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-rw-r--r--gfx/thebes/gfxHarfBuzzShaper.cpp1724
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diff --git a/gfx/thebes/gfxHarfBuzzShaper.cpp b/gfx/thebes/gfxHarfBuzzShaper.cpp
new file mode 100644
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+++ b/gfx/thebes/gfxHarfBuzzShaper.cpp
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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/. */
+
+#include "nsString.h"
+#include "gfxContext.h"
+#include "gfxFontConstants.h"
+#include "gfxHarfBuzzShaper.h"
+#include "gfxFontUtils.h"
+#include "gfxTextRun.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/intl/String.h"
+#include "mozilla/intl/UnicodeProperties.h"
+#include "mozilla/intl/UnicodeScriptCodes.h"
+#include "nsUnicodeProperties.h"
+
+#include "harfbuzz/hb.h"
+#include "harfbuzz/hb-ot.h"
+
+#include <algorithm>
+
+#define FloatToFixed(f) (65536 * (f))
+#define FixedToFloat(f) ((f) * (1.0 / 65536.0))
+// Right shifts of negative (signed) integers are undefined, as are overflows
+// when converting unsigned to negative signed integers.
+// (If speed were an issue we could make some 2's complement assumptions.)
+#define FixedToIntRound(f) \
+ ((f) > 0 ? ((32768 + (f)) >> 16) : -((32767 - (f)) >> 16))
+
+using namespace mozilla; // for AutoSwap_* types
+using namespace mozilla::unicode; // for Unicode property lookup
+
+/*
+ * Creation and destruction; on deletion, release any font tables we're holding
+ */
+
+gfxHarfBuzzShaper::gfxHarfBuzzShaper(gfxFont* aFont)
+ : gfxFontShaper(aFont),
+ mHBFont(nullptr),
+ mBuffer(nullptr),
+ mCallbackData(),
+ mKernTable(nullptr),
+ mHmtxTable(nullptr),
+ mVmtxTable(nullptr),
+ mVORGTable(nullptr),
+ mLocaTable(nullptr),
+ mGlyfTable(nullptr),
+ mCmapTable(nullptr),
+ mCmapFormat(-1),
+ mSubtableOffset(0),
+ mUVSTableOffset(0),
+ mNumLongHMetrics(0),
+ mNumLongVMetrics(0),
+ mDefaultVOrg(-1.0),
+ mUseFontGetGlyph(aFont->ProvidesGetGlyph()),
+ mIsSymbolFont(false),
+ mUseFontGlyphWidths(aFont->ProvidesGlyphWidths()),
+ mInitialized(false),
+ mVerticalInitialized(false),
+ mUseVerticalPresentationForms(false),
+ mLoadedLocaGlyf(false),
+ mLocaLongOffsets(false) {}
+
+gfxHarfBuzzShaper::~gfxHarfBuzzShaper() {
+ // hb_*_destroy functions are safe to call on nullptr
+ hb_blob_destroy(mCmapTable);
+ hb_blob_destroy(mHmtxTable);
+ hb_blob_destroy(mKernTable);
+ hb_blob_destroy(mVmtxTable);
+ hb_blob_destroy(mVORGTable);
+ hb_blob_destroy(mLocaTable);
+ hb_blob_destroy(mGlyfTable);
+ hb_font_destroy(mHBFont);
+ hb_buffer_destroy(mBuffer);
+}
+
+#define UNICODE_BMP_LIMIT 0x10000
+
+hb_codepoint_t gfxHarfBuzzShaper::GetNominalGlyph(
+ hb_codepoint_t unicode) const {
+ hb_codepoint_t gid = 0;
+
+ if (mUseFontGetGlyph) {
+ gid = mFont->GetGlyph(unicode, 0);
+ } else {
+ // we only instantiate a harfbuzz shaper if there's a cmap available
+ NS_ASSERTION(mCmapTable && (mCmapFormat > 0) && (mSubtableOffset > 0),
+ "cmap data not correctly set up, expect disaster");
+
+ uint32_t length;
+ const uint8_t* data = (const uint8_t*)hb_blob_get_data(mCmapTable, &length);
+
+ switch (mCmapFormat) {
+ case 4:
+ gid =
+ unicode < UNICODE_BMP_LIMIT
+ ? gfxFontUtils::MapCharToGlyphFormat4(
+ data + mSubtableOffset, length - mSubtableOffset, unicode)
+ : 0;
+ break;
+ case 10:
+ gid = gfxFontUtils::MapCharToGlyphFormat10(data + mSubtableOffset,
+ unicode);
+ break;
+ case 12:
+ case 13:
+ gid = gfxFontUtils::MapCharToGlyphFormat12or13(data + mSubtableOffset,
+ unicode);
+ break;
+ default:
+ NS_WARNING("unsupported cmap format, glyphs will be missing");
+ break;
+ }
+ }
+
+ if (!gid) {
+ if (mIsSymbolFont) {
+ // For legacy MS Symbol fonts, we try mapping the given character code
+ // to the PUA range used by these fonts' cmaps.
+ if (auto pua = gfxFontUtils::MapLegacySymbolFontCharToPUA(unicode)) {
+ gid = GetNominalGlyph(pua);
+ }
+ if (gid) {
+ return gid;
+ }
+ }
+ switch (unicode) {
+ case 0xA0:
+ // if there's no glyph for &nbsp;, just use the space glyph instead.
+ gid = mFont->GetSpaceGlyph();
+ break;
+ case 0x2010:
+ case 0x2011:
+ // For Unicode HYPHEN and NON-BREAKING HYPHEN, fall back to the ASCII
+ // HYPHEN-MINUS as a substitute.
+ gid = GetNominalGlyph('-');
+ break;
+ }
+ }
+
+ return gid;
+}
+
+hb_codepoint_t gfxHarfBuzzShaper::GetVariationGlyph(
+ hb_codepoint_t unicode, hb_codepoint_t variation_selector) const {
+ if (mUseFontGetGlyph) {
+ return mFont->GetGlyph(unicode, variation_selector);
+ }
+
+ NS_ASSERTION(mFont->GetFontEntry()->HasCmapTable(),
+ "we cannot be using this font!");
+ NS_ASSERTION(mCmapTable && (mCmapFormat > 0) && (mSubtableOffset > 0),
+ "cmap data not correctly set up, expect disaster");
+
+ uint32_t length;
+ const uint8_t* data = (const uint8_t*)hb_blob_get_data(mCmapTable, &length);
+
+ if (mUVSTableOffset) {
+ hb_codepoint_t gid = gfxFontUtils::MapUVSToGlyphFormat14(
+ data + mUVSTableOffset, unicode, variation_selector);
+ if (gid) {
+ return gid;
+ }
+ }
+
+ uint32_t compat = gfxFontUtils::GetUVSFallback(unicode, variation_selector);
+ if (compat) {
+ switch (mCmapFormat) {
+ case 4:
+ if (compat < UNICODE_BMP_LIMIT) {
+ return gfxFontUtils::MapCharToGlyphFormat4(
+ data + mSubtableOffset, length - mSubtableOffset, compat);
+ }
+ break;
+ case 10:
+ return gfxFontUtils::MapCharToGlyphFormat10(data + mSubtableOffset,
+ compat);
+ break;
+ case 12:
+ case 13:
+ return gfxFontUtils::MapCharToGlyphFormat12or13(data + mSubtableOffset,
+ compat);
+ break;
+ }
+ }
+
+ return 0;
+}
+
+static int VertFormsGlyphCompare(const void* aKey, const void* aElem) {
+ return int(*((hb_codepoint_t*)(aKey))) - int(*((uint16_t*)(aElem)));
+}
+
+// Return a vertical presentation-form codepoint corresponding to the
+// given Unicode value, or 0 if no such form is available.
