint8_t providedBits, uint8_t requestedBits) {
return requestedBits != 0 && (providedBits & requestedBits) == requestedBits;
}
bool FontLanguage::supportsHbScript(hb_script_t script) const {
static_assert(SCRIPT_TAG('J', 'p', 'a', 'n') == HB_TAG('J', 'p', 'a', 'n'),
"The Minikin script and HarfBuzz hb_script_t have different encodings.");
if (script == mScript) return true;
return supportsScript(mSubScriptBits, scriptToSubScriptBits(script));
}
int FontLanguage::calcScoreFor(const FontLanguages& supported) const {
int score = 0;
for (size_t i = 0; i < supported.size(); ++i) {
if (isEqualScript(supported[i]) ||
supportsScript(supported[i].mSubScriptBits, mSubScriptBits)) {
if (mLanguage == supported[i].mLanguage) {
return 2;
} else {
score = 1;
}
}
}
if (score == 1) {
return score;
}
if (supportsScript(supported.getUnionOfSubScriptBits(), mSubScriptBits)) {
// Gives score of 2 only if the language matches all of the font languages except for the
// exact match case handled above.
return (mLanguage == supported[0].mLanguage && supported.isAllTheSameLanguage()) ? 2 : 1;
}
return 0;
}
FontLanguages::FontLanguages(std::vector<FontLanguage>&& languages)
: mLanguages(std::move(languages)) {
if (mLanguages.empty()) {
return;
}
const FontLanguage& lang = mLanguages[0];
mIsAllTheSameLanguage = true;
mUnionOfSubScriptBits = lang.mSubScriptBits;
for (size_t i = 1; i < mLanguages.size(); ++i) {
mUnionOfSubScriptBits |= mLanguages[i].mSubScriptBits;
if (mIsAllTheSameLanguage && lang.mLanguage != mLanguages[i].mLanguage) {
mIsAllTheSameLanguage = false;
}
}
}
#undef SCRIPT_TAG
} // namespace android
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