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			679 lines
		
	
	
	
		
			26 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			679 lines
		
	
	
	
		
			26 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| #include "MathMLTextRunFactory.h"
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| 
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| #include "mozilla/ArrayUtils.h"
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| #include "mozilla/BinarySearch.h"
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| #include "mozilla/ComputedStyle.h"
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| #include "mozilla/ComputedStyleInlines.h"
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| #include "mozilla/StaticPrefs_mathml.h"
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| #include "mozilla/intl/UnicodeScriptCodes.h"
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| 
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| #include "nsStyleConsts.h"
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| #include "nsTextFrameUtils.h"
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| #include "nsFontMetrics.h"
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| #include "nsDeviceContext.h"
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| 
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| using namespace mozilla;
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| 
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| /*
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|   Entries for the mathvariant lookup tables.  mKey represents the Unicode
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|   character to be transformed and is used for searching the tables.
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|   mReplacement represents the mapped mathvariant Unicode character.
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| */
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| typedef struct {
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|   uint32_t mKey;
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|   uint32_t mReplacement;
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| } MathVarMapping;
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| 
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| /*
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|  Lookup tables for use with mathvariant mappings to transform a unicode
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|  character point to another unicode character that indicates the proper output.
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|  mKey represents one of two concepts.
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|  1.  In the Latin table it represents a hole in the mathematical alphanumeric
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|      block, where the character that should occupy that position is located
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|      elsewhere.
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|  2.  It represents an Arabic letter.
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| 
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|   As a replacement, 0 is reserved to indicate no mapping was found.
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| */
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| static const MathVarMapping gArabicInitialMapTable[] = {
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|     {0x628, 0x1EE21}, {0x62A, 0x1EE35}, {0x62B, 0x1EE36}, {0x62C, 0x1EE22},
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|     {0x62D, 0x1EE27}, {0x62E, 0x1EE37}, {0x633, 0x1EE2E}, {0x634, 0x1EE34},
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|     {0x635, 0x1EE31}, {0x636, 0x1EE39}, {0x639, 0x1EE2F}, {0x63A, 0x1EE3B},
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|     {0x641, 0x1EE30}, {0x642, 0x1EE32}, {0x643, 0x1EE2A}, {0x644, 0x1EE2B},
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|     {0x645, 0x1EE2C}, {0x646, 0x1EE2D}, {0x647, 0x1EE24}, {0x64A, 0x1EE29}};
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| 
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| static const MathVarMapping gArabicTailedMapTable[] = {
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|     {0x62C, 0x1EE42}, {0x62D, 0x1EE47}, {0x62E, 0x1EE57}, {0x633, 0x1EE4E},
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|     {0x634, 0x1EE54}, {0x635, 0x1EE51}, {0x636, 0x1EE59}, {0x639, 0x1EE4F},
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|     {0x63A, 0x1EE5B}, {0x642, 0x1EE52}, {0x644, 0x1EE4B}, {0x646, 0x1EE4D},
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|     {0x64A, 0x1EE49}, {0x66F, 0x1EE5F}, {0x6BA, 0x1EE5D}};
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| 
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| static const MathVarMapping gArabicStretchedMapTable[] = {
