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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /gfx/thebes/gfxFont.h
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'gfx/thebes/gfxFont.h')
-rw-r--r--gfx/thebes/gfxFont.h2378
1 files changed, 2378 insertions, 0 deletions
diff --git a/gfx/thebes/gfxFont.h b/gfx/thebes/gfxFont.h
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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: set ts=4 et sw=2 tw=80:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_FONT_H
+#define GFX_FONT_H
+
+#include <new>
+#include <utility>
+#include <functional>
+#include "PLDHashTable.h"
+#include "ThebesRLBoxTypes.h"
+#include "gfxFontVariations.h"
+#include "gfxRect.h"
+#include "gfxTypes.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/FontPropertyTypes.h"
+#include "mozilla/HashTable.h"
+#include "mozilla/MemoryReporting.h"
+#include "mozilla/MruCache.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/RWLock.h"
+#include "mozilla/TypedEnumBits.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/gfx/FontPaletteCache.h"
+#include "mozilla/gfx/MatrixFwd.h"
+#include "mozilla/gfx/Point.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/intl/UnicodeScriptCodes.h"
+#include "nsCOMPtr.h"
+#include "nsColor.h"
+#include "nsTHashMap.h"
+#include "nsTHashSet.h"
+#include "nsExpirationTracker.h"
+#include "nsFontMetrics.h"
+#include "nsHashKeys.h"
+#include "nsIMemoryReporter.h"
+#include "nsIObserver.h"
+#include "nsISupports.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "nsTHashtable.h"
+#include "nscore.h"
+#include "DrawMode.h"
+
+// Only required for function bodies
+#include "gfxFontEntry.h"
+#include "gfxFontFeatures.h"
+
+class gfxContext;
+class gfxGraphiteShaper;
+class gfxHarfBuzzShaper;
+class gfxGlyphExtents;
+class gfxMathTable;
+class gfxPattern;
+class gfxShapedText;
+class gfxShapedWord;
+class gfxSkipChars;
+class gfxTextRun;
+class nsIEventTarget;
+class nsITimer;
+struct gfxTextRunDrawCallbacks;
+
+namespace mozilla {
+class SVGContextPaint;
+namespace layout {
+class TextDrawTarget;
+}
+} // namespace mozilla
+
+typedef struct _cairo cairo_t;
+typedef struct _cairo_scaled_font cairo_scaled_font_t;
+
+#define FONT_MAX_SIZE 2000.0
+
+#define SMALL_CAPS_SCALE_FACTOR 0.8
+
+// The skew factor used for synthetic-italic [oblique] fonts;
+// we use a platform-dependent value to harmonize with the platform's own APIs.
+#ifdef XP_WIN
+# define OBLIQUE_SKEW_FACTOR 0.3f
+#elif defined(MOZ_WIDGET_GTK)
+# define OBLIQUE_SKEW_FACTOR 0.2f
+#else
+# define OBLIQUE_SKEW_FACTOR 0.25f
+#endif
+
+struct gfxFontStyle {
+ using FontStretch = mozilla::FontStretch;
+ using FontSlantStyle = mozilla::FontSlantStyle;
+ using FontWeight = mozilla::FontWeight;
+ using FontSizeAdjust = mozilla::StyleFontSizeAdjust;
+
+ gfxFontStyle();
+ gfxFontStyle(FontSlantStyle aStyle, FontWeight aWeight, FontStretch aStretch,
+ gfxFloat aSize, const FontSizeAdjust& aSizeAdjust,
+ bool aSystemFont, bool aPrinterFont, bool aWeightSynthesis,
+ bool aStyleSynthesis, bool aSmallCapsSynthesis,
+ bool aPositionSynthesis, uint32_t aLanguageOverride);
+ // Features are composed of (1) features from style rules (2) features
+ // from feature settings rules and (3) family-specific features. (1) and
+ // (3) are guaranteed to be mutually exclusive
+
+ // custom opentype feature settings
+ CopyableTArray<gfxFontFeature> featureSettings;
+
+ // Some font-variant property values require font-specific settings
+ // defined via @font-feature-values rules. These are resolved after
+ // font matching occurs.
+
+ // -- list of value tags for specific alternate features
+ mozilla::StyleFontVariantAlternates variantAlternates;
+
+ // -- object used to look these up once the font is matched
+ RefPtr<gfxFontFeatureValueSet> featureValueLookup;
+
+ // opentype variation settings
+ CopyableTArray<gfxFontVariation> variationSettings;
+
+ // The logical size of the font, in pixels
+ gfxFloat size;
+
+ // The optical size value to apply (if supported); negative means none.
+ float autoOpticalSize = -1.0f;
+
+ // The aspect-value (ie., the ratio actualsize:actualxheight) that any
+ // actual physical font created from this font structure must have when
+ // rendering or measuring a string. A value of -1.0 means no adjustment
+ // needs to be done; otherwise the value must be nonnegative.
+ float sizeAdjust;
+
+ // baseline offset, used when simulating sub/superscript glyphs
+ float baselineOffset;
+
+ // Language system tag, to override document language;
+ // an OpenType "language system" tag represented as a 32-bit integer
+ // (see http://www.microsoft.com/typography/otspec/languagetags.htm).
+ // Normally 0, so font rendering will use the document or element language
+ // (see above) to control any language-specific rendering, but the author
+ // can override this for cases where the options implemented in the font
+ // do not directly match the actual language. (E.g. lang may be Macedonian,
+ // but the font in use does not explicitly support this; the author can
+ // use font-language-override to request the Serbian option in the font
+ // in order to get correct glyph shapes.)
+ uint32_t languageOverride;
+
+ // The Font{Weight,Stretch,SlantStyle} fields are each a 16-bit type.
+
+ // The weight of the font: 100, 200, ... 900.
+ FontWeight weight;
+
+ // The stretch of the font
+ FontStretch stretch;
+
+ // The style of font
+ FontSlantStyle style;
+
+ // Whether face-selection properties weight/style/stretch are all 'normal'
+ bool IsNormalStyle() const {
+ return weight.IsNormal() && style.IsNormal() && stretch.IsNormal();
+ }
+
+ // We pack these three small-integer fields into a single byte to avoid
+ // overflowing an 8-byte boundary [in a 64-bit build] and ending up with
+ // 7 bytes of padding at the end of the struct.
+
+ // caps variant (small-caps, petite-caps, etc.)
+ uint8_t variantCaps : 3; // uses range 0..6
+
+ // sub/superscript variant
+ uint8_t variantSubSuper : 2; // uses range 0..2
+
+ // font metric used as basis of font-size-adjust
+ uint8_t sizeAdjustBasis : 3; // uses range 0..4
+
+ // Say that this font is a system font and therefore does not
+ // require certain fixup that we do for fonts from untrusted
+ // sources.
+ bool systemFont : 1;
+
+ // Say that this font is used for print or print preview.
+ bool printerFont : 1;
+
+ // Used to imitate -webkit-font-smoothing: antialiased
+ bool useGrayscaleAntialiasing : 1;
+
+ // Whether synthetic styles are allowed (required, in the case of position)
+ bool allowSyntheticWeight : 1;
+ bool allowSyntheticStyle : 1;
+ bool allowSyntheticSmallCaps : 1;
+ bool useSyntheticPosition : 1;
+
+ // some variant features require fallback which complicates the shaping
+ // code, so set up a bool to indicate when shaping with fallback is needed
+ bool noFallbackVariantFeatures : 1;
+
+ // Return the final adjusted font size for the given aspect ratio.
+ // Not meant to be called when sizeAdjustBasis is NONE.
+ gfxFloat GetAdjustedSize(gfxFloat aspect) const {
+ MOZ_ASSERT(
+ FontSizeAdjust::Tag(sizeAdjustBasis) != FontSizeAdjust::Tag::None,
+ "Not meant to be called when sizeAdjustBasis is none");
+ gfxFloat adjustedSize =
+ std::max(NS_round(size * (sizeAdjust / aspect)), 1.0);
+ return std::min(adjustedSize, FONT_MAX_SIZE);
+ }
+
+ // Some callers want to take a short-circuit path if they can be sure the
+ // adjusted size will be zero.
+ bool AdjustedSizeMustBeZero() const {
+ return size == 0.0 ||
+ (FontSizeAdjust::Tag(sizeAdjustBasis) != FontSizeAdjust::Tag::None &&
+ sizeAdjust == 0.0);
+ }
+
+ PLDHashNumber Hash() const;
+
+ // Adjust this style to simulate sub/superscript (as requested in the
+ // variantSubSuper field) using size and baselineOffset instead.
+ void AdjustForSubSuperscript(int32_t aAppUnitsPerDevPixel);
+
+ // Should this style cause the given font entry to use synthetic bold?
+ bool NeedsSyntheticBold(gfxFontEntry* aFontEntry) const {
+ return weight.IsBold() && allowSyntheticWeight &&
+ !aFontEntry->SupportsBold();
+ }
+
+ bool Equals(const gfxFontStyle& other) const {
+ return mozilla::NumbersAreBitwiseIdentical(size, other.size) &&
+ (style == other.style) && (weight == other.weight) &&
+ (stretch == other.stretch) && (variantCaps == other.variantCaps) &&
+ (variantSubSuper == other.variantSubSuper) &&
+ (allowSyntheticWeight == other.allowSyntheticWeight) &&
+ (allowSyntheticStyle == other.allowSyntheticStyle) &&
+ (allowSyntheticSmallCaps == other.allowSyntheticSmallCaps) &&
+ (useSyntheticPosition == other.useSyntheticPosition) &&
+ (systemFont == other.systemFont) &&
+ (printerFont == other.printerFont) &&
+ (useGrayscaleAntialiasing == other.useGrayscaleAntialiasing) &&
+ (baselineOffset == other.baselineOffset) &&
+ mozilla::NumbersAreBitwiseIdentical(sizeAdjust, other.sizeAdjust) &&
+ (sizeAdjustBasis == other.sizeAdjustBasis) &&
+ (featureSettings == other.featureSettings) &&
+ (variantAlternates == other.variantAlternates) &&
+ (featureValueLookup == other.featureValueLookup) &&
+ (variationSettings == other.variationSettings) &&
+ (languageOverride == other.languageOverride) &&
+ mozilla::NumbersAreBitwiseIdentical(autoOpticalSize,
+ other.autoOpticalSize);
+ }
+};
+
+/**
+ * Font cache design:
+ *
+ * The mFonts hashtable contains most fonts, indexed by (gfxFontEntry*, style).
+ * It maintains a strong reference to the fonts it contains.
+ * Whenever a font is accessed, it is marked as used to move it to a new
+ * generation in the tracker to avoid expiration.
+ * The expiration tracker will only expire fonts with a single reference, the
+ * cache itself. Fonts with more than one reference are marked as used.
+ *
+ * We're using 3 generations with a ten-second generation interval, so
+ * zero-refcount fonts will be deleted 20-30 seconds after their refcount
+ * goes to zero, if timer events fire in a timely manner.
+ *
+ * The font cache also handles timed expiration of cached ShapedWords
+ * for "persistent" fonts: it has a repeating timer, and notifies
+ * each cached font to "age" its shaped words. The words will be released
+ * by the fonts if they get aged three times without being re-used in the
+ * meantime.
+ *
+ * Note that the ShapedWord timeout is much larger than the font timeout,
+ * so that in the case of a short-lived font, we'll discard the gfxFont
+ * completely, with all its words, and avoid the cost of aging the words
+ * individually. That only happens with longer-lived fonts.
+ */
+struct FontCacheSizes {
+ FontCacheSizes() : mFontInstances(0), mShapedWords(0) {}
+
+ size_t mFontInstances; // memory used by instances of gfxFont subclasses
+ size_t mShapedWords; // memory used by the per-font shapedWord caches
+};
+
+class gfxFontCache final
+ : public ExpirationTrackerImpl<gfxFont, 3, mozilla::Mutex,
+ mozilla::MutexAutoLock> {
+ protected:
+ // Expiration tracker implementation.
+ enum { FONT_TIMEOUT_SECONDS = 10 };
+
+ typedef mozilla::Mutex Lock;
+ typedef mozilla::MutexAutoLock AutoLock;
+
+ // This protects the ExpirationTracker tables.
+ Lock mMutex = Lock("fontCacheExpirationMutex");
+
+ Lock& GetMutex() override { return mMutex; }
+
+ public:
+ explicit gfxFontCache(nsIEventTarget* aEventTarget);
+ ~gfxFontCache();
+
+ enum { SHAPED_WORD_TIMEOUT_SECONDS = 60 };
+
+ /*
+ * Get the global gfxFontCache. You must call Init() before
+ * calling this method --- the result will not be null.
+ */
+ static gfxFontCache* GetCache() { return gGlobalCache; }
+
+ static nsresult Init();
+ // It's OK to call this even if Init() has not been called.
