diff options
Diffstat (limited to 'layout/generic/MathMLTextRunFactory.cpp')
| -rw-r--r-- | layout/generic/MathMLTextRunFactory.cpp | 679 |
1 files changed, 679 insertions, 0 deletions
diff --git a/layout/generic/MathMLTextRunFactory.cpp b/layout/generic/MathMLTextRunFactory.cpp new file mode 100644 index 0000000000..a04062ba80 --- /dev/null +++ b/layout/generic/MathMLTextRunFactory.cpp @@ -0,0 +1,679 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "MathMLTextRunFactory.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/BinarySearch.h" +#include "mozilla/ComputedStyle.h" +#include "mozilla/ComputedStyleInlines.h" +#include "mozilla/StaticPrefs_mathml.h" +#include "mozilla/intl/UnicodeScriptCodes.h" + +#include "nsStyleConsts.h" +#include "nsTextFrameUtils.h" +#include "nsFontMetrics.h" +#include "nsDeviceContext.h" + +using namespace mozilla; + +/* + Entries for the mathvariant lookup tables. mKey represents the Unicode + character to be transformed and is used for searching the tables. + mReplacement represents the mapped mathvariant Unicode character. +*/ +typedef struct { + uint32_t mKey; + uint32_t mReplacement; +} MathVarMapping; + +/* + Lookup tables for use with mathvariant mappings to transform a unicode + character point to another unicode character that indicates the proper output. + mKey represents one of two concepts. + 1. In the Latin table it represents a hole in the mathematical alphanumeric + block, where the character that should occupy that position is located + elsewhere. + 2. It represents an Arabic letter. + + As a replacement, 0 is reserved to indicate no mapping was found. +*/ +static const MathVarMapping gArabicInitialMapTable[] = { + {0x628, 0x1EE21}, {0x62A, 0x1EE35}, {0x62B, 0x1EE36}, {0x62C, 0x1EE22}, + {0x62D, 0x1EE27}, {0x62E, 0x1EE37}, {0x633, 0x1EE2E}, {0x634, 0x1EE34}, + {0x635, 0x1EE31}, {0x636, 0x1EE39}, {0x639, 0x1EE2F}, {0x63A, 0x1EE3B}, + {0x641, 0x1EE30}, {0x642, 0x1EE32}, {0x643, 0x1EE2A}, {0x644, 0x1EE2B}, + {0x645, 0x1EE2C}, {0x646, 0x1EE2D}, {0x647, 0x1EE24}, {0x64A, 0x1EE29}}; + +static const MathVarMapping gArabicTailedMapTable[] = { + {0x62C, 0x1EE42}, {0x62D, 0x1EE47}, {0x62E, 0x1EE57}, {0x633, 0x1EE4E}, + {0x634, 0x1EE54}, {0x635, 0x1EE51}, {0x636, 0x1EE59}, {0x639, 0x1EE4F}, + {0x63A, 0x1EE5B}, {0x642, 0x1EE52}, {0x644, 0x1EE4B}, {0x646, 0x1EE4D}, + {0x64A, 0x1EE49}, {0x66F, 0x1EE5F}, {0x6BA, 0x1EE5D}}; + +static const MathVarMapping gArabicStretchedMapTable[] = { + {0x628, 0x1EE61}, {0x62A, 0x1EE75}, {0x62B, 0x1EE76}, {0x62C, 0x1EE62}, + {0x62D, 0x1EE67}, {0x62E, 0x1EE77}, {0x633, 0x1EE6E}, {0x634, 0x1EE74}, + {0x635, 0x1EE71}, {0x636, 0x1EE79}, {0x637, 0x1EE68}, {0x638, 0x1EE7A}, + {0x639, 0x1EE6F}, {0x63A, 0x1EE7B}, {0x641, 0x1EE70}, {0x642, 0x1EE72}, + {0x643, 0x1EE6A}, {0x645, 0x1EE6C}, {0x646, 0x1EE6D}, {0x647, 0x1EE64}, + {0x64A, 0x1EE69}, {0x66E, 0x1EE7C}, {0x6A1, 0x1EE7E}}; + +static const MathVarMapping gArabicLoopedMapTable[] = { + {0x627, 0x1EE80}, {0x628, 0x1EE81}, {0x62A, 0x1EE95}, {0x62B, 0x1EE96}, + {0x62C, 0x1EE82}, {0x62D, 