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|     {0x628, 0x1EE61}, {0x62A, 0x1EE75}, {0x62B, 0x1EE76}, {0x62C, 0x1EE62},
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|     {0x62D, 0x1EE67}, {0x62E, 0x1EE77}, {0x633, 0x1EE6E}, {0x634, 0x1EE74},
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|     {0x635, 0x1EE71}, {0x636, 0x1EE79}, {0x637, 0x1EE68}, {0x638, 0x1EE7A},
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|     {0x639, 0x1EE6F}, {0x63A, 0x1EE7B}, {0x641, 0x1EE70}, {0x642, 0x1EE72},
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|     {0x643, 0x1EE6A}, {0x645, 0x1EE6C}, {0x646, 0x1EE6D}, {0x647, 0x1EE64},
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|     {0x64A, 0x1EE69}, {0x66E, 0x1EE7C}, {0x6A1, 0x1EE7E}};
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| 
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| static const MathVarMapping gArabicLoopedMapTable[] = {
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|     {0x627, 0x1EE80}, {0x628, 0x1EE81}, {0x62A, 0x1EE95}, {0x62B, 0x1EE96},
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|     {0x62C, 0x1EE82}, {0x62D, 0x1EE87}, {0x62E, 0x1EE97}, {0x62F, 0x1EE83},
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|     {0x630, 0x1EE98}, {0x631, 0x1EE93}, {0x632, 0x1EE86}, {0x633, 0x1EE8E},
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|     {0x634, 0x1EE94}, {0x635, 0x1EE91}, {0x636, 0x1EE99}, {0x637, 0x1EE88},
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|     {0x638, 0x1EE9A}, {0x639, 0x1EE8F}, {0x63A, 0x1EE9B}, {0x641, 0x1EE90},
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|     {0x642, 0x1EE92}, {0x644, 0x1EE8B}, {0x645, 0x1EE8C}, {0x646, 0x1EE8D},
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|     {0x647, 0x1EE84}, {0x648, 0x1EE85}, {0x64A, 0x1EE89}};
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| 
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| static const MathVarMapping gArabicDoubleMapTable[] = {
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|     {0x628, 0x1EEA1}, {0x62A, 0x1EEB5}, {0x62B, 0x1EEB6}, {0x62C, 0x1EEA2},
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|     {0x62D, 0x1EEA7}, {0x62E, 0x1EEB7}, {0x62F, 0x1EEA3}, {0x630, 0x1EEB8},
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|     {0x631, 0x1EEB3}, {0x632, 0x1EEA6}, {0x633, 0x1EEAE}, {0x634, 0x1EEB4},
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|     {0x635, 0x1EEB1}, {0x636, 0x1EEB9}, {0x637, 0x1EEA8}, {0x638, 0x1EEBA},
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|     {0x639, 0x1EEAF}, {0x63A, 0x1EEBB}, {0x641, 0x1EEB0}, {0x642, 0x1EEB2},
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|     {0x644, 0x1EEAB}, {0x645, 0x1EEAC}, {0x646, 0x1EEAD}, {0x648, 0x1EEA5},
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|     {0x64A, 0x1EEA9}};
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| 
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| static const MathVarMapping gLatinExceptionMapTable[] = {
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|     {0x1D455, 0x210E}, {0x1D49D, 0x212C}, {0x1D4A0, 0x2130}, {0x1D4A1, 0x2131},
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|     {0x1D4A3, 0x210B}, {0x1D4A4, 0x2110}, {0x1D4A7, 0x2112}, {0x1D4A8, 0x2133},
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|     {0x1D4AD, 0x211B}, {0x1D4BA, 0x212F}, {0x1D4BC, 0x210A}, {0x1D4C4, 0x2134},
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|     {0x1D506, 0x212D}, {0x1D50B, 0x210C}, {0x1D50C, 0x2111}, {0x1D515, 0x211C},
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|     {0x1D51D, 0x2128}, {0x1D53A, 0x2102}, {0x1D53F, 0x210D}, {0x1D545, 0x2115},
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|     {0x1D547, 0x2119}, {0x1D548, 0x211A}, {0x1D549, 0x211D}, {0x1D551, 0x2124}};
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| 
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| namespace {
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| 
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| struct MathVarMappingWrapper {
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|   const MathVarMapping* const mTable;
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|   explicit MathVarMappingWrapper(const MathVarMapping* aTable)
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|       : mTable(aTable) {}
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|   uint32_t operator[](size_t index) const { return mTable[index].mKey; }
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| };
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| 
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| }  // namespace
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| 
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| // Finds a MathVarMapping struct with the specified key (aKey) within aTable.
