gecko-dev/gfx/thebes/gfxCoreTextShaper.cpp

707 lines
30 KiB
C++

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/ArrayUtils.h"
#include "gfxCoreTextShaper.h"
#include "gfxMacFont.h"
#include "gfxFontUtils.h"
#include "gfxTextRun.h"
#include "mozilla/gfx/2D.h"
#include <algorithm>
using namespace mozilla;
// standard font descriptors that we construct the first time they're needed
CTFontDescriptorRef gfxCoreTextShaper::sDefaultFeaturesDescriptor = nullptr;
CTFontDescriptorRef gfxCoreTextShaper::sDisableLigaturesDescriptor = nullptr;
CTFontDescriptorRef gfxCoreTextShaper::sIndicFeaturesDescriptor = nullptr;
CTFontDescriptorRef gfxCoreTextShaper::sIndicDisableLigaturesDescriptor = nullptr;
gfxCoreTextShaper::gfxCoreTextShaper(gfxMacFont *aFont)
: gfxFontShaper(aFont)
{
// Create our CTFontRef
mCTFont = CreateCTFontWithFeatures(aFont->GetAdjustedSize(),
GetDefaultFeaturesDescriptor());
// Set up the default attribute dictionary that we will need each time we
// create a CFAttributedString (unless we need to use custom features,
// in which case a new dictionary will be created on the fly).
mAttributesDict = ::CFDictionaryCreate(kCFAllocatorDefault,
(const void**) &kCTFontAttributeName,
(const void**) &mCTFont,
1, // count of attributes
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
}
gfxCoreTextShaper::~gfxCoreTextShaper()
{
if (mAttributesDict) {
::CFRelease(mAttributesDict);
}
if (mCTFont) {
::CFRelease(mCTFont);
}
}
static bool
IsBuggyIndicScript(int32_t aScript)
{
return aScript == MOZ_SCRIPT_BENGALI || aScript == MOZ_SCRIPT_KANNADA;
}
bool
gfxCoreTextShaper::ShapeText(gfxContext *aContext,
const char16_t *aText,
uint32_t aOffset,
uint32_t aLength,
int32_t aScript,
bool aVertical,
gfxShapedText *aShapedText)
{
// Create a CFAttributedString with text and style info, so we can use CoreText to lay it out.
bool isRightToLeft = aShapedText->IsRightToLeft();
uint32_t length = aLength;
// we need to bidi-wrap the text if the run is RTL,
// or if it is an LTR run but may contain (overridden) RTL chars
bool bidiWrap = isRightToLeft;
if (!bidiWrap && !aShapedText->TextIs8Bit()) {
uint32_t i;
for (i = 0; i < length; ++i) {
if (gfxFontUtils::PotentialRTLChar(aText[i])) {
bidiWrap = true;
break;
}
}
}
// If there's a possibility of any bidi, we wrap the text with direction overrides
// to ensure neutrals or characters that were bidi-overridden in HTML behave properly.
const UniChar beginLTR[] = { 0x202d, 0x20 };
const UniChar beginRTL[] = { 0x202e, 0x20 };
const UniChar endBidiWrap[] = { 0x20, 0x2e, 0x202c };
uint32_t startOffset;
CFStringRef stringObj;
if (bidiWrap) {
startOffset = isRightToLeft ?
mozilla::ArrayLength(beginRTL) : mozilla::ArrayLength(beginLTR);
CFMutableStringRef mutableString =
::CFStringCreateMutable(kCFAllocatorDefault,
length + startOffset + mozilla::ArrayLength(endBidiWrap));
::CFStringAppendCharacters(mutableString,
isRightToLeft ? beginRTL : beginLTR,
startOffset);
::CFStringAppendCharacters(mutableString, reinterpret_cast<const UniChar*>(aText), length);
::CFStringAppendCharacters(mutableString,
endBidiWrap, mozilla::ArrayLength(endBidiWrap));
stringObj = mutableString;
} else {
startOffset = 0;
stringObj = ::CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault,
reinterpret_cast<const UniChar*>(aText),
length, kCFAllocatorNull);
}
CFDictionaryRef attrObj;
CTFontRef tempCTFont = nullptr;
if (IsBuggyIndicScript(aScript)) {
// To work around buggy Indic AAT fonts shipped with OS X,
// we re-enable the Line Initial Smart Swashes feature that is needed
// for "split vowels" to work in at least Bengali and Kannada fonts.