0x1EE87}, {0x62E, 0x1EE97}, {0x62F, 0x1EE83}, + {0x630, 0x1EE98}, {0x631, 0x1EE93}, {0x632, 0x1EE86}, {0x633, 0x1EE8E}, + {0x634, 0x1EE94}, {0x635, 0x1EE91}, {0x636, 0x1EE99}, {0x637, 0x1EE88}, + {0x638, 0x1EE9A}, {0x639, 0x1EE8F}, {0x63A, 0x1EE9B}, {0x641, 0x1EE90}, + {0x642, 0x1EE92}, {0x644, 0x1EE8B}, {0x645, 0x1EE8C}, {0x646, 0x1EE8D}, + {0x647, 0x1EE84}, {0x648, 0x1EE85}, {0x64A, 0x1EE89}}; + +static const MathVarMapping gArabicDoubleMapTable[] = { + {0x628, 0x1EEA1}, {0x62A, 0x1EEB5}, {0x62B, 0x1EEB6}, {0x62C, 0x1EEA2}, + {0x62D, 0x1EEA7}, {0x62E, 0x1EEB7}, {0x62F, 0x1EEA3}, {0x630, 0x1EEB8}, + {0x631, 0x1EEB3}, {0x632, 0x1EEA6}, {0x633, 0x1EEAE}, {0x634, 0x1EEB4}, + {0x635, 0x1EEB1}, {0x636, 0x1EEB9}, {0x637, 0x1EEA8}, {0x638, 0x1EEBA}, + {0x639, 0x1EEAF}, {0x63A, 0x1EEBB}, {0x641, 0x1EEB0}, {0x642, 0x1EEB2}, + {0x644, 0x1EEAB}, {0x645, 0x1EEAC}, {0x646, 0x1EEAD}, {0x648, 0x1EEA5}, + {0x64A, 0x1EEA9}}; + +static const MathVarMapping gLatinExceptionMapTable[] = { + {0x1D455, 0x210E}, {0x1D49D, 0x212C}, {0x1D4A0, 0x2130}, {0x1D4A1, 0x2131}, + {0x1D4A3, 0x210B}, {0x1D4A4, 0x2110}, {0x1D4A7, 0x2112}, {0x1D4A8, 0x2133}, + {0x1D4AD, 0x211B}, {0x1D4BA, 0x212F}, {0x1D4BC, 0x210A}, {0x1D4C4, 0x2134}, + {0x1D506, 0x212D}, {0x1D50B, 0x210C}, {0x1D50C, 0x2111}, {0x1D515, 0x211C}, + {0x1D51D, 0x2128}, {0x1D53A, 0x2102}, {0x1D53F, 0x210D}, {0x1D545, 0x2115}, + {0x1D547, 0x2119}, {0x1D548, 0x211A}, {0x1D549, 0x211D}, {0x1D551, 0x2124}}; + +namespace { + +struct MathVarMappingWrapper { + const MathVarMapping* const mTable; + explicit MathVarMappingWrapper(const MathVarMapping* aTable) + : mTable(aTable) {} + uint32_t operator[](size_t index) const { return mTable[index].mKey; } +}; + +} // namespace + +// Finds a MathVarMapping struct with the specified key (aKey) within aTable. +// aTable must be an array, whose length is specified by aNumElements +static uint32_t MathvarMappingSearch(uint32_t aKey, + const MathVarMapping* aTable, + uint32_t aNumElements) { + size_t index; + if (BinarySearch(MathVarMappingWrapper(aTable), 0, aNumElements, aKey, + &index)) { + return aTable[index].mReplacement; + } + + return 0; +} + +#define GREEK_UPPER_THETA 0x03F4 +#define HOLE_GREEK_UPPER_THETA 0x03A2 +#define NABLA 0x2207 +#define PARTIAL_DIFFERENTIAL 0x2202 +#define GREEK_UPPER_ALPHA 0x0391 +#define GREEK_UPPER_OMEGA 0x03A9 +#define GREEK_LOWER_ALPHA 0x03B1 +#define GREEK_LOWER_OMEGA 0x03C9 +#define GREEK_LUNATE_EPSILON_SYMBOL 0x03F5 +#define GREEK_THETA_SYMBOL 0x03D1 +#define GREEK_KAPPA_SYMBOL 0x03F0 +#define GREEK_PHI_SYMBOL 0x03D5 +#define GREEK_RHO_SYMBOL 0x03F1 +#define GREEK_PI_SYMBOL 0x03D6 +#define GREEK_LETTER_DIGAMMA 0x03DC +#define GREEK_SMALL_LETTER_DIGAMMA 0x03DD +#define MATH_BOLD_CAPITAL_DIGAMMA 0x1D7CA +#define MATH_BOLD_SMALL_DIGAMMA 0x1D7CB + +#define LATIN_SMALL_LETTER_DOTLESS_I 0x0131 +#define LATIN_SMALL_LETTER_DOTLESS_J 0x0237 + +#define MATH_ITALIC_SMALL_DOTLESS_I 0x1D6A4 +#define MATH_ITALIC_SMALL_DOTLESS_J 0x1D6A5 + +#define MATH_BOLD_UPPER_A 0x1D400 +#define MATH_ITALIC_UPPER_A 0x1D434 +#define