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| // aTable must be an array, whose length is specified by aNumElements
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| static uint32_t MathvarMappingSearch(uint32_t aKey,
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|                                      const MathVarMapping* aTable,
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|                                      uint32_t aNumElements) {
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|   size_t index;
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|   if (BinarySearch(MathVarMappingWrapper(aTable), 0, aNumElements, aKey,
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|                    &index)) {
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|     return aTable[index].mReplacement;
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|   }
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| 
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|   return 0;
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| }
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| 
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| #define GREEK_UPPER_THETA 0x03F4
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| #define HOLE_GREEK_UPPER_THETA 0x03A2
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| #define NABLA 0x2207
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| #define PARTIAL_DIFFERENTIAL 0x2202
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| #define GREEK_UPPER_ALPHA 0x0391
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| #define GREEK_UPPER_OMEGA 0x03A9
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| #define GREEK_LOWER_ALPHA 0x03B1
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| #define GREEK_LOWER_OMEGA 0x03C9
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| #define GREEK_LUNATE_EPSILON_SYMBOL 0x03F5
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| #define GREEK_THETA_SYMBOL 0x03D1
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| #define GREEK_KAPPA_SYMBOL 0x03F0
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| #define GREEK_PHI_SYMBOL 0x03D5
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| #define GREEK_RHO_SYMBOL 0x03F1
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| #define GREEK_PI_SYMBOL 0x03D6
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| #define GREEK_LETTER_DIGAMMA 0x03DC
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| #define GREEK_SMALL_LETTER_DIGAMMA 0x03DD
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| #define MATH_BOLD_CAPITAL_DIGAMMA 0x1D7CA
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| #define MATH_BOLD_SMALL_DIGAMMA 0x1D7CB
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| 
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| #define LATIN_SMALL_LETTER_DOTLESS_I 0x0131
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| #define LATIN_SMALL_LETTER_DOTLESS_J 0x0237
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| 
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| #define MATH_ITALIC_SMALL_DOTLESS_I 0x1D6A4
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| #define MATH_ITALIC_SMALL_DOTLESS_J 0x1D6A5
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| 
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| #define MATH_BOLD_UPPER_A 0x1D400
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| #define MATH_ITALIC_UPPER_A 0x1D434
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| #define MATH_BOLD_SMALL_A 0x1D41A
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| #define MATH_BOLD_UPPER_ALPHA 0x1D6A8
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| #define MATH_BOLD_SMALL_ALPHA 0x1D6C2
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| #define MATH_ITALIC_UPPER_ALPHA 0x1D6E2
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| #define MATH_BOLD_DIGIT_ZERO 0x1D7CE
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| #define MATH_DOUBLE_STRUCK_ZERO 0x1D7D8
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| 
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| #define MATH_BOLD_UPPER_THETA 0x1D6B9
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| #define MATH_BOLD_NABLA 0x1D6C1
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| #define MATH_BOLD_PARTIAL_DIFFERENTIAL 0x1D6DB
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| #define MATH_BOLD_EPSILON_SYMBOL 0x1D6DC
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| #define MATH_BOLD_THETA_SYMBOL 0x1D6DD
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| #define MATH_BOLD_KAPPA_SYMBOL 0x1D6DE
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| #define MATH_BOLD_PHI_SYMBOL 0x1D6DF
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| #define MATH_BOLD_RHO_SYMBOL 0x1D6E0
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| #define MATH_BOLD_PI_SYMBOL 0x1D6E1
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| 
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| /*
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|   Performs the character mapping needed to implement MathML's mathvariant
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|   attribute.  It takes a unicode character and maps it to its appropriate
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|   mathvariant counterpart specified by aMathVar.  The mapped character is
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|   typically located within Unicode's mathematical blocks (0x1D***, 0x1EE**) but
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|   there are exceptions which this function accounts for.
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|   Characters without a valid mapping or valid aMathvar value are returned
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|   unaltered.  Characters already in the mathematical blocks (or are one of the
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|   exceptions) are never transformed.
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|   Acceptable values for aMathVar are specified in layout/style/nsStyleConsts.h.