+ static void Shutdown();
+
+ // Look up a font in the cache. Returns null if there's nothing matching
+ // in the cache
+ already_AddRefed<gfxFont> Lookup(const gfxFontEntry* aFontEntry,
+ const gfxFontStyle* aStyle,
+ const gfxCharacterMap* aUnicodeRangeMap);
+
+ // We created a new font (presumably because Lookup returned null);
+ // put it in the cache. The font's refcount should be nonzero. It is
+ // allowable to add a new font even if there is one already in the
+ // cache with the same key, as we may race with other threads to do
+ // the insertion -- in that case we will return the original font,
+ // and destroy the new one.
+ already_AddRefed<gfxFont> MaybeInsert(gfxFont* aFont);
+
+ bool MaybeDestroy(gfxFont* aFont);
+
+ // Cleans out the hashtable and removes expired fonts waiting for cleanup.
+ // Other gfxFont objects may be still in use but they will be pushed
+ // into the expiration queues and removed.
+ void Flush();
+
+ void FlushShapedWordCaches();
+ void NotifyGlyphsChanged();
+
+ void AgeCachedWords();
+
+ void RunWordCacheExpirationTimer() {
+ if (!mTimerRunning) {
+ mozilla::MutexAutoLock lock(mMutex);
+ if (!mTimerRunning && mWordCacheExpirationTimer) {
+ mWordCacheExpirationTimer->InitWithNamedFuncCallback(
+ WordCacheExpirationTimerCallback, this,
+ SHAPED_WORD_TIMEOUT_SECONDS * 1000, nsITimer::TYPE_REPEATING_SLACK,
+ "gfxFontCache::WordCacheExpiration");
+ mTimerRunning = true;
+ }
+ }
+ }
+ void PauseWordCacheExpirationTimer() {
+ if (mTimerRunning) {
+ mozilla::MutexAutoLock lock(mMutex);
+ if (mTimerRunning && mWordCacheExpirationTimer) {
+ mWordCacheExpirationTimer->Cancel();
+ mTimerRunning = false;
+ }
+ }
+ }
+
+ void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+ FontCacheSizes* aSizes) const;
+ void AddSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+ FontCacheSizes* aSizes) const;
+
+ protected:
+ class MemoryReporter final : public nsIMemoryReporter {
+ ~MemoryReporter() = default;
+
+ public:
+ NS_DECL_ISUPPORTS
+ NS_DECL_NSIMEMORYREPORTER
+ };
+
+ // Observer for notifications that the font cache cares about
+ class Observer final : public nsIObserver {
+ ~Observer() = default;
+
+ public:
+ NS_DECL_ISUPPORTS
+ NS_DECL_NSIOBSERVER
+ };
+
+ nsresult AddObject(gfxFont* aFont) {
+ AutoLock lock(mMutex);
+ return AddObjectLocked(aFont, lock);
+ }
+
+ // This gets called when the timeout has expired on a single-refcount
+ // font; we just delete it.
+ void NotifyExpiredLocked(gfxFont* aFont, const AutoLock&)
+ MOZ_REQUIRES(mMutex) override;
+ void NotifyHandlerEnd() override;
+
+ void DestroyDiscard(nsTArray<gfxFont*>& aDiscard);
+
+ static gfxFontCache* gGlobalCache;
+
+ struct MOZ_STACK_CLASS Key {
+ const gfxFontEntry* mFontEntry;
+ const gfxFontStyle* mStyle;
+ const gfxCharacterMap* mUnicodeRangeMap;
+ Key(const gfxFontEntry* aFontEntry, const gfxFontStyle* aStyle,
+ const gfxCharacterMap* aUnicodeRangeMap)
+ : mFontEntry(aFontEntry),
+ mStyle(aStyle),
+ mUnicodeRangeMap(aUnicodeRangeMap) {}
+ };
+
+ class HashEntry : public PLDHashEntryHdr {
+ public:
+ typedef const Key& KeyType;
+ typedef const Key* KeyTypePointer;
+
+ // When constructing a new entry in the hashtable, we'll leave this
+ // blank. The caller of Put() will fill this in.
+ explicit HashEntry(KeyTypePointer aStr) {}
+
+ bool KeyEquals(const KeyTypePointer aKey) const;
+ static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
+ static PLDHashNumber HashKey(const KeyTypePointer aKey) {
+ return mozilla::HashGeneric(aKey->mStyle->Hash(), aKey->mFontEntry,
+ aKey->mUnicodeRangeMap);
+ }
+ enum { ALLOW_MEMMOVE = true };
+
+ gfxFont* MOZ_UNSAFE_REF("tracking for deferred deletion") mFont = nullptr;
+ };
+
+ nsTHashtable<HashEntry> mFonts MOZ_GUARDED_BY(mMutex);
+
+ nsTArray<gfxFont*> mTrackerDiscard MOZ_GUARDED_BY(mMutex);
+
+ static void WordCacheExpirationTimerCallback(nsITimer* aTimer, void* aCache);
+
+ nsCOMPtr<nsITimer> mWordCacheExpirationTimer MOZ_GUARDED_BY(mMutex);
+ std::atomic<bool> mTimerRunning = false;
+};
+
+class gfxTextPerfMetrics {
+ public:
+ struct TextCounts {
+ uint32_t numContentTextRuns;
+ uint32_t numChromeTextRuns;
+ uint32_t numChars;
+ uint32_t maxTextRunLen;
+ uint32_t wordCacheSpaceRules;
+ uint32_t wordCacheLong;
+ uint32_t wordCacheHit;
+ uint32_t wordCacheMiss;
+ uint32_t fallbackPrefs;
+ uint32_t fallbackSystem;
+ uint32_t textrunConst;
+ uint32_t textrunDestr;
+ uint32_t genericLookups;
+ };
+
+ uint32_t reflowCount;
+
+ // counts per reflow operation
+ TextCounts current;
+
+ // totals for the lifetime of a document
+ TextCounts cumulative;
+
+ gfxTextPerfMetrics() { memset(this, 0, sizeof(gfxTextPerfMetrics)); }
+
+ // add current totals to cumulative ones
+ void Accumulate() {
+ if (current.numChars == 0) {
+ return;
+ }
+ cumulative.numContentTextRuns += current.numContentTextRuns;
+ cumulative.numChromeTextRuns += current.numChromeTextRuns;
+ cumulative.numChars += current.numChars;
+ if (current.maxTextRunLen > cumulative.maxTextRunLen) {
+ cumulative.maxTextRunLen = current.maxTextRunLen;
+ }
+ cumulative.wordCacheSpaceRules += current.wordCacheSpaceRules;
+ cumulative.wordCacheLong += current.wordCacheLong;
+ cumulative.wordCacheHit += current.wordCacheHit;
+ cumulative.wordCacheMiss += current.wordCacheMiss;
+ cumulative.fallbackPrefs += current.fallbackPrefs;
+ cumulative.fallbackSystem += current.fallbackSystem;
+ cumulative.textrunConst += current.textrunConst;
+ cumulative.textrunDestr += current.textrunDestr;
+ cumulative.genericLookups += current.genericLookups;
+ memset(&current, 0, sizeof(current));
+ }
+};
+
+namespace mozilla {
+namespace gfx {
+
+class UnscaledFont;
+
+// Flags that live in the gfxShapedText::mFlags field.
+// (Note that gfxTextRun has an additional mFlags2 field for use
+// by textrun clients like nsTextFrame.)
+//
+// If you add a flag, please add support for it in gfxTextRun::Dump.
+enum class ShapedTextFlags : uint16_t {
+ /**
+ * When set, the text is RTL.
+ */
+ TEXT_IS_RTL = 0x0001,
+ /**
+ * When set, spacing is enabled and the textrun needs to call GetSpacing
+ * on the spacing provider.
+ */
+ TEXT_ENABLE_SPACING = 0x0002,
+ /**
+ * When set, the text has no characters above 255 and it is stored
+ * in the textrun in 8-bit format.
+ */
+ TEXT_IS_8BIT = 0x0004,
+ /**
+ * When set, GetHyphenationBreaks may return true for some character
+ * positions, otherwise it will always return false for all characters.
+ */
+ TEXT_ENABLE_HYPHEN_BREAKS = 0x0008,
+ /**
+ * When set, the RunMetrics::mBoundingBox field will be initialized
+ * properly based on glyph extents, in particular, glyph extents that
+ * overflow the standard font-box (the box defined by the ascent, descent
+ * and advance width of the glyph). When not set, it may just be the
+ * standard font-box even if glyphs overflow.
+ */
+ TEXT_NEED_BOUNDING_BOX = 0x0010,
+ /**
+ * When set, optional ligatures are disabled. Ligatures that are
+ * required for legible text should still be enabled.
+ */
+ TEXT_DISABLE_OPTIONAL_LIGATURES = 0x0020,
+ /**
+ * When set, the textrun should favour speed of construction over
+ * quality. This may involve disabling ligatures and/or kerning or
+ * other effects.
+ */
+ TEXT_OPTIMIZE_SPEED = 0x0040,
+ /**
+ * When set, the textrun should discard control characters instead of
+ * turning them into hexboxes.
+ */
+ TEXT_HIDE_CONTROL_CHARACTERS = 0x0080,
+
+ /**
+ * nsTextFrameThebes sets these, but they're defined here rather than
+ * in nsTextFrameUtils.h because ShapedWord creation/caching also needs
+ * to check the _INCOMING flag
+ */
+ TEXT_TRAILING_ARABICCHAR = 0x0100,
+ /**
+ * When set, the previous character for this textrun was an Arabic
+ * character. This is used for the context detection necessary for
+ * bidi.numeral implementation.
+ */
+ TEXT_INCOMING_ARABICCHAR = 0x0200,
+
+ /**
+ * Set if the textrun should use the OpenType 'math' script.
+ */
+ TEXT_USE_MATH_SCRIPT = 0x0400,
+
+ /*
+ * Bit 0x0800 is currently unused.
+ */
+
+ /**
+ * Field for orientation of the textrun and glyphs within it.
+ * Possible values of the TEXT_ORIENT_MASK field:
+ * TEXT_ORIENT_HORIZONTAL
+ * TEXT_ORIENT_VERTICAL_UPRIGHT
+ * TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT
+ * TEXT_ORIENT_VERTICAL_SIDEWAYS_LEFT
+ * TEXT_ORIENT_VERTICAL_MIXED
+ * For all VERTICAL settings, the x and y coordinates of glyph
+ * positions are exchanged, so that simple advances are vertical.
+ *
+ * The MIXED value indicates vertical textRuns for which the CSS
+ * text-orientation property is 'mixed', but is never used for
+ * individual glyphRuns; it will be resolved to either UPRIGHT
+ * or SIDEWAYS_RIGHT according to the UTR50 properties of the
+ * characters, and separate glyphRuns created for the resulting
+ * glyph orientations.
+ */
+ TEXT_ORIENT_MASK = 0x7000,
+ TEXT_ORIENT_HORIZONTAL = 0x0000,
+ TEXT_ORIENT_VERTICAL_UPRIGHT = 0x1000,
+ TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT = 0x2000,
+ TEXT_ORIENT_VERTICAL_MIXED = 0x3000,
+ TEXT_ORIENT_VERTICAL_SIDEWAYS_LEFT = 0x4000,
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(ShapedTextFlags)
+} // namespace gfx
+} // namespace mozilla
+
+class gfxTextRunFactory {
+ // Used by stylo
+ NS_INLINE_DECL_THREADSAFE_REFCOUNTING(gfxTextRunFactory)
+
+ public:
+ typedef mozilla::gfx::DrawTarget DrawTarget;
+
+ /**
+ * This record contains all the parameters needed to initialize a textrun.
+ */
+ struct MOZ_STACK_CLASS Parameters {
+ // Shape text params suggesting where the textrun will be rendered
+ DrawTarget* mDrawTarget;
+ // Pointer to arbitrary user data (which should outlive the textrun)
+ void* mUserData;
+ // A description of which characters have been stripped from the original
+ // DOM string to produce the characters in the textrun. May be null
+ // if that information is not relevant.
+ gfxSkipChars* mSkipChars;
+ // A list of where linebreaks are currently placed in the textrun. May
+ // be null if mInitialBreakCount is zero.
+ uint32_t* mInitialBreaks;
+ uint32_t mInitialBreakCount;
+ // The ratio to use to convert device pixels to application layout units
+ int32_t mAppUnitsPerDevUnit;
+ };
+
+ protected:
+ // Protected destructor, to discourage deletion outside of Release():
+ virtual ~gfxTextRunFactory();
+};
+
+/**
+ * gfxFontShaper
+ *
+ * This class implements text shaping (character to glyph mapping and
+ * glyph layout). There is a gfxFontShaper subclass for each text layout
+ * technology (uniscribe, core text, harfbuzz,....) we support.
+ *
+ * The shaper is responsible for setting up glyph data in gfxTextRuns.
+ *
+ * A generic, platform-independent shaper relies only on the standard
+ * gfxFont interface and can work with any concrete subclass of gfxFont.
+ *
+ * Platform-specific implementations designed to interface to platform
+ * shaping APIs such as Uniscribe or CoreText may rely on features of a
+ * specific font subclass to access native font references
+ * (such as CTFont, HFONT, DWriteFont, etc).
