1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/thebes/gfxScriptItemizer.cpp Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,246 @@
1.4 +/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + * This file is based on usc_impl.c from ICU 4.2.0.1, slightly adapted
1.11 + * for use within Mozilla Gecko, separate from a standard ICU build.
1.12 + *
1.13 + * The original ICU license of the code follows:
1.14 + *
1.15 + * ICU License - ICU 1.8.1 and later
1.16 + *
1.17 + * COPYRIGHT AND PERMISSION NOTICE
1.18 + *
1.19 + * Copyright (c) 1995-2009 International Business Machines Corporation and
1.20 + * others
1.21 + *
1.22 + * All rights reserved.
1.23 + *
1.24 + * Permission is hereby granted, free of charge, to any person obtaining a
1.25 + * copy of this software and associated documentation files (the "Software"),
1.26 + * to deal in the Software without restriction, including without limitation
1.27 + * the rights to use, copy, modify, merge, publish, distribute, and/or sell
1.28 + * copies of the Software, and to permit persons to whom the Software is
1.29 + * furnished to do so, provided that the above copyright notice(s) and this
1.30 + * permission notice appear in all copies of the Software and that both the
1.31 + * above copyright notice(s) and this permission notice appear in supporting
1.32 + * documentation.
1.33 + *
1.34 + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1.35 + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1.36 + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
1.37 + * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS INCLUDED IN THIS NOTICE
1.38 + * BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES,
1.39 + * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
1.40 + * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
1.41 + * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
1.42 + * SOFTWARE.
1.43 + *
1.44 + * Except as contained in this notice, the name of a copyright holder shall
1.45 + * not be used in advertising or otherwise to promote the sale, use or other
1.46 + * dealings in this Software without prior written authorization of the
1.47 + * copyright holder.
1.48 + *
1.49 + * All trademarks and registered trademarks mentioned herein are the property
1.50 + * of their respective owners.
1.51 + */
1.52 +
1.53 +#include "gfxScriptItemizer.h"
1.54 +#include "nsUnicodeProperties.h"
1.55 +#include "nsCharTraits.h"
1.56 +#include "harfbuzz/hb.h"
1.57 +
1.58 +#define MOD(sp) ((sp) % PAREN_STACK_DEPTH)
1.59 +#define LIMIT_INC(sp) (((sp) < PAREN_STACK_DEPTH)? (sp) + 1 : PAREN_STACK_DEPTH)
1.60 +#define INC(sp,count) (MOD((sp) + (count)))
1.61 +#define INC1(sp) (INC(sp, 1))
1.62 +#define DEC(sp,count) (MOD((sp) + PAREN_STACK_DEPTH - (count)))
1.63 +#define DEC1(sp) (DEC(sp, 1))
1.64 +#define STACK_IS_EMPTY() (pushCount <= 0)
1.65 +#define STACK_IS_NOT_EMPTY() (! STACK_IS_EMPTY())
1.66 +#define TOP() (parenStack[parenSP])
1.67 +#define SYNC_FIXUP() (fixupCount = 0)
1.68 +
1.69 +void
1.70 +gfxScriptItemizer::push(uint32_t endPairChar, int32_t scriptCode)
1.71 +{
1.72 + pushCount = LIMIT_INC(pushCount);
1.73 + fixupCount = LIMIT_INC(fixupCount);
1.74 +
1.75 + parenSP = INC1(parenSP);
1.76 + parenStack[parenSP].endPairChar = endPairChar;
1.77 + parenStack[parenSP].scriptCode = scriptCode;
1.78 +}
1.79 +
1.80 +void
1.81 +gfxScriptItemizer::pop()
1.82 +{
1.83 + if (STACK_IS_EMPTY()) {
1.84 + return;
1.85 + }
1.86 +
1.87 + if (fixupCount > 0) {
1.88 + fixupCount -= 1;
1.89 + }
1.90 +
1.91 + pushCount -= 1;
1.92 + parenSP = DEC1(parenSP);
1.93 +
1.94 + /* If the stack is now empty, reset the stack
1.95 + pointers to their initial values.
1.96 + */
1.97 + if (STACK_IS_EMPTY()) {
1.98 + parenSP = -1;
1.99 + }
1.100 +}
1.101 +
1.102 +void
1.103 +gfxScriptItemizer::fixup(int32_t scriptCode)
1.104 +{
1.105 + int32_t fixupSP = DEC(parenSP, fixupCount);
1.106 +
1.107 + while (fixupCount-- > 0) {
1.108 + fixupSP = INC1(fixupSP);
1.109 + parenStack[fixupSP].scriptCode = scriptCode;
1.110 + }
1.111 +}
1.112 +
1.113 +static inline bool
1.114 +SameScript(int32_t runScript, int32_t currCharScript)
1.115 +{
1.116 + return runScript <= MOZ_SCRIPT_INHERITED ||
1.117 + currCharScript <= MOZ_SCRIPT_INHERITED ||
1.118 + currCharScript == runScript;
1.119 +}
1.120 +
1.121 +// Return whether the char has a mirrored-pair counterpart.
