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gecko-dev/gfx/thebes/gfxFontUtils.h
Jonathan Kew bc843f9f73 Bug 1758721 - Preload font prefs that may be needed at textrun-construction time, to avoid use of the (main-thread-only) preference service. r=lsalzman 
This doesn't in itself make them thread-safe, but it provides a basis to do so by avoiding
dependence on the Preferences service at textrun-construction time.

The FontPrefs record is inert once constructed, so one approach to worker-thread use would
be to make it refcounted, and have the worker hold a strong reference to the record it's using,
so that it won't be affected if the main thread handles a pref-change and replaces its
FontPrefs. Alternatively, maybe we can just protect access with the same lock as other uses
of the font list, once that is in place (bug 1756474).

Differential Revision: https://phabricator.services.mozilla.com/D140914
2022-03-13 09:58:40 +00:00

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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 <string.h>
#include <algorithm>
#include <new>
#include <utility>
#include "gfxPlatform.h"
#include "ipc/IPCMessageUtils.h"
#include "ipc/IPCMessageUtilsSpecializations.h"
#include "mozilla/Assertions.h"
#include "mozilla/Attributes.h"
#include "mozilla/Casting.h"
#include "mozilla/EndianUtils.h"
#include "mozilla/FontPropertyTypes.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/UniquePtr.h"
#include "nsStringFwd.h"
#include "nsTArray.h"
#include "nscore.h"
#include "zlib.h"
class PickleIterator;
class gfxFontEntry;
struct gfxFontVariationAxis;
struct gfxFontVariationInstance;
namespace mozilla {
class Encoding;
namespace gfx {
struct DeviceColor;
}
} // namespace mozilla
/* 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(MessageWriter* aWriter, const paramType& aParam) {
WriteParam(aWriter, aParam.mBlockIndex);
WriteParam(aWriter, aParam.mBlocks);
}
static bool Read(MessageReader* aReader, paramType* aResult) {
return ReadParam(aReader, &aResult->mBlockIndex) &&
ReadParam(aReader, &aResult->mBlocks);
}
};
template <>
struct ParamTraits<gfxSparseBitSet::Block> {
typedef gfxSparseBitSet::Block paramType;
static void Write(MessageWriter* aWriter, const paramType& aParam) {
aWriter->WriteBytes(&aParam, sizeof(aParam));
}
static bool Read(MessageReader* aReader, paramType* aResult) {
return aReader->ReadBytesInto(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.
// Note that blocks in SharedBitSet may not be 4-byte aligned, so we don't
// try to optimize by casting to uint32_t* here and processing 4 bytes at
// once, as this could result in misaligned access.
uint8_t* dst = reinterpret_cast<uint8_t*>(&mBlocks[mBlockIndex[i]].mBits);
const uint8_t* src =
reinterpret_cast<const uint8_t*>(&blocks[blockIndex[i]].mBits);
for (uint32_t j = 0; j < BLOCK_SIZE; ++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,
bool aIsSymbolFont);
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,
bool* aIsSymbolFont);
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);
// For legacy MS Symbol fonts, we try mapping 8-bit character codes to the
// Private Use range at U+F0xx used by the cmaps in these fonts.
static MOZ_ALWAYS_INLINE uint32_t MapLegacySymbolFontCharToPUA(uint32_t aCh) {
return aCh >= 0x20 && aCh <= 0xff ? 0xf000 + aCh : 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 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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