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gecko-dev/gfx/thebes/gfxFontUtils.h

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* 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/. */
#ifndef GFX_FONT_UTILS_H
#define GFX_FONT_UTILS_H
#include "gfxFontVariations.h"
#include "gfxPlatform.h"
#include "nsComponentManagerUtils.h"
#include "nsTArray.h"
#include "ipc/IPCMessageUtils.h"
#include "mozilla/Casting.h"
#include "mozilla/Encoding.h"
#include "mozilla/EndianUtils.h"
#include "mozilla/Likely.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/UniquePtr.h"
#include "zlib.h"
#include <algorithm>
/* Bug 341128 - w32api defines min/max which causes problems with <bitset> */
#ifdef __MINGW32__
# undef min
# undef max
#endif
#undef ERROR /* defined by Windows.h, conflicts with some generated bindings \
code when this gets indirectly included via shared font list \
*/
typedef struct hb_blob_t hb_blob_t;
class SharedBitSet;
class gfxSparseBitSet {
private:
friend class SharedBitSet;
enum { BLOCK_SIZE = 32 }; // ==> 256 codepoints per block
enum { BLOCK_SIZE_BITS = BLOCK_SIZE * 8 };
enum { NO_BLOCK = 0xffff }; // index value indicating missing (empty) block
struct Block {
explicit Block(unsigned char memsetValue = 0) {
memset(mBits, memsetValue, BLOCK_SIZE);
}
uint8_t mBits[BLOCK_SIZE];
};
public:
gfxSparseBitSet() = default;
bool Equals(const gfxSparseBitSet* aOther) const {
if (mBlockIndex.Length() != aOther->mBlockIndex.Length()) {
return false;
}
size_t n = mBlockIndex.Length();
for (size_t i = 0; i < n; ++i) {
uint32_t b1 = mBlockIndex[i];
uint32_t b2 = aOther->mBlockIndex[i];
if ((b1 == NO_BLOCK) != (b2 == NO_BLOCK)) {
return false;
}
if (b1 == NO_BLOCK) {
continue;
}
if (memcmp(&mBlocks[b1].mBits, &aOther->mBlocks[b2].mBits, BLOCK_SIZE) !=
0) {
return false;
}
}
return true;
}
bool test(uint32_t aIndex) const {
uint32_t i = aIndex / BLOCK_SIZE_BITS;
if (i >= mBlockIndex.Length() || mBlockIndex[i] == NO_BLOCK) {
return false;
}
const Block& block = mBlocks[mBlockIndex[i]];
return ((block.mBits[(aIndex >> 3) & (BLOCK_SIZE - 1)]) &
(1 << (aIndex & 0x7))) != 0;
}
// dump out contents of bitmap
void Dump(const char* aPrefix, eGfxLog aWhichLog) const;
bool TestRange(uint32_t aStart, uint32_t aEnd) {
// start point is beyond the end of the block array? return false
// immediately
uint32_t startBlock = aStart / BLOCK_SIZE_BITS;
uint32_t blockLen = mBlockIndex.Length();
if (startBlock >= blockLen) {
return false;
}
// check for blocks in range, if none, return false
bool hasBlocksInRange = false;
uint32_t endBlock = aEnd / BLOCK_SIZE_BITS;
for (uint32_t bi = startBlock; bi <= endBlock; bi++) {
if (bi < blockLen && mBlockIndex[bi] != NO_BLOCK) {
hasBlocksInRange = true;
break;
}
}
if (!hasBlocksInRange) {
return false;
}
// first block, check bits
if (mBlockIndex[startBlock] != NO_BLOCK) {
const Block& block = mBlocks[mBlockIndex[startBlock]];
uint32_t start = aStart;
uint32_t end = std::min(aEnd, ((startBlock + 1) * BLOCK_SIZE_BITS) - 1);
for (uint32_t i = start; i <= end; i++) {
if ((block.mBits[(i >> 3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7))) {
return true;
}
}
}
if (endBlock == startBlock) {
return false;
}
// [2..n-1] blocks check bytes
for (uint32_t i = startBlock + 1; i < endBlock; i++) {
if (i >= blockLen || mBlockIndex[i] == NO_BLOCK) {
continue;
}
const Block& block = mBlocks[mBlockIndex[i]];
for (uint32_t index = 0; index < BLOCK_SIZE; index++) {
if (block.mBits[index]) {
return true;
}
}
}
// last block, check bits
if (endBlock < blockLen && mBlockIndex[endBlock] != NO_BLOCK) {
const Block& block = mBlocks[mBlockIndex[endBlock]];
uint32_t start = endBlock * BLOCK_SIZE_BITS;
uint32_t end = aEnd;
for (uint32_t i = start; i <= end; i++) {
if ((block.mBits[(i >> 3) & (BLOCK_SIZE - 1)]) & (1 << (i & 0x7))) {
return true;
}
}
}
return false;
}
void set(uint32_t aIndex) {
uint32_t i = aIndex / BLOCK_SIZE_BITS;
while (i >= mBlockIndex.Length()) {
mBlockIndex.AppendElement(NO_BLOCK);
}
if (mBlockIndex[i] == NO_BLOCK) {
mBlocks.AppendElement();
MOZ_ASSERT(mBlocks.Length() < 0xffff, "block index overflow!");
mBlockIndex[i] = static_cast<uint16_t>(mBlocks.Length() - 1);
}
Block& block = mBlocks[mBlockIndex[i]];
block.mBits[(aIndex >> 3) & (BLOCK_SIZE - 1)] |= 1 << (aIndex & 0x7);
}
void set(uint32_t aIndex, bool aValue) {
if (aValue) {
set(aIndex);
} else {
clear(aIndex);
}
}
void SetRange(uint32_t aStart, uint32_t aEnd) {
const uint32_t startIndex = aStart / BLOCK_SIZE_BITS;
const uint32_t endIndex = aEnd / BLOCK_SIZE_BITS;
while (endIndex >= mBlockIndex.Length()) {
mBlockIndex.AppendElement(NO_BLOCK);
}
for (uint32_t i = startIndex; i <= endIndex; ++i) {
const uint32_t blockFirstBit = i * BLOCK_SIZE_BITS;
const uint32_t blockLastBit = blockFirstBit + BLOCK_SIZE_BITS - 1;
if (mBlockIndex[i] == NO_BLOCK) {
bool fullBlock = (aStart <= blockFirstBit && aEnd >= blockLastBit);
mBlocks.AppendElement(Block(fullBlock ? 0xFF : 0));
