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gecko-dev/gfx/thebes/gfxFont.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: set ts=4 et sw=4 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 "gfxTypes.h"
#include "gfxFontEntry.h"
#include "nsString.h"
#include "gfxPoint.h"
#include "gfxPattern.h"
#include "nsTArray.h"
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "gfxRect.h"
#include "nsExpirationTracker.h"
#include "gfxPlatform.h"
#include "nsIAtom.h"
#include "mozilla/HashFunctions.h"
#include "nsIMemoryReporter.h"
#include "nsIObserver.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/Attributes.h"
#include <algorithm>
#include "DrawMode.h"
#include "nsDataHashtable.h"
#include "harfbuzz/hb.h"
#include "mozilla/gfx/2D.h"
#include "nsColor.h"
typedef struct _cairo cairo_t;
typedef struct _cairo_scaled_font cairo_scaled_font_t;
//typedef struct gr_face gr_face;
#ifdef DEBUG
#include <stdio.h>
#endif
class gfxContext;
class gfxTextRun;
class gfxFont;
class gfxGlyphExtents;
class gfxShapedText;
class gfxShapedWord;
class gfxSkipChars;
class gfxTextContextPaint;
#define FONT_MAX_SIZE 2000.0
#define NO_FONT_LANGUAGE_OVERRIDE 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 0.3
#elif defined(MOZ_WIDGET_GTK)
#define OBLIQUE_SKEW_FACTOR 0.2
#else
#define OBLIQUE_SKEW_FACTOR 0.25
#endif
struct gfxTextRunDrawCallbacks;
namespace mozilla {
namespace gfx {
class GlyphRenderingOptions;
} // namespace gfx
} // namespace mozilla
struct gfxFontStyle {
gfxFontStyle();
gfxFontStyle(uint8_t aStyle, uint16_t aWeight, int16_t aStretch,
gfxFloat aSize, nsIAtom *aLanguage, bool aExplicitLanguage,
float aSizeAdjust, bool aSystemFont,
bool aPrinterFont,
bool aWeightSynthesis, bool aStyleSynthesis,
const nsString& aLanguageOverride);
gfxFontStyle(const gfxFontStyle& aStyle);
// the language (may be an internal langGroup code rather than an actual
// language code) specified in the document or element's lang property,
// or inferred from the charset
RefPtr<nsIAtom> language;
// Features are composed of (1) features from style rules (2) features
// from feature setttings rules and (3) family-specific features. (1) and
// (3) are guaranteed to be mutually exclusive
// custom opentype feature settings
nsTArray<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
nsTArray<gfxAlternateValue> alternateValues;
// -- object used to look these up once the font is matched
RefPtr<gfxFontFeatureValueSet> featureValueLookup;
// The logical size of the font, in pixels
gfxFloat size;
// 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 weight of the font: 100, 200, ... 900.
uint16_t weight;
// The stretch of the font (the sum of various NS_FONT_STRETCH_*
// constants; see gfxFontConstants.h).
int8_t stretch;
// 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;
// The style of font (normal, italic, oblique)
uint8_t style : 2;
// Whether synthetic styles are allowed
bool allowSyntheticWeight : 1;
bool allowSyntheticStyle : 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;
// whether the |language| field comes from explicit lang tagging in the
// document, or was inferred from charset/system locale
bool explicitLanguage : 1;
// caps variant (small-caps, petite-caps, etc.)
uint8_t variantCaps;
// sub/superscript variant
uint8_t variantSubSuper;
// Return the final adjusted font size for the given aspect ratio.
// Not meant to be called when sizeAdjust = -1.0.
gfxFloat GetAdjustedSize(gfxFloat aspect) const {
NS_ASSERTION(sizeAdjust >= 0.0, "Not meant to be called when sizeAdjust = -1.0");
gfxFloat adjustedSize = std::max(NS_round(size*(sizeAdjust/aspect)), 1.0);
return std::min(adjustedSize, FONT_MAX_SIZE);
}
PLDHashNumber Hash() const {
return ((style + (systemFont << 7) +
(weight << 8)) + uint32_t(size*1000) + uint32_t(sizeAdjust*1000)) ^
nsISupportsHashKey::HashKey(language);
}
int8_t ComputeWeight() const;
// Adjust this style to simulate sub/superscript (as requested in the
// variantSubSuper field) using size and baselineOffset instead.