MATH_BOLD_SMALL_A 0x1D41A +#define MATH_BOLD_UPPER_ALPHA 0x1D6A8 +#define MATH_BOLD_SMALL_ALPHA 0x1D6C2 +#define MATH_ITALIC_UPPER_ALPHA 0x1D6E2 +#define MATH_BOLD_DIGIT_ZERO 0x1D7CE +#define MATH_DOUBLE_STRUCK_ZERO 0x1D7D8 + +#define MATH_BOLD_UPPER_THETA 0x1D6B9 +#define MATH_BOLD_NABLA 0x1D6C1 +#define MATH_BOLD_PARTIAL_DIFFERENTIAL 0x1D6DB +#define MATH_BOLD_EPSILON_SYMBOL 0x1D6DC +#define MATH_BOLD_THETA_SYMBOL 0x1D6DD +#define MATH_BOLD_KAPPA_SYMBOL 0x1D6DE +#define MATH_BOLD_PHI_SYMBOL 0x1D6DF +#define MATH_BOLD_RHO_SYMBOL 0x1D6E0 +#define MATH_BOLD_PI_SYMBOL 0x1D6E1 + +/* + Performs the character mapping needed to implement MathML's mathvariant + attribute. It takes a unicode character and maps it to its appropriate + mathvariant counterpart specified by aMathVar. The mapped character is + typically located within Unicode's mathematical blocks (0x1D***, 0x1EE**) but + there are exceptions which this function accounts for. + Characters without a valid mapping or valid aMathvar value are returned + unaltered. Characters already in the mathematical blocks (or are one of the + exceptions) are never transformed. + Acceptable values for aMathVar are specified in layout/style/nsStyleConsts.h. + The transformable characters can be found at: + http://lists.w3.org/Archives/Public/www-math/2013Sep/0012.html and + https://en.wikipedia.org/wiki/Mathematical_Alphanumeric_Symbols +*/ +static uint32_t MathVariant(uint32_t aCh, StyleMathVariant aMathVar) { + uint32_t baseChar; + enum CharacterType { + kIsLatin, + kIsGreekish, + kIsNumber, + kIsArabic, + }; + CharacterType varType; + + int8_t multiplier; + + if (aMathVar <= StyleMathVariant::Normal) { + // nothing to do here + return aCh; + } + if (aMathVar > StyleMathVariant::Stretched) { + NS_ASSERTION(false, "Illegal mathvariant value"); + return aCh; + } + + // Exceptional characters with at most one possible transformation + if (aCh == HOLE_GREEK_UPPER_THETA) { + // Nothing at this code point is transformed + return aCh; + } + if (aCh == GREEK_LETTER_DIGAMMA) { + if (aMathVar == StyleMathVariant::Bold) { + return MATH_BOLD_CAPITAL_DIGAMMA; + } + return aCh; + } + if (aCh == GREEK_SMALL_LETTER_DIGAMMA) { + if (aMathVar == StyleMathVariant::Bold) { + return MATH_BOLD_SMALL_DIGAMMA; + } + return aCh; + } + if (aCh == LATIN_SMALL_LETTER_DOTLESS_I) { + if (aMathVar == StyleMathVariant::Italic) { + return MATH_ITALIC_SMALL_DOTLESS_I; + } + return aCh; + } + if (aCh == LATIN_SMALL_LETTER_DOTLESS_J) { + if (aMathVar == StyleMathVariant::Italic) { + return MATH_ITALIC_SMALL_DOTLESS_J; + } + return aCh; + } + + // The Unicode mathematical blocks are divided into four segments: Latin, + // Greek, numbers and Arabic. In the case of the first three + // baseChar represents the relative order in which the characters are + // encoded in the Unicode mathematical block, normalised to the first + // character of that sequence. + // + if ('A' <= aCh && aCh <= 'Z') { + baseChar = aCh - 'A'; + varType = kIsLatin; + } else if ('a' <= aCh && aCh <= 'z') { + // Lowercase