// Affected fonts include Bangla MN, Bangla Sangam MN, Kannada MN,
// Kannada Sangam MN. See bugs 686225, 728557, 953231, 1145515.
tempCTFont =
CreateCTFontWithFeatures(::CTFontGetSize(mCTFont),
aShapedText->DisableLigatures()
? GetIndicDisableLigaturesDescriptor()
: GetIndicFeaturesDescriptor());
} else if (aShapedText->DisableLigatures()) {
// For letterspacing (or maybe other situations) we need to make
// a copy of the CTFont with the ligature feature disabled.
tempCTFont =
CreateCTFontWithFeatures(::CTFontGetSize(mCTFont),
GetDisableLigaturesDescriptor());
}
if (tempCTFont) {
attrObj =
::CFDictionaryCreate(kCFAllocatorDefault,
(const void**) &kCTFontAttributeName,
(const void**) &tempCTFont,
1, // count of attributes
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
// Having created the dict, we're finished with our temporary
// Indic and/or ligature-disabled CTFontRef.
::CFRelease(tempCTFont);
} else {
// The default case is to use our preallocated attr dict
attrObj = mAttributesDict;
::CFRetain(attrObj);
}
// Now we can create an attributed string
CFAttributedStringRef attrStringObj =
::CFAttributedStringCreate(kCFAllocatorDefault, stringObj, attrObj);
::CFRelease(stringObj);
// Create the CoreText line from our string, then we're done with it
CTLineRef line = ::CTLineCreateWithAttributedString(attrStringObj);
::CFRelease(attrStringObj);
// and finally retrieve the glyph data and store into the gfxTextRun
CFArrayRef glyphRuns = ::CTLineGetGlyphRuns(line);
uint32_t numRuns = ::CFArrayGetCount(glyphRuns);
// Iterate through the glyph runs.
// Note that this includes the bidi wrapper, so we have to be careful
// not to include the extra glyphs from there
bool success = true;
for (uint32_t runIndex = 0; runIndex < numRuns; runIndex++) {
CTRunRef aCTRun =
(CTRunRef)::CFArrayGetValueAtIndex(glyphRuns, runIndex);
// If the range is purely within bidi-wrapping text, ignore it.
CFRange range = ::CTRunGetStringRange(aCTRun);
if (uint32_t(range.location + range.length) <= startOffset ||
range.location - startOffset >= aLength) {
continue;
}
CFDictionaryRef runAttr = ::CTRunGetAttributes(aCTRun);
if (runAttr != attrObj) {
// If Core Text manufactured a new dictionary, this may indicate
// unexpected font substitution. In that case, we fail (and fall
// back to harfbuzz shaping)...
const void* font1 = ::CFDictionaryGetValue(attrObj, kCTFontAttributeName);
const void* font2 = ::CFDictionaryGetValue(runAttr, kCTFontAttributeName);
if (font1 != font2) {
// ...except that if the fallback was only for a variation
// selector that is otherwise unsupported, we just ignore it.
if (range.length == 1 &&
gfxFontUtils::IsVarSelector(aText[range.location -
startOffset])) {
continue;
}
NS_WARNING("unexpected font fallback in Core Text");
success = false;
break;
}
}
if (SetGlyphsFromRun(aShapedText, aOffset, aLength, aCTRun, startOffset) != NS_OK) {
success = false;
break;
}
}
::CFRelease(attrObj);
::CFRelease(line);
return success;
}
#define SMALL_GLYPH_RUN 128 // preallocated size of our auto arrays for per-glyph data;
// some testing indicates that 90%+ of glyph runs will fit
// without requiring a separate allocation
nsresult
gfxCoreTextShaper::SetGlyphsFromRun(gfxShapedText *aShapedText,
uint32_t aOffset,
uint32_t aLength,
CTRunRef aCTRun,
int32_t aStringOffset)
{
// The word has been bidi-wrapped; aStringOffset is the number
// of chars at the beginning of the CTLine that we should skip.