void AdjustForSubSuperscript(int32_t aAppUnitsPerDevPixel);
bool Equals(const gfxFontStyle& other) const {
return
(*reinterpret_cast<const uint64_t*>(&size) ==
*reinterpret_cast<const uint64_t*>(&other.size)) &&
(style == other.style) &&
(variantCaps == other.variantCaps) &&
(variantSubSuper == other.variantSubSuper) &&
(allowSyntheticWeight == other.allowSyntheticWeight) &&
(allowSyntheticStyle == other.allowSyntheticStyle) &&
(systemFont == other.systemFont) &&
(printerFont == other.printerFont) &&
(useGrayscaleAntialiasing == other.useGrayscaleAntialiasing) &&
(explicitLanguage == other.explicitLanguage) &&
(weight == other.weight) &&
(stretch == other.stretch) &&
(language == other.language) &&
(baselineOffset == other.baselineOffset) &&
(*reinterpret_cast<const uint32_t*>(&sizeAdjust) ==
*reinterpret_cast<const uint32_t*>(&other.sizeAdjust)) &&
(featureSettings == other.featureSettings) &&
(languageOverride == other.languageOverride) &&
(alternateValues == other.alternateValues) &&
(featureValueLookup == other.featureValueLookup);
}
static void ParseFontFeatureSettings(const nsString& aFeatureString,
nsTArray<gfxFontFeature>& aFeatures);
static uint32_t ParseFontLanguageOverride(const nsString& aLangTag);
};
struct gfxTextRange {
enum {
// flags for recording the kind of font-matching that was used
kFontGroup = 0x0001,
kPrefsFallback = 0x0002,
kSystemFallback = 0x0004
};
gfxTextRange(uint32_t aStart, uint32_t aEnd,
gfxFont* aFont, uint8_t aMatchType,
uint16_t aOrientation)
: start(aStart),
end(aEnd),
font(aFont),
matchType(aMatchType),
orientation(aOrientation)
{ }
uint32_t Length() const { return end - start; }
uint32_t start, end;
RefPtr<gfxFont> font;
uint8_t matchType;
uint16_t orientation;
};
/**
* Font cache design:
*
* The mFonts hashtable contains most fonts, indexed by (gfxFontEntry*, style).
* It does not add a reference to the fonts it contains.
* When a font's refcount decreases to zero, instead of deleting it we
* add it to our expiration tracker.
* The expiration tracker tracks fonts with zero refcount. After a certain
* period of time, such fonts expire and are deleted.
*
* 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 nsExpirationTracker<gfxFont,3> {
public:
enum {
FONT_TIMEOUT_SECONDS = 10,
SHAPED_WORD_TIMEOUT_SECONDS = 60
};
gfxFontCache();
~gfxFontCache();
/*
* 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 an addrefed pointer, or null
// if there's nothing matching in the cache
already_AddRefed<gfxFont>
Lookup(const gfxFontEntry* aFontEntry,
const gfxFontStyle* aStyle,
const gfxCharacterMap* aUnicodeRangeMap = nullptr);
// 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; we'll forget about the old one.
void AddNew(gfxFont *aFont);
// The font's refcount has gone to zero; give ownership of it to
// the cache. We delete it if it's not acquired again after a certain
// amount of time.
void NotifyReleased(gfxFont *aFont);
// This gets called when the timeout has expired on a zero-refcount
// font; we just delete it.
virtual void NotifyExpired(gfxFont *aFont) override;
// 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() {
mFonts.Clear();
AgeAllGenerations();
}
void FlushShapedWordCaches();
void AddSizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf,
FontCacheSizes* aSizes) const;
void AddSizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf,
FontCacheSizes* aSizes) const;
protected:
class MemoryReporter final : public nsIMemoryReporter
{
~MemoryReporter() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIMEMORYREPORTER
};
// Observer for notifications that the font cache cares about
class Observer final
: public nsIObserver
{
~Observer() {}
public:
NS_DECL_ISUPPORTS
NS_DECL_NSIOBSERVER
};
void DestroyFont(gfxFont *aFont);
static gfxFontCache *gGlobalCache;
struct 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) : mFont(nullptr) { }
HashEntry(const HashEntry& toCopy) : mFont(toCopy.mFont) { }
~HashEntry() { }
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* mFont;
};
nsTHashtable<HashEntry> mFonts;
static void WordCacheExpirationTimerCallback(nsITimer* aTimer, void* aCache);
nsCOMPtr<nsITimer> mWordCacheExpirationTimer;
};
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));
}
};
class gfxTextRunFactory {
NS_INLINE_DECL_REFCOUNTING(gfxTextRunFactory)
public:
typedef mozilla::gfx::DrawTarget DrawTarget;
// Flags in the mask 0xFFFF0000 are reserved for textrun clients
// Flags in the mask 0x0000F000 are reserved for per-platform fonts
// Flags in the mask 0x00000FFF are set by the textrun creator.
enum {
CACHE_TEXT_FLAGS = 0xF0000000,
USER_TEXT_FLAGS = 0x0FFF0000,
TEXTRUN_TEXT_FLAGS = 0x0000FFFF,
SETTABLE_FLAGS = CACHE_TEXT_FLAGS | USER_TEXT_FLAGS,
/**
* When set, the text string pointer used to create the text run
* is guaranteed to be available during the lifetime of the text run.
*/
TEXT_IS_PERSISTENT = 0x0001,
/**
* When set, the text is known to be all-ASCII (< 128).
*/
TEXT_IS_ASCII = 0x0002,
/**
* When set, the text is RTL.
*/
TEXT_IS_RTL = 0x0004,
/**
* When set, spacing is enabled and the textrun needs to call GetSpacing
* on the spacing provider.