+ */
+
+class gfxFontShaper {
+ public:
+ typedef mozilla::gfx::DrawTarget DrawTarget;
+ typedef mozilla::intl::Script Script;
+
+ enum class RoundingFlags : uint8_t { kRoundX = 0x01, kRoundY = 0x02 };
+
+ explicit gfxFontShaper(gfxFont* aFont) : mFont(aFont) {
+ NS_ASSERTION(aFont, "shaper requires a valid font!");
+ }
+
+ virtual ~gfxFontShaper() = default;
+
+ // Shape a piece of text and store the resulting glyph data into
+ // aShapedText. Parameters aOffset/aLength indicate the range of
+ // aShapedText to be updated; aLength is also the length of aText.
+ virtual bool ShapeText(DrawTarget* aDrawTarget, const char16_t* aText,
+ uint32_t aOffset, uint32_t aLength, Script aScript,
+ nsAtom* aLanguage, // may be null, indicating no
+ // lang-specific shaping to be
+ // applied
+ bool aVertical, RoundingFlags aRounding,
+ gfxShapedText* aShapedText) = 0;
+
+ gfxFont* GetFont() const { return mFont; }
+
+ static void MergeFontFeatures(
+ const gfxFontStyle* aStyle, const nsTArray<gfxFontFeature>& aFontFeatures,
+ bool aDisableLigatures, const nsACString& aFamilyName, bool aAddSmallCaps,
+ void (*aHandleFeature)(uint32_t, uint32_t, void*),
+ void* aHandleFeatureData);
+
+ protected:
+ // the font this shaper is working with. The font owns a UniquePtr reference
+ // to this object, and will destroy it before it dies. Thus, mFont will always
+ // be valid.
+ gfxFont* MOZ_NON_OWNING_REF mFont;
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(gfxFontShaper::RoundingFlags)
+
+/*
+ * gfxShapedText is an abstract superclass for gfxShapedWord and gfxTextRun.
+ * These are objects that store a list of zero or more glyphs for each
+ * character. For each glyph we store the glyph ID, the advance, and possibly
+ * x/y-offsets. The idea is that a string is rendered by a loop that draws each
+ * glyph at its designated offset from the current point, then advances the
+ * current point by the glyph's advance in the direction of the textrun (LTR or
+ * RTL). Each glyph advance is always rounded to the nearest appunit; this
+ * ensures consistent results when dividing the text in a textrun into multiple
+ * text frames (frame boundaries are always aligned to appunits). We optimize
+ * for the case where a character has a single glyph and zero xoffset and
+ * yoffset, and the glyph ID and advance are in a reasonable range so we can
+ * pack all necessary data into 32 bits.
+ *
+ * gfxFontShaper can shape text into either a gfxShapedWord (cached by a
+ * gfxFont) or directly into a gfxTextRun (for cases where we want to shape
+ * textruns in their entirety rather than using cached words, because there may
+ * be layout features that depend on the inter-word spaces).
+ */
+class gfxShapedText {
+ public:
+ typedef mozilla::intl::Script Script;
+
+ gfxShapedText(uint32_t aLength, mozilla::gfx::ShapedTextFlags aFlags,
+ uint16_t aAppUnitsPerDevUnit)
+ : mLength(aLength),
+ mFlags(aFlags),
+ mAppUnitsPerDevUnit(aAppUnitsPerDevUnit) {}
+
+ virtual ~gfxShapedText() = default;
+
+ /**
+ * This class records the information associated with a character in the
+ * input string. It's optimized for the case where there is one glyph
+ * representing that character alone.
+ *
+ * A character can have zero or more associated glyphs. Each glyph
+ * has an advance width and an x and y offset.
+ * A character may be the start of a cluster.
+ * A character may be the start of a ligature group.
+ * A character can be "missing", indicating that the system is unable
+ * to render the character.
+ *
+ * All characters in a ligature group conceptually share all the glyphs
+ * associated with the characters in a group.
+ */
+ class CompressedGlyph {
+ public:
+ enum {
+ // Indicates that a cluster and ligature group starts at this
+ // character; this character has a single glyph with a reasonable
+ // advance and zero offsets. A "reasonable" advance
+ // is one that fits in the available bits (currently 12) (specified
+ // in appunits).
+ FLAG_IS_SIMPLE_GLYPH = 0x80000000U,
+
+ // These flags are applicable to both "simple" and "complex" records.
+ COMMON_FLAGS_MASK = 0x70000000U,
+
+ // Indicates whether a linebreak is allowed before this character;
+ // this is a two-bit field that holds a FLAG_BREAK_TYPE_xxx value
+ // indicating the kind of linebreak (if any) allowed here.
+ FLAGS_CAN_BREAK_BEFORE = 0x60000000U,
+
+ FLAGS_CAN_BREAK_SHIFT = 29,
+ FLAG_BREAK_TYPE_NONE = 0,
+ FLAG_BREAK_TYPE_NORMAL = 1,
+ FLAG_BREAK_TYPE_HYPHEN = 2,
+ // Allow break before this position if needed to avoid overflow:
+ FLAG_BREAK_TYPE_EMERGENCY_WRAP = 3,
+
+ FLAG_CHAR_IS_SPACE = 0x10000000U,
+
+ // Fields present only when FLAG_IS_SIMPLE_GLYPH is /true/.
+ // The advance is stored in appunits as a 12-bit field:
+ ADVANCE_MASK = 0x0FFF0000U,
+ ADVANCE_SHIFT = 16,
+ // and the glyph ID is stored in the low 16 bits.
+ GLYPH_MASK = 0x0000FFFFU,
+
+ // Fields present only when FLAG_IS_SIMPLE_GLYPH is /false/.
+ // Non-simple glyphs may or may not have glyph data in the
+ // corresponding mDetailedGlyphs entry. They have a glyph count
+ // stored in the low 16 bits, and the following flag bits:
+ GLYPH_COUNT_MASK = 0x0000FFFFU,
+
+ // When NOT set, indicates that this character corresponds to a
+ // missing glyph and should be skipped (or possibly, render the character
+ // Unicode value in some special way). If there are glyphs,
+ // the mGlyphID is actually the UTF16 character code. The bit is
+ // inverted so we can memset the array to zero to indicate all missing.
+ FLAG_NOT_MISSING = 0x010000,
+ FLAG_NOT_CLUSTER_START = 0x020000,
+ FLAG_NOT_LIGATURE_GROUP_START = 0x040000,
+ // Flag bit 0x080000 is currently unused.
+
+ // Certain types of characters are marked so that they can be given
+ // special treatment in rendering. This may require use of a "complex"
+ // CompressedGlyph record even for a character that would otherwise be
+ // treated as "simple".
+ CHAR_TYPE_FLAGS_MASK = 0xF00000,
+ FLAG_CHAR_IS_TAB = 0x100000,
+ FLAG_CHAR_IS_NEWLINE = 0x200000,
+ // Per CSS Text Decoration Module Level 3, emphasis marks are not
+ // drawn for any character in Unicode categories Z*, Cc, Cf, and Cn
+ // which is not combined with any combining characters. This flag is
+ // set for all those characters except 0x20 whitespace.
+ FLAG_CHAR_NO_EMPHASIS_MARK = 0x400000,
+ // Per CSS Text, letter-spacing is not applied to formatting chars
+ // (category Cf). We mark those in the textrun so as to be able to
+ // skip them when setting up spacing in nsTextFrame.
+ FLAG_CHAR_IS_FORMATTING_CONTROL = 0x800000,
+
+ // The bits 0x0F000000 are currently unused in non-simple glyphs.
+ };
+
+ // "Simple glyphs" have a simple glyph ID, simple advance and their
+ // x and y offsets are zero. Also the glyph extents do not overflow
+ // the font-box defined by the font ascent, descent and glyph advance width.
+ // These case is optimized to avoid storing DetailedGlyphs.
+
+ // Returns true if the glyph ID aGlyph fits into the compressed
+ // representation
+ static bool IsSimpleGlyphID(uint32_t aGlyph) {
+ return (aGlyph & GLYPH_MASK) == aGlyph;
+ }
+ // Returns true if the advance aAdvance fits into the compressed
+ // representation. aAdvance is in appunits.
+ static bool IsSimpleAdvance(uint32_t aAdvance) {
+ return (aAdvance & (ADVANCE_MASK >> ADVANCE_SHIFT)) == aAdvance;
+ }
+
+ bool IsSimpleGlyph() const { return mValue & FLAG_IS_SIMPLE_GLYPH; }
+ uint32_t GetSimpleAdvance() const {
+ MOZ_ASSERT(IsSimpleGlyph());
+ return (mValue & ADVANCE_MASK) >> ADVANCE_SHIFT;
+ }
+ uint32_t GetSimpleGlyph() const {
+ MOZ_ASSERT(IsSimpleGlyph());
+ return mValue & GLYPH_MASK;
+ }
+
+ bool IsMissing() const {
+ return !(mValue & (FLAG_NOT_MISSING | FLAG_IS_SIMPLE_GLYPH));
+ }
+ bool IsClusterStart() const {
+ return IsSimpleGlyph() || !(mValue & FLAG_NOT_CLUSTER_START);
+ }
+ bool IsLigatureGroupStart() const {
+ return IsSimpleGlyph() || !(mValue & FLAG_NOT_LIGATURE_GROUP_START);
+ }
+ bool IsLigatureContinuation() const {
+ return !IsSimpleGlyph() &&
+ (mValue & (FLAG_NOT_LIGATURE_GROUP_START | FLAG_NOT_MISSING)) ==
+ (FLAG_NOT_LIGATURE_GROUP_START | FLAG_NOT_MISSING);
+ }
+
+ // Return true if the original character was a normal (breakable,
+ // trimmable) space (U+0020). Not true for other characters that
+ // may happen to map to the space glyph (U+00A0).
+ bool CharIsSpace() const { return mValue & FLAG_CHAR_IS_SPACE; }
+
+ bool CharIsTab() const {
+ return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_TAB);
+ }
+ bool CharIsNewline() const {
+ return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_NEWLINE);
+ }
+ bool CharMayHaveEmphasisMark() const {
+ return !CharIsSpace() &&
+ (IsSimpleGlyph() || !(mValue & FLAG_CHAR_NO_EMPHASIS_MARK));
+ }
+ bool CharIsFormattingControl() const {
+ return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_FORMATTING_CONTROL);
+ }
+
+ uint32_t CharTypeFlags() const {
+ return IsSimpleGlyph() ? 0 : (mValue & CHAR_TYPE_FLAGS_MASK);
+ }
+
+ void SetClusterStart(bool aIsClusterStart) {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ if (aIsClusterStart) {
+ mValue &= ~FLAG_NOT_CLUSTER_START;
+ } else {
+ mValue |= FLAG_NOT_CLUSTER_START;
+ }
+ }
+
+ uint8_t CanBreakBefore() const {
+ return (mValue & FLAGS_CAN_BREAK_BEFORE) >> FLAGS_CAN_BREAK_SHIFT;
+ }
+ // Returns FLAGS_CAN_BREAK_BEFORE if the setting changed, 0 otherwise
+ uint32_t SetCanBreakBefore(uint8_t aCanBreakBefore) {
+ MOZ_ASSERT(aCanBreakBefore <= 3, "Bogus break-flags value!");
+ uint32_t breakMask = (uint32_t(aCanBreakBefore) << FLAGS_CAN_BREAK_SHIFT);
+ uint32_t toggle = breakMask ^ (mValue & FLAGS_CAN_BREAK_BEFORE);
+ mValue ^= toggle;
+ return toggle;
+ }
+
+ // Create a CompressedGlyph value representing a simple glyph with
+ // no extra flags (line-break or is_space) set.
+ static CompressedGlyph MakeSimpleGlyph(uint32_t aAdvanceAppUnits,
+ uint32_t aGlyph) {
+ MOZ_ASSERT(IsSimpleAdvance(aAdvanceAppUnits));
+ MOZ_ASSERT(IsSimpleGlyphID(aGlyph));
+ CompressedGlyph g;
+ g.mValue =
+ FLAG_IS_SIMPLE_GLYPH | (aAdvanceAppUnits << ADVANCE_SHIFT) | aGlyph;
+ return g;
+ }
+
+ // Assign a simple glyph value to an existing CompressedGlyph record,
+ // preserving line-break/is-space flags if present.
+ CompressedGlyph& SetSimpleGlyph(uint32_t aAdvanceAppUnits,
+ uint32_t aGlyph) {
+ MOZ_ASSERT(!CharTypeFlags(), "Char type flags lost");
+ mValue = (mValue & COMMON_FLAGS_MASK) |
+ MakeSimpleGlyph(aAdvanceAppUnits, aGlyph).mValue;
+ return *this;
+ }
+
+ // Create a CompressedGlyph value representing a complex glyph record,
+ // without any line-break or char-type flags.