MOZ_ASSERT(mBlocks.Length() < 0xffff, "block index overflow!");
mBlockIndex[i] = static_cast<uint16_t>(mBlocks.Length() - 1);
if (fullBlock) {
continue;
}
}
Block& block = mBlocks[mBlockIndex[i]];
const uint32_t start =
aStart > blockFirstBit ? aStart - blockFirstBit : 0;
const uint32_t end =
std::min<uint32_t>(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
for (uint32_t bit = start; bit <= end; ++bit) {
block.mBits[bit >> 3] |= 1 << (bit & 0x7);
}
}
}
void clear(uint32_t aIndex) {
uint32_t i = aIndex / BLOCK_SIZE_BITS;
if (i >= mBlockIndex.Length()) {
return;
}
if (mBlockIndex[i] == NO_BLOCK) {
mBlocks.AppendElement();
MOZ_ASSERT(mBlocks.Length() < 0xffff, "block index overflow!");
mBlockIndex[i] = static_cast<uint16_t>(mBlocks.Length() - 1);
}
Block& block = mBlocks[mBlockIndex[i]];
block.mBits[(aIndex >> 3) & (BLOCK_SIZE - 1)] &= ~(1 << (aIndex & 0x7));
}
void ClearRange(uint32_t aStart, uint32_t aEnd) {
const uint32_t startIndex = aStart / BLOCK_SIZE_BITS;
const uint32_t endIndex = aEnd / BLOCK_SIZE_BITS;
for (uint32_t i = startIndex; i <= endIndex; ++i) {
if (i >= mBlockIndex.Length()) {
return;
}
if (mBlockIndex[i] == NO_BLOCK) {
continue;
}
const uint32_t blockFirstBit = i * BLOCK_SIZE_BITS;
Block& block = mBlocks[mBlockIndex[i]];
const uint32_t start =
aStart > blockFirstBit ? aStart - blockFirstBit : 0;
const uint32_t end =
std::min<uint32_t>(aEnd - blockFirstBit, BLOCK_SIZE_BITS - 1);
for (uint32_t bit = start; bit <= end; ++bit) {
block.mBits[bit >> 3] &= ~(1 << (bit & 0x7));
}
}
}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
return mBlocks.ShallowSizeOfExcludingThis(aMallocSizeOf) +
mBlockIndex.ShallowSizeOfExcludingThis(aMallocSizeOf);
}
size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
}
// clear out all blocks in the array
void reset() {
mBlocks.Clear();
mBlockIndex.Clear();
}
// set this bitset to the union of its current contents and another
void Union(const gfxSparseBitSet& aBitset) {
// ensure mBlocks is large enough
uint32_t blockCount = aBitset.mBlockIndex.Length();
while (blockCount > mBlockIndex.Length()) {
mBlockIndex.AppendElement(NO_BLOCK);
}
// for each block that may be present in aBitset...
for (uint32_t i = 0; i < blockCount; ++i) {
// if it is missing (implicitly empty), just skip
if (aBitset.mBlockIndex[i] == NO_BLOCK) {
continue;
}
// if the block is missing in this set, just copy the other
if (mBlockIndex[i] == NO_BLOCK) {
mBlocks.AppendElement(aBitset.mBlocks[aBitset.mBlockIndex[i]]);
MOZ_ASSERT(mBlocks.Length() < 0xffff, "block index overflow!");
mBlockIndex[i] = static_cast<uint16_t>(mBlocks.Length() - 1);
continue;
}
// else set existing block to the union of both
uint32_t* dst =
reinterpret_cast<uint32_t*>(&mBlocks[mBlockIndex[i]].mBits);
const uint32_t* src = reinterpret_cast<const uint32_t*>(
&aBitset.mBlocks[aBitset.mBlockIndex[i]].mBits);
for (uint32_t j = 0; j < BLOCK_SIZE / 4; ++j) {
dst[j] |= src[j];
}
}
}
inline void Union(const SharedBitSet& aBitset);
void Compact() {
// TODO: Discard any empty blocks, and adjust index accordingly.
// (May not be worth doing, though, because we so rarely clear bits
// that were previously set.)
mBlocks.Compact();
mBlockIndex.Compact();
}
uint32_t GetChecksum() const {
uint32_t check =
adler32(0, reinterpret_cast<const uint8_t*>(mBlockIndex.Elements()),
mBlockIndex.Length() * sizeof(uint16_t));
check = adler32(check, reinterpret_cast<const uint8_t*>(mBlocks.Elements()),
mBlocks.Length() * sizeof(Block));
return check;
}
private:
friend struct IPC::ParamTraits<gfxSparseBitSet>;
friend struct IPC::ParamTraits<gfxSparseBitSet::Block>;
CopyableTArray<uint16_t> mBlockIndex;
CopyableTArray<Block> mBlocks;
};
namespace IPC {
template <>
struct ParamTraits<gfxSparseBitSet> {
typedef gfxSparseBitSet paramType;
static void Write(Message* aMsg, const paramType& aParam) {
WriteParam(aMsg, aParam.mBlockIndex);
WriteParam(aMsg, aParam.mBlocks);
}
static bool Read(const Message* aMsg, PickleIterator* aIter,
paramType* aResult) {
return ReadParam(aMsg, aIter, &aResult->mBlockIndex) &&
ReadParam(aMsg, aIter, &aResult->mBlocks);
}
};
template <>
struct ParamTraits<gfxSparseBitSet::Block> {
typedef gfxSparseBitSet::Block paramType;
static void Write(Message* aMsg, const paramType& aParam) {
aMsg->WriteBytes(&aParam, sizeof(aParam));
}
static bool Read(const Message* aMsg, PickleIterator* aIter,
paramType* aResult) {
return aMsg->ReadBytesInto(aIter, aResult, sizeof(*aResult));
}
};
} // namespace IPC
/**
* SharedBitSet is a version of gfxSparseBitSet that is intended to be used
* in a shared-memory block, and can be used regardless of the address at which
* the block has been mapped. The SharedBitSet cannot be modified once it has
* been created.
*
* Max size of a SharedBitSet = 4352 * 32 ; blocks
* + 4352 * 2 ; index
* + 4 ; counts
* = 147972 bytes
*
* Therefore, SharedFontList must be able to allocate a contiguous block of at
* least this size.
