/* -*- 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/Util.h" #include "nsAlgorithm.h" #include "prmem.h" #include "nsString.h" #include "nsBidiUtils.h" #include "gfxTypes.h" #include "nsPromiseFlatString.h" #include "gfxContext.h" #include "gfxPlatform.h" #include "gfxPlatformMac.h" #include "gfxCoreTextShaper.h" #include "gfxMacFont.h" #include "gfxFontTest.h" #include "gfxFontUtils.h" #include "gfxQuartzSurface.h" #include "gfxMacPlatformFontList.h" #include "gfxUserFontSet.h" #include "nsUnicodeRange.h" using namespace mozilla; // standard font descriptors that we construct the first time they're needed CTFontDescriptorRef gfxCoreTextShaper::sDefaultFeaturesDescriptor = NULL; CTFontDescriptorRef gfxCoreTextShaper::sDisableLigaturesDescriptor = NULL; gfxCoreTextShaper::gfxCoreTextShaper(gfxMacFont *aFont) : gfxFontShaper(aFont) { // Create our CTFontRef if (gfxMacPlatformFontList::UseATSFontEntry()) { ATSFontEntry *fe = static_cast(aFont->GetFontEntry()); mCTFont = ::CTFontCreateWithPlatformFont(fe->GetATSFontRef(), aFont->GetAdjustedSize(), NULL, GetDefaultFeaturesDescriptor()); } else { mCTFont = ::CTFontCreateWithGraphicsFont(aFont->GetCGFontRef(), aFont->GetAdjustedSize(), NULL, GetDefaultFeaturesDescriptor()); } // Set up the default attribute dictionary that we will need each time we create a CFAttributedString 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); } } bool gfxCoreTextShaper::ShapeWord(gfxContext *aContext, gfxShapedWord *aShapedWord, const PRUnichar *aText) { // Create a CFAttributedString with text and style info, so we can use CoreText to lay it out. bool isRightToLeft = aShapedWord->IsRightToLeft(); uint32_t length = aShapedWord->Length(); // 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 && !aShapedWord->TextIs8Bit()) { const PRUnichar *text = aShapedWord->TextUnicode(); uint32_t i; for (i = 0; i < length; ++i) { if (gfxFontUtils::PotentialRTLChar(text[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, aText, length); ::CFStringAppendCharacters(mutableString, endBidiWrap, mozilla::ArrayLength(endBidiWrap)); stringObj = mutableString; } else { startOffset = 0; stringObj = ::CFStringCreateWithCharactersNoCopy(kCFAllocatorDefault, aText, length, kCFAllocatorNull); } CFDictionaryRef attrObj; if (aShapedWord->DisableLigatures()) { // For letterspacing (or maybe other situations) we need to make a copy of the CTFont // with the ligature feature disabled CTFontRef ctFont = CreateCTFontWithDisabledLigatures(::CTFontGetSize(mCTFont)); attrObj = ::CFDictionaryCreate(kCFAllocatorDefault, (const void**) &kCTFontAttributeName, (const void**) &ctFont, 1, // count of attributes &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); // Having created the dict, we're finished with our ligature-disabled CTFontRef ::CFRelease(ctFont); } else { attrObj = mAttributesDict; ::CFRetain(attrObj); } // Now we can create an attributed string CFAttributedStringRef attrStringObj = ::CFAttributedStringCreate(kCFAllocatorDefault, stringObj, attrObj); ::CFRelease(stringObj); ::CFRelease(attrObj); // 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 (SetGlyphsFromRun(aShapedWord, aCTRun, startOffset) != NS_OK) { success = false; break; } } ::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(gfxShapedWord *aShapedWord, 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 = aShapedWord->IsRightToLeft() ? -1 : 1; int32_t numGlyphs = ::CTRunGetGlyphCount(aCTRun); if (numGlyphs == 0) { return NS_OK; } int32_t wordLength = aShapedWord->Length(); // 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 glyphsArray; nsAutoArrayPtr positionsArray; nsAutoArrayPtr glyphToCharArray; const CGGlyph* glyphs = NULL; const CGPoint* positions = NULL; const CFIndex* glyphToChar = NULL; // 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), NULL, NULL, NULL); nsAutoTArray detailedGlyphs; gfxTextRun::CompressedGlyph g; // 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; nsAutoTArray charToGlyphArray; if (!charToGlyphArray.SetLength(stringRange.length)) { 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 = aShapedWord->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 = NS_MAX(charEnd, 0); charEnd = NS_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 = NS_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 = NS_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 = NS_MAX(baseCharIndex, 0); endCharIndex = NS_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 = aShapedWord->AppUnitsPerDevUnit(); 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) && aShapedWord->IsClusterStart(baseCharIndex) && positions[glyphStart].y == 0.0) { aShapedWord->SetSimpleGlyph(baseCharIndex, g.