+ static CompressedGlyph MakeComplex(bool aClusterStart,
+ bool aLigatureStart) {
+ CompressedGlyph g;
+ g.mValue = FLAG_NOT_MISSING |
+ (aClusterStart ? 0 : FLAG_NOT_CLUSTER_START) |
+ (aLigatureStart ? 0 : FLAG_NOT_LIGATURE_GROUP_START);
+ return g;
+ }
+
+ // Assign a complex glyph value to an existing CompressedGlyph record,
+ // preserving line-break/char-type flags if present.
+ // This sets the glyphCount to zero; it will be updated when we call
+ // gfxShapedText::SetDetailedGlyphs.
+ CompressedGlyph& SetComplex(bool aClusterStart, bool aLigatureStart) {
+ mValue = (mValue & COMMON_FLAGS_MASK) | CharTypeFlags() |
+ MakeComplex(aClusterStart, aLigatureStart).mValue;
+ return *this;
+ }
+
+ /**
+ * Mark a glyph record as being a missing-glyph.
+ * Missing glyphs are treated as ligature group starts; don't mess with
+ * the cluster-start flag (see bugs 618870 and 619286).
+ * We also preserve the glyph count here, as this is used after any
+ * required DetailedGlyphs (to store the char code for a hexbox) has been
+ * set up.
+ * This must be called *after* SetDetailedGlyphs is used for the relevant
+ * offset in the shaped-word, because that will mark it as not-missing.
+ */
+ CompressedGlyph& SetMissing() {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ mValue &= ~(FLAG_NOT_MISSING | FLAG_NOT_LIGATURE_GROUP_START);
+ return *this;
+ }
+
+ uint32_t GetGlyphCount() const {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ return mValue & GLYPH_COUNT_MASK;
+ }
+ void SetGlyphCount(uint32_t aGlyphCount) {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ MOZ_ASSERT(GetGlyphCount() == 0, "Glyph count already set");
+ MOZ_ASSERT(aGlyphCount <= 0xffff, "Glyph count out of range");
+ mValue |= FLAG_NOT_MISSING | aGlyphCount;
+ }
+
+ void SetIsSpace() { mValue |= FLAG_CHAR_IS_SPACE; }
+ void SetIsTab() {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ mValue |= FLAG_CHAR_IS_TAB;
+ }
+ void SetIsNewline() {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ mValue |= FLAG_CHAR_IS_NEWLINE;
+ }
+ void SetNoEmphasisMark() {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ mValue |= FLAG_CHAR_NO_EMPHASIS_MARK;
+ }
+ void SetIsFormattingControl() {
+ MOZ_ASSERT(!IsSimpleGlyph());
+ mValue |= FLAG_CHAR_IS_FORMATTING_CONTROL;
+ }
+
+ private:
+ uint32_t mValue;
+ };
+
+ // Accessor for the array of CompressedGlyph records, which will be in
+ // a different place in gfxShapedWord vs gfxTextRun
+ virtual const CompressedGlyph* GetCharacterGlyphs() const = 0;
+ virtual CompressedGlyph* GetCharacterGlyphs() = 0;
+
+ /**
+ * When the glyphs for a character don't fit into a CompressedGlyph record
+ * in SimpleGlyph format, we use an array of DetailedGlyphs instead.
+ */
+ struct DetailedGlyph {
+ // The glyphID, or the Unicode character if this is a missing glyph
+ uint32_t mGlyphID;
+ // The advance of the glyph, in appunits.
+ // mAdvance is in the text direction (RTL or LTR),
+ // and will normally be non-negative (although this is not guaranteed)
+ int32_t mAdvance;
+ // The offset from the glyph's default position, in line-relative
+ // coordinates (so mOffset.x is an offset in the line-right direction,
+ // and mOffset.y is an offset in line-downwards direction).
+ // These values are in floating-point appUnits.
+ mozilla::gfx::Point mOffset;
+ };
+
+ // Store DetailedGlyph records for the given index. (This does not modify
+ // the associated CompressedGlyph character-type or break flags.)
+ void SetDetailedGlyphs(uint32_t aIndex, uint32_t aGlyphCount,
+ const DetailedGlyph* aGlyphs);
+
+ void SetMissingGlyph(uint32_t aIndex, uint32_t aChar, gfxFont* aFont);
+
+ void SetIsSpace(uint32_t aIndex) {
+ GetCharacterGlyphs()[aIndex].SetIsSpace();
+ }
+
+ bool HasDetailedGlyphs() const { return mDetailedGlyphs != nullptr; }
+
+ bool IsLigatureGroupStart(uint32_t aPos) {
+ NS_ASSERTION(aPos < GetLength(), "aPos out of range");
+ return GetCharacterGlyphs()[aPos].IsLigatureGroupStart();
+ }
+
+ // NOTE that this must not be called for a character offset that does
+ // not have any DetailedGlyph records; callers must have verified that
+ // GetCharacterGlyphs()[aCharIndex].GetGlyphCount() is greater than zero.
+ DetailedGlyph* GetDetailedGlyphs(uint32_t aCharIndex) const {
+ NS_ASSERTION(GetCharacterGlyphs() && HasDetailedGlyphs() &&
+ !GetCharacterGlyphs()[aCharIndex].IsSimpleGlyph() &&
+ GetCharacterGlyphs()[aCharIndex].GetGlyphCount() > 0,
+ "invalid use of GetDetailedGlyphs; check the caller!");
+ return mDetailedGlyphs->Get(aCharIndex);
+ }
+
+ void ApplyTrackingToClusters(gfxFloat aTrackingAdjustment, uint32_t aOffset,
+ uint32_t aLength);
+
+ // Mark clusters in the CompressedGlyph records, starting at aOffset,
+ // based on the Unicode properties of the text in aString.
+ // This is also responsible to set the IsSpace flag for space characters.
+ void SetupClusterBoundaries(uint32_t aOffset, const char16_t* aString,
+ uint32_t aLength);
+ // In 8-bit text, there won't actually be any clusters, but we still need
+ // the space-marking functionality.
+ void SetupClusterBoundaries(uint32_t aOffset, const uint8_t* aString,
+ uint32_t aLength);
+
+ mozilla::gfx::ShapedTextFlags GetFlags() const { return mFlags; }
+
+ bool IsVertical() const {
+ return (GetFlags() & mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_MASK) !=
+ mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_HORIZONTAL;
+ }
+
+ bool UseCenterBaseline() const {
+ mozilla::gfx::ShapedTextFlags orient =
+ GetFlags() & mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_MASK;
+ return orient ==
+ mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_MIXED ||
+ orient ==
+ mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_UPRIGHT;
+ }
+
+ bool IsRightToLeft() const {
+ return (GetFlags() & mozilla::gfx::ShapedTextFlags::TEXT_IS_RTL) ==
+ mozilla::gfx::ShapedTextFlags::TEXT_IS_RTL;
+ }
+
+ bool IsSidewaysLeft() const {
+ return (GetFlags() & mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_MASK) ==
+ mozilla::gfx::ShapedTextFlags::TEXT_ORIENT_VERTICAL_SIDEWAYS_LEFT;
+ }
+
+ // Return true if the logical inline direction is reversed compared to
+ // normal physical coordinates (i.e. if it is leftwards or upwards)
+ bool IsInlineReversed() const { return IsSidewaysLeft() != IsRightToLeft(); }
+
+ gfxFloat GetDirection() const { return IsInlineReversed() ? -1.0f : 1.0f; }
+
+ bool DisableLigatures() const {
+ return (GetFlags() &
+ mozilla::gfx::ShapedTextFlags::TEXT_DISABLE_OPTIONAL_LIGATURES) ==
+ mozilla::gfx::ShapedTextFlags::TEXT_DISABLE_OPTIONAL_LIGATURES;
+ }
+
+ bool TextIs8Bit() const {
+ return (GetFlags() & mozilla::gfx::ShapedTextFlags::TEXT_IS_8BIT) ==
+ mozilla::gfx::ShapedTextFlags::TEXT_IS_8BIT;
+ }
+
+ int32_t GetAppUnitsPerDevUnit() const { return mAppUnitsPerDevUnit; }
+
+ uint32_t GetLength() const { return mLength; }
+
+ bool FilterIfIgnorable(uint32_t aIndex, uint32_t aCh);
+
+ protected:
+ // Allocate aCount DetailedGlyphs for the given index
+ DetailedGlyph* AllocateDetailedGlyphs(uint32_t aCharIndex, uint32_t aCount);
+
+ // Ensure the glyph on the given index is complex glyph so that we can use
+ // it to record specific characters that layout may need to detect.
+ void EnsureComplexGlyph(uint32_t aIndex, CompressedGlyph& aGlyph) {
+ MOZ_ASSERT(GetCharacterGlyphs() + aIndex == &aGlyph);
+ if (aGlyph.IsSimpleGlyph()) {
+ DetailedGlyph details = {aGlyph.GetSimpleGlyph(),
+ (int32_t)aGlyph.GetSimpleAdvance(),
+ mozilla::gfx::Point()};
+ aGlyph.SetComplex(true, true);
+ SetDetailedGlyphs(aIndex, 1, &details);
+ }
+ }
+
+ // For characters whose glyph data does not fit the "simple" glyph criteria
+ // in CompressedGlyph, we use a sorted array to store the association
+ // between the source character offset and an index into an array
+ // DetailedGlyphs. The CompressedGlyph record includes a count of
+ // the number of DetailedGlyph records that belong to the character,
+ // starting at the given index.
+ class DetailedGlyphStore {
+ public:
+ DetailedGlyphStore() = default;
+
+ // This is optimized for the most common calling patterns:
+ // we rarely need random access to the records, access is most commonly
+ // sequential through the textRun, so we record the last-used index
+ // and check whether the caller wants the same record again, or the
+ // next; if not, it's most likely we're starting over from the start
+ // of the run, so we check the first entry before resorting to binary
+ // search as a last resort.
+ // NOTE that this must not be called for a character offset that does
+ // not have any DetailedGlyph records; callers must have verified that
+ // mCharacterGlyphs[aOffset].GetGlyphCount() is greater than zero
+ // before calling this, otherwise the assertions here will fire (in a
+ // debug build), and we'll probably crash.
+ DetailedGlyph* Get(uint32_t aOffset) {
+ NS_ASSERTION(mOffsetToIndex.Length() > 0, "no detailed glyph records!");
+ DetailedGlyph* details = mDetails.Elements();
+ // check common cases (fwd iteration, initial entry, etc) first
+ if (mLastUsed < mOffsetToIndex.Length() - 1 &&
+ aOffset == mOffsetToIndex[mLastUsed + 1].mOffset) {
+ ++mLastUsed;
+ } else if (aOffset == mOffsetToIndex[0].mOffset) {
+ mLastUsed = 0;
+ } else if (aOffset == mOffsetToIndex[mLastUsed].mOffset) {
+ // do nothing
+ } else if (mLastUsed > 0 &&
+ aOffset == mOffsetToIndex[mLastUsed - 1].mOffset) {
+ --mLastUsed;
+ } else {
+ mLastUsed = mOffsetToIndex.BinaryIndexOf(aOffset, CompareToOffset());
+ }
+ NS_ASSERTION(mLastUsed != nsTArray<DGRec>::NoIndex,
+ "detailed glyph record missing!");
+ return details + mOffsetToIndex[mLastUsed].mIndex;
+ }
+
+ DetailedGlyph* Allocate(uint32_t aOffset, uint32_t aCount) {
+ uint32_t detailIndex = mDetails.Length();
+ DetailedGlyph* details = mDetails.AppendElements(aCount);
+ // We normally set up glyph records sequentially, so the common case
+ // here is to append new records to the mOffsetToIndex array;
+ // test for that before falling back to the InsertElementSorted
+ // method.
+ if (mOffsetToIndex.Length() == 0 ||
+ aOffset > mOffsetToIndex[mOffsetToIndex.Length() - 1].mOffset) {
+ mOffsetToIndex.AppendElement(DGRec(aOffset, detailIndex));
+ } else {
+ mOffsetToIndex.InsertElementSorted(DGRec(aOffset, detailIndex),
+ CompareRecordOffsets());
+ }
+ return details;
+ }
+
+ size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) {
+ return aMallocSizeOf(this) +
+ mDetails.ShallowSizeOfExcludingThis(aMallocSizeOf) +
+ mOffsetToIndex.ShallowSizeOfExcludingThis(aMallocSizeOf);
+ }
+
+ private:
+ struct DGRec {
+ DGRec(const uint32_t& aOffset, const uint32_t& aIndex)
+ : mOffset(aOffset), mIndex(aIndex) {}
+ uint32_t mOffset; // source character offset in the textrun
+ uint32_t mIndex; // index where this char's DetailedGlyphs begin
+ };
+
+ struct CompareToOffset {
+ bool Equals(const DGRec& a, const uint32_t& b) const {
+ return a.mOffset == b;
+ }
+ bool LessThan(const DGRec& a, const uint32_t& b) const {
+ return a.mOffset < b;
+ }
+ };
+
+ struct CompareRecordOffsets {
+ bool Equals(const DGRec& a, const DGRec& b) const {
+ return a.mOffset == b.mOffset;
+ }
+ bool LessThan(const DGRec& a, const DGRec& b) const {
+ return a.mOffset < b.mOffset;
+ }
+ };
+
+ // Concatenated array of all the DetailedGlyph records needed for the
+ // textRun; individual character offsets are associated with indexes
+ // into this array via the mOffsetToIndex table.