characters are placed immediately after the uppercase + // characters in the Unicode mathematical block. The constant subtraction + // represents the number of characters between the start of the sequence + // (capital A) and the first lowercase letter. + baseChar = MATH_BOLD_SMALL_A - MATH_BOLD_UPPER_A + aCh - 'a'; + varType = kIsLatin; + } else if ('0' <= aCh && aCh <= '9') { + baseChar = aCh - '0'; + varType = kIsNumber; + } else if (GREEK_UPPER_ALPHA <= aCh && aCh <= GREEK_UPPER_OMEGA) { + baseChar = aCh - GREEK_UPPER_ALPHA; + varType = kIsGreekish; + } else if (GREEK_LOWER_ALPHA <= aCh && aCh <= GREEK_LOWER_OMEGA) { + // Lowercase Greek comes after uppercase Greek. + // Note in this instance the presence of an additional character (Nabla) + // between the end of the uppercase Greek characters and the lowercase + // ones. + baseChar = + MATH_BOLD_SMALL_ALPHA - MATH_BOLD_UPPER_ALPHA + aCh - GREEK_LOWER_ALPHA; + varType = kIsGreekish; + } else if (0x0600 <= aCh && aCh <= 0x06FF) { + // Arabic characters are defined within this range + varType = kIsArabic; + } else { + switch (aCh) { + case GREEK_UPPER_THETA: + baseChar = MATH_BOLD_UPPER_THETA - MATH_BOLD_UPPER_ALPHA; + break; + case NABLA: + baseChar = MATH_BOLD_NABLA - MATH_BOLD_UPPER_ALPHA; + break; + case PARTIAL_DIFFERENTIAL: + baseChar = MATH_BOLD_PARTIAL_DIFFERENTIAL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_LUNATE_EPSILON_SYMBOL: + baseChar = MATH_BOLD_EPSILON_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_THETA_SYMBOL: + baseChar = MATH_BOLD_THETA_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_KAPPA_SYMBOL: + baseChar = MATH_BOLD_KAPPA_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_PHI_SYMBOL: + baseChar = MATH_BOLD_PHI_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_RHO_SYMBOL: + baseChar = MATH_BOLD_RHO_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + case GREEK_PI_SYMBOL: + baseChar = MATH_BOLD_PI_SYMBOL - MATH_BOLD_UPPER_ALPHA; + break; + default: + return aCh; + } + + varType = kIsGreekish; + } + + if (varType == kIsNumber) { + switch (aMathVar) { + // Each possible number mathvariant is encoded in a single, contiguous + // block. For example the beginning of the double struck number range + // follows immediately after the end of the bold number range. + // multiplier represents the order of the sequences relative to the first + // one. + case StyleMathVariant::Bold: + multiplier = 0; + break; + case StyleMathVariant::DoubleStruck: + multiplier = 1; + break; + case StyleMathVariant::SansSerif: + multiplier = 2; + break; + case StyleMathVariant::BoldSansSerif: + multiplier = 3; + break; + case StyleMathVariant::Monospace: + multiplier = 4; + break; + default: + // This mathvariant isn't defined for numbers or is otherwise normal + return aCh; + } + // As the ranges are contiguous, to find the desired mathvariant range it + // is sufficient to multiply the position within the sequence order + // (multiplier) with the period of the sequence (which is constant for all + // number sequences) and to