// aCTRun is a glyph run from the CoreText layout process.
int32_t direction = aShapedText->IsRightToLeft() ? -1 : 1;
int32_t numGlyphs = ::CTRunGetGlyphCount(aCTRun);
if (numGlyphs == 0) {
return NS_OK;
}
int32_t wordLength = aLength;
// character offsets get really confusing here, as we have to keep track of
// (a) the text in the actual textRun we're constructing
// (c) the string that was handed to CoreText, which contains the text of the font run
// plus directional-override padding
// (d) the CTRun currently being processed, which may be a sub-run of the CoreText line
// (but may extend beyond the actual font run into the bidi wrapping text).
// aStringOffset tells us how many initial characters of the line to ignore.
// get the source string range within the CTLine's text
CFRange stringRange = ::CTRunGetStringRange(aCTRun);
// skip the run if it is entirely outside the actual range of the font run
if (stringRange.location - aStringOffset + stringRange.length <= 0 ||
stringRange.location - aStringOffset >= wordLength) {
return NS_OK;
}
// retrieve the laid-out glyph data from the CTRun
nsAutoArrayPtr<CGGlyph> glyphsArray;
nsAutoArrayPtr<CGPoint> positionsArray;
nsAutoArrayPtr<CFIndex> glyphToCharArray;
const CGGlyph* glyphs = nullptr;
const CGPoint* positions = nullptr;
const CFIndex* glyphToChar = nullptr;
// Testing indicates that CTRunGetGlyphsPtr (almost?) always succeeds,
// and so allocating a new array and copying data with CTRunGetGlyphs
// will be extremely rare.
// If this were not the case, we could use an nsAutoTArray<> to
// try and avoid the heap allocation for small runs.
// It's possible that some future change to CoreText will mean that
// CTRunGetGlyphsPtr fails more often; if this happens, nsAutoTArray<>
// may become an attractive option.
glyphs = ::CTRunGetGlyphsPtr(aCTRun);
if (!glyphs) {
glyphsArray = new (std::nothrow) CGGlyph[numGlyphs];
if (!glyphsArray) {
return NS_ERROR_OUT_OF_MEMORY;
}
::CTRunGetGlyphs(aCTRun, ::CFRangeMake(0, 0), glyphsArray.get());
glyphs = glyphsArray.get();
}
positions = ::CTRunGetPositionsPtr(aCTRun);
if (!positions) {
positionsArray = new (std::nothrow) CGPoint[numGlyphs];
if (!positionsArray) {
return NS_ERROR_OUT_OF_MEMORY;
}
::CTRunGetPositions(aCTRun, ::CFRangeMake(0, 0), positionsArray.get());
positions = positionsArray.get();
}
// Remember that the glyphToChar indices relate to the CoreText line,
// not to the beginning of the textRun, the font run,
// or the stringRange of the glyph run
glyphToChar = ::CTRunGetStringIndicesPtr(aCTRun);
if (!glyphToChar) {
glyphToCharArray = new (std::nothrow) CFIndex[numGlyphs];
if (!glyphToCharArray) {
return NS_ERROR_OUT_OF_MEMORY;
}
::CTRunGetStringIndices(aCTRun, ::CFRangeMake(0, 0), glyphToCharArray.get());
glyphToChar = glyphToCharArray.get();
}
double runWidth = ::CTRunGetTypographicBounds(aCTRun, ::CFRangeMake(0, 0),
nullptr, nullptr, nullptr);
nsAutoTArray<gfxShapedText::DetailedGlyph,1> detailedGlyphs;
gfxShapedText::CompressedGlyph g;
gfxShapedText::CompressedGlyph *charGlyphs =
aShapedText->GetCharacterGlyphs() + aOffset;
// CoreText gives us the glyphindex-to-charindex mapping, which relates each glyph
// to a source text character; we also need the charindex-to-glyphindex mapping to
// find the glyph for a given char. Note that some chars may not map to any glyph
// (ligature continuations), and some may map to several glyphs (eg Indic split vowels).