+ nsTArray<DetailedGlyph> mDetails;
+
+ // For each character offset that needs DetailedGlyphs, we record the
+ // index in mDetails where the list of glyphs begins. This array is
+ // sorted by mOffset.
+ nsTArray<DGRec> mOffsetToIndex;
+
+ // Records the most recently used index into mOffsetToIndex, so that
+ // we can support sequential access more quickly than just doing
+ // a binary search each time.
+ nsTArray<DGRec>::index_type mLastUsed = 0;
+ };
+
+ mozilla::UniquePtr<DetailedGlyphStore> mDetailedGlyphs;
+
+ // Number of char16_t characters and CompressedGlyph glyph records
+ uint32_t mLength;
+
+ // Shaping flags (direction, ligature-suppression)
+ mozilla::gfx::ShapedTextFlags mFlags;
+
+ uint16_t mAppUnitsPerDevUnit;
+};
+
+/*
+ * gfxShapedWord: an individual (space-delimited) run of text shaped with a
+ * particular font, without regard to external context.
+ *
+ * The glyph data is copied into gfxTextRuns as needed from the cache of
+ * ShapedWords associated with each gfxFont instance.
+ */
+class gfxShapedWord final : public gfxShapedText {
+ public:
+ typedef mozilla::intl::Script Script;
+
+ // Create a ShapedWord that can hold glyphs for aLength characters,
+ // with mCharacterGlyphs sized appropriately.
+ //
+ // Returns null on allocation failure (does NOT use infallible alloc)
+ // so caller must check for success.
+ //
+ // This does NOT perform shaping, so the returned word contains no
+ // glyph data; the caller must call gfxFont::ShapeText() with appropriate
+ // parameters to set up the glyphs.
+ static gfxShapedWord* Create(const uint8_t* aText, uint32_t aLength,
+ Script aRunScript, nsAtom* aLanguage,
+ uint16_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags,
+ gfxFontShaper::RoundingFlags aRounding) {
+ NS_ASSERTION(aLength <= gfxPlatform::GetPlatform()->WordCacheCharLimit(),
+ "excessive length for gfxShapedWord!");
+
+ // Compute size needed including the mCharacterGlyphs array
+ // and a copy of the original text
+ uint32_t size = offsetof(gfxShapedWord, mCharGlyphsStorage) +
+ aLength * (sizeof(CompressedGlyph) + sizeof(uint8_t));
+ void* storage = malloc(size);
+ if (!storage) {
+ return nullptr;
+ }
+
+ // Construct in the pre-allocated storage, using placement new
+ return new (storage) gfxShapedWord(aText, aLength, aRunScript, aLanguage,
+ aAppUnitsPerDevUnit, aFlags, aRounding);
+ }
+
+ static gfxShapedWord* Create(const char16_t* aText, uint32_t aLength,
+ Script aRunScript, nsAtom* aLanguage,
+ uint16_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags,
+ gfxFontShaper::RoundingFlags aRounding) {
+ NS_ASSERTION(aLength <= gfxPlatform::GetPlatform()->WordCacheCharLimit(),
+ "excessive length for gfxShapedWord!");
+
+ // In the 16-bit version of Create, if the TEXT_IS_8BIT flag is set,
+ // then we convert the text to an 8-bit version and call the 8-bit
+ // Create function instead.
+ if (aFlags & mozilla::gfx::ShapedTextFlags::TEXT_IS_8BIT) {
+ nsAutoCString narrowText;
+ LossyAppendUTF16toASCII(nsDependentSubstring(aText, aLength), narrowText);
+ return Create((const uint8_t*)(narrowText.BeginReading()), aLength,
+ aRunScript, aLanguage, aAppUnitsPerDevUnit, aFlags,
+ aRounding);
+ }
+
+ uint32_t size = offsetof(gfxShapedWord, mCharGlyphsStorage) +
+ aLength * (sizeof(CompressedGlyph) + sizeof(char16_t));
+ void* storage = malloc(size);
+ if (!storage) {
+ return nullptr;
+ }
+
+ return new (storage) gfxShapedWord(aText, aLength, aRunScript, aLanguage,
+ aAppUnitsPerDevUnit, aFlags, aRounding);
+ }
+
+ // Override operator delete to properly free the object that was
+ // allocated via malloc.
+ void operator delete(void* p) { free(p); }
+
+ const CompressedGlyph* GetCharacterGlyphs() const override {
+ return &mCharGlyphsStorage[0];
+ }
+ CompressedGlyph* GetCharacterGlyphs() override {
+ return &mCharGlyphsStorage[0];
+ }
+
+ const uint8_t* Text8Bit() const {
+ NS_ASSERTION(TextIs8Bit(), "invalid use of Text8Bit()");
+ return reinterpret_cast<const uint8_t*>(mCharGlyphsStorage + GetLength());
+ }
+
+ const char16_t* TextUnicode() const {
+ NS_ASSERTION(!TextIs8Bit(), "invalid use of TextUnicode()");
+ return reinterpret_cast<const char16_t*>(mCharGlyphsStorage + GetLength());
+ }
+
+ char16_t GetCharAt(uint32_t aOffset) const {
+ NS_ASSERTION(aOffset < GetLength(), "aOffset out of range");
+ return TextIs8Bit() ? char16_t(Text8Bit()[aOffset])
+ : TextUnicode()[aOffset];
+ }
+
+ Script GetScript() const { return mScript; }
+ nsAtom* GetLanguage() const { return mLanguage.get(); }
+
+ gfxFontShaper::RoundingFlags GetRounding() const { return mRounding; }
+
+ void ResetAge() { mAgeCounter = 0; }
+ uint32_t IncrementAge() { return ++mAgeCounter; }
+
+ // Helper used when hashing a word for the shaped-word caches
+ static uint32_t HashMix(uint32_t aHash, char16_t aCh) {
+ return (aHash >> 28) ^ (aHash << 4) ^ aCh;
+ }
+
+ size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
+
+ private:
+ // so that gfxTextRun can share our DetailedGlyphStore class
+ friend class gfxTextRun;
+
+ // Construct storage for a ShapedWord, ready to receive glyph data
+ gfxShapedWord(const uint8_t* aText, uint32_t aLength, Script aRunScript,
+ nsAtom* aLanguage, uint16_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags,
+ gfxFontShaper::RoundingFlags aRounding)
+ : gfxShapedText(aLength,
+ aFlags | mozilla::gfx::ShapedTextFlags::TEXT_IS_8BIT,
+ aAppUnitsPerDevUnit),
+ mLanguage(aLanguage),
+ mScript(aRunScript),
+ mRounding(aRounding),
+ mAgeCounter(0) {
+ memset(mCharGlyphsStorage, 0, aLength * sizeof(CompressedGlyph));
+ uint8_t* text = reinterpret_cast<uint8_t*>(&mCharGlyphsStorage[aLength]);
+ memcpy(text, aText, aLength * sizeof(uint8_t));
+ SetupClusterBoundaries(0, aText, aLength);
+ }
+
+ gfxShapedWord(const char16_t* aText, uint32_t aLength, Script aRunScript,
+ nsAtom* aLanguage, uint16_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags,
+ gfxFontShaper::RoundingFlags aRounding)
+ : gfxShapedText(aLength, aFlags, aAppUnitsPerDevUnit),
+ mLanguage(aLanguage),
+ mScript(aRunScript),
+ mRounding(aRounding),
+ mAgeCounter(0) {
+ memset(mCharGlyphsStorage, 0, aLength * sizeof(CompressedGlyph));
+ char16_t* text = reinterpret_cast<char16_t*>(&mCharGlyphsStorage[aLength]);
+ memcpy(text, aText, aLength * sizeof(char16_t));
+ SetupClusterBoundaries(0, aText, aLength);
+ }
+
+ RefPtr<nsAtom> mLanguage;
+ Script mScript;
+
+ gfxFontShaper::RoundingFlags mRounding;
+
+ // With multithreaded shaping, this may be updated by any thread.
+ std::atomic<uint32_t> mAgeCounter;
+
+ // The mCharGlyphsStorage array is actually a variable-size member;
+ // when the ShapedWord is created, its size will be increased as necessary
+ // to allow the proper number of glyphs to be stored.
+ // The original text, in either 8-bit or 16-bit form, will be stored
+ // immediately following the CompressedGlyphs.
+ CompressedGlyph mCharGlyphsStorage[1];
+};
+
+class GlyphBufferAzure;
+struct TextRunDrawParams;
+struct FontDrawParams;
+struct EmphasisMarkDrawParams;
+
+class gfxFont {
+ friend class gfxHarfBuzzShaper;
+ friend class gfxGraphiteShaper;
+
+ protected:
+ using DrawTarget = mozilla::gfx::DrawTarget;
+ using Script = mozilla::intl::Script;
+ using SVGContextPaint = mozilla::SVGContextPaint;
+
+ using RoundingFlags = gfxFontShaper::RoundingFlags;
+ using ShapedTextFlags = mozilla::gfx::ShapedTextFlags;
+
+ public:
+ using FontSlantStyle = mozilla::FontSlantStyle;
+ using FontSizeAdjust = mozilla::StyleFontSizeAdjust;
+
+ NS_INLINE_DECL_THREADSAFE_REFCOUNTING_WITH_DESTROY(gfxFont, MaybeDestroy())
+ int32_t GetRefCount() { return int32_t(mRefCnt); }
+
+ // options to specify the kind of AA to be used when creating a font
+ typedef enum : uint8_t {
+ kAntialiasDefault,
+ kAntialiasNone,
+ kAntialiasGrayscale,
+ kAntialiasSubpixel
+ } AntialiasOption;
+
+ protected:
+ gfxFont(const RefPtr<mozilla::gfx::UnscaledFont>& aUnscaledFont,
+ gfxFontEntry* aFontEntry, const gfxFontStyle* aFontStyle,
+ AntialiasOption anAAOption = kAntialiasDefault);
+
+ virtual ~gfxFont();
+
+ void MaybeDestroy() {
+ bool destroy = true;
+ if (gfxFontCache* fc = gfxFontCache::GetCache()) {
+ destroy = fc->MaybeDestroy(this);
+ }
+ if (destroy) {
+ Destroy();
+ }
+ }
+
+ public:
+ void Destroy() {
+ MOZ_ASSERT(GetRefCount() == 0);
+ delete this;
+ }
+
+ bool Valid() const { return mIsValid; }
+
+ // options for the kind of bounding box to return from measurement
+ typedef enum {
+ LOOSE_INK_EXTENTS,
+ // A box that encloses all the painted pixels, and may
+ // include sidebearings and/or additional ascent/descent
+ // within the glyph cell even if the ink is smaller.
+ TIGHT_INK_EXTENTS,
+ // A box that tightly encloses all the painted pixels
+ // (although actually on Windows, at least, it may be
+ // slightly larger than strictly necessary because
+ // we can't get precise extents with ClearType).
+ TIGHT_HINTED_OUTLINE_EXTENTS
+ // A box that tightly encloses the glyph outline,
+ // ignoring possible antialiasing pixels that extend
+ // beyond this.
+ // NOTE: The default implementation of gfxFont::Measure(),
+ // which works with the glyph extents cache, does not
+ // differentiate between this and TIGHT_INK_EXTENTS.
+ // Whether the distinction is important depends on the
+ // antialiasing behavior of the platform; currently the
+ // distinction is only implemented in the gfxWindowsFont
+ // subclass, because of ClearType's tendency to paint
+ // outside the hinted outline.
+ // Also NOTE: it is relatively expensive to request this,
+ // as it does not use cached glyph extents in the font.
+ } BoundingBoxType;
+
+ const nsCString& GetName() const { return mFontEntry->Name(); }
+ const gfxFontStyle* GetStyle() const { return &mStyle; }
+
+ virtual gfxFont* CopyWithAntialiasOption(AntialiasOption anAAOption) const {
+ // platforms where this actually matters should override
+ return nullptr;
+ }
+
+ gfxFloat GetAdjustedSize() const {
+ // mAdjustedSize is cached here if not already set to a non-zero value;
+ // but it may be overridden by a value computed in metrics initialization
+ // from font-size-adjust.
+ if (mAdjustedSize < 0.0) {
+ mAdjustedSize = mStyle.AdjustedSizeMustBeZero()
+ ? 0.0
+ : mStyle.size * mFontEntry->mSizeAdjust;
+ }
+ return mAdjustedSize;
+ }
+
+ float FUnitsToDevUnitsFactor() const {
+ // check this was set up during font initialization
+ NS_ASSERTION(mFUnitsConvFactor >= 0.0f, "mFUnitsConvFactor not valid");
+ return mFUnitsConvFactor;
+ }
+
+ // check whether this is an sfnt we can potentially use with harfbuzz
+ bool FontCanSupportHarfBuzz() const { return mFontEntry->HasCmapTable(); }
+
+ // check whether this is an sfnt we can potentially use with Graphite
+ bool FontCanSupportGraphite() const {
+ return mFontEntry->HasGraphiteTables();
+ }
+
+ // Whether this is a font that may be doing full-color rendering,
+ // and therefore needs us to use a mask for text-shadow even when
+ // we're not actually blurring.