+hb_codepoint_t gfxHarfBuzzShaper::GetVerticalPresentationForm(
+ hb_codepoint_t aUnicode) {
+ static const uint16_t sVerticalForms[][2] = {
+ {0x2013, 0xfe32}, // EN DASH
+ {0x2014, 0xfe31}, // EM DASH
+ {0x2025, 0xfe30}, // TWO DOT LEADER
+ {0x2026, 0xfe19}, // HORIZONTAL ELLIPSIS
+ {0x3001, 0xfe11}, // IDEOGRAPHIC COMMA
+ {0x3002, 0xfe12}, // IDEOGRAPHIC FULL STOP
+ {0x3008, 0xfe3f}, // LEFT ANGLE BRACKET
+ {0x3009, 0xfe40}, // RIGHT ANGLE BRACKET
+ {0x300a, 0xfe3d}, // LEFT DOUBLE ANGLE BRACKET
+ {0x300b, 0xfe3e}, // RIGHT DOUBLE ANGLE BRACKET
+ {0x300c, 0xfe41}, // LEFT CORNER BRACKET
+ {0x300d, 0xfe42}, // RIGHT CORNER BRACKET
+ {0x300e, 0xfe43}, // LEFT WHITE CORNER BRACKET
+ {0x300f, 0xfe44}, // RIGHT WHITE CORNER BRACKET
+ {0x3010, 0xfe3b}, // LEFT BLACK LENTICULAR BRACKET
+ {0x3011, 0xfe3c}, // RIGHT BLACK LENTICULAR BRACKET
+ {0x3014, 0xfe39}, // LEFT TORTOISE SHELL BRACKET
+ {0x3015, 0xfe3a}, // RIGHT TORTOISE SHELL BRACKET
+ {0x3016, 0xfe17}, // LEFT WHITE LENTICULAR BRACKET
+ {0x3017, 0xfe18}, // RIGHT WHITE LENTICULAR BRACKET
+ {0xfe4f, 0xfe34}, // WAVY LOW LINE
+ {0xff01, 0xfe15}, // FULLWIDTH EXCLAMATION MARK
+ {0xff08, 0xfe35}, // FULLWIDTH LEFT PARENTHESIS
+ {0xff09, 0xfe36}, // FULLWIDTH RIGHT PARENTHESIS
+ {0xff0c, 0xfe10}, // FULLWIDTH COMMA
+ {0xff1a, 0xfe13}, // FULLWIDTH COLON
+ {0xff1b, 0xfe14}, // FULLWIDTH SEMICOLON
+ {0xff1f, 0xfe16}, // FULLWIDTH QUESTION MARK
+ {0xff3b, 0xfe47}, // FULLWIDTH LEFT SQUARE BRACKET
+ {0xff3d, 0xfe48}, // FULLWIDTH RIGHT SQUARE BRACKET
+ {0xff3f, 0xfe33}, // FULLWIDTH LOW LINE
+ {0xff5b, 0xfe37}, // FULLWIDTH LEFT CURLY BRACKET
+ {0xff5d, 0xfe38} // FULLWIDTH RIGHT CURLY BRACKET
+ };
+ const uint16_t* charPair = static_cast<const uint16_t*>(
+ bsearch(&aUnicode, sVerticalForms, ArrayLength(sVerticalForms),
+ sizeof(sVerticalForms[0]), VertFormsGlyphCompare));
+ return charPair ? charPair[1] : 0;
+}
+
+static hb_bool_t HBGetNominalGlyph(hb_font_t* font, void* font_data,
+ hb_codepoint_t unicode,
+ hb_codepoint_t* glyph, void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+
+ if (fcd->mShaper->UseVerticalPresentationForms()) {
+ hb_codepoint_t verticalForm =
+ gfxHarfBuzzShaper::GetVerticalPresentationForm(unicode);
+ if (verticalForm) {
+ *glyph = fcd->mShaper->GetNominalGlyph(verticalForm);
+ if (*glyph != 0) {
+ return true;
+ }
+ }
+ // fall back to the non-vertical form if we didn't find an alternate
+ }
+
+ *glyph = fcd->mShaper->GetNominalGlyph(unicode);
+ return *glyph != 0;
+}
+
+static hb_bool_t HBGetVariationGlyph(hb_font_t* font, void* font_data,
+ hb_codepoint_t unicode,
+ hb_codepoint_t variation_selector,
+ hb_codepoint_t* glyph, void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+
+ if (fcd->mShaper->UseVerticalPresentationForms()) {
+ hb_codepoint_t verticalForm =
+ gfxHarfBuzzShaper::GetVerticalPresentationForm(unicode);
+ if (verticalForm) {
+ *glyph =
+ fcd->mShaper->GetVariationGlyph(verticalForm, variation_selector);
+ if (*glyph != 0) {
+ return true;
+ }
+ }
+ // fall back to the non-vertical form if we didn't find an alternate
+ }
+
+ *glyph = fcd->mShaper->GetVariationGlyph(unicode, variation_selector);
+ return *glyph != 0;
+}
+
+// Glyph metrics structures, shared (with appropriate reinterpretation of
+// field names) by horizontal and vertical metrics tables.
+struct LongMetric {
+ AutoSwap_PRUint16 advanceWidth; // or advanceHeight, when vertical
+ AutoSwap_PRInt16 lsb; // or tsb, when vertical
+};
+
+struct GlyphMetrics {
+ LongMetric metrics[1]; // actually numberOfLongMetrics
+ // the variable-length metrics[] array is immediately followed by:
+ // AutoSwap_PRUint16 leftSideBearing[];
+};
+
+hb_position_t gfxHarfBuzzShaper::GetGlyphHAdvance(hb_codepoint_t glyph) const {
+ // font did not implement GetGlyphWidth, so get an unhinted value
+ // directly from the font tables
+
+ NS_ASSERTION((mNumLongHMetrics > 0) && mHmtxTable != nullptr,
+ "font is lacking metrics, we shouldn't be here");
+
+ if (glyph >= uint32_t(mNumLongHMetrics)) {
+ glyph = mNumLongHMetrics - 1;
+ }
+
+ // glyph must be valid now, because we checked during initialization
+ // that mNumLongHMetrics is > 0, and that the metrics table is large enough
+ // to contain mNumLongHMetrics records
+ const ::GlyphMetrics* metrics = reinterpret_cast<const ::GlyphMetrics*>(
+ hb_blob_get_data(mHmtxTable, nullptr));
+ return FloatToFixed(mFont->FUnitsToDevUnitsFactor() *
+ uint16_t(metrics->metrics[glyph].advanceWidth));
+}
+
+hb_position_t gfxHarfBuzzShaper::GetGlyphVAdvance(hb_codepoint_t glyph) {
+ InitializeVertical();
+
+ if (!mVmtxTable) {
+ // Must be a "vertical" font that doesn't actually have vertical metrics.
+ // Return an invalid (negative) value to tell the caller to fall back to
+ // something else.
+ return -1;
+ }
+
+ NS_ASSERTION(mNumLongVMetrics > 0,
+ "font is lacking metrics, we shouldn't be here");
+
+ if (glyph >= uint32_t(mNumLongVMetrics)) {
+ glyph = mNumLongVMetrics - 1;
+ }
+
+ // glyph must be valid now, because we checked during initialization
+ // that mNumLongVMetrics is > 0, and that the metrics table is large enough
+ // to contain mNumLongVMetrics records
+ const ::GlyphMetrics* metrics = reinterpret_cast<const ::GlyphMetrics*>(
+ hb_blob_get_data(mVmtxTable, nullptr));
+ return FloatToFixed(mFont->FUnitsToDevUnitsFactor() *
+ uint16_t(metrics->metrics[glyph].advanceWidth));
+}
+
+/* static */
+hb_position_t gfxHarfBuzzShaper::HBGetGlyphHAdvance(hb_font_t* font,
+ void* font_data,
+ hb_codepoint_t glyph,
+ void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+ const gfxHarfBuzzShaper* shaper = fcd->mShaper;
+ if (shaper->mUseFontGlyphWidths) {
+ return shaper->GetFont()->GetGlyphWidth(glyph);
+ }
+ return shaper->GetGlyphHAdvance(glyph);
+}
+
+/* static */
+hb_position_t gfxHarfBuzzShaper::HBGetGlyphVAdvance(hb_font_t* font,
+ void* font_data,
+ hb_codepoint_t glyph,
+ void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+ // Currently, we don't offer gfxFont subclasses a method to override this
+ // and provide hinted platform-specific vertical advances (analogous to the
+ // GetGlyphWidth method for horizontal advances). If that proves necessary,
+ // we'll add a new gfxFont method and call it from here.
+ hb_position_t advance = fcd->mShaper->GetGlyphVAdvance(glyph);
+ if (advance < 0) {
+ // Not available (e.g. broken metrics in the font); use a fallback value.
+ advance = FloatToFixed(fcd->mShaper->GetFont()
+ ->GetMetrics(nsFontMetrics::eVertical)
+ .aveCharWidth);
+ }
+ // We negate the value from GetGlyphVAdvance here because harfbuzz shapes
+ // with a coordinate system where positive is upwards, whereas the inline
+ // direction in which glyphs advance is downwards.
+ return -advance;
+}
+
+struct VORG {
+ AutoSwap_PRUint16 majorVersion;
+ AutoSwap_PRUint16 minorVersion;
+ AutoSwap_PRInt16 defaultVertOriginY;
+ AutoSwap_PRUint16 numVertOriginYMetrics;
+};
+
+struct VORGrec {
+ AutoSwap_PRUint16 glyphIndex;
+ AutoSwap_PRInt16 vertOriginY;
+};
+
+/* static */
+hb_bool_t gfxHarfBuzzShaper::HBGetGlyphVOrigin(hb_font_t* font, void* font_data,
+ hb_codepoint_t glyph,
+ hb_position_t* x,
+ hb_position_t* y,
+ void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+ fcd->mShaper->GetGlyphVOrigin(glyph, x, y);
+ return true;
+}
+
+void gfxHarfBuzzShaper::GetGlyphVOrigin(hb_codepoint_t aGlyph,
+ hb_position_t* aX,
+ hb_position_t* aY) const {
+ *aX = 0.5 * (mUseFontGlyphWidths ? mFont->GetGlyphWidth(aGlyph)
+ : GetGlyphHAdvance(aGlyph));
+
+ if (mVORGTable) {
+ // We checked in Initialize() that the VORG table is safely readable,
+ // so no length/bounds-check needed here.