*/
class SharedBitSet {
private:
// We use the same Block type as gfxSparseBitSet.
typedef gfxSparseBitSet::Block Block;
enum { BLOCK_SIZE = gfxSparseBitSet::BLOCK_SIZE };
enum { BLOCK_SIZE_BITS = gfxSparseBitSet::BLOCK_SIZE_BITS };
enum { NO_BLOCK = gfxSparseBitSet::NO_BLOCK };
public:
static const size_t kMaxSize = 147972; // see above
// Returns the size needed for a SharedBitSet version of the given
// gfxSparseBitSet.
static size_t RequiredSize(const gfxSparseBitSet& aBitset) {
size_t total = sizeof(SharedBitSet);
size_t len = aBitset.mBlockIndex.Length();
total += len * sizeof(uint16_t); // add size for index array
// add size for blocks, excluding any missing ones
for (uint16_t i = 0; i < len; i++) {
if (aBitset.mBlockIndex[i] != NO_BLOCK) {
total += sizeof(Block);
}
}
MOZ_ASSERT(total <= kMaxSize);
return total;
}
// Create a SharedBitSet in the provided buffer, initializing it with the
// contents of aBitset.
static SharedBitSet* Create(void* aBuffer, size_t aBufSize,
const gfxSparseBitSet& aBitset) {
MOZ_ASSERT(aBufSize >= RequiredSize(aBitset));
return new (aBuffer) SharedBitSet(aBitset);
}
bool test(uint32_t aIndex) const {
const auto i = static_cast<uint16_t>(aIndex / BLOCK_SIZE_BITS);
if (i >= mBlockIndexCount) {
return false;
}
const uint16_t* const blockIndex =
reinterpret_cast<const uint16_t*>(this + 1);
if (blockIndex[i] == NO_BLOCK) {
return false;
}
const Block* const blocks =
reinterpret_cast<const Block*>(blockIndex + mBlockIndexCount);
const Block& block = blocks[blockIndex[i]];
return ((block.mBits[(aIndex >> 3) & (BLOCK_SIZE - 1)]) &
(1 << (aIndex & 0x7))) != 0;
}
bool Equals(const gfxSparseBitSet* aOther) const {
if (mBlockIndexCount != aOther->mBlockIndex.Length()) {
return false;
}
const uint16_t* const blockIndex =
reinterpret_cast<const uint16_t*>(this + 1);
const Block* const blocks =
reinterpret_cast<const Block*>(blockIndex + mBlockIndexCount);
for (uint16_t i = 0; i < mBlockIndexCount; ++i) {
uint16_t index = blockIndex[i];
uint16_t otherIndex = aOther->mBlockIndex[i];
if ((index == NO_BLOCK) != (otherIndex == NO_BLOCK)) {
return false;
}
if (index == NO_BLOCK) {
continue;
}
const Block& b1 = blocks[index];
const Block& b2 = aOther->mBlocks[otherIndex];
if (memcmp(&b1.mBits, &b2.mBits, BLOCK_SIZE) != 0) {
return false;
}
}
return true;
}
private:
friend class gfxSparseBitSet;
SharedBitSet() = delete;
explicit SharedBitSet(const gfxSparseBitSet& aBitset)
: mBlockIndexCount(
mozilla::AssertedCast<uint16_t>(aBitset.mBlockIndex.Length())),
mBlockCount(0) {
uint16_t* blockIndex = reinterpret_cast<uint16_t*>(this + 1);
Block* blocks = reinterpret_cast<Block*>(blockIndex + mBlockIndexCount);
for (uint16_t i = 0; i < mBlockIndexCount; i++) {
if (aBitset.mBlockIndex[i] != NO_BLOCK) {
const Block& srcBlock = aBitset.mBlocks[aBitset.mBlockIndex[i]];
std::memcpy(&blocks[mBlockCount], &srcBlock, sizeof(Block));
blockIndex[i] = mBlockCount;
mBlockCount++;
} else {
blockIndex[i] = NO_BLOCK;
}
}
}
// We never manage SharedBitSet as a "normal" object, it's a view onto a
// buffer of shared memory. So we should never be trying to call this.
~SharedBitSet() = delete;
uint16_t mBlockIndexCount;
uint16_t mBlockCount;
// After the two "header" fields above, we have a block index array
// of uint16_t[mBlockIndexCount], followed by mBlockCount Block records.
};
// Union the contents of a SharedBitSet with the target gfxSparseBitSet
inline void gfxSparseBitSet::Union(const SharedBitSet& aBitset) {
// ensure mBlockIndex is large enough
while (mBlockIndex.Length() < aBitset.mBlockIndexCount) {
mBlockIndex.AppendElement(NO_BLOCK);
}
auto blockIndex = reinterpret_cast<const uint16_t*>(&aBitset + 1);
auto blocks =
reinterpret_cast<const Block*>(blockIndex + aBitset.mBlockIndexCount);
for (uint32_t i = 0; i < aBitset.mBlockIndexCount; ++i) {
// if it is missing (implicitly empty) in source, just skip
if (blockIndex[i] == NO_BLOCK) {
continue;
}
// if the block is missing, just copy from source bitset
if (mBlockIndex[i] == NO_BLOCK) {
mBlocks.AppendElement(blocks[blockIndex[i]]);
MOZ_ASSERT(mBlocks.Length() < 0xffff, "block index overflow");
mBlockIndex[i] = uint16_t(mBlocks.Length() - 1);
continue;
}
// else set existing target block to the union of both
uint32_t* dst = reinterpret_cast<uint32_t*>(&mBlocks[mBlockIndex[i]].mBits);
const uint32_t* src =
reinterpret_cast<const uint32_t*>(&blocks[blockIndex[i]].mBits);
for (uint32_t j = 0; j < BLOCK_SIZE / 4; ++j) {
dst[j] |= src[j];
}
}
}
#define TRUETYPE_TAG(a, b, c, d) ((a) << 24 | (b) << 16 | (c) << 8 | (d))
namespace mozilla {
// Byte-swapping types and name table structure definitions moved from
// gfxFontUtils.cpp to .h file so that gfxFont.cpp can also refer to them
#pragma pack(1)
struct AutoSwap_PRUint16 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint16& operator=(const uint16_t aValue) {
this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
return *this;
}
#else
MOZ_IMPLICIT AutoSwap_PRUint16(uint16_t aValue) {
value = mozilla::NativeEndian::swapToBigEndian(aValue);
}
#endif
operator uint16_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
operator uint32_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
operator uint64_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
private:
uint16_t value;
};
struct AutoSwap_PRInt16 {
#ifdef __SUNPRO_CC
AutoSwap_PRInt16& operator=(const int16_t aValue) {
this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
return *this;
}
#else
MOZ_IMPLICIT AutoSwap_PRInt16(int16_t aValue) {
value = mozilla::NativeEndian::swapToBigEndian(aValue);
}
#endif
operator int16_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
operator uint32_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
private:
int16_t value;
};
struct AutoSwap_PRUint32 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint32& operator=(const uint32_t aValue) {
this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
return *this;
}
#else
MOZ_IMPLICIT AutoSwap_PRUint32(uint32_t aValue) {
value = mozilla::NativeEndian::swapToBigEndian(aValue);
}
#endif
operator uint32_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
private:
uint32_t value;
};
struct AutoSwap_PRInt32 {
#ifdef __SUNPRO_CC
AutoSwap_PRInt32& operator=(const int32_t aValue) {
this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
return *this;
}
#else
MOZ_IMPLICIT AutoSwap_PRInt32(int32_t aValue) {
value = mozilla::NativeEndian::swapToBigEndian(aValue);
}
#endif
operator int32_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
private:
int32_t value;
};
struct AutoSwap_PRUint64 {
#ifdef __SUNPRO_CC
AutoSwap_PRUint64& operator=(const uint64_t aValue) {
this->value = mozilla::NativeEndian::swapToBigEndian(aValue);
return *this;
}
#else
MOZ_IMPLICIT AutoSwap_PRUint64(uint64_t aValue) {
value = mozilla::NativeEndian::swapToBigEndian(aValue);
}
#endif
operator uint64_t() const {
return mozilla::NativeEndian::swapFromBigEndian(value);
}
private:
uint64_t value;
};
struct AutoSwap_PRUint24 {
operator uint32_t() const {
return value[0] << 16 | value[1] << 8 | value[2];
}
private:
AutoSwap_PRUint24() = default;
uint8_t value[3];
};
struct SFNTHeader {
AutoSwap_PRUint32 sfntVersion; // Fixed, 0x00010000 for version 1.0.