+ bool AlwaysNeedsMaskForShadow() const {
+ return mFontEntry->TryGetColorGlyphs() || mFontEntry->TryGetSVGData(this) ||
+ mFontEntry->HasFontTable(TRUETYPE_TAG('C', 'B', 'D', 'T')) ||
+ mFontEntry->HasFontTable(TRUETYPE_TAG('s', 'b', 'i', 'x'));
+ }
+
+ // whether a feature is supported by the font (limited to a small set
+ // of features for which some form of fallback needs to be implemented)
+ bool SupportsFeature(Script aScript, uint32_t aFeatureTag);
+
+ // whether the font supports "real" small caps, petite caps etc.
+ // aFallbackToSmallCaps true when petite caps should fallback to small caps
+ bool SupportsVariantCaps(Script aScript, uint32_t aVariantCaps,
+ bool& aFallbackToSmallCaps,
+ bool& aSyntheticLowerToSmallCaps,
+ bool& aSyntheticUpperToSmallCaps);
+
+ // whether the font supports subscript/superscript feature
+ // for fallback, need to verify that all characters in the run
+ // have variant substitutions
+ bool SupportsSubSuperscript(uint32_t aSubSuperscript, const uint8_t* aString,
+ uint32_t aLength, Script aRunScript);
+
+ bool SupportsSubSuperscript(uint32_t aSubSuperscript, const char16_t* aString,
+ uint32_t aLength, Script aRunScript);
+
+ // whether the specified feature will apply to the given character
+ bool FeatureWillHandleChar(Script aRunScript, uint32_t aFeature,
+ uint32_t aUnicode);
+
+ // Subclasses may choose to look up glyph ids for characters.
+ // If they do not override this, gfxHarfBuzzShaper will fetch the cmap
+ // table and use that.
+ virtual bool ProvidesGetGlyph() const { return false; }
+ // Map unicode character to glyph ID.
+ // Only used if ProvidesGetGlyph() returns true.
+ virtual uint32_t GetGlyph(uint32_t unicode, uint32_t variation_selector) {
+ return 0;
+ }
+
+ // Return the advance of a glyph.
+ gfxFloat GetGlyphAdvance(uint16_t aGID, bool aVertical = false);
+
+ // Return the advance of a given Unicode char in isolation.
+ // Returns -1.0 if the char is not supported.
+ gfxFloat GetCharAdvance(uint32_t aUnicode, bool aVertical = false);
+
+ gfxFloat SynthesizeSpaceWidth(uint32_t aCh);
+
+ // Work out whether cairo will snap inter-glyph spacing to pixels
+ // when rendering to the given drawTarget.
+ RoundingFlags GetRoundOffsetsToPixels(DrawTarget* aDrawTarget);
+
+ virtual bool ShouldHintMetrics() const { return true; }
+ virtual bool ShouldRoundXOffset(cairo_t* aCairo) const { return true; }
+
+ // Return the font's owned harfbuzz shaper, creating and initializing it if
+ // necessary; returns null if shaper initialization has failed.
+ gfxHarfBuzzShaper* GetHarfBuzzShaper();
+
+ // Font metrics
+ struct Metrics {
+ gfxFloat capHeight;
+ gfxFloat xHeight;
+ gfxFloat strikeoutSize;
+ gfxFloat strikeoutOffset;
+ gfxFloat underlineSize;
+ gfxFloat underlineOffset;
+
+ gfxFloat internalLeading;
+ gfxFloat externalLeading;
+
+ gfxFloat emHeight;
+ gfxFloat emAscent;
+ gfxFloat emDescent;
+ gfxFloat maxHeight;
+ gfxFloat maxAscent;
+ gfxFloat maxDescent;
+ gfxFloat maxAdvance;
+
+ gfxFloat aveCharWidth;
+ gfxFloat spaceWidth;
+ gfxFloat zeroWidth; // -1 if there was no zero glyph
+ gfxFloat ideographicWidth; // -1 if kWaterIdeograph is not supported
+
+ gfxFloat ZeroOrAveCharWidth() const {
+ return zeroWidth >= 0 ? zeroWidth : aveCharWidth;
+ }
+ };
+ // Unicode character used as basis for 'ic' unit:
+ static constexpr uint32_t kWaterIdeograph = 0x6C34;
+
+ typedef nsFontMetrics::FontOrientation Orientation;
+
+ const Metrics& GetMetrics(Orientation aOrientation) {
+ if (aOrientation == nsFontMetrics::eHorizontal) {
+ return GetHorizontalMetrics();
+ }
+ if (!mVerticalMetrics) {
+ CreateVerticalMetrics();
+ }
+ return *mVerticalMetrics;
+ }
+
+ struct Baselines {
+ gfxFloat mAlphabetic;
+ gfxFloat mHanging;
+ gfxFloat mIdeographic;
+ };
+ Baselines GetBaselines(Orientation aOrientation);
+
+ /**
+ * We let layout specify spacing on either side of any
+ * character. We need to specify both before and after
+ * spacing so that substring measurement can do the right things.
+ * These values are in appunits. They're always an integral number of
+ * appunits, but we specify them in floats in case very large spacing
+ * values are required.
+ */
+ struct Spacing {
+ gfxFloat mBefore;
+ gfxFloat mAfter;
+ };
+ /**
+ * Metrics for a particular string
+ */
+ struct RunMetrics {
+ RunMetrics() { mAdvanceWidth = mAscent = mDescent = 0.0; }
+
+ void CombineWith(const RunMetrics& aOther, bool aOtherIsOnLeft);
+
+ // can be negative (partly due to negative spacing).
+ // Advance widths should be additive: the advance width of the
+ // (offset1, length1) plus the advance width of (offset1 + length1,
+ // length2) should be the advance width of (offset1, length1 + length2)
+ gfxFloat mAdvanceWidth;
+
+ // For zero-width substrings, these must be zero!
+ gfxFloat mAscent; // always non-negative
+ gfxFloat mDescent; // always non-negative
+
+ // Bounding box that is guaranteed to include everything drawn.
+ // If a tight boundingBox was requested when these metrics were
+ // generated, this will tightly wrap the glyphs, otherwise it is
+ // "loose" and may be larger than the true bounding box.
+ // Coordinates are relative to the baseline left origin, so typically
+ // mBoundingBox.y == -mAscent
+ gfxRect mBoundingBox;
+ };
+
+ /**
+ * Draw a series of glyphs to aContext. The direction of aTextRun must
+ * be honoured.
+ * @param aStart the first character to draw
+ * @param aEnd draw characters up to here
+ * @param aPt the baseline origin; the left end of the baseline
+ * for LTR textruns, the right end for RTL textruns.
+ * On return, this will be updated to the other end of the baseline.
+ * In application units, really!
+ * @param aRunParams record with drawing parameters, see TextRunDrawParams.
+ * Particular fields of interest include
+ * .spacing spacing to insert before and after characters (for RTL
+ * glyphs, before-spacing is inserted to the right of characters). There
+ * are aEnd - aStart elements in this array, unless it's null to indicate
+ * that there is no spacing.
+ * .drawMode specifies whether the fill or stroke of the glyph should be
+ * drawn, or if it should be drawn into the current path
+ * .contextPaint information about how to construct the fill and
+ * stroke pattern. Can be nullptr if we are not stroking the text, which
+ * indicates that the current source from context should be used for fill
+ * .context the Thebes graphics context to which we're drawing
+ * .dt Moz2D DrawTarget to which we're drawing
+ *
+ * Callers guarantee:
+ * -- aStart and aEnd are aligned to cluster and ligature boundaries
+ * -- all glyphs use this font
+ */
+ void Draw(const gfxTextRun* aTextRun, uint32_t aStart, uint32_t aEnd,
+ mozilla::gfx::Point* aPt, TextRunDrawParams& aRunParams,
+ mozilla::gfx::ShapedTextFlags aOrientation);
+
+ /**
+ * Draw the emphasis marks for the given text run. Its prerequisite
+ * and output are similiar to the method Draw().
+ * @param aPt the baseline origin of the emphasis marks.
+ * @param aParams some drawing parameters, see EmphasisMarkDrawParams.
+ */
+ void DrawEmphasisMarks(const gfxTextRun* aShapedText,
+ mozilla::gfx::Point* aPt, uint32_t aOffset,
+ uint32_t aCount,
+ const EmphasisMarkDrawParams& aParams);
+
+ /**
+ * Measure a run of characters. See gfxTextRun::Metrics.
+ * @param aTight if false, then return the union of the glyph extents
+ * with the font-box for the characters (the rectangle with x=0,width=
+ * the advance width for the character run,y=-(font ascent), and height=
+ * font ascent + font descent). Otherwise, we must return as tight as possible
+ * an approximation to the area actually painted by glyphs.
+ * @param aDrawTargetForTightBoundingBox when aTight is true, this must
+ * be non-null.
+ * @param aSpacing spacing to insert before and after glyphs. The bounding box
+ * need not include the spacing itself, but the spacing affects the glyph
+ * positions. null if there is no spacing.
+ *
+ * Callers guarantee:
+ * -- aStart and aEnd are aligned to cluster and ligature boundaries
+ * -- all glyphs use this font
+ *
+ * The default implementation just uses font metrics and aTextRun's
+ * advances, and assumes no characters fall outside the font box. In
+ * general this is insufficient, because that assumption is not always true.
+ */
+ virtual RunMetrics Measure(const gfxTextRun* aTextRun, uint32_t aStart,
+ uint32_t aEnd, BoundingBoxType aBoundingBoxType,
+ DrawTarget* aDrawTargetForTightBoundingBox,
+ Spacing* aSpacing,
+ mozilla::gfx::ShapedTextFlags aOrientation);
+ /**
+ * Line breaks have been changed at the beginning and/or end of a substring
+ * of the text. Reshaping may be required; glyph updating is permitted.
+ * @return true if anything was changed, false otherwise
+ */
+ bool NotifyLineBreaksChanged(gfxTextRun* aTextRun, uint32_t aStart,
+ uint32_t aLength) {
+ return false;
+ }
+
+ // Expiration tracking
+ nsExpirationState* GetExpirationState() { return &mExpirationState; }
+
+ // Get the glyphID of a space
+ uint16_t GetSpaceGlyph() const { return mSpaceGlyph; }
+
+ gfxGlyphExtents* GetOrCreateGlyphExtents(int32_t aAppUnitsPerDevUnit);
+
+ void SetupGlyphExtents(DrawTarget* aDrawTarget, uint32_t aGlyphID,
+ bool aNeedTight, gfxGlyphExtents* aExtents);
+
+ virtual bool AllowSubpixelAA() const { return true; }
+
+ bool ApplySyntheticBold() const { return mApplySyntheticBold; }
+
+ float AngleForSyntheticOblique() const;
+ float SkewForSyntheticOblique() const;
+
+ // Amount by which synthetic bold "fattens" the glyphs:
+ // For size S up to a threshold size T, we use (0.25 + 3S / 4T),
+ // so that the result ranges from 0.25 to 1.0; thereafter,
+ // simply use (S / T).
+ gfxFloat GetSyntheticBoldOffset() const {
+ gfxFloat size = GetAdjustedSize();
+ const gfxFloat threshold = 48.0;
+ return size < threshold ? (0.25 + 0.75 * size / threshold)
+ : (size / threshold);
+ }
+
+ gfxFontEntry* GetFontEntry() const { return mFontEntry.get(); }
+ bool HasCharacter(uint32_t ch) const {
+ if (!mIsValid || (mUnicodeRangeMap && !mUnicodeRangeMap->test(ch))) {
+ return false;
+ }
+ return mFontEntry->HasCharacter(ch);
+ }
+
+ const gfxCharacterMap* GetUnicodeRangeMap() const {
+ return mUnicodeRangeMap.get();
+ }
+
+ void SetUnicodeRangeMap(gfxCharacterMap* aUnicodeRangeMap) {
+ mUnicodeRangeMap = aUnicodeRangeMap;
+ }
+
+ uint16_t GetUVSGlyph(uint32_t aCh, uint32_t aVS) const {
+ if (!mIsValid) {
+ return 0;
+ }
+ return mFontEntry->GetUVSGlyph(aCh, aVS);
+ }
+
+ template <typename T>
+ bool InitFakeSmallCapsRun(nsPresContext* aPresContext,
+ DrawTarget* aDrawTarget, gfxTextRun* aTextRun,
+ const T* aText, uint32_t aOffset, uint32_t aLength,
+ FontMatchType aMatchType,
+ mozilla::gfx::ShapedTextFlags aOrientation,
+ Script aScript, nsAtom* aLanguage,
+ bool aSyntheticLower, bool aSyntheticUpper);
+
+ // call the (virtual) InitTextRun method to do glyph generation/shaping,
+ // limiting the length of text passed by processing the run in multiple
+ // segments if necessary
+ template <typename T>
+ bool SplitAndInitTextRun(DrawTarget* aDrawTarget, gfxTextRun* aTextRun,
+ const T* aString, uint32_t aRunStart,
+ uint32_t aRunLength, Script aRunScript,
+ nsAtom* aLanguage,
+ mozilla::gfx::ShapedTextFlags aOrientation);
+
+ // Get a ShapedWord representing a single space for use in setting up a
+ // gfxTextRun.