+ const VORG* vorg =
+ reinterpret_cast<const VORG*>(hb_blob_get_data(mVORGTable, nullptr));
+
+ const VORGrec* lo = reinterpret_cast<const VORGrec*>(vorg + 1);
+ const VORGrec* hi = lo + uint16_t(vorg->numVertOriginYMetrics);
+ const VORGrec* limit = hi;
+ while (lo < hi) {
+ const VORGrec* mid = lo + (hi - lo) / 2;
+ if (uint16_t(mid->glyphIndex) < aGlyph) {
+ lo = mid + 1;
+ } else {
+ hi = mid;
+ }
+ }
+
+ if (lo < limit && uint16_t(lo->glyphIndex) == aGlyph) {
+ *aY = FloatToFixed(GetFont()->FUnitsToDevUnitsFactor() *
+ int16_t(lo->vertOriginY));
+ } else {
+ *aY = FloatToFixed(GetFont()->FUnitsToDevUnitsFactor() *
+ int16_t(vorg->defaultVertOriginY));
+ }
+ return;
+ }
+
+ if (mVmtxTable) {
+ bool emptyGlyf;
+ const Glyf* glyf = FindGlyf(aGlyph, &emptyGlyf);
+ if (glyf) {
+ if (emptyGlyf) {
+ *aY = 0;
+ return;
+ }
+
+ const ::GlyphMetrics* metrics = reinterpret_cast<const ::GlyphMetrics*>(
+ hb_blob_get_data(mVmtxTable, nullptr));
+ int16_t lsb;
+ if (aGlyph < hb_codepoint_t(mNumLongVMetrics)) {
+ // Glyph is covered by the first (advance & sidebearing) array
+ lsb = int16_t(metrics->metrics[aGlyph].lsb);
+ } else {
+ // Glyph is covered by the second (sidebearing-only) array
+ const AutoSwap_PRInt16* sidebearings =
+ reinterpret_cast<const AutoSwap_PRInt16*>(
+ &metrics->metrics[mNumLongVMetrics]);
+ lsb = int16_t(sidebearings[aGlyph - mNumLongVMetrics]);
+ }
+ *aY = FloatToFixed(mFont->FUnitsToDevUnitsFactor() *
+ (lsb + int16_t(glyf->yMax)));
+ return;
+ } else {
+ // XXX TODO: not a truetype font; need to get glyph extents
+ // via some other API?
+ // For now, fall through to default code below.
+ }
+ }
+
+ if (mDefaultVOrg < 0.0) {
+ // XXX should we consider using OS/2 sTypo* metrics if available?
+
+ gfxFontEntry::AutoTable hheaTable(GetFont()->GetFontEntry(),
+ TRUETYPE_TAG('h', 'h', 'e', 'a'));
+ if (hheaTable) {
+ uint32_t len;
+ const MetricsHeader* hhea = reinterpret_cast<const MetricsHeader*>(
+ hb_blob_get_data(hheaTable, &len));
+ if (len >= sizeof(MetricsHeader)) {
+ // divide up the default advance we're using (1em) in proportion
+ // to ascender:descender from the hhea table
+ int16_t a = int16_t(hhea->ascender);
+ int16_t d = int16_t(hhea->descender);
+ mDefaultVOrg = FloatToFixed(GetFont()->GetAdjustedSize() * a / (a - d));
+ }
+ }
+
+ if (mDefaultVOrg < 0.0) {
+ // Last resort, for non-sfnt fonts: get the horizontal metrics and
+ // compute a default VOrg from their ascent and descent.
+ const gfxFont::Metrics& mtx = mFont->GetHorizontalMetrics();
+ gfxFloat advance =
+ mFont->GetMetrics(nsFontMetrics::eVertical).aveCharWidth;
+ gfxFloat ascent = mtx.emAscent;
+ gfxFloat height = ascent + mtx.emDescent;
+ // vOrigin that will place the glyph so that its origin is shifted
+ // down most of the way within overall (vertical) advance, in
+ // proportion to the font ascent as a part of the overall font
+ // height.
+ mDefaultVOrg = FloatToFixed(advance * ascent / height);
+ }
+ }
+
+ *aY = mDefaultVOrg;
+}
+
+static hb_bool_t HBGetGlyphExtents(hb_font_t* font, void* font_data,
+ hb_codepoint_t glyph,
+ hb_glyph_extents_t* extents,
+ void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+ return fcd->mShaper->GetGlyphExtents(glyph, extents);
+}
+
+// Find the data for glyph ID |aGlyph| in the 'glyf' table, if present.
+// Returns null if not found, otherwise pointer to the beginning of the
+// glyph's data. Sets aEmptyGlyf true if there is no actual data;
+// otherwise, it's guaranteed that we can read at least the bounding box.
+const gfxHarfBuzzShaper::Glyf* gfxHarfBuzzShaper::FindGlyf(
+ hb_codepoint_t aGlyph, bool* aEmptyGlyf) const {
+ if (!mLoadedLocaGlyf) {
+ mLoadedLocaGlyf = true; // only try this once; if it fails, this
+ // isn't a truetype font
+ gfxFontEntry* entry = mFont->GetFontEntry();
+ uint32_t len;
+ gfxFontEntry::AutoTable headTable(entry, TRUETYPE_TAG('h', 'e', 'a', 'd'));
+ if (!headTable) {
+ return nullptr;
+ }
+ const HeadTable* head =
+ reinterpret_cast<const HeadTable*>(hb_blob_get_data(headTable, &len));
+ if (len < sizeof(HeadTable)) {
+ return nullptr;
+ }
+ mLocaLongOffsets = int16_t(head->indexToLocFormat) > 0;
+ mLocaTable = entry->GetFontTable(TRUETYPE_TAG('l', 'o', 'c', 'a'));
+ mGlyfTable = entry->GetFontTable(TRUETYPE_TAG('g', 'l', 'y', 'f'));
+ }
+
+ if (!mLocaTable || !mGlyfTable) {
+ // it's not a truetype font
+ return nullptr;
+ }
+
+ uint32_t offset; // offset of glyph record in the 'glyf' table
+ uint32_t len;
+ const char* data = hb_blob_get_data(mLocaTable, &len);
+ if (mLocaLongOffsets) {
+ if ((aGlyph + 1) * sizeof(AutoSwap_PRUint32) > len) {
+ return nullptr;
+ }
+ const AutoSwap_PRUint32* offsets =
+ reinterpret_cast<const AutoSwap_PRUint32*>(data);
+ offset = offsets[aGlyph];
+ *aEmptyGlyf = (offset == uint16_t(offsets[aGlyph + 1]));
+ } else {
+ if ((aGlyph + 1) * sizeof(AutoSwap_PRUint16) > len) {
+ return nullptr;
+ }
+ const AutoSwap_PRUint16* offsets =
+ reinterpret_cast<const AutoSwap_PRUint16*>(data);
+ offset = uint16_t(offsets[aGlyph]);
+ *aEmptyGlyf = (offset == uint16_t(offsets[aGlyph + 1]));
+ offset *= 2;
+ }
+
+ data = hb_blob_get_data(mGlyfTable, &len);
+ if (offset + sizeof(Glyf) > len) {
+ return nullptr;
+ }
+
+ return reinterpret_cast<const Glyf*>(data + offset);
+}
+
+hb_bool_t gfxHarfBuzzShaper::GetGlyphExtents(
+ hb_codepoint_t aGlyph, hb_glyph_extents_t* aExtents) const {
+ bool emptyGlyf;
+ const Glyf* glyf = FindGlyf(aGlyph, &emptyGlyf);
+ if (!glyf) {
+ // TODO: for non-truetype fonts, get extents some other way?
+ return false;
+ }
+
+ if (emptyGlyf) {
+ aExtents->x_bearing = 0;
+ aExtents->y_bearing = 0;
+ aExtents->width = 0;
+ aExtents->height = 0;
+ return true;
+ }
+
+ double f = mFont->FUnitsToDevUnitsFactor();
+ aExtents->x_bearing = FloatToFixed(int16_t(glyf->xMin) * f);
+ aExtents->width =
+ FloatToFixed((int16_t(glyf->xMax) - int16_t(glyf->xMin)) * f);
+
+ // Our y-coordinates are positive-downwards, whereas harfbuzz assumes
+ // positive-upwards; hence the apparently-reversed subtractions here.
+ aExtents->y_bearing = FloatToFixed(int16_t(glyf->yMax) * f -
+ mFont->GetHorizontalMetrics().emAscent);
+ aExtents->height =
+ FloatToFixed((int16_t(glyf->yMin) - int16_t(glyf->yMax)) * f);
+
+ return true;
+}
+
+static hb_bool_t HBGetContourPoint(hb_font_t* font, void* font_data,
+ unsigned int point_index,
+ hb_codepoint_t glyph, hb_position_t* x,
+ hb_position_t* y, void* user_data) {
+ /* not yet implemented - no support for used of hinted contour points
+ to fine-tune anchor positions in GPOS AnchorFormat2 */
+ return false;
+}
+
+struct KernHeaderFmt0 {
+ AutoSwap_PRUint16 nPairs;
+ AutoSwap_PRUint16 searchRange;
+ AutoSwap_PRUint16 entrySelector;
+ AutoSwap_PRUint16 rangeShift;
+};
+
+struct KernPair {
+ AutoSwap_PRUint16 left;
+ AutoSwap_PRUint16 right;
+ AutoSwap_PRInt16 value;
+};
+
+// Find a kern pair in a Format 0 subtable.