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(aShapedWord->IsClusterStart(baseCharIndex), true, detailedGlyphs.Length()); aShapedWord->SetGlyphs(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) { g.SetComplex(inOrder && aShapedWord->IsClusterStart(baseCharIndex), false, 0); aShapedWord->SetGlyphs(baseCharIndex, g, nullptr); } glyphStart = glyphEnd; charStart = charEnd; } return NS_OK; } // 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. void gfxCoreTextShaper::CreateDefaultFeaturesDescriptor() { if (sDefaultFeaturesDescriptor != NULL) { return; } SInt16 val = kSmartSwashType; CFNumberRef swashesType = ::CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &val); val = kLineInitialSwashesOffSelector; CFNumberRef lineInitialsOffSelector = ::CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &val); CFTypeRef keys[] = { kCTFontFeatureTypeIdentifierKey, kCTFontFeatureSelectorIdentifierKey }; CFTypeRef values[] = { swashesType, lineInitialsOffSelector }; CFDictionaryRef featureSettings[2]; featureSettings[0] = ::CFDictionaryCreate(kCFAllocatorDefault, (const void **) keys, (const void **) values, ArrayLength(keys), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); ::CFRelease(lineInitialsOffSelector); val = kLineFinalSwashesOffSelector; CFNumberRef lineFinalsOffSelector = ::CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &val); values[1] = lineFinalsOffSelector; featureSettings[1] = ::CFDictionaryCreate(kCFAllocatorDefault, (const void **) keys, (const void **) values, ArrayLength(keys), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); ::CFRelease(lineFinalsOffSelector); ::CFRelease(swashesType); CFArrayRef featuresArray = ::CFArrayCreate(kCFAllocatorDefault, (const void **) featureSettings, ArrayLength(featureSettings), &kCFTypeArrayCallBacks); ::CFRelease(featureSettings[0]); ::CFRelease(featureSettings[1]); const CFTypeRef attrKeys[] = { kCTFontFeatureSettingsAttribute }; const CFTypeRef attrValues[] = { featuresArray }; CFDictionaryRef attributesDict = ::CFDictionaryCreate(kCFAllocatorDefault, (const void **) attrKeys, (const void **) attrValues, ArrayLength(attrKeys), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); ::CFRelease(featuresArray); sDefaultFeaturesDescriptor = ::CTFontDescriptorCreateWithAttributes(attributesDict); ::CFRelease(attributesDict); } // Create a CTFontRef, with the Common Ligatures feature disabled CTFontRef gfxCoreTextShaper::CreateCTFontWithDisabledLigatures(CGFloat aSize) { if (sDisableLigaturesDescriptor == NULL) { // initialize cached descriptor to turn off the Common Ligatures feature SInt16 val = kLigaturesType; CFNumberRef ligaturesType = ::CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &val); val = kCommonLigaturesOffSelector; CFNumberRef commonLigaturesOffSelector = ::CFNumberCreate(kCFAllocatorDefault, kCFNumberSInt16Type, &val); const CFTypeRef keys[] = { kCTFontFeatureTypeIdentifierKey, kCTFontFeatureSelectorIdentifierKey }; const CFTypeRef values[] = { ligaturesType, commonLigaturesOffSelector }; CFDictionaryRef featureSettingDict = ::CFDictionaryCreate(kCFAllocatorDefault, (const void **) keys, (const void **) values, ArrayLength(keys), &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); ::CFRelease(ligaturesType); ::CFRelease(commonLigaturesOffSelector); CFArrayRef featuresArray = ::CFArrayCreate(kCFAllocatorDefault, (const void **) &featureSettingDict, 1, &kCFTypeArrayCallBacks); ::CFRelease(featureSettingDict); CFDictionaryRef attributesDict = ::CFDictionaryCreate(kCFAllocatorDefault, (const void **) &kCTFontFeatureSettingsAttribute, (const void **) &featuresArray, 1, // count of keys & values &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks); ::CFRelease(featuresArray); sDisableLigaturesDescriptor = ::CTFontDescriptorCreateCopyWithAttributes(GetDefaultFeaturesDescriptor(), attributesDict); ::CFRelease(attributesDict); } if (gfxMacPlatformFontList::UseATSFontEntry()) { ATSFontEntry *fe = static_cast(mFont->GetFontEntry()); return ::CTFontCreateWithPlatformFont(fe->GetATSFontRef(), aSize, NULL, sDisableLigaturesDescriptor); } gfxMacFont *f = static_cast(mFont); return ::CTFontCreateWithGraphicsFont(f->GetCGFontRef(), aSize, NULL, sDisableLigaturesDescriptor); } void gfxCoreTextShaper::Shutdown() // [static] { if (sDisableLigaturesDescriptor != NULL) { ::CFRelease(sDisableLigaturesDescriptor); sDisableLigaturesDescriptor = NULL; } if (sDefaultFeaturesDescriptor != NULL) { ::CFRelease(sDefaultFeaturesDescriptor); sDefaultFeaturesDescriptor = NULL; } }