AutoSwap_PRUint16 numTables; // Number of tables.
AutoSwap_PRUint16 searchRange; // (Maximum power of 2 <= numTables) x 16.
AutoSwap_PRUint16 entrySelector; // Log2(maximum power of 2 <= numTables).
AutoSwap_PRUint16 rangeShift; // NumTables x 16-searchRange.
};
struct TTCHeader {
AutoSwap_PRUint32 ttcTag; // 4 -byte identifier 'ttcf'.
AutoSwap_PRUint16 majorVersion;
AutoSwap_PRUint16 minorVersion;
AutoSwap_PRUint32 numFonts;
// followed by:
// AutoSwap_PRUint32 offsetTable[numFonts]
};
struct TableDirEntry {
AutoSwap_PRUint32 tag; // 4 -byte identifier.
AutoSwap_PRUint32 checkSum; // CheckSum for this table.
AutoSwap_PRUint32 offset; // Offset from beginning of TrueType font file.
AutoSwap_PRUint32 length; // Length of this table.
};
struct HeadTable {
enum {
HEAD_VERSION = 0x00010000,
HEAD_MAGIC_NUMBER = 0x5F0F3CF5,
HEAD_CHECKSUM_CALC_CONST = 0xB1B0AFBA
};
AutoSwap_PRUint32 tableVersionNumber; // Fixed, 0x00010000 for version 1.0.
AutoSwap_PRUint32 fontRevision; // Set by font manufacturer.
AutoSwap_PRUint32
checkSumAdjustment; // To compute: set it to 0, sum the entire font as
// ULONG, then store 0xB1B0AFBA - sum.
AutoSwap_PRUint32 magicNumber; // Set to 0x5F0F3CF5.
AutoSwap_PRUint16 flags;
AutoSwap_PRUint16
unitsPerEm; // Valid range is from 16 to 16384. This value should be a
// power of 2 for fonts that have TrueType outlines.
AutoSwap_PRUint64 created; // Number of seconds since 12:00 midnight, January
// 1, 1904. 64-bit integer
AutoSwap_PRUint64 modified; // Number of seconds since 12:00 midnight,
// January 1, 1904. 64-bit integer
AutoSwap_PRInt16 xMin; // For all glyph bounding boxes.
AutoSwap_PRInt16 yMin; // For all glyph bounding boxes.
AutoSwap_PRInt16 xMax; // For all glyph bounding boxes.
AutoSwap_PRInt16 yMax; // For all glyph bounding boxes.
AutoSwap_PRUint16 macStyle; // Bit 0: Bold (if set to 1);
AutoSwap_PRUint16 lowestRecPPEM; // Smallest readable size in pixels.
AutoSwap_PRInt16 fontDirectionHint;
AutoSwap_PRInt16 indexToLocFormat;
AutoSwap_PRInt16 glyphDataFormat;
};
struct OS2Table {
AutoSwap_PRUint16 version; // 0004 = OpenType 1.5
AutoSwap_PRInt16 xAvgCharWidth;
AutoSwap_PRUint16 usWeightClass;
AutoSwap_PRUint16 usWidthClass;
AutoSwap_PRUint16 fsType;
AutoSwap_PRInt16 ySubscriptXSize;
AutoSwap_PRInt16 ySubscriptYSize;
AutoSwap_PRInt16 ySubscriptXOffset;
AutoSwap_PRInt16 ySubscriptYOffset;
AutoSwap_PRInt16 ySuperscriptXSize;
AutoSwap_PRInt16 ySuperscriptYSize;
AutoSwap_PRInt16 ySuperscriptXOffset;
AutoSwap_PRInt16 ySuperscriptYOffset;
AutoSwap_PRInt16 yStrikeoutSize;
AutoSwap_PRInt16 yStrikeoutPosition;
AutoSwap_PRInt16 sFamilyClass;
uint8_t panose[10];
AutoSwap_PRUint32 unicodeRange1;
AutoSwap_PRUint32 unicodeRange2;
AutoSwap_PRUint32 unicodeRange3;
AutoSwap_PRUint32 unicodeRange4;
uint8_t achVendID[4];
AutoSwap_PRUint16 fsSelection;
AutoSwap_PRUint16 usFirstCharIndex;
AutoSwap_PRUint16 usLastCharIndex;
AutoSwap_PRInt16 sTypoAscender;
AutoSwap_PRInt16 sTypoDescender;
AutoSwap_PRInt16 sTypoLineGap;
AutoSwap_PRUint16 usWinAscent;
AutoSwap_PRUint16 usWinDescent;
AutoSwap_PRUint32 codePageRange1;
AutoSwap_PRUint32 codePageRange2;
AutoSwap_PRInt16 sxHeight;
AutoSwap_PRInt16 sCapHeight;
AutoSwap_PRUint16 usDefaultChar;
AutoSwap_PRUint16 usBreakChar;
AutoSwap_PRUint16 usMaxContext;
};
struct PostTable {
AutoSwap_PRUint32 version;
AutoSwap_PRInt32 italicAngle;
AutoSwap_PRInt16 underlinePosition;
AutoSwap_PRUint16 underlineThickness;
AutoSwap_PRUint32 isFixedPitch;
AutoSwap_PRUint32 minMemType42;
AutoSwap_PRUint32 maxMemType42;
AutoSwap_PRUint32 minMemType1;
AutoSwap_PRUint32 maxMemType1;
};
// This structure is used for both 'hhea' and 'vhea' tables.