+// The aSubtable parameter points to the subtable itself, NOT its header,
+// as the header structure differs between Windows and Mac (v0 and v1.0)
+// versions of the 'kern' table.
+// aSubtableLen is the length of the subtable EXCLUDING its header.
+// If the pair <aFirstGlyph,aSecondGlyph> is found, the kerning value is
+// added to aValue, so that multiple subtables can accumulate a total
+// kerning value for a given pair.
+static void GetKernValueFmt0(const void* aSubtable, uint32_t aSubtableLen,
+ uint16_t aFirstGlyph, uint16_t aSecondGlyph,
+ int32_t& aValue, bool aIsOverride = false,
+ bool aIsMinimum = false) {
+ const KernHeaderFmt0* hdr =
+ reinterpret_cast<const KernHeaderFmt0*>(aSubtable);
+
+ const KernPair* lo = reinterpret_cast<const KernPair*>(hdr + 1);
+ const KernPair* hi = lo + uint16_t(hdr->nPairs);
+ const KernPair* limit = hi;
+
+ if (reinterpret_cast<const char*>(aSubtable) + aSubtableLen <
+ reinterpret_cast<const char*>(hi)) {
+ // subtable is not large enough to contain the claimed number
+ // of kern pairs, so just ignore it
+ return;
+ }
+
+#define KERN_PAIR_KEY(l, r) (uint32_t((uint16_t(l) << 16) + uint16_t(r)))
+
+ uint32_t key = KERN_PAIR_KEY(aFirstGlyph, aSecondGlyph);
+ while (lo < hi) {
+ const KernPair* mid = lo + (hi - lo) / 2;
+ if (KERN_PAIR_KEY(mid->left, mid->right) < key) {
+ lo = mid + 1;
+ } else {
+ hi = mid;
+ }
+ }
+
+ if (lo < limit && KERN_PAIR_KEY(lo->left, lo->right) == key) {
+ if (aIsOverride) {
+ aValue = int16_t(lo->value);
+ } else if (aIsMinimum) {
+ aValue = std::max(aValue, int32_t(lo->value));
+ } else {
+ aValue += int16_t(lo->value);
+ }
+ }
+}
+
+// Get kerning value from Apple (version 1.0) kern table,
+// subtable format 2 (simple N x M array of kerning values)
+
+// See http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html
+// for details of version 1.0 format 2 subtable.
+
+struct KernHeaderVersion1Fmt2 {
+ KernTableSubtableHeaderVersion1 header;
+ AutoSwap_PRUint16 rowWidth;
+ AutoSwap_PRUint16 leftOffsetTable;
+ AutoSwap_PRUint16 rightOffsetTable;
+ AutoSwap_PRUint16 array;
+};
+
+struct KernClassTableHdr {
+ AutoSwap_PRUint16 firstGlyph;
+ AutoSwap_PRUint16 nGlyphs;
+ AutoSwap_PRUint16 offsets[1]; // actually an array of nGlyphs entries
+};
+
+static int16_t GetKernValueVersion1Fmt2(const void* aSubtable,
+ uint32_t aSubtableLen,
+ uint16_t aFirstGlyph,
+ uint16_t aSecondGlyph) {
+ if (aSubtableLen < sizeof(KernHeaderVersion1Fmt2)) {
+ return 0;
+ }
+
+ const char* base = reinterpret_cast<const char*>(aSubtable);
+ const char* subtableEnd = base + aSubtableLen;
+
+ const KernHeaderVersion1Fmt2* h =
+ reinterpret_cast<const KernHeaderVersion1Fmt2*>(aSubtable);
+ uint32_t offset = h->array;
+
+ const KernClassTableHdr* leftClassTable =
+ reinterpret_cast<const KernClassTableHdr*>(base +
+ uint16_t(h->leftOffsetTable));
+ if (reinterpret_cast<const char*>(leftClassTable) +
+ sizeof(KernClassTableHdr) >
+ subtableEnd) {
+ return 0;
+ }
+ if (aFirstGlyph >= uint16_t(leftClassTable->firstGlyph)) {
+ aFirstGlyph -= uint16_t(leftClassTable->firstGlyph);
+ if (aFirstGlyph < uint16_t(leftClassTable->nGlyphs)) {
+ if (reinterpret_cast<const char*>(leftClassTable) +
+ sizeof(KernClassTableHdr) + aFirstGlyph * sizeof(uint16_t) >=
+ subtableEnd) {
+ return 0;
+ }
+ offset = uint16_t(leftClassTable->offsets[aFirstGlyph]);
+ }
+ }
+
+ const KernClassTableHdr* rightClassTable =
+ reinterpret_cast<const KernClassTableHdr*>(base +
+ uint16_t(h->rightOffsetTable));
+ if (reinterpret_cast<const char*>(rightClassTable) +
+ sizeof(KernClassTableHdr) >
+ subtableEnd) {
+ return 0;
+ }
+ if (aSecondGlyph >= uint16_t(rightClassTable->firstGlyph)) {
+ aSecondGlyph -= uint16_t(rightClassTable->firstGlyph);
+ if (aSecondGlyph < uint16_t(rightClassTable->nGlyphs)) {
+ if (reinterpret_cast<const char*>(rightClassTable) +
+ sizeof(KernClassTableHdr) + aSecondGlyph * sizeof(uint16_t) >=
+ subtableEnd) {
+ return 0;
+ }
+ offset += uint16_t(rightClassTable->offsets[aSecondGlyph]);
+ }
+ }
+
+ const AutoSwap_PRInt16* pval =
+ reinterpret_cast<const AutoSwap_PRInt16*>(base + offset);
+ if (reinterpret_cast<const char*>(pval + 1) >= subtableEnd) {
+ return 0;
+ }
+ return *pval;
+}
+
+// Get kerning value from Apple (version 1.0) kern table,
+// subtable format 3 (simple N x M array of kerning values)
+
+// See http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html
+// for details of version 1.0 format 3 subtable.
+
+struct KernHeaderVersion1Fmt3 {
+ KernTableSubtableHeaderVersion1 header;
+ AutoSwap_PRUint16 glyphCount;
+ uint8_t kernValueCount;
+ uint8_t leftClassCount;
+ uint8_t rightClassCount;
+ uint8_t flags;
+};
+
+static int16_t GetKernValueVersion1Fmt3(const void* aSubtable,
+ uint32_t aSubtableLen,
+ uint16_t aFirstGlyph,
+ uint16_t aSecondGlyph) {
+ // check that we can safely read the header fields
+ if (aSubtableLen < sizeof(KernHeaderVersion1Fmt3)) {
+ return 0;
+ }
+
+ const KernHeaderVersion1Fmt3* hdr =
+ reinterpret_cast<const KernHeaderVersion1Fmt3*>(aSubtable);
+ if (hdr->flags != 0) {
+ return 0;
+ }
+
+ uint16_t glyphCount = hdr->glyphCount;
+
+ // check that table is large enough for the arrays
+ if (sizeof(KernHeaderVersion1Fmt3) + hdr->kernValueCount * sizeof(int16_t) +
+ glyphCount + glyphCount + hdr->leftClassCount * hdr->rightClassCount >
+ aSubtableLen) {
+ return 0;
+ }
+
+ if (aFirstGlyph >= glyphCount || aSecondGlyph >= glyphCount) {
+ // glyphs are out of range for the class tables
+ return 0;
+ }
+
+ // get pointers to the four arrays within the subtable
+ const AutoSwap_PRInt16* kernValue =
+ reinterpret_cast<const AutoSwap_PRInt16*>(hdr + 1);
+ const uint8_t* leftClass =
+ reinterpret_cast<const uint8_t*>(kernValue + hdr->kernValueCount);
+ const uint8_t* rightClass = leftClass + glyphCount;
+ const uint8_t* kernIndex = rightClass + glyphCount;
+
+ uint8_t lc = leftClass[aFirstGlyph];
+ uint8_t rc = rightClass[aSecondGlyph];
+ if (lc >= hdr->leftClassCount || rc >= hdr->rightClassCount) {
+ return 0;
+ }
+
+ uint8_t ki = kernIndex[leftClass[aFirstGlyph] * hdr->rightClassCount +
+ rightClass[aSecondGlyph]];
+ if (ki >= hdr->kernValueCount) {
+ return 0;
+ }
+
+ return kernValue[ki];
+}
+
+#define KERN0_COVERAGE_HORIZONTAL 0x0001
+#define KERN0_COVERAGE_MINIMUM 0x0002
+#define KERN0_COVERAGE_CROSS_STREAM 0x0004
+#define KERN0_COVERAGE_OVERRIDE 0x0008
+#define KERN0_COVERAGE_RESERVED 0x00F0
+
+#define KERN1_COVERAGE_VERTICAL 0x8000
+#define KERN1_COVERAGE_CROSS_STREAM 0x4000
+#define KERN1_COVERAGE_VARIATION 0x2000
+#define KERN1_COVERAGE_RESERVED 0x1F00
+
+hb_position_t gfxHarfBuzzShaper::GetHKerning(uint16_t aFirstGlyph,
+ uint16_t aSecondGlyph) const {
+ // We want to ignore any kern pairs involving <space>, because we are
+ // handling words in isolation, the only space characters seen here are
+ // the ones artificially added by the textRun code.