// We set the glyph index to NO_GLYPH for chars that have no associated glyph, and we
// record the last glyph index for cases where the char maps to several glyphs,
// so that our clumping will include all the glyph fragments for the character.
// The charToGlyph array is indexed by char position within the stringRange of the glyph run.
static const int32_t NO_GLYPH = -1;
AutoFallibleTArray<int32_t,SMALL_GLYPH_RUN> charToGlyphArray;
if (!charToGlyphArray.SetLength(stringRange.length, fallible)) {
return NS_ERROR_OUT_OF_MEMORY;
}
int32_t *charToGlyph = charToGlyphArray.Elements();
for (int32_t offset = 0; offset < stringRange.length; ++offset) {
charToGlyph[offset] = NO_GLYPH;
}
for (int32_t i = 0; i < numGlyphs; ++i) {
int32_t loc = glyphToChar[i] - stringRange.location;
if (loc >= 0 && loc < stringRange.length) {
charToGlyph[loc] = i;
}
}
// Find character and glyph clumps that correspond, allowing for ligatures,
// indic reordering, split glyphs, etc.
//
// The idea is that we'll find a character sequence starting at the first char of stringRange,
// and extend it until it includes the character associated with the first glyph;
// we also extend it as long as there are "holes" in the range of glyphs. So we
// will eventually have a contiguous sequence of characters, starting at the beginning
// of the range, that map to a contiguous sequence of glyphs, starting at the beginning
// of the glyph array. That's a clump; then we update the starting positions and repeat.
//
// NB: In the case of RTL layouts, we iterate over the stringRange in reverse.
//
// This may find characters that fall outside the range 0:wordLength,
// so we won't necessarily use everything we find here.
bool isRightToLeft = aShapedText->IsRightToLeft();
int32_t glyphStart = 0; // looking for a clump that starts at this glyph index
int32_t charStart = isRightToLeft ?
stringRange.length - 1 : 0; // and this char index (in the stringRange of the glyph run)
while (glyphStart < numGlyphs) { // keep finding groups until all glyphs are accounted for
bool inOrder = true;
int32_t charEnd = glyphToChar[glyphStart] - stringRange.location;
NS_WARN_IF_FALSE(charEnd >= 0 && charEnd < stringRange.length,
"glyph-to-char mapping points outside string range");
// clamp charEnd to the valid range of the string
charEnd = std::max(charEnd, 0);
charEnd = std::min(charEnd, int32_t(stringRange.length));
int32_t glyphEnd = glyphStart;
int32_t charLimit = isRightToLeft ? -1 : stringRange.length;
do {
// This is normally executed once for each iteration of the outer loop,
// but in unusual cases where the character/glyph association is complex,
// the initial character range might correspond to a non-contiguous
// glyph range with "holes" in it. If so, we will repeat this loop to
// extend the character range until we have a contiguous glyph sequence.