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|   The transformable characters can be found at:
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|   http://lists.w3.org/Archives/Public/www-math/2013Sep/0012.html and
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|   https://en.wikipedia.org/wiki/Mathematical_Alphanumeric_Symbols
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| */
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| static uint32_t MathVariant(uint32_t aCh, StyleMathVariant aMathVar) {
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|   uint32_t baseChar;
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|   enum CharacterType {
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|     kIsLatin,
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|     kIsGreekish,
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|     kIsNumber,
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|     kIsArabic,
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|   };
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|   CharacterType varType;
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| 
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|   int8_t multiplier;
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| 
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|   if (aMathVar <= StyleMathVariant::Normal) {
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|     // nothing to do here
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|     return aCh;
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|   }
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|   if (aMathVar > StyleMathVariant::Stretched) {
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|     NS_ASSERTION(false, "Illegal mathvariant value");
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|     return aCh;
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|   }
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| 
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|   // Exceptional characters with at most one possible transformation
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|   if (aCh == HOLE_GREEK_UPPER_THETA) {
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|     // Nothing at this code point is transformed
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|     return aCh;
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|   }
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|   if (aCh == GREEK_LETTER_DIGAMMA) {
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|     if (aMathVar == StyleMathVariant::Bold) {
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|       return MATH_BOLD_CAPITAL_DIGAMMA;
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|     }
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|     return aCh;
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|   }
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|   if (aCh == GREEK_SMALL_LETTER_DIGAMMA) {
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|     if (aMathVar == StyleMathVariant::Bold) {
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|       return MATH_BOLD_SMALL_DIGAMMA;
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|     }
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|     return aCh;
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|   }
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|   if (aCh == LATIN_SMALL_LETTER_DOTLESS_I) {
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|     if (aMathVar == StyleMathVariant::Italic) {
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|       return MATH_ITALIC_SMALL_DOTLESS_I;
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|     }
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|     return aCh;
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|   }
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|   if (aCh == LATIN_SMALL_LETTER_DOTLESS_J) {
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|     if (aMathVar == StyleMathVariant::Italic) {
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|       return MATH_ITALIC_SMALL_DOTLESS_J;
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|     }
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|     return aCh;
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|   }
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| 
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|   // The Unicode mathematical blocks are divided into four segments: Latin,
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|   // Greek, numbers and Arabic.  In the case of the first three
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|   // baseChar represents the relative order in which the characters are
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|   // encoded in the Unicode mathematical block, normalised to the first
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|   // character of that sequence.
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|   //
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|   if ('A' <= aCh && aCh <= 'Z') {
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|     baseChar = aCh - 'A';
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|     varType = kIsLatin;
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|   } else if ('a' <= aCh && aCh <= 'z') {
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|     // Lowercase characters are placed immediately after the uppercase
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|     // characters in the Unicode mathematical block.  The constant subtraction
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|     // represents the number of characters between the start of the sequence
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|     // (capital A) and the first lowercase letter.
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|     baseChar = MATH_BOLD_SMALL_A - MATH_BOLD_UPPER_A + aCh - 'a';
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|     varType = kIsLatin;
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|   } else if ('0' <= aCh && aCh <= '9') {
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|     baseChar = aCh - '0';
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|     varType = kIsNumber;
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|   } else if (GREEK_UPPER_ALPHA <= aCh && aCh <= GREEK_UPPER_OMEGA) {
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|     baseChar = aCh - GREEK_UPPER_ALPHA;
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|     varType = kIsGreekish;
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|   } else if (GREEK_LOWER_ALPHA <= aCh && aCh <= GREEK_LOWER_OMEGA) {
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|     // Lowercase Greek comes after uppercase Greek.
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|     // Note in this instance the presence of an additional character (Nabla)
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|     // between the end of the uppercase Greek characters and the lowercase
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|     // ones.
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|     baseChar =
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|         MATH_BOLD_SMALL_ALPHA - MATH_BOLD_UPPER_ALPHA + aCh - GREEK_LOWER_ALPHA;
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|     varType = kIsGreekish;
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|   } else if (0x0600 <= aCh && aCh <= 0x06FF) {
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|     // Arabic characters are defined within this range
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|     varType = kIsArabic;
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|   } else {
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|     switch (aCh) {
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|       case GREEK_UPPER_THETA:
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|         baseChar = MATH_BOLD_UPPER_THETA - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case NABLA:
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|         baseChar = MATH_BOLD_NABLA - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case PARTIAL_DIFFERENTIAL:
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|         baseChar = MATH_BOLD_PARTIAL_DIFFERENTIAL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_LUNATE_EPSILON_SYMBOL:
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|         baseChar = MATH_BOLD_EPSILON_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_THETA_SYMBOL:
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|         baseChar = MATH_BOLD_THETA_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_KAPPA_SYMBOL:
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|         baseChar = MATH_BOLD_KAPPA_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_PHI_SYMBOL:
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|         baseChar = MATH_BOLD_PHI_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_RHO_SYMBOL:
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|         baseChar = MATH_BOLD_RHO_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       case GREEK_PI_SYMBOL:
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|         baseChar = MATH_BOLD_PI_SYMBOL - MATH_BOLD_UPPER_ALPHA;
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|         break;
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|       default:
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|         return aCh;
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|     }
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| 
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|     varType = kIsGreekish;
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|   }
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| 
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|   if (varType == kIsNumber) {
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|     switch (aMathVar) {
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|       // Each possible number mathvariant is encoded in a single, contiguous
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|       // block.  For example the beginning of the double struck number range
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|       // follows immediately after the end of the bold number range.