+ uint32_t spaceGlyph = mFont->GetSpaceGlyph();
+ if (aFirstGlyph == spaceGlyph || aSecondGlyph == spaceGlyph) {
+ return 0;
+ }
+
+ if (!mKernTable) {
+ mKernTable =
+ mFont->GetFontEntry()->GetFontTable(TRUETYPE_TAG('k', 'e', 'r', 'n'));
+ if (!mKernTable) {
+ mKernTable = hb_blob_get_empty();
+ }
+ }
+
+ uint32_t len;
+ const char* base = hb_blob_get_data(mKernTable, &len);
+ if (len < sizeof(KernTableVersion0)) {
+ return 0;
+ }
+ int32_t value = 0;
+
+ // First try to interpret as "version 0" kern table
+ // (see http://www.microsoft.com/typography/otspec/kern.htm)
+ const KernTableVersion0* kern0 =
+ reinterpret_cast<const KernTableVersion0*>(base);
+ if (uint16_t(kern0->version) == 0) {
+ uint16_t nTables = kern0->nTables;
+ uint32_t offs = sizeof(KernTableVersion0);
+ for (uint16_t i = 0; i < nTables; ++i) {
+ if (offs + sizeof(KernTableSubtableHeaderVersion0) > len) {
+ break;
+ }
+ const KernTableSubtableHeaderVersion0* st0 =
+ reinterpret_cast<const KernTableSubtableHeaderVersion0*>(base + offs);
+ uint16_t subtableLen = uint16_t(st0->length);
+ if (offs + subtableLen > len) {
+ break;
+ }
+ offs += subtableLen;
+ uint16_t coverage = st0->coverage;
+ if (!(coverage & KERN0_COVERAGE_HORIZONTAL)) {
+ // we only care about horizontal kerning (for now)
+ continue;
+ }
+ if (coverage & (KERN0_COVERAGE_CROSS_STREAM | KERN0_COVERAGE_RESERVED)) {
+ // we don't support cross-stream kerning, and
+ // reserved bits should be zero;
+ // ignore the subtable if not
+ continue;
+ }
+ uint8_t format = (coverage >> 8);
+ switch (format) {
+ case 0:
+ GetKernValueFmt0(st0 + 1, subtableLen - sizeof(*st0), aFirstGlyph,
+ aSecondGlyph, value,
+ (coverage & KERN0_COVERAGE_OVERRIDE) != 0,
+ (coverage & KERN0_COVERAGE_MINIMUM) != 0);
+ break;
+ default:
+ // TODO: implement support for other formats,
+ // if they're ever used in practice
+#if DEBUG
+ {
+ char buf[1024];
+ SprintfLiteral(buf,
+ "unknown kern subtable in %s: "
+ "ver 0 format %d\n",
+ mFont->GetName().get(), format);
+ NS_WARNING(buf);
+ }
+#endif
+ break;
+ }
+ }
+ } else {
+ // It wasn't a "version 0" table; check if it is Apple version 1.0
+ // (see http://developer.apple.com/fonts/TTRefMan/RM06/Chap6kern.html)
+ const KernTableVersion1* kern1 =
+ reinterpret_cast<const KernTableVersion1*>(base);
+ if (uint32_t(kern1->version) == 0x00010000) {
+ uint32_t nTables = kern1->nTables;
+ uint32_t offs = sizeof(KernTableVersion1);
+ for (uint32_t i = 0; i < nTables; ++i) {
+ if (offs + sizeof(KernTableSubtableHeaderVersion1) > len) {
+ break;
+ }
+ const KernTableSubtableHeaderVersion1* st1 =
+ reinterpret_cast<const KernTableSubtableHeaderVersion1*>(base +
+ offs);
+ uint32_t subtableLen = uint32_t(st1->length);
+ offs += subtableLen;
+ uint16_t coverage = st1->coverage;
+ if (coverage & (KERN1_COVERAGE_VERTICAL | KERN1_COVERAGE_CROSS_STREAM |
+ KERN1_COVERAGE_VARIATION | KERN1_COVERAGE_RESERVED)) {
+ // we only care about horizontal kerning (for now),
+ // we don't support cross-stream kerning,
+ // we don't support variations,
+ // reserved bits should be zero;
+ // ignore the subtable if not
+ continue;
+ }
+ uint8_t format = (coverage & 0xff);
+ switch (format) {
+ case 0:
+ GetKernValueFmt0(st1 + 1, subtableLen - sizeof(*st1), aFirstGlyph,
+ aSecondGlyph, value);
+ break;
+ case 2:
+ value = GetKernValueVersion1Fmt2(st1, subtableLen, aFirstGlyph,
+ aSecondGlyph);
+ break;
+ case 3:
+ value = GetKernValueVersion1Fmt3(st1, subtableLen, aFirstGlyph,
+ aSecondGlyph);
+ break;
+ default:
+ // TODO: implement support for other formats.
+ // Note that format 1 cannot be supported here,
+ // as it requires the full glyph array to run the FSM,
+ // not just the current glyph pair.
+#if DEBUG
+ {
+ char buf[1024];
+ SprintfLiteral(buf,
+ "unknown kern subtable in %s: "
+ "ver 0 format %d\n",
+ mFont->GetName().get(), format);
+ NS_WARNING(buf);
+ }
+#endif
+ break;
+ }
+ }
+ }
+ }
+
+ if (value != 0) {
+ return FloatToFixed(mFont->FUnitsToDevUnitsFactor() * value);
+ }
+ return 0;
+}
+
+static hb_position_t HBGetHKerning(hb_font_t* font, void* font_data,
+ hb_codepoint_t first_glyph,
+ hb_codepoint_t second_glyph,
+ void* user_data) {
+ const gfxHarfBuzzShaper::FontCallbackData* fcd =
+ static_cast<const gfxHarfBuzzShaper::FontCallbackData*>(font_data);
+ return fcd->mShaper->GetHKerning(first_glyph, second_glyph);
+}
+
+/*
+ * HarfBuzz unicode property callbacks
+ */
+
+static hb_codepoint_t HBGetMirroring(hb_unicode_funcs_t* ufuncs,
+ hb_codepoint_t aCh, void* user_data) {
+ return intl::UnicodeProperties::CharMirror(aCh);
+}
+
+static hb_unicode_general_category_t HBGetGeneralCategory(
+ hb_unicode_funcs_t* ufuncs, hb_codepoint_t aCh, void* user_data) {
+ return hb_unicode_general_category_t(GetGeneralCategory(aCh));
+}
+
+static hb_script_t HBGetScript(hb_unicode_funcs_t* ufuncs, hb_codepoint_t aCh,
+ void* user_data) {
+ return hb_script_t(
+ GetScriptTagForCode(intl::UnicodeProperties::GetScriptCode(aCh)));
+}
+
+static hb_unicode_combining_class_t HBGetCombiningClass(
+ hb_unicode_funcs_t* ufuncs, hb_codepoint_t aCh, void* user_data) {
+ return hb_unicode_combining_class_t(
+ intl::UnicodeProperties::GetCombiningClass(aCh));
+}
+
+static hb_bool_t HBUnicodeCompose(hb_unicode_funcs_t* ufuncs, hb_codepoint_t a,
+ hb_codepoint_t b, hb_codepoint_t* ab,
+ void* user_data) {
+ char32_t ch = intl::String::ComposePairNFC(a, b);
+ if (ch > 0) {
+ *ab = ch;
+ return true;
+ }
+
+ return false;
+}
+
+static hb_bool_t HBUnicodeDecompose(hb_unicode_funcs_t* ufuncs,
+ hb_codepoint_t ab, hb_codepoint_t* a,
+ hb_codepoint_t* b, void* user_data) {
+#ifdef MOZ_WIDGET_ANDROID
+ // Hack for the SamsungDevanagari font, bug 1012365:
+ // support U+0972 by decomposing it.