NS_ASSERTION((direction > 0 && charEnd < charLimit) ||
(direction < 0 && charEnd > charLimit),
"no characters left in range?");
charEnd += direction;
while (charEnd != charLimit && charToGlyph[charEnd] == NO_GLYPH) {
charEnd += direction;
}
// find the maximum glyph index covered by the clump so far
if (isRightToLeft) {
for (int32_t i = charStart; i > charEnd; --i) {
if (charToGlyph[i] != NO_GLYPH) {
// update extent of glyph range
glyphEnd = std::max(glyphEnd, charToGlyph[i] + 1);
}
}
} else {
for (int32_t i = charStart; i < charEnd; ++i) {
if (charToGlyph[i] != NO_GLYPH) {
// update extent of glyph range
glyphEnd = std::max(glyphEnd, charToGlyph[i] + 1);
}
}
}
if (glyphEnd == glyphStart + 1) {
// for the common case of a single-glyph clump, we can skip the following checks
break;
}
if (glyphEnd == glyphStart) {
// no glyphs, try to extend the clump
continue;
}
// check whether all glyphs in the range are associated with the characters
// in our clump; if not, we have a discontinuous range, and should extend it
// unless we've reached the end of the text
bool allGlyphsAreWithinCluster = true;
int32_t prevGlyphCharIndex = charStart;
for (int32_t i = glyphStart; i < glyphEnd; ++i) {
int32_t glyphCharIndex = glyphToChar[i] - stringRange.location;
if (isRightToLeft) {
if (glyphCharIndex > charStart || glyphCharIndex <= charEnd) {
allGlyphsAreWithinCluster = false;
break;
}
if (glyphCharIndex > prevGlyphCharIndex) {
inOrder = false;
}
prevGlyphCharIndex = glyphCharIndex;
} else {
if (glyphCharIndex < charStart || glyphCharIndex >= charEnd) {
allGlyphsAreWithinCluster = false;
break;
}
if (glyphCharIndex < prevGlyphCharIndex) {
inOrder = false;
}
prevGlyphCharIndex = glyphCharIndex;
}
}
if (allGlyphsAreWithinCluster) {
break;
}
} while (charEnd != charLimit);
NS_WARN_IF_FALSE(glyphStart < glyphEnd,
"character/glyph clump contains no glyphs!");
if (glyphStart == glyphEnd) {
++glyphStart; // make progress - avoid potential infinite loop
charStart = charEnd;
continue;
}
NS_WARN_IF_FALSE(charStart != charEnd,
"character/glyph clump contains no characters!");
if (charStart == charEnd) {
glyphStart = glyphEnd; // this is bad - we'll discard the glyph(s),
// as there's nowhere to attach them
continue;
}
// Now charStart..charEnd is a ligature clump, corresponding to glyphStart..glyphEnd;
// Set baseCharIndex to the char we'll actually attach the glyphs to (1st of ligature),
// and endCharIndex to the limit (position beyond the last char),
// adjusting for the offset of the stringRange relative to the textRun.
int32_t baseCharIndex, endCharIndex;
if (isRightToLeft) {
while (charEnd >= 0 && charToGlyph[charEnd] == NO_GLYPH) {
charEnd--;
}
baseCharIndex = charEnd + stringRange.location - aStringOffset + 1;
endCharIndex = charStart + stringRange.location - aStringOffset + 1;
} else {
while (charEnd < stringRange.length && charToGlyph[charEnd] == NO_GLYPH) {
charEnd++;
}
baseCharIndex = charStart + stringRange.location - aStringOffset;
endCharIndex = charEnd + stringRange.location - aStringOffset;
}
// Then we check if the clump falls outside our actual string range; if so, just go to the next.
if (endCharIndex <= 0 || baseCharIndex >= wordLength) {
glyphStart = glyphEnd;
charStart = charEnd;
continue;
}
// Ensure we won't try to go beyond the valid length of the word's text
baseCharIndex = std::max(baseCharIndex, 0);
endCharIndex = std::min(endCharIndex, wordLength);