// The field names here are those of the horizontal version; the
// vertical table just exchanges vertical and horizontal coordinates.
struct MetricsHeader {
AutoSwap_PRUint32 version;
AutoSwap_PRInt16 ascender;
AutoSwap_PRInt16 descender;
AutoSwap_PRInt16 lineGap;
AutoSwap_PRUint16 advanceWidthMax;
AutoSwap_PRInt16 minLeftSideBearing;
AutoSwap_PRInt16 minRightSideBearing;
AutoSwap_PRInt16 xMaxExtent;
AutoSwap_PRInt16 caretSlopeRise;
AutoSwap_PRInt16 caretSlopeRun;
AutoSwap_PRInt16 caretOffset;
AutoSwap_PRInt16 reserved1;
AutoSwap_PRInt16 reserved2;
AutoSwap_PRInt16 reserved3;
AutoSwap_PRInt16 reserved4;
AutoSwap_PRInt16 metricDataFormat;
AutoSwap_PRUint16 numOfLongMetrics;
};
struct MaxpTableHeader {
AutoSwap_PRUint32 version; // CFF: 0x00005000; TrueType: 0x00010000
AutoSwap_PRUint16 numGlyphs;
// truetype version has additional fields that we don't currently use
};
// old 'kern' table, supported on Windows
// see http://www.microsoft.com/typography/otspec/kern.htm
struct KernTableVersion0 {
AutoSwap_PRUint16 version; // 0x0000
AutoSwap_PRUint16 nTables;
};
struct KernTableSubtableHeaderVersion0 {
AutoSwap_PRUint16 version;
AutoSwap_PRUint16 length;
AutoSwap_PRUint16 coverage;
};
// newer Mac-only 'kern' table, ignored by Windows
// see http://developer.apple.com/textfonts/TTRefMan/RM06/Chap6kern.html
struct KernTableVersion1 {
AutoSwap_PRUint32 version; // 0x00010000
AutoSwap_PRUint32 nTables;
};
struct KernTableSubtableHeaderVersion1 {
AutoSwap_PRUint32 length;
AutoSwap_PRUint16 coverage;
AutoSwap_PRUint16 tupleIndex;
};
struct COLRHeader {
AutoSwap_PRUint16 version;
AutoSwap_PRUint16 numBaseGlyphRecord;
AutoSwap_PRUint32 offsetBaseGlyphRecord;
AutoSwap_PRUint32 offsetLayerRecord;
AutoSwap_PRUint16 numLayerRecords;
};
struct CPALHeaderVersion0 {
AutoSwap_PRUint16 version;
AutoSwap_PRUint16 numPaletteEntries;
AutoSwap_PRUint16 numPalettes;
AutoSwap_PRUint16 numColorRecords;
AutoSwap_PRUint32 offsetFirstColorRecord;
};
#pragma pack()
// Return just the highest bit of the given value, i.e., the highest
// power of 2 that is <= value, or zero if the input value is zero.
inline uint32_t FindHighestBit(uint32_t value) {
// propagate highest bit into all lower bits of the value
value |= (value >> 1);
value |= (value >> 2);
value |= (value >> 4);
value |= (value >> 8);
value |= (value >> 16);
// isolate the leftmost bit
return (value & ~(value >> 1));
}
} // namespace mozilla
// used for overlaying name changes without touching original font data
struct FontDataOverlay {
// overlaySrc != 0 ==> use overlay
uint32_t overlaySrc; // src offset from start of font data
uint32_t overlaySrcLen; // src length
uint32_t overlayDest; // dest offset from start of font data
};
enum gfxUserFontType {
GFX_USERFONT_UNKNOWN = 0,
GFX_USERFONT_OPENTYPE = 1,
GFX_USERFONT_SVG = 2,
GFX_USERFONT_WOFF = 3,
GFX_USERFONT_WOFF2 = 4
};
extern const uint8_t sCJKCompatSVSTable[];
class gfxFontUtils {
public:
// these are public because gfxFont.cpp also looks into the name table
enum {
NAME_ID_FAMILY = 1,
NAME_ID_STYLE = 2,
NAME_ID_UNIQUE = 3,
NAME_ID_FULL = 4,
NAME_ID_VERSION = 5,
NAME_ID_POSTSCRIPT = 6,
NAME_ID_PREFERRED_FAMILY = 16,
NAME_ID_PREFERRED_STYLE = 17,
PLATFORM_ALL = -1,
PLATFORM_ID_UNICODE = 0, // Mac OS uses this typically
PLATFORM_ID_MAC = 1,
PLATFORM_ID_ISO = 2,
PLATFORM_ID_MICROSOFT = 3,
ENCODING_ID_MAC_ROMAN = 0, // traditional Mac OS script manager encodings
ENCODING_ID_MAC_JAPANESE =
1, // (there are others defined, but some were never
ENCODING_ID_MAC_TRAD_CHINESE =
2, // implemented by Apple, and I have never seen them
ENCODING_ID_MAC_KOREAN = 3, // used in font names)
ENCODING_ID_MAC_ARABIC = 4,
ENCODING_ID_MAC_HEBREW = 5,
ENCODING_ID_MAC_GREEK = 6,
ENCODING_ID_MAC_CYRILLIC = 7,
ENCODING_ID_MAC_DEVANAGARI = 9,
ENCODING_ID_MAC_GURMUKHI = 10,
ENCODING_ID_MAC_GUJARATI = 11,
ENCODING_ID_MAC_SIMP_CHINESE = 25,
ENCODING_ID_MICROSOFT_SYMBOL = 0, // Microsoft platform encoding IDs
ENCODING_ID_MICROSOFT_UNICODEBMP = 1,
ENCODING_ID_MICROSOFT_SHIFTJIS = 2,
ENCODING_ID_MICROSOFT_PRC = 3,
ENCODING_ID_MICROSOFT_BIG5 = 4,
ENCODING_ID_MICROSOFT_WANSUNG = 5,
ENCODING_ID_MICROSOFT_JOHAB = 6,
ENCODING_ID_MICROSOFT_UNICODEFULL = 10,
LANG_ALL = -1,
LANG_ID_MAC_ENGLISH = 0, // many others are defined, but most don't affect
LANG_ID_MAC_HEBREW =
10, // the charset; should check all the central/eastern
LANG_ID_MAC_JAPANESE = 11, // european codes, though
LANG_ID_MAC_ARABIC = 12,
LANG_ID_MAC_ICELANDIC = 15,
LANG_ID_MAC_TURKISH = 17,
LANG_ID_MAC_TRAD_CHINESE = 19,
LANG_ID_MAC_URDU = 20,
LANG_ID_MAC_KOREAN = 23,
LANG_ID_MAC_POLISH = 25,
LANG_ID_MAC_FARSI = 31,
LANG_ID_MAC_SIMP_CHINESE = 33,
LANG_ID_MAC_ROMANIAN = 37,
LANG_ID_MAC_CZECH = 38,
LANG_ID_MAC_SLOVAK = 39,
LANG_ID_MICROSOFT_EN_US =
0x0409, // with Microsoft platformID, EN US lang code
CMAP_MAX_CODEPOINT = 0x10ffff // maximum possible Unicode codepoint
// contained in a cmap
};
// name table has a header, followed by name records, followed by string data
struct NameHeader {
mozilla::AutoSwap_PRUint16 format; // Format selector (=0).
mozilla::AutoSwap_PRUint16 count; // Number of name records.
mozilla::AutoSwap_PRUint16 stringOffset; // Offset to start of string
// storage (from start of table)
};
struct NameRecord {
mozilla::AutoSwap_PRUint16 platformID; // Platform ID
mozilla::AutoSwap_PRUint16 encodingID; // Platform-specific encoding ID
mozilla::AutoSwap_PRUint16 languageID; // Language ID
mozilla::AutoSwap_PRUint16 nameID; // Name ID.
mozilla::AutoSwap_PRUint16 length; // String length (in bytes).
mozilla::AutoSwap_PRUint16 offset; // String offset from start of storage
// (in bytes).