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|       // multiplier represents the order of the sequences relative to the first
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|       // one.
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|       case StyleMathVariant::Bold:
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|         multiplier = 0;
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|         break;
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|       case StyleMathVariant::DoubleStruck:
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|         multiplier = 1;
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|         break;
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|       case StyleMathVariant::SansSerif:
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|         multiplier = 2;
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|         break;
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|       case StyleMathVariant::BoldSansSerif:
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|         multiplier = 3;
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|         break;
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|       case StyleMathVariant::Monospace:
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|         multiplier = 4;
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|         break;
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|       default:
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|         // This mathvariant isn't defined for numbers or is otherwise normal
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|         return aCh;
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|     }
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|     // As the ranges are contiguous, to find the desired mathvariant range it
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|     // is sufficient to multiply the position within the sequence order
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|     // (multiplier) with the period of the sequence (which is constant for all
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|     // number sequences) and to add the character point of the first character
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|     // within the number mathvariant range.
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|     // To this the baseChar calculated earlier is added to obtain the final
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|     // code point.
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|     return baseChar +
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|            multiplier * (MATH_DOUBLE_STRUCK_ZERO - MATH_BOLD_DIGIT_ZERO) +
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|            MATH_BOLD_DIGIT_ZERO;
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|   } else if (varType == kIsGreekish) {
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|     switch (aMathVar) {
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|       case StyleMathVariant::Bold:
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|         multiplier = 0;
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|         break;
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|       case StyleMathVariant::Italic:
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|         multiplier = 1;
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|         break;
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|       case StyleMathVariant::BoldItalic:
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|         multiplier = 2;
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|         break;
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|       case StyleMathVariant::BoldSansSerif:
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|         multiplier = 3;
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|         break;
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|       case StyleMathVariant::SansSerifBoldItalic:
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|         multiplier = 4;
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|         break;
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|       default:
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|         // This mathvariant isn't defined for Greek or is otherwise normal
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|         return aCh;
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|     }
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|     // See the kIsNumber case for an explanation of the following calculation
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|     return baseChar + MATH_BOLD_UPPER_ALPHA +
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|            multiplier * (MATH_ITALIC_UPPER_ALPHA - MATH_BOLD_UPPER_ALPHA);
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|   }
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| 
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|   uint32_t tempChar;
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|   uint32_t newChar;
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|   if (varType == kIsArabic) {
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|     const MathVarMapping* mapTable;
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|     uint32_t tableLength;
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|     switch (aMathVar) {
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|       /* The Arabic mathematical block is not continuous, nor does it have a
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|        * monotonic mapping to the unencoded characters, requiring the use of a
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|        * lookup table.
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|        */
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|       case StyleMathVariant::Initial:
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|         mapTable = gArabicInitialMapTable;
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|         tableLength = ArrayLength(gArabicInitialMapTable);
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|         break;
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|       case StyleMathVariant::Tailed:
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|         mapTable = gArabicTailedMapTable;
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|         tableLength = ArrayLength(gArabicTailedMapTable);
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|         break;
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|       case StyleMathVariant::Stretched:
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|         mapTable = gArabicStretchedMapTable;
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|         tableLength = ArrayLength(gArabicStretchedMapTable);
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|         break;
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|       case StyleMathVariant::Looped:
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|         mapTable = gArabicLoopedMapTable;
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|         tableLength = ArrayLength(gArabicLoopedMapTable);
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|         break;
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|       case StyleMathVariant::DoubleStruck:
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|         mapTable = gArabicDoubleMapTable;
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|         tableLength = ArrayLength(gArabicDoubleMapTable);
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|         break;
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|       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);
 | |
|   }
 | |
| }
 | 