// Now we're ready to set the glyph info in the textRun; measure the glyph width
// of the first (perhaps only) glyph, to see if it is "Simple"
int32_t appUnitsPerDevUnit = aShapedText->GetAppUnitsPerDevUnit();
double toNextGlyph;
if (glyphStart < numGlyphs-1) {
toNextGlyph = positions[glyphStart+1].x - positions[glyphStart].x;
} else {
toNextGlyph = positions[0].x + runWidth - positions[glyphStart].x;
}
int32_t advance = int32_t(toNextGlyph * appUnitsPerDevUnit);
// Check if it's a simple one-to-one mapping
int32_t glyphsInClump = glyphEnd - glyphStart;
if (glyphsInClump == 1 &&
gfxTextRun::CompressedGlyph::IsSimpleGlyphID(glyphs[glyphStart]) &&
gfxTextRun::CompressedGlyph::IsSimpleAdvance(advance) &&
charGlyphs[baseCharIndex].IsClusterStart() &&
positions[glyphStart].y == 0.0)
{
charGlyphs[baseCharIndex].SetSimpleGlyph(advance,
glyphs[glyphStart]);
} else {
// collect all glyphs in a list to be assigned to the first char;
// there must be at least one in the clump, and we already measured its advance,
// hence the placement of the loop-exit test and the measurement of the next glyph
while (1) {
gfxTextRun::DetailedGlyph *details = detailedGlyphs.AppendElement();
details->mGlyphID = glyphs[glyphStart];
details->mXOffset = 0;
details->mYOffset = -positions[glyphStart].y * appUnitsPerDevUnit;
details->mAdvance = advance;
if (++glyphStart >= glyphEnd) {
break;
}
if (glyphStart < numGlyphs-1) {
toNextGlyph = positions[glyphStart+1].x - positions[glyphStart].x;
} else {
toNextGlyph = positions[0].x + runWidth - positions[glyphStart].x;
}
advance = int32_t(toNextGlyph * appUnitsPerDevUnit);
}
gfxTextRun::CompressedGlyph g;
g.SetComplex(charGlyphs[baseCharIndex].IsClusterStart(),
true, detailedGlyphs.Length());
aShapedText->SetGlyphs(aOffset + baseCharIndex, g, detailedGlyphs.Elements());
detailedGlyphs.Clear();
}
// the rest of the chars in the group are ligature continuations, no associated glyphs
while (++baseCharIndex != endCharIndex && baseCharIndex < wordLength) {
gfxShapedText::CompressedGlyph &g = charGlyphs[baseCharIndex];
NS_ASSERTION(!g.IsSimpleGlyph(), "overwriting a simple glyph");
g.SetComplex(inOrder && g.IsClusterStart(), false, 0);
}
glyphStart = glyphEnd;
charStart = charEnd;
}
return NS_OK;
}
#undef SMALL_GLYPH_RUN
// Construct the font attribute descriptor that we'll apply by default when
// creating a CTFontRef. This will turn off line-edge swashes by default,
// because we don't know the actual line breaks when doing glyph shaping.
// We also cache feature descriptors for shaping with disabled ligatures, and
// for buggy Indic AAT font workarounds, created on an as-needed basis.
#define MAX_FEATURES 3 // max used by any of our Get*Descriptor functions
CTFontDescriptorRef
gfxCoreTextShaper::CreateFontFeaturesDescriptor(
const std::pair<SInt16,SInt16> aFeatures[],
size_t aCount)
{
MOZ_ASSERT(aCount <= MAX_FEATURES);
CFDictionaryRef featureSettings[MAX_FEATURES];
for (size_t i = 0; i < aCount; i++) {
CFNumberRef type = ::CFNumberCreate(kCFAllocatorDefault,
kCFNumberSInt16Type,
&aFeatures[i].first);
CFNumberRef selector = ::CFNumberCreate(kCFAllocatorDefault,
kCFNumberSInt16Type,
&aFeatures[i].second);
CFTypeRef keys[] = { kCTFontFeatureTypeIdentifierKey,
kCTFontFeatureSelectorIdentifierKey };
CFTypeRef values[] = { type, selector };
featureSettings[i] =
::CFDictionaryCreate(kCFAllocatorDefault,
(const void **) keys,
(const void **) values,
ArrayLength(keys),