add the character point of the first character + // within the number mathvariant range. + // To this the baseChar calculated earlier is added to obtain the final + // code point. + return baseChar + + multiplier * (MATH_DOUBLE_STRUCK_ZERO - MATH_BOLD_DIGIT_ZERO) + + MATH_BOLD_DIGIT_ZERO; + } else if (varType == kIsGreekish) { + switch (aMathVar) { + case StyleMathVariant::Bold: + multiplier = 0; + break; + case StyleMathVariant::Italic: + multiplier = 1; + break; + case StyleMathVariant::BoldItalic: + multiplier = 2; + break; + case StyleMathVariant::BoldSansSerif: + multiplier = 3; + break; + case StyleMathVariant::SansSerifBoldItalic: + multiplier = 4; + break; + default: + // This mathvariant isn't defined for Greek or is otherwise normal + return aCh; + } + // See the kIsNumber case for an explanation of the following calculation + return baseChar + MATH_BOLD_UPPER_ALPHA + + multiplier * (MATH_ITALIC_UPPER_ALPHA - MATH_BOLD_UPPER_ALPHA); + } + + uint32_t tempChar; + uint32_t newChar; + if (varType == kIsArabic) { + const MathVarMapping* mapTable; + uint32_t tableLength; + switch (aMathVar) { + /* The Arabic mathematical block is not continuous, nor does it have a + * monotonic mapping to the unencoded characters, requiring the use of a + * lookup table. + */ + case StyleMathVariant::Initial: + mapTable = gArabicInitialMapTable; + tableLength = ArrayLength(gArabicInitialMapTable); + break; + case StyleMathVariant::Tailed: + mapTable = gArabicTailedMapTable; + tableLength = ArrayLength(gArabicTailedMapTable); + break; + case StyleMathVariant::Stretched: + mapTable = gArabicStretchedMapTable; + tableLength = ArrayLength(gArabicStretchedMapTable); + break; + case StyleMathVariant::Looped: + mapTable = gArabicLoopedMapTable; + tableLength = ArrayLength(gArabicLoopedMapTable); + break; + case StyleMathVariant::DoubleStruck: + mapTable = gArabicDoubleMapTable; + tableLength = ArrayLength(gArabicDoubleMapTable); + break; + default: + // No valid transformations exist + return aCh; + } + newChar = MathvarMappingSearch(aCh, mapTable, tableLength); + } else { + // Must be Latin + if (aMathVar > StyleMathVariant::Monospace) { + // Latin doesn't support the Arabic mathvariants + return aCh; + } + multiplier = uint8_t(aMathVar) - 2; + // This is possible because the values for StyleMathVariant::* are + // chosen to coincide with the order in which the encoded mathvariant + // characters are located within their unicode block (less an offset to + // avoid _NONE and _NORMAL variants) + // See the kIsNumber case for an explanation of the following calculation + tempChar = baseChar + MATH_BOLD_UPPER_A + + multiplier * (MATH_ITALIC_UPPER_A - MATH_BOLD_UPPER_A); + // There are roughly twenty characters that are located outside of the + // mathematical block, so the spaces where they ought to be are used + // as keys for a lookup table containing the correct character mappings. + newChar = MathvarMappingSearch(tempChar, gLatinExceptionMapTable, + ArrayLength(gLatinExceptionMapTable)); + } + + if (newChar) { + return