+ bool ProcessSingleSpaceShapedWord(
+ DrawTarget* aDrawTarget, bool aVertical, int32_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags, RoundingFlags aRounding,
+ const std::function<void(gfxShapedWord*)>& aCallback);
+
+ // Called by the gfxFontCache timer to increment the age of all the words,
+ // so that they'll expire after a sufficient period of non-use.
+ // Returns true if the cache is now empty, otherwise false.
+ bool AgeCachedWords();
+
+ // Discard all cached word records; called on memory-pressure notification.
+ void ClearCachedWords() {
+ mozilla::AutoWriteLock lock(mLock);
+ if (mWordCache) {
+ ClearCachedWordsLocked();
+ }
+ }
+ void ClearCachedWordsLocked() MOZ_REQUIRES(mLock) {
+ MOZ_ASSERT(mWordCache);
+ mWordCache->clear();
+ }
+
+ // Glyph rendering/geometry has changed, so invalidate data as necessary.
+ void NotifyGlyphsChanged() const;
+
+ virtual void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+ FontCacheSizes* aSizes) const;
+ virtual void AddSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf,
+ FontCacheSizes* aSizes) const;
+
+ typedef enum {
+ FONT_TYPE_DWRITE,
+ FONT_TYPE_GDI,
+ FONT_TYPE_FT2,
+ FONT_TYPE_MAC,
+ FONT_TYPE_OS2,
+ FONT_TYPE_CAIRO,
+ FONT_TYPE_FONTCONFIG
+ } FontType;
+
+ virtual FontType GetType() const = 0;
+
+ const RefPtr<mozilla::gfx::UnscaledFont>& GetUnscaledFont() const {
+ return mUnscaledFont;
+ }
+
+ virtual already_AddRefed<mozilla::gfx::ScaledFont> GetScaledFont(
+ const TextRunDrawParams& aRunParams) = 0;
+ already_AddRefed<mozilla::gfx::ScaledFont> GetScaledFont(
+ mozilla::gfx::DrawTarget* aDrawTarget);
+
+ // gfxFont implementations may cache ScaledFont versions other than the
+ // default, so InitializeScaledFont must support explicitly specifying
+ // which ScaledFonts to initialize.
+ void InitializeScaledFont(
+ const RefPtr<mozilla::gfx::ScaledFont>& aScaledFont);
+
+ bool KerningDisabled() const { return mKerningSet && !mKerningEnabled; }
+
+ /**
+ * Subclass this object to be notified of glyph changes. Delete the object
+ * when no longer needed.
+ */
+ class GlyphChangeObserver {
+ public:
+ virtual ~GlyphChangeObserver() {
+ if (mFont) {
+ mFont->RemoveGlyphChangeObserver(this);
+ }
+ }
+ // This gets called when the gfxFont dies.
+ void ForgetFont() { mFont = nullptr; }
+ virtual void NotifyGlyphsChanged() = 0;
+
+ protected:
+ explicit GlyphChangeObserver(gfxFont* aFont) : mFont(aFont) {
+ mFont->AddGlyphChangeObserver(this);
+ }
+ // This pointer is nulled by ForgetFont in the gfxFont's
+ // destructor. Before the gfxFont dies.
+ gfxFont* MOZ_NON_OWNING_REF mFont;
+ };
+ friend class GlyphChangeObserver;
+
+ bool GlyphsMayChange() const {
+ // Currently only fonts with SVG glyphs can have animated glyphs
+ return mFontEntry->TryGetSVGData(this);
+ }
+
+ static void DestroySingletons() {
+ delete sScriptTagToCode;
+ delete sDefaultFeatures;
+ }
+
+ // Call TryGetMathTable() to try and load the Open Type MATH table.
+ // If (and ONLY if) TryGetMathTable() has returned true, the MathTable()
+ // method may be called to access the gfxMathTable data.
+ bool TryGetMathTable();
+ gfxMathTable* MathTable() const {
+ MOZ_RELEASE_ASSERT(mMathTable,
+ "A successful call to TryGetMathTable() must be "
+ "performed before calling this function");
+ return mMathTable;
+ }
+
+ // Return a cloned font resized and offset to simulate sub/superscript
+ // glyphs. This does not add a reference to the returned font.
+ already_AddRefed<gfxFont> GetSubSuperscriptFont(
+ int32_t aAppUnitsPerDevPixel) const;
+
+ bool HasColorGlyphFor(uint32_t aCh, uint32_t aNextCh);
+
+ protected:
+ virtual const Metrics& GetHorizontalMetrics() const = 0;
+
+ void CreateVerticalMetrics();
+
+ bool MeasureGlyphs(const gfxTextRun* aTextRun, uint32_t aStart, uint32_t aEnd,
+ BoundingBoxType aBoundingBoxType,
+ DrawTarget* aRefDrawTarget, Spacing* aSpacing,
+ gfxGlyphExtents* aExtents, bool aIsRTL,
+ bool aNeedsGlyphExtents, RunMetrics& aMetrics,
+ gfxFloat* aAdvanceMin, gfxFloat* aAdvanceMax);
+
+ bool MeasureGlyphs(const gfxTextRun* aTextRun, uint32_t aStart, uint32_t aEnd,
+ BoundingBoxType aBoundingBoxType,
+ DrawTarget* aRefDrawTarget, Spacing* aSpacing, bool aIsRTL,
+ RunMetrics& aMetrics);
+
+ // Template parameters for DrawGlyphs/DrawOneGlyph, used to select
+ // simplified versions of the methods in the most common cases.
+ enum class FontComplexityT { SimpleFont, ComplexFont };
+ enum class SpacingT { NoSpacing, HasSpacing };
+
+ // Output a run of glyphs at *aPt, which is updated to follow the last glyph
+ // in the run. This method also takes account of any letter-spacing provided
+ // in aRunParams.
+ template <FontComplexityT FC, SpacingT S>
+ bool DrawGlyphs(const gfxShapedText* aShapedText,
+ uint32_t aOffset, // offset in the textrun
+ uint32_t aCount, // length of run to draw
+ mozilla::gfx::Point* aPt,
+ // transform for mOffset field in DetailedGlyph records,
+ // to account for rotations (may be null)
+ const mozilla::gfx::Matrix* aOffsetMatrix,
+ GlyphBufferAzure& aBuffer);
+
+ // Output a single glyph at *aPt.
+ // Normal glyphs are simply accumulated in aBuffer until it is full and
+ // gets flushed, but SVG or color-font glyphs will instead be rendered
+ // directly to the destination (found from the buffer's parameters).
+ template <FontComplexityT FC>
+ void DrawOneGlyph(uint32_t aGlyphID, const mozilla::gfx::Point& aPt,
+ GlyphBufferAzure& aBuffer, bool* aEmittedGlyphs);
+
+ // Helper for DrawOneGlyph to handle missing glyphs, rendering either
+ // nothing (for default-ignorables) or a missing-glyph hexbox.
+ bool DrawMissingGlyph(const TextRunDrawParams& aRunParams,
+ const FontDrawParams& aFontParams,
+ const gfxShapedText::DetailedGlyph* aDetails,
+ const mozilla::gfx::Point& aPt);
+
+ // set the font size and offset used for
+ // synthetic subscript/superscript glyphs
+ void CalculateSubSuperSizeAndOffset(int32_t aAppUnitsPerDevPixel,
+ gfxFloat& aSubSuperSizeRatio,
+ float& aBaselineOffset);
+
+ // Return a font that is a "clone" of this one, but reduced to 80% size
+ // (and with variantCaps set to normal). This does not add a reference to
+ // the returned font.
+ already_AddRefed<gfxFont> GetSmallCapsFont() const;
+
+ // subclasses may provide (possibly hinted) glyph widths (in font units);
+ // if they do not override this, harfbuzz will use unhinted widths
+ // derived from the font tables
+ virtual bool ProvidesGlyphWidths() const { return false; }
+
+ // The return value is interpreted as a horizontal advance in 16.16 fixed
+ // point format.
+ virtual int32_t GetGlyphWidth(uint16_t aGID) { return -1; }
+
+ virtual bool GetGlyphBounds(uint16_t aGID, gfxRect* aBounds,
+ bool aTight = false) {
+ return false;
+ }
+
+ bool IsSpaceGlyphInvisible(DrawTarget* aRefDrawTarget,
+ const gfxTextRun* aTextRun);
+
+ void AddGlyphChangeObserver(GlyphChangeObserver* aObserver);
+ void RemoveGlyphChangeObserver(GlyphChangeObserver* aObserver);
+
+ // whether font contains substitution lookups containing spaces
+ bool HasSubstitutionRulesWithSpaceLookups(Script aRunScript) const;
+
+ // do spaces participate in shaping rules? if so, can't used word cache
+ // Note that this function uses HasGraphiteSpaceContextuals, so it can only
+ // return a "hint" to the correct answer. The calling code must ensure it
+ // performs safe actions independent of the value returned.
+ tainted_boolean_hint SpaceMayParticipateInShaping(Script aRunScript) const;
+
+ // For 8-bit text, expand to 16-bit and then call the following method.
+ bool ShapeText(DrawTarget* aContext, const uint8_t* aText,
+ uint32_t aOffset, // dest offset in gfxShapedText
+ uint32_t aLength, Script aScript, nsAtom* aLanguage,
+ bool aVertical, RoundingFlags aRounding,
+ gfxShapedText* aShapedText); // where to store the result
+
+ // Call the appropriate shaper to generate glyphs for aText and store
+ // them into aShapedText.
+ virtual bool ShapeText(DrawTarget* aContext, const char16_t* aText,
+ uint32_t aOffset, uint32_t aLength, Script aScript,
+ nsAtom* aLanguage, bool aVertical,
+ RoundingFlags aRounding, gfxShapedText* aShapedText);
+
+ // Helper to adjust for synthetic bold and set character-type flags
+ // in the shaped text; implementations of ShapeText should call this
+ // after glyph shaping has been completed.
+ void PostShapingFixup(DrawTarget* aContext, const char16_t* aText,
+ uint32_t aOffset, // position within aShapedText
+ uint32_t aLength, bool aVertical,
+ gfxShapedText* aShapedText);
+
+ // Shape text directly into a range within a textrun, without using the
+ // font's word cache. Intended for use when the font has layout features
+ // that involve space, and therefore require shaping complete runs rather
+ // than isolated words, or for long strings that are inefficient to cache.
+ // This will split the text on "invalid" characters (tab/newline) that are
+ // not handled via normal shaping, but does not otherwise divide up the
+ // text.
+ template <typename T>
+ bool ShapeTextWithoutWordCache(DrawTarget* aDrawTarget, const T* aText,
+ uint32_t aOffset, uint32_t aLength,
+ Script aScript, nsAtom* aLanguage,
+ bool aVertical, RoundingFlags aRounding,
+ gfxTextRun* aTextRun);
+
+ // Shape a fragment of text (a run that is known to contain only
+ // "valid" characters, no newlines/tabs/other control chars).
+ // All non-wordcache shaping goes through here; this is the function
+ // that will ensure we don't pass excessively long runs to the various
+ // platform shapers.
+ template <typename T>
+ bool ShapeFragmentWithoutWordCache(DrawTarget* aDrawTarget, const T* aText,
+ uint32_t aOffset, uint32_t aLength,
+ Script aScript, nsAtom* aLanguage,
+ bool aVertical, RoundingFlags aRounding,
+ gfxTextRun* aTextRun);
+
+ void CheckForFeaturesInvolvingSpace() const;
+
+ // Get a ShapedWord representing the given text (either 8- or 16-bit)
+ // for use in setting up a gfxTextRun.
+ template <typename T, typename Func>
+ bool ProcessShapedWordInternal(DrawTarget* aDrawTarget, const T* aText,
+ uint32_t aLength, uint32_t aHash,
+ Script aRunScript, nsAtom* aLanguage,
+ bool aVertical, int32_t aAppUnitsPerDevUnit,
+ mozilla::gfx::ShapedTextFlags aFlags,
+ RoundingFlags aRounding,
+ gfxTextPerfMetrics* aTextPerf, Func aCallback);
+
+ // whether a given feature is included in feature settings from both the
+ // font and the style. aFeatureOn set if resolved feature value is non-zero
+ bool HasFeatureSet(uint32_t aFeature, bool& aFeatureOn);
+
+ // used when analyzing whether a font has space contextual lookups
+ static mozilla::Atomic<nsTHashMap<nsUint32HashKey, Script>*> sScriptTagToCode;
+ static mozilla::Atomic<nsTHashSet<uint32_t>*> sDefaultFeatures;
+
+ RefPtr<gfxFontEntry> mFontEntry;
+ mutable mozilla::RWLock mLock;
+
+ // Note that WordCacheKey contains a pointer to the text of the word, which
+ // must be valid for as long as the key is in use. When using for a Lookup,
+ // the string may be local/temporary, but when storing in the HashMap, we
+ // set the Key text pointer to reference the text in the associated
+ // gfxShapedWord that is being stored.