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
::CFRelease(selector);
::CFRelease(type);
}
CFArrayRef featuresArray =
::CFArrayCreate(kCFAllocatorDefault,
(const void **) featureSettings,
aCount, // not ArrayLength(featureSettings), as we
// may not have used all the allocated slots
&kCFTypeArrayCallBacks);
for (size_t i = 0; i < aCount; i++) {
::CFRelease(featureSettings[i]);
}
const CFTypeRef attrKeys[] = { kCTFontFeatureSettingsAttribute };
const CFTypeRef attrValues[] = { featuresArray };
CFDictionaryRef attributesDict =
::CFDictionaryCreate(kCFAllocatorDefault,
(const void **) attrKeys,
(const void **) attrValues,
ArrayLength(attrKeys),
&kCFTypeDictionaryKeyCallBacks,
&kCFTypeDictionaryValueCallBacks);
::CFRelease(featuresArray);
CTFontDescriptorRef descriptor =
::CTFontDescriptorCreateWithAttributes(attributesDict);
::CFRelease(attributesDict);
return descriptor;
}
CTFontDescriptorRef
gfxCoreTextShaper::GetDefaultFeaturesDescriptor()
{
if (sDefaultFeaturesDescriptor == nullptr) {
const std::pair<SInt16,SInt16> kDefaultFeatures[] = {
{ kSmartSwashType, kLineInitialSwashesOffSelector },
{ kSmartSwashType, kLineFinalSwashesOffSelector }
};
sDefaultFeaturesDescriptor =
CreateFontFeaturesDescriptor(kDefaultFeatures,
ArrayLength(kDefaultFeatures));
}
return sDefaultFeaturesDescriptor;
}
CTFontDescriptorRef
gfxCoreTextShaper::GetDisableLigaturesDescriptor()
{
if (sDisableLigaturesDescriptor == nullptr) {
const std::pair<SInt16,SInt16> kDisableLigatures[] = {
{ kSmartSwashType, kLineInitialSwashesOffSelector },
{ kSmartSwashType, kLineFinalSwashesOffSelector },
{ kLigaturesType, kCommonLigaturesOffSelector }
};
sDisableLigaturesDescriptor =
CreateFontFeaturesDescriptor(kDisableLigatures,
ArrayLength(kDisableLigatures));
}
return sDisableLigaturesDescriptor;
}
CTFontDescriptorRef
gfxCoreTextShaper::GetIndicFeaturesDescriptor()
{
if (sIndicFeaturesDescriptor == nullptr) {
const std::pair<SInt16,SInt16> kIndicFeatures[] = {
{ kSmartSwashType, kLineFinalSwashesOffSelector }
};
sIndicFeaturesDescriptor =
CreateFontFeaturesDescriptor(kIndicFeatures,
ArrayLength(kIndicFeatures));
}
return sIndicFeaturesDescriptor;
}
CTFontDescriptorRef
gfxCoreTextShaper::GetIndicDisableLigaturesDescriptor()
{
if (sIndicDisableLigaturesDescriptor == nullptr) {
const std::pair<SInt16,SInt16> kIndicDisableLigatures[] = {
{ kSmartSwashType, kLineFinalSwashesOffSelector },
{ kLigaturesType, kCommonLigaturesOffSelector }
};
sIndicDisableLigaturesDescriptor =
CreateFontFeaturesDescriptor(kIndicDisableLigatures,
ArrayLength(kIndicDisableLigatures));
}
return sIndicDisableLigaturesDescriptor;
}
CTFontRef
gfxCoreTextShaper::CreateCTFontWithFeatures(CGFloat aSize,
CTFontDescriptorRef aDescriptor)
{
gfxMacFont *f = static_cast<gfxMacFont*>(mFont);
return ::CTFontCreateWithGraphicsFont(f->GetCGFontRef(), aSize, nullptr,
aDescriptor);
}
void
gfxCoreTextShaper::Shutdown() // [static]
{
if (sIndicDisableLigaturesDescriptor != nullptr) {
::CFRelease(sIndicDisableLigaturesDescriptor);
sIndicDisableLigaturesDescriptor = nullptr;
}
if (sIndicFeaturesDescriptor != nullptr) {
::CFRelease(sIndicFeaturesDescriptor);
sIndicFeaturesDescriptor = nullptr;
}
if (sDisableLigaturesDescriptor != nullptr) {
::CFRelease(sDisableLigaturesDescriptor);
sDisableLigaturesDescriptor = nullptr;
}
if (sDefaultFeaturesDescriptor != nullptr) {
::CFRelease(sDefaultFeaturesDescriptor);
sDefaultFeaturesDescriptor = nullptr;
}
}