14e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/* 24e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Copyright (C) 2015 The Android Open Source Project 34e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 44e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Licensed under the Apache License, Version 2.0 (the "License"); 54e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * you may not use this file except in compliance with the License. 64e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * You may obtain a copy of the License at 74e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 84e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * http://www.apache.org/licenses/LICENSE-2.0 94e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * 104e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Unless required by applicable law or agreed to in writing, software 114e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * distributed under the License is distributed on an "AS IS" BASIS, 124e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 134e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * See the License for the specific language governing permissions and 144e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * limitations under the License. 154e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 164e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 174e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka#define LOG_TAG "Minikin" 184e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 194e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka#include "LayoutUtils.h" 204e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 2114e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonakanamespace minikin { 2214e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka 23acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakaconst uint16_t CHAR_NBSP = 0x00A0; 24acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka 25acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka/* 26acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka * Determine whether the code unit is a word space for the purposes of justification. 27acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka */ 28acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakabool isWordSpace(uint16_t code_unit) { 29acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka return code_unit == ' ' || code_unit == CHAR_NBSP; 30acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka} 31acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka 324e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 334e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * For the purpose of layout, a word break is a boundary with no 344e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * kerning or complex script processing. This is necessarily a 354e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * heuristic, but should be accurate most of the time. 364e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 37acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakastatic bool isWordBreakAfter(uint16_t c) { 38acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonaka if (isWordSpace(c) || (c >= 0x2000 && c <= 0x200a) || c == 0x3000) { 394e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // spaces 404e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return true; 414e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 424e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // Note: kana is not included, as sophisticated fonts may kern kana 434e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return false; 444e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 454e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 46acd401d02981af51419f4b740abb2c41e4980fdbSeigo Nonakastatic bool isWordBreakBefore(uint16_t c) { 474e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // CJK ideographs (and yijing hexagram symbols) 484e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return isWordBreakAfter(c) || (c >= 0x3400 && c <= 0x9fff); 494e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 504e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 514e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 524e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of previous word break. It is either < offset or == 0. 534e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 544e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakasize_t getPrevWordBreakForCache( 554e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka const uint16_t* chars, size_t offset, size_t len) { 564e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset == 0) return 0; 574e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset > len) offset = len; 584e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[offset - 1])) { 594e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset - 1; 604e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 614e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset - 1; i > 0; i--) { 624e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i]) || isWordBreakAfter(chars[i - 1])) { 634e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 644e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 654e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 664e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return 0; 674e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 684e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka 694e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka/** 704e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka * Return offset of next word break. It is either > offset or == len. 714e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka */ 724e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonakasize_t getNextWordBreakForCache( 734e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka const uint16_t* chars, size_t offset, size_t len) { 744e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (offset >= len) return len; 754e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakAfter(chars[offset])) { 764e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return offset + 1; 774e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 784e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka for (size_t i = offset + 1; i < len; i++) { 794e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // No need to check isWordBreakAfter(chars[i - 1]) since it is checked 804e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // in previous iteration. Note that isWordBreakBefore returns true 814e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka // whenever isWordBreakAfter returns true. 824e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka if (isWordBreakBefore(chars[i])) { 834e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return i; 844e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 854e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka } 864e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka return len; 874e3adc6fb2073d5b466b88b8f5329d281038aba1Seigo Nonaka} 8814e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka 8914e2d136aaef271ba131f917cf5f27baa31ae5adSeigo Nonaka} // namespace minikin 90