+ if (ab == 0x0972) {
+ *a = 0x0905;
+ *b = 0x0945;
+ return true;
+ }
+#endif
+
+ char32_t decomp[2] = {0};
+ if (intl::String::DecomposeRawNFD(ab, decomp)) {
+ if (decomp[1] || decomp[0] != ab) {
+ *a = decomp[0];
+ *b = decomp[1];
+ return true;
+ }
+ }
+
+ return false;
+}
+
+static void AddOpenTypeFeature(const uint32_t& aTag, uint32_t& aValue,
+ void* aUserArg) {
+ nsTArray<hb_feature_t>* features =
+ static_cast<nsTArray<hb_feature_t>*>(aUserArg);
+
+ hb_feature_t feat = {0, 0, 0, UINT_MAX};
+ feat.tag = aTag;
+ feat.value = aValue;
+ features->AppendElement(feat);
+}
+
+/*
+ * gfxFontShaper override to initialize the text run using HarfBuzz
+ */
+
+static hb_font_funcs_t* sHBFontFuncs = nullptr;
+static hb_font_funcs_t* sNominalGlyphFunc = nullptr;
+static hb_unicode_funcs_t* sHBUnicodeFuncs = nullptr;
+static const hb_script_t sMathScript =
+ hb_ot_tag_to_script(HB_TAG('m', 'a', 't', 'h'));
+
+bool gfxHarfBuzzShaper::Initialize() {
+ if (mInitialized) {
+ return mHBFont != nullptr;
+ }
+ mInitialized = true;
+ mCallbackData.mShaper = this;
+
+ if (!sHBFontFuncs) {
+ // static function callback pointers, initialized by the first
+ // harfbuzz shaper used
+ sHBFontFuncs = hb_font_funcs_create();
+ hb_font_funcs_set_nominal_glyph_func(sHBFontFuncs, HBGetNominalGlyph,
+ nullptr, nullptr);
+ hb_font_funcs_set_variation_glyph_func(sHBFontFuncs, HBGetVariationGlyph,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_h_advance_func(sHBFontFuncs, HBGetGlyphHAdvance,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_v_advance_func(sHBFontFuncs, HBGetGlyphVAdvance,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_v_origin_func(sHBFontFuncs, HBGetGlyphVOrigin,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_extents_func(sHBFontFuncs, HBGetGlyphExtents,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_contour_point_func(sHBFontFuncs, HBGetContourPoint,
+ nullptr, nullptr);
+ hb_font_funcs_set_glyph_h_kerning_func(sHBFontFuncs, HBGetHKerning, nullptr,
+ nullptr);
+ hb_font_funcs_make_immutable(sHBFontFuncs);
+
+ sNominalGlyphFunc = hb_font_funcs_create();
+ hb_font_funcs_set_nominal_glyph_func(sNominalGlyphFunc, HBGetNominalGlyph,
+ nullptr, nullptr);
+ hb_font_funcs_make_immutable(sNominalGlyphFunc);
+
+ sHBUnicodeFuncs = hb_unicode_funcs_create(hb_unicode_funcs_get_empty());
+ hb_unicode_funcs_set_mirroring_func(sHBUnicodeFuncs, HBGetMirroring,
+ nullptr, nullptr);
+ hb_unicode_funcs_set_script_func(sHBUnicodeFuncs, HBGetScript, nullptr,
+ nullptr);
+ hb_unicode_funcs_set_general_category_func(
+ sHBUnicodeFuncs, HBGetGeneralCategory, nullptr, nullptr);
+ hb_unicode_funcs_set_combining_class_func(
+ sHBUnicodeFuncs, HBGetCombiningClass, nullptr, nullptr);
+ hb_unicode_funcs_set_compose_func(sHBUnicodeFuncs, HBUnicodeCompose,
+ nullptr, nullptr);
+ hb_unicode_funcs_set_decompose_func(sHBUnicodeFuncs, HBUnicodeDecompose,
+ nullptr, nullptr);
+ hb_unicode_funcs_make_immutable(sHBUnicodeFuncs);
+ }
+
+ gfxFontEntry* entry = mFont->GetFontEntry();
+ if (!mUseFontGetGlyph) {
+ // get the cmap table and find offset to our subtable
+ mCmapTable = entry->GetFontTable(TRUETYPE_TAG('c', 'm', 'a', 'p'));
+ if (!mCmapTable) {
+ NS_WARNING("failed to load cmap, glyphs will be missing");
+ return false;
+ }
+ uint32_t len;
+ const uint8_t* data = (const uint8_t*)hb_blob_get_data(mCmapTable, &len);
+ mCmapFormat = gfxFontUtils::FindPreferredSubtable(
+ data, len, &mSubtableOffset, &mUVSTableOffset, &mIsSymbolFont);
+ if (mCmapFormat <= 0) {
+ return false;
+ }
+ }
+
+ if (!mUseFontGlyphWidths) {
+ // If font doesn't implement GetGlyphWidth, we will be reading
+ // the metrics table directly, so make sure we can load it.
+ if (!LoadHmtxTable()) {
+ return false;
+ }
+ }
+
+ mBuffer = hb_buffer_create();
+ hb_buffer_set_unicode_funcs(mBuffer, sHBUnicodeFuncs);
+ hb_buffer_set_cluster_level(mBuffer,
+ HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
+
+ auto* funcs =
+ mFont->GetFontEntry()->HasFontTable(TRUETYPE_TAG('C', 'F', 'F', ' '))
+ ? sNominalGlyphFunc
+ : sHBFontFuncs;
+ mHBFont = CreateHBFont(mFont, funcs, &mCallbackData);
+
+ return true;
+}
+
+hb_font_t* gfxHarfBuzzShaper::CreateHBFont(gfxFont* aFont,
+ hb_font_funcs_t* aFontFuncs,
+ FontCallbackData* aCallbackData) {
+ auto face(aFont->GetFontEntry()->GetHBFace());
+ hb_font_t* result = hb_font_create(face);
+
+ if (aFontFuncs && aCallbackData) {
+ if (aFontFuncs == sNominalGlyphFunc) {
+ hb_font_t* subfont = hb_font_create_sub_font(result);
+ hb_font_destroy(result);
+ result = subfont;
+ }
+ hb_font_set_funcs(result, aFontFuncs, aCallbackData, nullptr);
+ }
+ hb_font_set_ppem(result, aFont->GetAdjustedSize(), aFont->GetAdjustedSize());
+ uint32_t scale = FloatToFixed(aFont->GetAdjustedSize()); // 16.16 fixed-point
+ hb_font_set_scale(result, scale, scale);
+
+ AutoTArray<gfxFontVariation, 8> vars;
+ aFont->GetFontEntry()->GetVariationsForStyle(vars, *aFont->GetStyle());
+ if (vars.Length() > 0) {
+ // Fortunately, the hb_variation_t struct is compatible with our
+ // gfxFontVariation, so we can simply cast here.
+ static_assert(
+ sizeof(gfxFontVariation) == sizeof(hb_variation_t) &&
+ offsetof(gfxFontVariation, mTag) == offsetof(hb_variation_t, tag) &&
+ offsetof(gfxFontVariation, mValue) ==
+ offsetof(hb_variation_t, value),
+ "Gecko vs HarfBuzz struct mismatch!");
+ auto hbVars = reinterpret_cast<const hb_variation_t*>(vars.Elements());
+ hb_font_set_variations(result, hbVars, vars.Length());
+ }
+
+ return result;
+}
+
+bool gfxHarfBuzzShaper::LoadHmtxTable() {
+ // Read mNumLongHMetrics from metrics-head table without caching its
+ // blob, and preload/cache the metrics table.
+ gfxFontEntry* entry = mFont->GetFontEntry();
+ gfxFontEntry::AutoTable hheaTable(entry, TRUETYPE_TAG('h', 'h', 'e', 'a'));
+ if (hheaTable) {
+ uint32_t len;
+ const MetricsHeader* hhea = reinterpret_cast<const MetricsHeader*>(
+ hb_blob_get_data(hheaTable, &len));
+ if (len >= sizeof(MetricsHeader)) {
+ mNumLongHMetrics = hhea->numOfLongMetrics;
+ if (mNumLongHMetrics > 0 && int16_t(hhea->metricDataFormat) == 0) {
+ // no point reading metrics if number of entries is zero!
+ // in that case, we won't be able to use this font
+ // (this method will return FALSE below if mHmtxTable
+ // is null)
+ mHmtxTable = entry->GetFontTable(TRUETYPE_TAG('h', 'm', 't', 'x'));
+ if (mHmtxTable && hb_blob_get_length(mHmtxTable) <
+ mNumLongHMetrics * sizeof(LongMetric)) {
+ // metrics table is not large enough for the claimed
+ // number of entries: invalid, do not use.
+ hb_blob_destroy(mHmtxTable);
+ mHmtxTable = nullptr;
+ }
+ }
+ }
+ }
+ if (!mHmtxTable) {
+ return false;
+ }
+ return true;
+}
+
+void gfxHarfBuzzShaper::InitializeVertical() {
+ // We only do this once. If we don't have a mHmtxTable after that,
+ // we'll be making up fallback metrics.
+ if (mVerticalInitialized) {
+ return;
+ }
+ mVerticalInitialized = true;
+
+ if (!mHmtxTable) {
+ if (!LoadHmtxTable()) {
+ return;
+ }
+ }
+
+ // Load vertical metrics if present in the font; if not, we'll synthesize
+ // vertical glyph advances based on (horizontal) ascent/descent metrics.
+ gfxFontEntry* entry = mFont->GetFontEntry();
+ gfxFontEntry::AutoTable vheaTable(entry, TRUETYPE_TAG('v', 'h', 'e', 'a'));
+ if (vheaTable) {
+ uint32_t len;
+ const MetricsHeader* vhea = reinterpret_cast<const MetricsHeader*>(
+ hb_blob_get_data(vheaTable, &len));
+ if (len >= sizeof(MetricsHeader)) {
+ mNumLongVMetrics = vhea->numOfLongMetrics;
+ gfxFontEntry::AutoTable maxpTable(entry,
+ TRUETYPE_TAG('m', 'a', 'x', 'p'));
+ int numGlyphs = -1; // invalid if we fail to read 'maxp'
+ if (maxpTable &&
+ hb_blob_get_length(maxpTable) >= sizeof(MaxpTableHeader)) {
+ const MaxpTableHeader* maxp = reinterpret_cast<const MaxpTableHeader*>(
+ hb_blob_get_data(maxpTable, nullptr));
+ numGlyphs = uint16_t(maxp->numGlyphs);
+ }
+ if (mNumLongVMetrics > 0 && mNumLongVMetrics <= numGlyphs &&
+ int16_t(vhea->metricDataFormat) == 0) {
+ mVmtxTable = entry->GetFontTable(TRUETYPE_TAG('v', 'm', 't', 'x'));
+ if (mVmtxTable &&
+ hb_blob_get_length(mVmtxTable) <
+ mNumLongVMetrics * sizeof(LongMetric) +
+ (numGlyphs - mNumLongVMetrics) * sizeof(int16_t)) {
+ // metrics table is not large enough for the claimed
+ // number of entries: invalid, do not use.