+ struct WordCacheKey {
+ union {
+ const uint8_t* mSingle;
+ const char16_t* mDouble;
+ } mText;
+ uint32_t mLength;
+ ShapedTextFlags mFlags;
+ Script mScript;
+ RefPtr<nsAtom> mLanguage;
+ int32_t mAppUnitsPerDevUnit;
+ PLDHashNumber mHashKey;
+ bool mTextIs8Bit;
+ RoundingFlags mRounding;
+
+ WordCacheKey(const uint8_t* aText, uint32_t aLength, uint32_t aStringHash,
+ Script aScriptCode, nsAtom* aLanguage,
+ int32_t aAppUnitsPerDevUnit, ShapedTextFlags aFlags,
+ RoundingFlags aRounding)
+ : mLength(aLength),
+ mFlags(aFlags),
+ mScript(aScriptCode),
+ mLanguage(aLanguage),
+ mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
+ mHashKey(aStringHash + static_cast<int32_t>(aScriptCode) +
+ aAppUnitsPerDevUnit * 0x100 + uint16_t(aFlags) * 0x10000 +
+ int(aRounding) + (aLanguage ? aLanguage->hash() : 0)),
+ mTextIs8Bit(true),
+ mRounding(aRounding) {
+ NS_ASSERTION(aFlags & ShapedTextFlags::TEXT_IS_8BIT,
+ "8-bit flag should have been set");
+ mText.mSingle = aText;
+ }
+
+ WordCacheKey(const char16_t* aText, uint32_t aLength, uint32_t aStringHash,
+ Script aScriptCode, nsAtom* aLanguage,
+ int32_t aAppUnitsPerDevUnit, ShapedTextFlags aFlags,
+ RoundingFlags aRounding)
+ : mLength(aLength),
+ mFlags(aFlags),
+ mScript(aScriptCode),
+ mLanguage(aLanguage),
+ mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
+ mHashKey(aStringHash + static_cast<int32_t>(aScriptCode) +
+ aAppUnitsPerDevUnit * 0x100 + uint16_t(aFlags) * 0x10000 +
+ int(aRounding)),
+ mTextIs8Bit(false),
+ mRounding(aRounding) {
+ // We can NOT assert that TEXT_IS_8BIT is false in aFlags here,
+ // because this might be an 8bit-only word from a 16-bit textrun,
+ // in which case the text we're passed is still in 16-bit form,
+ // and we'll have to use an 8-to-16bit comparison in KeyEquals.
+ mText.mDouble = aText;
+ }
+
+ bool Matches(const WordCacheKey& aLookup) const;
+
+ class HashPolicy {
+ public:
+ typedef WordCacheKey Key;
+ typedef WordCacheKey Lookup;
+ static mozilla::HashNumber hash(const Lookup& aLookup) {
+ return aLookup.mHashKey;
+ }
+ static bool match(const Key& aKey, const Lookup& aLookup);
+ };
+ };
+
+ mozilla::UniquePtr<
+ mozilla::HashMap<WordCacheKey, mozilla::UniquePtr<gfxShapedWord>,
+ WordCacheKey::HashPolicy>>
+ mWordCache MOZ_GUARDED_BY(mLock);
+
+ static const uint32_t kShapedWordCacheMaxAge = 3;
+
+ nsTArray<mozilla::UniquePtr<gfxGlyphExtents>> mGlyphExtentsArray
+ MOZ_GUARDED_BY(mLock);
+ mozilla::UniquePtr<nsTHashSet<GlyphChangeObserver*>> mGlyphChangeObservers
+ MOZ_GUARDED_BY(mLock);
+
+ // a copy of the font without antialiasing, if needed for separate
+ // measurement by mathml code
+ mozilla::Atomic<gfxFont*> mNonAAFont;
+
+ // we create either or both of these shapers when needed, depending
+ // whether the font has graphite tables, and whether graphite shaping
+ // is actually enabled
+ mozilla::Atomic<gfxHarfBuzzShaper*> mHarfBuzzShaper;
+ mozilla::Atomic<gfxGraphiteShaper*> mGraphiteShaper;
+
+ // If a userfont with unicode-range specified, contains map of *possible*
+ // ranges supported by font. This is set during user-font initialization,
+ // before the font is available to other threads, and thereafter is inert
+ // so no guard is needed.
+ RefPtr<gfxCharacterMap> mUnicodeRangeMap;
+
+ // This is immutable once initialized by the constructor, so does not need
+ // locking.
+ RefPtr<mozilla::gfx::UnscaledFont> mUnscaledFont;
+
+ mozilla::Atomic<mozilla::gfx::ScaledFont*> mAzureScaledFont;
+
+ // For vertical metrics, created on demand.
+ mozilla::Atomic<Metrics*> mVerticalMetrics;
+
+ // Table used for MathML layout.
+ mozilla::Atomic<gfxMathTable*> mMathTable;
+
+ gfxFontStyle mStyle;
+ mutable gfxFloat mAdjustedSize;
+
+ // Tracking adjustment to be applied for CSS px size mCachedTrackingSize.
+ gfxFloat mTracking = 0.0;
+ gfxFloat mCachedTrackingSize = -1.0;
+
+ // Conversion factor from font units to dev units; note that this may be
+ // zero (in the degenerate case where mAdjustedSize has become zero).
+ // This is OK because we only multiply by this factor, never divide.
+ float mFUnitsConvFactor;
+
+ // This is guarded by gfxFontCache::GetCache()->GetMutex() but it is difficult
+ // to annotate that fact.
+ nsExpirationState mExpirationState;
+
+ // Glyph ID of the font's <space> glyph, zero if missing
+ uint16_t mSpaceGlyph = 0;
+
+ // the AA setting requested for this font - may affect glyph bounds
+ AntialiasOption mAntialiasOption;
+
+ bool mIsValid;
+
+ // use synthetic bolding for environments where this is not supported
+ // by the platform
+ bool mApplySyntheticBold;
+
+ bool mKerningSet; // kerning explicitly set?
+ bool mKerningEnabled; // if set, on or off?
+
+ mozilla::Atomic<bool> mMathInitialized; // TryGetMathTable() called?
+
+ // Helper for subclasses that want to initialize standard metrics from the
+ // tables of sfnt (TrueType/OpenType) fonts.
+ // This will use mFUnitsConvFactor if it is already set, else compute it
+ // from mAdjustedSize and the unitsPerEm in the font's 'head' table.
+ // Returns TRUE and sets mIsValid=TRUE if successful;
+ // Returns TRUE but leaves mIsValid=FALSE if the font seems to be broken.
+ // Returns FALSE if the font does not appear to be an sfnt at all,
+ // and should be handled (if possible) using other APIs.
+ bool InitMetricsFromSfntTables(Metrics& aMetrics);
+
+ // Helper to calculate various derived metrics from the results of
+ // InitMetricsFromSfntTables or equivalent platform code
+ void CalculateDerivedMetrics(Metrics& aMetrics);
+
+ // some fonts have bad metrics, this method sanitize them.
+ // if this font has bad underline offset, aIsBadUnderlineFont should be true.
+ void SanitizeMetrics(Metrics* aMetrics, bool aIsBadUnderlineFont);
+
+ bool RenderSVGGlyph(gfxContext* aContext,
+ mozilla::layout::TextDrawTarget* aTextDrawer,
+ mozilla::gfx::Point aPoint, uint32_t aGlyphId,
+ SVGContextPaint* aContextPaint) const;
+ bool RenderSVGGlyph(gfxContext* aContext,
+ mozilla::layout::TextDrawTarget* aTextDrawer,
+ mozilla::gfx::Point aPoint, uint32_t aGlyphId,
+ SVGContextPaint* aContextPaint,
+ gfxTextRunDrawCallbacks* aCallbacks,
+ bool& aEmittedGlyphs) const;
+
+ bool RenderColorGlyph(DrawTarget* aDrawTarget, gfxContext* aContext,
+ mozilla::layout::TextDrawTarget* aTextDrawer,
+ const FontDrawParams& aFontParams,
+ const mozilla::gfx::Point& aPoint, uint32_t aGlyphId);
+
+ class ColorGlyphCache {
+ public:
+ ColorGlyphCache() = default;
+ ~ColorGlyphCache() = default;
+
+ void SetColors(mozilla::gfx::sRGBColor aCurrentColor,
+ mozilla::gfx::FontPalette* aPalette);
+
+ mozilla::HashMap<uint32_t, RefPtr<mozilla::gfx::SourceSurface>> mCache;
+
+ private:
+ mozilla::gfx::sRGBColor mCurrentColor;
+ RefPtr<mozilla::gfx::FontPalette> mPalette;
+ };
+ mozilla::UniquePtr<ColorGlyphCache> mColorGlyphCache;
+
+ // Subclasses can override to return true if the platform is able to render
+ // COLR-font glyphs directly, instead of us painting the layers explicitly.
+ // (Currently used only for COLR.v0 fonts on macOS.)
+ virtual bool UseNativeColrFontSupport() const { return false; }
+
+ // Bug 674909. When synthetic bolding text by drawing twice, need to
+ // render using a pixel offset in device pixels, otherwise text
+ // doesn't appear bolded, it appears as if a bad text shadow exists
+ // when a non-identity transform exists. Use an offset factor so that
+ // the second draw occurs at a constant offset in device pixels.
+ // This helper calculates the scale factor we need to apply to the
+ // synthetic-bold offset.
+ static mozilla::gfx::Float CalcXScale(DrawTarget* aDrawTarget);
+};
+
+// proportion of ascent used for x-height, if unable to read value from font
+#define DEFAULT_XHEIGHT_FACTOR 0.56f
+
+// Parameters passed to gfxFont methods for drawing glyphs from a textrun.
+// The TextRunDrawParams are set up once per textrun; the FontDrawParams
+// are dependent on the specific font, so they are set per GlyphRun.
+
+struct MOZ_STACK_CLASS TextRunDrawParams {
+ explicit TextRunDrawParams(mozilla::gfx::PaletteCache& aPaletteCache)
+ : paletteCache(aPaletteCache) {}
+
+ mozilla::gfx::PaletteCache& paletteCache;
+ RefPtr<mozilla::gfx::DrawTarget> dt;
+ gfxContext* context = nullptr;
+ gfxFont::Spacing* spacing = nullptr;
+ gfxTextRunDrawCallbacks* callbacks = nullptr;
+ mozilla::SVGContextPaint* runContextPaint = nullptr;
+ mozilla::layout::TextDrawTarget* textDrawer = nullptr;
+ mozilla::LayoutDeviceRect clipRect;
+ mozilla::gfx::Float direction = 1.0f;
+ double devPerApp = 1.0;
+ nscolor textStrokeColor = 0;
+ gfxPattern* textStrokePattern = nullptr;
+ const mozilla::gfx::StrokeOptions* strokeOpts = nullptr;
+ const mozilla::gfx::DrawOptions* drawOpts = nullptr;
+ nsAtom* fontPalette = nullptr;
+ DrawMode drawMode = DrawMode::GLYPH_FILL;
+ bool isVerticalRun = false;
+ bool isRTL = false;
+ bool paintSVGGlyphs = true;
+ bool allowGDI = true;
+ bool hasTextShadow = false;
+};
+
+struct MOZ_STACK_CLASS FontDrawParams {
+ RefPtr<mozilla::gfx::ScaledFont> scaledFont;
+ mozilla::SVGContextPaint* contextPaint;
+ mozilla::gfx::Float synBoldOnePixelOffset;
+ mozilla::gfx::Float obliqueSkew;
+ int32_t extraStrikes;
+ mozilla::gfx::DrawOptions drawOptions;
+ gfxFloat advanceDirection;
+ mozilla::gfx::sRGBColor currentColor;
+ RefPtr<mozilla::gfx::FontPalette> palette;
+ mozilla::gfx::Rect fontExtents;
+ bool isVerticalFont;
+ bool haveSVGGlyphs;
+ bool haveColorGlyphs;
+ bool hasTextShadow; // whether we're rendering with a text-shadow
+};
+
+struct MOZ_STACK_CLASS EmphasisMarkDrawParams {
+ EmphasisMarkDrawParams(gfxContext* aContext,
+ mozilla::gfx::PaletteCache& aPaletteCache)
+ : context(aContext), paletteCache(aPaletteCache) {}
+ gfxContext* context;
+ mozilla::gfx::PaletteCache& paletteCache;
+ gfxFont::Spacing* spacing;
+ gfxTextRun* mark;
+ gfxFloat advance;
+ gfxFloat direction;
+ bool isVertical;
+};
+
+#endif