newChar; + } else if (varType == kIsLatin) { + return tempChar; + } else { + // An Arabic character without a corresponding mapping + return aCh; + } +} + +#define TT_SSTY TRUETYPE_TAG('s', 's', 't', 'y') +#define TT_DTLS TRUETYPE_TAG('d', 't', 'l', 's') + +void MathMLTextRunFactory::RebuildTextRun( + nsTransformedTextRun* aTextRun, mozilla::gfx::DrawTarget* aRefDrawTarget, + gfxMissingFontRecorder* aMFR) { + gfxFontGroup* fontGroup = aTextRun->GetFontGroup(); + + nsAutoString convertedString; + AutoTArray<bool, 50> charsToMergeArray; + AutoTArray<bool, 50> deletedCharsArray; + AutoTArray<RefPtr<nsTransformedCharStyle>, 50> styleArray; + AutoTArray<uint8_t, 50> canBreakBeforeArray; + bool mergeNeeded = false; + + bool singleCharMI = + !!(aTextRun->GetFlags2() & nsTextFrameUtils::Flags::IsSingleCharMi); + + uint32_t length = aTextRun->GetLength(); + const char16_t* str = aTextRun->mString.BeginReading(); + const nsTArray<RefPtr<nsTransformedCharStyle>>& styles = aTextRun->mStyles; + nsFont font; + if (length) { + font = styles[0]->mFont; + + if (mSSTYScriptLevel || (mFlags & MATH_FONT_FEATURE_DTLS)) { + bool foundSSTY = false; + bool foundDTLS = false; + // We respect ssty settings explicitly set by the user + for (uint32_t i = 0; i < font.fontFeatureSettings.Length(); i++) { + if (font.fontFeatureSettings[i].mTag == TT_SSTY) { + foundSSTY = true; + } else if (font.fontFeatureSettings[i].mTag == TT_DTLS) { + foundDTLS = true; + } + } + if (mSSTYScriptLevel && !foundSSTY) { + uint8_t sstyLevel = 0; + float scriptScaling = + pow(styles[0]->mScriptSizeMultiplier, mSSTYScriptLevel); + static_assert(kMathMLDefaultScriptSizeMultiplier < 1, + "Shouldn't it make things smaller?"); + /* + An SSTY level of 2 is set if the scaling factor is less than or equal + to halfway between that for a scriptlevel of 1 (0.71) and that of a + scriptlevel of 2 (0.71^2), assuming the default script size + multiplier. An SSTY level of 1 is set if the script scaling factor is + less than or equal that for a scriptlevel of 1 assuming the default + script size multiplier. + + User specified values of script size multiplier will change the + scaling factor which mSSTYScriptLevel values correspond to. + + In the event that the script size multiplier actually makes things + larger, no change is made. + + To opt out of this change, add the following to the stylesheet: + "font-feature-settings: 'ssty' 0" + */ + if (scriptScaling <= (kMathMLDefaultScriptSizeMultiplier + + (kMathMLDefaultScriptSizeMultiplier * + kMathMLDefaultScriptSizeMultiplier)) / + 2) { + // Currently only the first two ssty settings are used, so two is + // large as we go + sstyLevel = 2; + } else if (scriptScaling <= kMathMLDefaultScriptSizeMultiplier) { + sstyLevel = 1; + } + if (sstyLevel) { + gfxFontFeature settingSSTY; + settingSSTY.mTag = TT_SSTY; + settingSSTY.mValue = sstyLevel; + font.fontFeatureSettings.AppendElement(settingSSTY); + } + } + /* + Apply the dtls font feature setting (dotless). + This gets applied to the base frame and all descendants of the