+ hb_blob_destroy(mVmtxTable);
+ mVmtxTable = nullptr;
+ }
+ }
+ }
+ }
+
+ // For CFF fonts only, load a VORG table if present.
+ if (entry->HasFontTable(TRUETYPE_TAG('C', 'F', 'F', ' '))) {
+ mVORGTable = entry->GetFontTable(TRUETYPE_TAG('V', 'O', 'R', 'G'));
+ if (mVORGTable) {
+ uint32_t len;
+ const VORG* vorg =
+ reinterpret_cast<const VORG*>(hb_blob_get_data(mVORGTable, &len));
+ if (len < sizeof(VORG) || uint16_t(vorg->majorVersion) != 1 ||
+ uint16_t(vorg->minorVersion) != 0 ||
+ len < sizeof(VORG) +
+ uint16_t(vorg->numVertOriginYMetrics) * sizeof(VORGrec)) {
+ // VORG table is an unknown version, or not large enough
+ // to be valid -- discard it.
+ NS_WARNING("discarding invalid VORG table");
+ hb_blob_destroy(mVORGTable);
+ mVORGTable = nullptr;
+ }
+ }
+ }
+}
+
+bool gfxHarfBuzzShaper::ShapeText(DrawTarget* aDrawTarget,
+ const char16_t* aText, uint32_t aOffset,
+ uint32_t aLength, Script aScript,
+ nsAtom* aLanguage, bool aVertical,
+ RoundingFlags aRounding,
+ gfxShapedText* aShapedText) {
+ mUseVerticalPresentationForms = false;
+
+ if (!Initialize()) {
+ return false;
+ }
+
+ if (aVertical) {
+ InitializeVertical();
+ if (!mFont->GetFontEntry()->SupportsOpenTypeFeature(
+ aScript, HB_TAG('v', 'e', 'r', 't'))) {
+ mUseVerticalPresentationForms = true;
+ }
+ }
+
+ const gfxFontStyle* style = mFont->GetStyle();
+
+ // determine whether petite-caps falls back to small-caps
+ bool addSmallCaps = false;
+ if (style->variantCaps != NS_FONT_VARIANT_CAPS_NORMAL) {
+ switch (style->variantCaps) {
+ case NS_FONT_VARIANT_CAPS_ALLPETITE:
+ case NS_FONT_VARIANT_CAPS_PETITECAPS:
+ bool synLower, synUpper;
+ mFont->SupportsVariantCaps(aScript, style->variantCaps, addSmallCaps,
+ synLower, synUpper);
+ break;
+ default:
+ break;
+ }
+ }
+
+ gfxFontEntry* entry = mFont->GetFontEntry();
+
+ // insert any merged features into hb_feature array
+ AutoTArray<hb_feature_t, 20> features;
+ MergeFontFeatures(style, entry->mFeatureSettings,
+ aShapedText->DisableLigatures(), entry->FamilyName(),
+ addSmallCaps, AddOpenTypeFeature, &features);
+
+ // For CJK script, match kerning and proportional-alternates (palt) features
+ // (and their vertical counterparts) as per spec:
+ // https://learn.microsoft.com/en-us/typography/opentype/spec/features_pt#tag-palt
+ // and disable kerning by default (for font-kerning:auto).
+ if (gfxTextRun::IsCJKScript(aScript)) {
+ hb_tag_t kern =
+ aVertical ? HB_TAG('v', 'k', 'r', 'n') : HB_TAG('k', 'e', 'r', 'n');
+ hb_tag_t alt =
+ aVertical ? HB_TAG('v', 'p', 'a', 'l') : HB_TAG('p', 'a', 'l', 't');
+ struct Cmp {
+ bool Equals(const hb_feature_t& a, const hb_tag_t& b) const {
+ return a.tag == b;
+ }
+ };
+ constexpr auto NoIndex = nsTArray<hb_feature_t>::NoIndex;
+ nsTArray<hb_feature_t>::index_type i = features.IndexOf(kern, 0, Cmp());
+ if (i == NoIndex) {
+ // Kerning was not explicitly set; override harfbuzz's default to disable
+ // it.
+ features.AppendElement(hb_feature_t{kern, 0, HB_FEATURE_GLOBAL_START,
+ HB_FEATURE_GLOBAL_END});
+ } else if (features[i].value) {
+ // If kerning was explicitly enabled), we also turn on proportional
+ // alternates, as per the OpenType feature registry.
+ // Bug 1798297: for the Yu Gothic UI font, we don't do this, because its
+ // 'palt' feature produces badly-spaced (overcrowded) kana glyphs.
+ if (!entry->FamilyName().EqualsLiteral("Yu Gothic UI")) {
+ if (features.IndexOf(alt, 0, Cmp()) == NoIndex) {
+ features.AppendElement(hb_feature_t{alt, 1, HB_FEATURE_GLOBAL_START,
+ HB_FEATURE_GLOBAL_END});
+ }
+ }
+ }
+ }
+
+ bool isRightToLeft = aShapedText->IsRightToLeft();
+
+ hb_buffer_set_direction(
+ mBuffer, aVertical
+ ? HB_DIRECTION_TTB
+ : (isRightToLeft ? HB_DIRECTION_RTL : HB_DIRECTION_LTR));
+ hb_script_t scriptTag;
+ if (aShapedText->GetFlags() & gfx::ShapedTextFlags::TEXT_USE_MATH_SCRIPT) {
+ scriptTag = sMathScript;
+ } else {
+ scriptTag = GetHBScriptUsedForShaping(aScript);
+ }
+ hb_buffer_set_script(mBuffer, scriptTag);
+
+ hb_language_t language;
+ if (style->languageOverride) {
+ language = hb_ot_tag_to_language(style->languageOverride);
+ } else if (entry->mLanguageOverride) {
+ language = hb_ot_tag_to_language(entry->mLanguageOverride);
+ } else if (aLanguage) {
+ nsCString langString;
+ aLanguage->ToUTF8String(langString);
+ language = hb_language_from_string(langString.get(), langString.Length());
+ } else {
+ language = hb_ot_tag_to_language(HB_OT_TAG_DEFAULT_LANGUAGE);
+ }
+ hb_buffer_set_language(mBuffer, language);
+
+ uint32_t length = aLength;
+ hb_buffer_add_utf16(mBuffer, reinterpret_cast<const uint16_t*>(aText), length,
+ 0, length);
+
+ hb_shape(mHBFont, mBuffer, features.Elements(), features.Length());
+
+ if (isRightToLeft) {
+ hb_buffer_reverse(mBuffer);
+ }
+
+ nsresult rv = SetGlyphsFromRun(aShapedText, aOffset, aLength, aText,
+ aVertical, aRounding);
+
+ NS_WARNING_ASSERTION(NS_SUCCEEDED(rv),
+ "failed to store glyphs into gfxShapedWord");
+ hb_buffer_clear_contents(mBuffer);
+
+ return NS_SUCCEEDED(rv);
+}
+
+#define SMALL_GLYPH_RUN \
+ 128 // some testing indicates that 90%+ of text runs
+ // will fit without requiring separate allocation
+ // for charToGlyphArray
+
+nsresult gfxHarfBuzzShaper::SetGlyphsFromRun(gfxShapedText* aShapedText,
+ uint32_t aOffset, uint32_t aLength,
+ const char16_t* aText,
+ bool aVertical,
+ RoundingFlags aRounding) {
+ typedef gfxShapedText::CompressedGlyph CompressedGlyph;
+
+ uint32_t numGlyphs;
+ const hb_glyph_info_t* ginfo = hb_buffer_get_glyph_infos(mBuffer, &numGlyphs);
+ if (numGlyphs == 0) {
+ return NS_OK;
+ }
+
+ AutoTArray<gfxTextRun::DetailedGlyph, 1> detailedGlyphs;
+
+ uint32_t wordLength = aLength;
+ static const int32_t NO_GLYPH = -1;
+ AutoTArray<int32_t, SMALL_GLYPH_RUN> charToGlyphArray;
+ if (!charToGlyphArray.SetLength(wordLength, fallible)) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ int32_t* charToGlyph = charToGlyphArray.Elements();
+ for (uint32_t offset = 0; offset < wordLength; ++offset) {
+ charToGlyph[offset] = NO_GLYPH;
+ }
+
+ for (uint32_t i = 0; i < numGlyphs; ++i) {
+ uint32_t loc = ginfo[i].cluster;
+ if (loc < wordLength) {
+ charToGlyph[loc] = i;
+ }
+ }
+
+ int32_t glyphStart = 0; // looking for a clump that starts at this glyph
+ int32_t charStart = 0; // and this char index within the range of the run
+
+ bool roundI, roundB;
+ if (aVertical) {
+ roundI = bool(aRounding & RoundingFlags::kRoundY);
+ roundB = bool(aRounding & RoundingFlags::kRoundX);
+ } else {
+ roundI = bool(aRounding & RoundingFlags::kRoundX);
+ roundB = bool(aRounding & RoundingFlags::kRoundY);
+ }
+
+ int32_t appUnitsPerDevUnit = aShapedText->GetAppUnitsPerDevUnit();
+ CompressedGlyph* charGlyphs = aShapedText->GetCharacterGlyphs() + aOffset;
+
+ // factor to convert 16.16 fixed-point pixels to app units
+ // (only used if not rounding)
+ double hb2appUnits = FixedToFloat(aShapedText->GetAppUnitsPerDevUnit());
+
+ // Residual from rounding of previous advance, for use in rounding the
+ // subsequent offset or advance appropriately. 16.16 fixed-point
+ //
+ // When rounding, the goal is to make the distance between glyphs and
+ // their base glyph equal to the integral number of pixels closest to that
+ // suggested by that shaper.