1.122 +// NOTE that this depends on the implementation of nsCharProps records in
1.123 +// nsUnicodeProperties, and may need to be updated if those structures change
1.124 +static inline bool
1.125 +HasMirroredChar(uint32_t aCh)
1.126 +{
1.127 + return GetCharProps1(aCh).mMirrorOffsetIndex != 0;
1.128 +}
1.129 +
1.130 +gfxScriptItemizer::gfxScriptItemizer(const char16_t *src, uint32_t length)
1.131 + : textPtr(src), textLength(length)
1.132 +{
1.133 + reset();
1.134 +}
1.135 +
1.136 +void
1.137 +gfxScriptItemizer::SetText(const char16_t *src, uint32_t length)
1.138 +{
1.139 + textPtr = src;
1.140 + textLength = length;
1.141 +
1.142 + reset();
1.143 +}
1.144 +
1.145 +bool
1.146 +gfxScriptItemizer::Next(uint32_t& aRunStart, uint32_t& aRunLimit,
1.147 + int32_t& aRunScript)
1.148 +{
1.149 + /* if we've fallen off the end of the text, we're done */
1.150 + if (scriptLimit >= textLength) {
1.151 + return false;
1.152 + }
1.153 +
1.154 + SYNC_FIXUP();
1.155 + scriptCode = MOZ_SCRIPT_COMMON;
1.156 +
1.157 + for (scriptStart = scriptLimit; scriptLimit < textLength; scriptLimit += 1) {
1.158 + uint32_t ch;
1.159 + int32_t sc;
1.160 + uint32_t startOfChar = scriptLimit;
1.161 +
1.162 + ch = textPtr[scriptLimit];
1.163 +
1.164 + /* decode UTF-16 (may be surrogate pair) */
1.165 + if (NS_IS_HIGH_SURROGATE(ch) && scriptLimit < textLength - 1) {
1.166 + uint32_t low = textPtr[scriptLimit + 1];
1.167 + if (NS_IS_LOW_SURROGATE(low)) {
1.168 + ch = SURROGATE_TO_UCS4(ch, low);
1.169 + scriptLimit += 1;
1.170 + }
1.171 + }
1.172 +
1.173 + // Get the nsCharProps2 record for the current character,
1.174 + // so we can read the script and (if needed) the gen category
1.175 + // without needing to do two multi-level lookups.
1.176 + // NOTE that this means we're relying on an implementation detail
1.177 + // of the nsUnicodeProperties tables, and might have to revise this
1.178 + // if the nsCharProps records used there are modified in future.
1.179 + const nsCharProps2& charProps = GetCharProps2(ch);
1.180 +
1.181 + // Initialize gc to UNASSIGNED; we'll only set it to the true GC
1.182 + // if the character has script=COMMON, otherwise we don't care.
1.183 + uint8_t gc = HB_UNICODE_GENERAL_CATEGORY_UNASSIGNED;
1.184 +
1.185 + sc = charProps.mScriptCode;
1.186 + if (sc == MOZ_SCRIPT_COMMON) {
1.187 + /*
1.188 + * Paired character handling:
1.189 + *
1.190 + * if it's an open character, push it onto the stack.
1.191 + * if it's a close character, find the matching open on the
1.192 + * stack, and use that script code. Any non-matching open
1.193 + * characters above it on the stack will be popped.
1.194 + *
1.195 + * We only do this if the script is COMMON; for chars with
1.196 + * specific script assignments, we just use them as-is.
1.197 + */
1.198 + gc = charProps.mCategory;
1.199 + if (gc == HB_UNICODE_GENERAL_CATEGORY_OPEN_PUNCTUATION) {
1.200 + uint32_t endPairChar = mozilla::unicode::GetMirroredChar(ch);
1.201 + if (endPairChar != ch) {
1.202 + push(endPairChar, scriptCode);
1.203 + }
1.204 + } else if (gc == HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION &&
1.205 + HasMirroredChar(ch))
1.206 + {
1.207 + while (STACK_IS_NOT_EMPTY() && TOP().endPairChar != ch) {
1.208 + pop();
1.209 + }
1.210 +
1.211 + if (STACK_IS_NOT_EMPTY()) {
1.212 + sc = TOP().scriptCode;
1.213 + }
1.214 + }
1.215 + }
1.216 +
1.217 + if (SameScript(scriptCode, sc)) {
1.218 + if (scriptCode <= MOZ_SCRIPT_INHERITED &&
1.219 + sc > MOZ_SCRIPT_INHERITED)
1.220 + {
1.221 + scriptCode = sc;
1.222 + fixup(scriptCode);
1.223 + }
1.224 +
1.225 + /*
1.226 + * if this character is a close paired character,
1.227 + * pop the matching open character from the stack
1.228 + */
1.229 + if (gc == HB_UNICODE_GENERAL_CATEGORY_CLOSE_PUNCTUATION &&
1.230 + HasMirroredChar(ch)) {
1.231 + pop();
1.232 + }
1.233 + } else {
1.234 + /*
1.235 + * reset scriptLimit in case it was advanced during reading a
1.236 + * multiple-code-unit character
1.237 + */
1.238 + scriptLimit = startOfChar;
1.239 +
1.240 + break;
1.241 + }
1.242 + }
1.243 +
1.244 + aRunStart = scriptStart;
1.245 + aRunLimit = scriptLimit;
1.246 + aRunScript = scriptCode;
1.247 +
1.248 + return true;
1.249 +}