};
// for reading big-endian font data on either big or little-endian platforms
static inline uint16_t ReadShortAt(const uint8_t* aBuf, uint32_t aIndex) {
return static_cast<uint16_t>(aBuf[aIndex] << 8) | aBuf[aIndex + 1];
}
static inline uint16_t ReadShortAt16(const uint16_t* aBuf, uint32_t aIndex) {
const uint8_t* buf = reinterpret_cast<const uint8_t*>(aBuf);
uint32_t index = aIndex << 1;
return static_cast<uint16_t>(buf[index] << 8) | buf[index + 1];
}
static inline uint32_t ReadUint24At(const uint8_t* aBuf, uint32_t aIndex) {
return ((aBuf[aIndex] << 16) | (aBuf[aIndex + 1] << 8) |
(aBuf[aIndex + 2]));
}
static inline uint32_t ReadLongAt(const uint8_t* aBuf, uint32_t aIndex) {
return ((aBuf[aIndex] << 24) | (aBuf[aIndex + 1] << 16) |
(aBuf[aIndex + 2] << 8) | (aBuf[aIndex + 3]));
}
static nsresult ReadCMAPTableFormat10(const uint8_t* aBuf, uint32_t aLength,
gfxSparseBitSet& aCharacterMap);
static nsresult ReadCMAPTableFormat12or13(const uint8_t* aBuf,
uint32_t aLength,
gfxSparseBitSet& aCharacterMap);
static nsresult ReadCMAPTableFormat4(const uint8_t* aBuf, uint32_t aLength,
gfxSparseBitSet& aCharacterMap);
static nsresult ReadCMAPTableFormat14(const uint8_t* aBuf, uint32_t aLength,
mozilla::UniquePtr<uint8_t[]>& aTable);
static uint32_t FindPreferredSubtable(const uint8_t* aBuf,
uint32_t aBufLength,
uint32_t* aTableOffset,
uint32_t* aUVSTableOffset);
static nsresult ReadCMAP(const uint8_t* aBuf, uint32_t aBufLength,
gfxSparseBitSet& aCharacterMap,
uint32_t& aUVSOffset);
static uint32_t MapCharToGlyphFormat4(const uint8_t* aBuf, uint32_t aLength,
char16_t aCh);
static uint32_t MapCharToGlyphFormat10(const uint8_t* aBuf, uint32_t aCh);
static uint32_t MapCharToGlyphFormat12or13(const uint8_t* aBuf, uint32_t aCh);
static uint16_t MapUVSToGlyphFormat14(const uint8_t* aBuf, uint32_t aCh,
uint32_t aVS);
// sCJKCompatSVSTable is a 'cmap' format 14 subtable that maps
// <char + var-selector> pairs to the corresponding Unicode
// compatibility ideograph codepoints.
static MOZ_ALWAYS_INLINE uint32_t GetUVSFallback(uint32_t aCh, uint32_t aVS) {
aCh = MapUVSToGlyphFormat14(sCJKCompatSVSTable, aCh, aVS);
return aCh >= 0xFB00 ? aCh + (0x2F800 - 0xFB00) : aCh;
}
static uint32_t MapCharToGlyph(const uint8_t* aCmapBuf, uint32_t aBufLength,
uint32_t aUnicode, uint32_t aVarSelector = 0);
#ifdef XP_WIN
// determine whether a font (which has already been sanitized, so is known
// to be a valid sfnt) is CFF format rather than TrueType
static bool IsCffFont(const uint8_t* aFontData);
#endif
// determine the format of font data
static gfxUserFontType DetermineFontDataType(const uint8_t* aFontData,
uint32_t aFontDataLength);
// Read the fullname from the sfnt data (used to save the original name
// prior to renaming the font for installation).
// This is called with sfnt data that has already been validated,
// so it should always succeed in finding the name table.
static nsresult GetFullNameFromSFNT(const uint8_t* aFontData,
uint32_t aLength, nsACString& aFullName);
// helper to get fullname from name table, constructing from family+style
// if no explicit fullname is present
static nsresult GetFullNameFromTable(hb_blob_t* aNameTable,
nsACString& aFullName);
// helper to get family name from name table
static nsresult GetFamilyNameFromTable(hb_blob_t* aNameTable,
nsACString& aFamilyName);
// Find the table directory entry for a given table tag, in a (validated)
// buffer of 'sfnt' data. Returns null if the tag is not present.
static mozilla::TableDirEntry* FindTableDirEntry(const void* aFontData,
uint32_t aTableTag);
// Return a blob that wraps a table found within a buffer of font data.
// The blob does NOT own its data; caller guarantees that the buffer
// will remain valid at least as long as the blob.
// Returns null if the specified table is not found.
// This method assumes aFontData is valid 'sfnt' data; before using this,
// caller is responsible to do any sanitization/validation necessary.
static hb_blob_t* GetTableFromFontData(const void* aFontData,
uint32_t aTableTag);
// create a new name table and build a new font with that name table
// appended on the end, returns true on success
static nsresult RenameFont(const nsAString& aName, const uint8_t* aFontData,
uint32_t aFontDataLength,
FallibleTArray<uint8_t>* aNewFont);
// read all names matching aNameID, returning in aNames array
static nsresult ReadNames(const char* aNameData, uint32_t aDataLen,
uint32_t aNameID, int32_t aPlatformID,
nsTArray<nsCString>& aNames);
// reads English or first name matching aNameID, returning in aName
// platform based on OS
static nsresult ReadCanonicalName(hb_blob_t* aNameTable, uint32_t aNameID,
nsCString& aName);
static nsresult ReadCanonicalName(const char* aNameData, uint32_t aDataLen,
uint32_t aNameID, nsCString& aName);
// convert a name from the raw name table data into an nsString,
// provided we know how; return true if successful, or false
// if we can't handle the encoding
static bool DecodeFontName(const char* aBuf, int32_t aLength,
uint32_t aPlatformCode, uint32_t aScriptCode,
uint32_t aLangCode, nsACString& dest);
static inline bool IsJoinCauser(uint32_t ch) { return (ch == 0x200D); }
// We treat Combining Grapheme Joiner (U+034F) together with the join
// controls (ZWJ, ZWNJ) here, because (like them) it is an invisible
// char that will be handled by the shaper even if not explicitly
// supported by the font. (See bug 1408366.)