+ // i.e. posInfo[n].x_advance - posInfo[n].x_offset + posInfo[n+1].x_offset
+ //
+ // The value of the residual is the part of the desired distance that has
+ // not been included in integer offsets.
+ hb_position_t residual = 0;
+
+ // keep track of y-position to set glyph offsets if needed
+ nscoord bPos = 0;
+
+ const hb_glyph_position_t* posInfo =
+ hb_buffer_get_glyph_positions(mBuffer, nullptr);
+
+ while (glyphStart < int32_t(numGlyphs)) {
+ int32_t charEnd = ginfo[glyphStart].cluster;
+ int32_t glyphEnd = glyphStart;
+ int32_t charLimit = wordLength;
+ while (charEnd < charLimit) {
+ // 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.
+ charEnd += 1;
+ while (charEnd != charLimit && charToGlyph[charEnd] == NO_GLYPH) {
+ charEnd += 1;
+ }
+
+ // find the maximum glyph index covered by the clump so far
+ for (int32_t i = charStart; i < charEnd; ++i) {
+ if (charToGlyph[i] != NO_GLYPH) {
+ glyphEnd = std::max(glyphEnd, charToGlyph[i] + 1);
+ // update extent of glyph range
+ }
+ }
+
+ 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;
+ for (int32_t i = glyphStart; i < glyphEnd; ++i) {
+ int32_t glyphCharIndex = ginfo[i].cluster;
+ if (glyphCharIndex < charStart || glyphCharIndex >= charEnd) {
+ allGlyphsAreWithinCluster = false;
+ break;
+ }
+ }
+ if (allGlyphsAreWithinCluster) {
+ break;
+ }
+ }
+
+ NS_ASSERTION(glyphStart < glyphEnd,
+ "character/glyph clump contains no glyphs!");
+ NS_ASSERTION(charStart != charEnd,
+ "character/glyph clump contains no characters!");
+
+ // 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;
+ while (charEnd < int32_t(wordLength) && charToGlyph[charEnd] == NO_GLYPH)
+ charEnd++;
+ baseCharIndex = charStart;
+ endCharIndex = charEnd;
+
+ // Then we check if the clump falls outside our actual string range;
+ // if so, just go to the next.
+ if (baseCharIndex >= int32_t(wordLength)) {
+ glyphStart = glyphEnd;
+ charStart = charEnd;
+ continue;
+ }
+ // Ensure we won't try to go beyond the valid length of the textRun's text
+ endCharIndex = std::min<int32_t>(endCharIndex, wordLength);
+
+ // Now we're ready to set the glyph info in the textRun
+ int32_t glyphsInClump = glyphEnd - glyphStart;
+
+ // Check for default-ignorable char that didn't get filtered, combined,
+ // etc by the shaping process, and remove from the run.
+ // (This may be done within harfbuzz eventually.)
+ if (glyphsInClump == 1 && baseCharIndex + 1 == endCharIndex &&
+ aShapedText->FilterIfIgnorable(aOffset + baseCharIndex,
+ aText[baseCharIndex])) {
+ glyphStart = glyphEnd;
+ charStart = charEnd;
+ continue;
+ }
+
+ // HarfBuzz gives us physical x- and y-coordinates, but we will store
+ // them as logical inline- and block-direction values in the textrun.
+
+ hb_position_t i_offset, i_advance; // inline-direction offset/advance
+ hb_position_t b_offset, b_advance; // block-direction offset/advance
+ if (aVertical) {
+ // our coordinate directions are the opposite of harfbuzz's
+ // when doing top-to-bottom shaping
+ i_offset = -posInfo[glyphStart].y_offset;
+ i_advance = -posInfo[glyphStart].y_advance;
+ b_offset = -posInfo[glyphStart].x_offset;
+ b_advance = -posInfo[glyphStart].x_advance;
+ } else {
+ i_offset = posInfo[glyphStart].x_offset;
+ i_advance = posInfo[glyphStart].x_advance;
+ b_offset = posInfo[glyphStart].y_offset;
+ b_advance = posInfo[glyphStart].y_advance;
+ }
+
+ nscoord iOffset, advance;
+ if (roundI) {
+ iOffset = appUnitsPerDevUnit * FixedToIntRound(i_offset + residual);
+ // Desired distance from the base glyph to the next reference point.
+ hb_position_t width = i_advance - i_offset;
+ int intWidth = FixedToIntRound(width);
+ residual = width - FloatToFixed(intWidth);
+ advance = appUnitsPerDevUnit * intWidth + iOffset;
+ } else {
+ iOffset = floor(hb2appUnits * i_offset + 0.5);
+ advance = floor(hb2appUnits * i_advance + 0.5);
+ }
+ // Check if it's a simple one-to-one mapping
+ if (glyphsInClump == 1 &&
+ CompressedGlyph::IsSimpleGlyphID(ginfo[glyphStart].codepoint) &&
+ CompressedGlyph::IsSimpleAdvance(advance) &&
+ charGlyphs[baseCharIndex].IsClusterStart() && iOffset == 0 &&
+ b_offset == 0 && b_advance == 0 && bPos == 0) {
+ charGlyphs[baseCharIndex].SetSimpleGlyph(advance,
+ ginfo[glyphStart].codepoint);
+ } 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 = ginfo[glyphStart].codepoint;
+
+ details->mAdvance = advance;
+
+ if (aVertical) {
+ details->mOffset.x =
+ bPos - (roundB ? appUnitsPerDevUnit * FixedToIntRound(b_offset)
+ : floor(hb2appUnits * b_offset + 0.5));
+ details->mOffset.y = iOffset;
+ } else {
+ details->mOffset.x = iOffset;
+ details->mOffset.y =
+ bPos - (roundB ? appUnitsPerDevUnit * FixedToIntRound(b_offset)
+ : floor(hb2appUnits * b_offset + 0.5));
+ }
+
+ if (b_advance != 0) {
+ bPos -= roundB ? appUnitsPerDevUnit * FixedToIntRound(b_advance)
+ : floor(hb2appUnits * b_advance + 0.5);
+ }
+ if (++glyphStart >= glyphEnd) {
+ break;
+ }
+
+ if (aVertical) {
+ i_offset = -posInfo[glyphStart].y_offset;
+ i_advance = -posInfo[glyphStart].y_advance;
+ b_offset = -posInfo[glyphStart].x_offset;
+ b_advance = -posInfo[glyphStart].x_advance;
+ } else {
+ i_offset = posInfo[glyphStart].x_offset;
+ i_advance = posInfo[glyphStart].x_advance;
+ b_offset = posInfo[glyphStart].y_offset;
+ b_advance = posInfo[glyphStart].y_advance;
+ }
+
+ if (roundI) {
+ iOffset = appUnitsPerDevUnit * FixedToIntRound(i_offset + residual);
+ // Desired distance to the next reference point. The
+ // residual is considered here, and includes the residual
+ // from the base glyph offset and subsequent advances, so
+ // that the distance from the base glyph is optimized
+ // rather than the distance from combining marks.
+ i_advance += residual;
+ int intAdvance = FixedToIntRound(i_advance);
+ residual = i_advance - FloatToFixed(intAdvance);
+ advance = appUnitsPerDevUnit * intAdvance;
+ } else {
+ iOffset = floor(hb2appUnits * i_offset + 0.5);
+ advance = floor(hb2appUnits * i_advance + 0.5);
+ }
+ }
+
+ aShapedText->SetDetailedGlyphs(aOffset + baseCharIndex,
+ detailedGlyphs.Length(),
+ detailedGlyphs.Elements());
+
+ detailedGlyphs.Clear();
+ }
+
+ // the rest of the chars in the group are ligature continuations,
+ // no associated glyphs
+ while (++baseCharIndex != endCharIndex &&
+ baseCharIndex < int32_t(wordLength)) {
+ CompressedGlyph& g = charGlyphs[baseCharIndex];
+ NS_ASSERTION(!g.IsSimpleGlyph(), "overwriting a simple glyph");
+ g.SetComplex(g.IsClusterStart(), false);
+ }
+
+ glyphStart = glyphEnd;
+ charStart = charEnd;
+ }
+
+ return NS_OK;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 01:43:11 +0000