base + frame of certain <mover> and <munderover> frames. + + See nsMathMLmunderoverFrame.cpp for a full description. + + To opt out of this change, add the following to the stylesheet: + "font-feature-settings: 'dtls' 0" + */ + if ((mFlags & MATH_FONT_FEATURE_DTLS) && !foundDTLS) { + gfxFontFeature settingDTLS; + settingDTLS.mTag = TT_DTLS; + settingDTLS.mValue = 1; + font.fontFeatureSettings.AppendElement(settingDTLS); + } + } + } + + StyleMathVariant mathVar = StyleMathVariant::None; + bool doMathvariantStyling = true; + + // Ensure it will be safe to call FindFontForChar in the loop below. + fontGroup->CheckForUpdatedPlatformList(); + + for (uint32_t i = 0; i < length; ++i) { + int extraChars = 0; + mathVar = styles[i]->mMathVariant; + + if (singleCharMI && mathVar == StyleMathVariant::None) { + mathVar = StyleMathVariant::Italic; + } + + uint32_t ch = str[i]; + if (i < length - 1 && NS_IS_SURROGATE_PAIR(ch, str[i + 1])) { + ch = SURROGATE_TO_UCS4(ch, str[i + 1]); + } + uint32_t ch2 = MathVariant(ch, mathVar); + + if (!StaticPrefs::mathml_mathvariant_styling_fallback_disabled() && + (mathVar == StyleMathVariant::Bold || + mathVar == StyleMathVariant::BoldItalic || + mathVar == StyleMathVariant::Italic)) { + if (ch == ch2 && ch != 0x20 && ch != 0xA0) { + // Don't apply the CSS style if a character cannot be + // transformed. There is an exception for whitespace as it is both + // common and innocuous. + doMathvariantStyling = false; + } + if (ch2 != ch) { + // Bug 930504. Some platforms do not have fonts for Mathematical + // Alphanumeric Symbols. Hence we check whether the transformed + // character is actually available. + FontMatchType matchType; + RefPtr<gfxFont> mathFont = fontGroup->FindFontForChar( + ch2, 0, 0, intl::Script::COMMON, nullptr, &matchType); + if (mathFont) { + // Don't apply the CSS style if there is a math font for at least one + // of the transformed character in this text run. + doMathvariantStyling = false; + } else { + // We fallback to the original character. + ch2 = ch; + if (aMFR) { + aMFR->RecordScript(intl::Script::MATHEMATICAL_NOTATION); + } + } + } + } + + deletedCharsArray.AppendElement(false); + charsToMergeArray.AppendElement(false); + styleArray.AppendElement(styles[i]); + canBreakBeforeArray.AppendElement(aTextRun->CanBreakLineBefore(i)); + + if (IS_IN_BMP(ch2)) { + convertedString.Append(ch2); + } else { + convertedString.Append(H_SURROGATE(ch2)); + convertedString.Append(L_SURROGATE(ch2)); + ++extraChars; + if (!IS_IN_BMP(ch)) { + deletedCharsArray.AppendElement( + true); // not exactly deleted, but + // the trailing surrogate is skipped + ++i; + } + } + + while (extraChars-- > 0) { + mergeNeeded = true; + charsToMergeArray.AppendElement(true); + styleArray.AppendElement(styles[i]); + canBreakBeforeArray.AppendElement(false); + } + } + + gfx::ShapedTextFlags flags; + gfxTextRunFactory::Parameters innerParams = + GetParametersForInner(aTextRun, &flags, aRefDrawTarget); + + RefPtr<nsTransformedTextRun> transformedChild; + RefPtr<gfxTextRun> cachedChild; + gfxTextRun* child; + + if (!StaticPrefs::mathml_mathvariant_styling_fallback_disabled() && + doMathvariantStyling) { + if (mathVar == StyleMathVariant::Bold) { + font.style = FontSlantStyle::NORMAL; + font.weight = FontWeight::BOLD; + } else if (mathVar == StyleMathVariant::Italic) { + font.style = FontSlantStyle::ITALIC; + font.weight = FontWeight::NORMAL; + } else if (mathVar == StyleMathVariant::BoldItalic) { + font.style = FontSlantStyle::ITALIC; + font.weight = FontWeight::BOLD; + } + } + gfxFontGroup* newFontGroup = nullptr; + + // Get the correct gfxFontGroup that corresponds to the earlier font changes. + if (length) { + font.size = font.size.ScaledBy(mFontInflation); + nsPresContext* pc = styles[0]->mPresContext; + nsFontMetrics::Params params; + params.language = styles[0]->mLanguage; + params.explicitLanguage = styles[0]->mExplicitLanguage; + params.userFontSet = pc->GetUserFontSet(); + params.textPerf = pc->GetTextPerfMetrics(); + params.featureValueLookup = pc->GetFontFeatureValuesLookup(); + RefPtr<nsFontMetrics> metrics = pc->GetMetricsFor(font, params); + newFontGroup = metrics->GetThebesFontGroup(); + } + + if (!newFontGroup) { + // If we can't get a new font group, fall back to the old one. Rendering + // will be incorrect, but not significantly so. + newFontGroup = fontGroup; + } + + if (mInnerTransformingTextRunFactory) { + transformedChild = mInnerTransformingTextRunFactory->MakeTextRun( + convertedString.BeginReading(), convertedString.Length(), &innerParams, + newFontGroup, flags, nsTextFrameUtils::Flags(), std::move(styleArray), + false); + child = transformedChild.get(); + } else { + cachedChild = newFontGroup->MakeTextRun( + convertedString.BeginReading(), convertedString.Length(), &innerParams, + flags, nsTextFrameUtils::Flags(), aMFR); + child = cachedChild.get(); + } + if (!child) return; + + typedef gfxTextRun::Range Range; + + // Copy potential linebreaks into child so they're preserved + // (and also child will be shaped appropriately) + NS_ASSERTION(convertedString.Length() == canBreakBeforeArray.Length(), + "Dropped characters or break-before values somewhere!"); + Range range(0, uint32_t(canBreakBeforeArray.Length())); + child->SetPotentialLineBreaks(range, canBreakBeforeArray.Elements()); + if (transformedChild) { + transformedChild->FinishSettingProperties(aRefDrawTarget, aMFR); + } + + aTextRun->ResetGlyphRuns(); + if (mergeNeeded) { + // Now merge multiple characters into one multi-glyph character as required + NS_ASSERTION(charsToMergeArray.Length() == child->GetLength(), + "source length mismatch"); + NS_ASSERTION(deletedCharsArray.Length() == aTextRun->GetLength(), + "destination length mismatch"); + MergeCharactersInTextRun(aTextRun, child, charsToMergeArray.Elements(), + deletedCharsArray.Elements()); + } else { + // No merging to do, so just copy; this produces a more optimized textrun. + // We can't steal the data because the child may be cached and stealing + // the data would break the cache. + aTextRun->CopyGlyphDataFrom(child, Range(child), 0); + } +} |