static inline bool IsJoinControl(uint32_t ch) {
return (ch == 0x200C || ch == 0x200D || ch == 0x034f);
}
enum {
kUnicodeVS1 = 0xFE00,
kUnicodeVS16 = 0xFE0F,
kUnicodeVS17 = 0xE0100,
kUnicodeVS256 = 0xE01EF
};
static inline bool IsVarSelector(uint32_t ch) {
return (ch >= kUnicodeVS1 && ch <= kUnicodeVS16) ||
(ch >= kUnicodeVS17 && ch <= kUnicodeVS256);
}
enum {
kUnicodeRegionalIndicatorA = 0x1F1E6,
kUnicodeRegionalIndicatorZ = 0x1F1FF
};
static inline bool IsRegionalIndicator(uint32_t aCh) {
return aCh >= kUnicodeRegionalIndicatorA &&
aCh <= kUnicodeRegionalIndicatorZ;
}
static inline bool IsInvalid(uint32_t ch) { return (ch == 0xFFFD); }
// Font code may want to know if there is the potential for bidi behavior
// to be triggered by any of the characters in a text run; this can be
// used to test that possibility.
enum {
kUnicodeBidiScriptsStart = 0x0590,
kUnicodeBidiScriptsEnd = 0x08FF,
kUnicodeBidiPresentationStart = 0xFB1D,
kUnicodeBidiPresentationEnd = 0xFEFC,
kUnicodeFirstHighSurrogateBlock = 0xD800,
kUnicodeRLM = 0x200F,
kUnicodeRLE = 0x202B,
kUnicodeRLO = 0x202E
};
static inline bool PotentialRTLChar(char16_t aCh) {
if (aCh >= kUnicodeBidiScriptsStart && aCh <= kUnicodeBidiScriptsEnd)
// bidi scripts Hebrew, Arabic, Syriac, Thaana, N'Ko are all encoded
// together
return true;
if (aCh == kUnicodeRLM || aCh == kUnicodeRLE || aCh == kUnicodeRLO)
// directional controls that trigger bidi layout
return true;
if (aCh >= kUnicodeBidiPresentationStart &&
aCh <= kUnicodeBidiPresentationEnd)
// presentation forms of Arabic and Hebrew letters
return true;
if ((aCh & 0xFF00) == kUnicodeFirstHighSurrogateBlock)
// surrogate that could be part of a bidi supplementary char
// (Cypriot, Aramaic, Phoenecian, etc)
return true;
// otherwise we know this char cannot trigger bidi reordering
return false;
}
// parse a simple list of font family names into
// an array of strings
static void ParseFontList(const nsACString& aFamilyList,
nsTArray<nsCString>& aFontList);
// for a given font list pref name, append list of font names
static void AppendPrefsFontList(const char* aPrefName,
nsTArray<nsCString>& aFontList,
bool aLocalized = false);
// for a given font list pref name, initialize a list of font names
static void GetPrefsFontList(const char* aPrefName,
nsTArray<nsCString>& aFontList,
bool aLocalized = false);
// generate a unique font name
static nsresult MakeUniqueUserFontName(nsAString& aName);
// for color layer from glyph using COLR and CPAL tables
static bool ValidateColorGlyphs(hb_blob_t* aCOLR, hb_blob_t* aCPAL);
static bool GetColorGlyphLayers(
hb_blob_t* aCOLR, hb_blob_t* aCPAL, uint32_t aGlyphId,
const mozilla::gfx::DeviceColor& aDefaultColor,
nsTArray<uint16_t>& aGlyphs,
nsTArray<mozilla::gfx::DeviceColor>& aColors);
static bool HasColorLayersForGlyph(hb_blob_t* aCOLR, uint32_t aGlyphId);
// Helper used to implement gfxFontEntry::GetVariation{Axes,Instances} for
// platforms where the native font APIs don't provide the info we want
// in a convenient form, or when native APIs are too expensive.
// (Not used on platforms -- currently, freetype -- where the font APIs
// expose variation instance details directly.)
static void GetVariationData(gfxFontEntry* aFontEntry,
nsTArray<gfxFontVariationAxis>* aAxes,
nsTArray<gfxFontVariationInstance>* aInstances);
// Helper method for reading localized family names from the name table
// of a single face.
static void ReadOtherFamilyNamesForFace(
const nsACString& aFamilyName, const char* aNameData,
uint32_t aDataLength, nsTArray<nsCString>& aOtherFamilyNames,
bool useFullName);
protected:
friend struct MacCharsetMappingComparator;
static nsresult ReadNames(const char* aNameData, uint32_t aDataLen,
uint32_t aNameID, int32_t aLangID,
int32_t aPlatformID, nsTArray<nsCString>& aNames);
// convert opentype name-table platform/encoding/language values to an
// Encoding object we can use to convert the name data to unicode
static const mozilla::Encoding* GetCharsetForFontName(uint16_t aPlatform,
uint16_t aScript,
uint16_t aLanguage);
struct MacFontNameCharsetMapping {
uint16_t mScript;
uint16_t mLanguage;
const mozilla::Encoding* mEncoding;
bool operator<(const MacFontNameCharsetMapping& rhs) const {
return (mScript < rhs.mScript) ||
((mScript == rhs.mScript) && (mLanguage < rhs.mLanguage));
}
};
static const MacFontNameCharsetMapping gMacFontNameCharsets[];
static const mozilla::Encoding* gISOFontNameCharsets[];
static const mozilla::Encoding* gMSFontNameCharsets[];
};
// Factors used to weight the distances between the available and target font
// properties during font-matching. These ensure that we respect the CSS-fonts
// requirement that font-stretch >> font-style >> font-weight; and in addition,
// a mismatch between the desired and actual glyph presentation (emoji vs text)
// will take precedence over any of the style attributes.
constexpr double kPresentationMismatch = 1.0e12;
constexpr double kStretchFactor = 1.0e8;
constexpr double kStyleFactor = 1.0e4;
constexpr double kWeightFactor = 1.0e0;
// style distance ==> [0,500]
static inline double StyleDistance(const mozilla::SlantStyleRange& aRange,
mozilla::FontSlantStyle aTargetStyle) {
const mozilla::FontSlantStyle minStyle = aRange.Min();
if (aTargetStyle == minStyle) {
return 0.0; // styles match exactly ==> 0
}
// bias added to angle difference when searching in the non-preferred
// direction from a target angle
const double kReverse = 100.0;
// bias added when we've crossed from positive to negative angles or
// vice versa
const double kNegate = 200.0;
if (aTargetStyle.IsNormal()) {
if (minStyle.IsOblique()) {
// to distinguish oblique 0deg from normal, we add 1.0 to the angle
const double minAngle = minStyle.ObliqueAngle();
if (minAngle >= 0.0) {
return 1.0 + minAngle;
}
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle >= 0.0) {
// [min,max] range includes 0.0, so just return our minimum
return 1.0;
}
// negative oblique is even worse than italic
return kNegate - maxAngle;
}
// must be italic, which is worse than any non-negative oblique;
// treat as a match in the wrong search direction
MOZ_ASSERT(minStyle.IsItalic());
return kReverse;
}
const double kDefaultAngle =
mozilla::FontSlantStyle::Oblique().ObliqueAngle();
if (aTargetStyle.IsItalic()) {
if (minStyle.IsOblique()) {
const double minAngle = minStyle.ObliqueAngle();
if (minAngle >= kDefaultAngle) {
return 1.0 + (minAngle - kDefaultAngle);
}
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle >= kDefaultAngle) {
return 1.0;
}
if (maxAngle > 0.0) {
// wrong direction but still > 0, add bias of 100
return kReverse + (kDefaultAngle - maxAngle);
}
// negative oblique angle, add bias of 300
return kReverse + kNegate + (kDefaultAngle - maxAngle);
}
// normal is worse than oblique > 0, but better than oblique <= 0
MOZ_ASSERT(minStyle.IsNormal());
return kNegate;
}
// target is oblique <angle>: four different cases depending on
// the value of the <angle>, which determines the preferred direction
// of search
const double targetAngle = aTargetStyle.ObliqueAngle();
if (targetAngle >= kDefaultAngle) {
if (minStyle.IsOblique()) {
const double minAngle = minStyle.ObliqueAngle();
if (minAngle >= targetAngle) {
return minAngle - targetAngle;
}
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle >= targetAngle) {
return 0.0;
}
if (maxAngle > 0.0) {
return kReverse + (targetAngle - maxAngle);
}
return kReverse + kNegate + (targetAngle - maxAngle);
}
if (minStyle.IsItalic()) {
return kReverse + kNegate;
}
return kReverse + kNegate + 1.0;
}
if (targetAngle <= -kDefaultAngle) {
if (minStyle.IsOblique()) {
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle <= targetAngle) {
return targetAngle - maxAngle;
}
const double minAngle = minStyle.ObliqueAngle();
if (minAngle <= targetAngle) {
return 0.0;
}
if (minAngle < 0.0) {
return kReverse + (minAngle - targetAngle);
}
return kReverse + kNegate + (minAngle - targetAngle);
}
if (minStyle.IsItalic()) {
return kReverse + kNegate;
}
return kReverse + kNegate + 1.0;
}
if (targetAngle >= 0.0) {
if (minStyle.IsOblique()) {
const double minAngle = minStyle.ObliqueAngle();
if (minAngle > targetAngle) {
return kReverse + (minAngle - targetAngle);
}
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle >= targetAngle) {
return 0.0;
}
if (maxAngle > 0.0) {
return targetAngle - maxAngle;
}
return kReverse + kNegate + (targetAngle - maxAngle);
}
if (minStyle.IsItalic()) {
return kReverse + kNegate - 2.0;
}
return kReverse + kNegate - 1.0;
}
// last case: (targetAngle < 0.0 && targetAngle > kDefaultAngle)
if (minStyle.IsOblique()) {
const mozilla::FontSlantStyle maxStyle = aRange.Max();
const double maxAngle = maxStyle.ObliqueAngle();
if (maxAngle < targetAngle) {
return kReverse + (targetAngle - maxAngle);
}
const double minAngle = minStyle.ObliqueAngle();
if (minAngle <= targetAngle) {
return 0.0;
}
if (minAngle < 0.0) {
return minAngle - targetAngle;
}
return kReverse + kNegate + (minAngle - targetAngle);
}
if (minStyle.IsItalic()) {
return kReverse + kNegate - 2.0;
}
return kReverse + kNegate - 1.0;
}
// stretch distance ==> [0,2000]
static inline double StretchDistance(const mozilla::StretchRange& aRange,
mozilla::FontStretch aTargetStretch) {
const double kReverseDistance = 1000.0;
mozilla::FontStretch minStretch = aRange.Min();
mozilla::FontStretch maxStretch = aRange.Max();
// The stretch value is a (non-negative) percentage; currently we support
// values in the range 0 .. 1000. (If the upper limit is ever increased,
// the kReverseDistance value used here may need to be adjusted.)
// If aTargetStretch is >100, we prefer larger values if available;
// if <=100, we prefer smaller values if available.
if (aTargetStretch < minStretch) {
if (aTargetStretch > mozilla::FontStretch::Normal()) {
return minStretch - aTargetStretch;
}
return (minStretch - aTargetStretch) + kReverseDistance;
}
if (aTargetStretch > maxStretch) {
if (aTargetStretch <= mozilla::FontStretch::Normal()) {
return aTargetStretch - maxStretch;
}
return (aTargetStretch - maxStretch) + kReverseDistance;
}
return 0.0;
}
// Calculate weight distance with values in the range (0..1000). In general,
// heavier weights match towards even heavier weights while lighter weights
// match towards even lighter weights. Target weight values in the range
// [400..500] are special, since they will first match up to 500, then down
// towards 0, then up again towards 999.
//
// Example: with target 600 and font weight 800, distance will be 200. With
// target 300 and font weight 600, distance will be 900, since heavier
// weights are farther away than lighter weights. If the target is 5 and the
// font weight 995, the distance would be 1590 for the same reason.
// weight distance ==> [0,1600]
static inline double WeightDistance(const mozilla::WeightRange& aRange,
mozilla::FontWeight aTargetWeight) {
const double kNotWithinCentralRange = 100.0;
const double kReverseDistance = 600.0;
mozilla::FontWeight minWeight = aRange.Min();
mozilla::FontWeight maxWeight = aRange.Max();
if (aTargetWeight >= minWeight && aTargetWeight <= maxWeight) {
// Target is within the face's range, so it's a perfect match
return 0.0;
}
if (aTargetWeight < mozilla::FontWeight(400)) {
// Requested a lighter-than-400 weight
if (maxWeight < aTargetWeight) {
return aTargetWeight - maxWeight;
}
// Add reverse-search penalty for bolder faces
return (minWeight - aTargetWeight) + kReverseDistance;
}
if (aTargetWeight > mozilla::FontWeight(500)) {
// Requested a bolder-than-500 weight
if (minWeight > aTargetWeight) {
return minWeight - aTargetWeight;
}
// Add reverse-search penalty for lighter faces
return (aTargetWeight - maxWeight) + kReverseDistance;
}
// Special case for requested weight in the [400..500] range
if (minWeight > aTargetWeight) {
if (minWeight <= mozilla::FontWeight(500)) {
// Bolder weight up to 500 is first choice
return minWeight - aTargetWeight;
}
// Other bolder weights get a reverse-search penalty
return (minWeight - aTargetWeight) + kReverseDistance;
}
// Lighter weights are not as good as bolder ones within [400..500]
return (aTargetWeight - maxWeight) + kNotWithinCentralRange;
}
#endif /* GFX_FONT_UTILS_H */
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