*/
TEXT_ENABLE_SPACING = 0x0008,
/**
* When set, GetHyphenationBreaks may return true for some character
* positions, otherwise it will always return false for all characters.
*/
TEXT_ENABLE_HYPHEN_BREAKS = 0x0010,
/**
* When set, the text has no characters above 255 and it is stored
* in the textrun in 8-bit format.
*/
TEXT_IS_8BIT = 0x0020,
/**
* 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 = 0x0040,
/**
* When set, optional ligatures are disabled. Ligatures that are
* required for legible text should still be enabled.
*/
TEXT_DISABLE_OPTIONAL_LIGATURES = 0x0080,
/**
* 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 = 0x0100,
/**
* For internal use by the memory reporter when accounting for
* storage used by textruns.
* Because the reporter may visit each textrun multiple times while
* walking the frame trees and textrun cache, it needs to mark
* textruns that have been seen so as to avoid multiple-accounting.
*/
TEXT_RUN_SIZE_ACCOUNTED = 0x0200,
/**
* When set, the textrun should discard control characters instead of
* turning them into hexboxes.
*/
TEXT_HIDE_CONTROL_CHARACTERS = 0x0400,
/**
* 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 = 0xF000,
TEXT_ORIENT_HORIZONTAL = 0x0000,
TEXT_ORIENT_VERTICAL_UPRIGHT = 0x1000,
TEXT_ORIENT_VERTICAL_SIDEWAYS_RIGHT = 0x2000,
TEXT_ORIENT_VERTICAL_SIDEWAYS_LEFT = 0x4000,
TEXT_ORIENT_VERTICAL_MIXED = 0x8000,
/**
* 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 = 0x20000000,
/**
* 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 = 0x40000000,
// Set if the textrun should use the OpenType 'math' script.
TEXT_USE_MATH_SCRIPT = 0x80000000,
TEXT_UNUSED_FLAGS = 0x10000000
};
/**
* This record contains all the parameters needed to initialize a textrun.
*/
struct 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::unicode::Script Script;
explicit gfxFontShaper(gfxFont *aFont)
: mFont(aFont)
{
NS_ASSERTION(aFont, "shaper requires a valid font!");
}
virtual ~gfxFontShaper() { }
// 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,
bool aVertical,
gfxShapedText *aShapedText) = 0;
gfxFont *GetFont() const { return mFont; }
static void
MergeFontFeatures(const gfxFontStyle *aStyle,
const nsTArray<gfxFontFeature>& aFontFeatures,
bool aDisableLigatures,
const nsAString& aFamilyName,
bool aAddSmallCaps,
void (*aHandleFeature)(const uint32_t&,
uint32_t&, void*),
void* aHandleFeatureData);
protected:
// Work out whether cairo will snap inter-glyph spacing to pixels.
static void GetRoundOffsetsToPixels(DrawTarget* aDrawTarget,
bool* aRoundX, bool* aRoundY);
// 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;
};
/*
* 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::unicode::Script Script;
gfxShapedText(uint32_t aLength, uint32_t aFlags,
int32_t aAppUnitsPerDevUnit)
: mLength(aLength)
, mFlags(aFlags)
, mAppUnitsPerDevUnit(aAppUnitsPerDevUnit)
{ }
virtual ~gfxShapedText() { }
/**
* 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:
CompressedGlyph() { mValue = 0; }
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,
// 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,
FLAG_CHAR_IS_SPACE = 0x10000000U,
// The advance is stored in appunits
ADVANCE_MASK = 0x0FFF0000U,
ADVANCE_SHIFT = 16,
GLYPH_MASK = 0x0000FFFFU,
// Non-simple glyphs may or may not have glyph data in the
// corresponding mDetailedGlyphs entry. They have the following
// flag bits:
// 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 = 0x01,
FLAG_NOT_CLUSTER_START = 0x02,
FLAG_NOT_LIGATURE_GROUP_START = 0x04,
FLAG_CHAR_IS_TAB = 0x08,
FLAG_CHAR_IS_NEWLINE = 0x10,
// 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 = 0x20,
CHAR_TYPE_FLAGS_MASK = 0x38,
GLYPH_COUNT_MASK = 0x00FFFF00U,
GLYPH_COUNT_SHIFT = 8
};
// "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) != 0; }
uint32_t GetSimpleAdvance() const { return (mValue & ADVANCE_MASK) >> ADVANCE_SHIFT; }
uint32_t GetSimpleGlyph() const { return mValue & GLYPH_MASK; }
bool IsMissing() const { return (mValue & (FLAG_NOT_MISSING|FLAG_IS_SIMPLE_GLYPH)) == 0; }
bool IsClusterStart() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) || !(mValue & FLAG_NOT_CLUSTER_START);
}
bool IsLigatureGroupStart() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) || !(mValue & FLAG_NOT_LIGATURE_GROUP_START);
}
bool IsLigatureContinuation() const {
return (mValue & FLAG_IS_SIMPLE_GLYPH) == 0 &&
(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) != 0;
}
bool CharIsTab() const {
return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_TAB) != 0;
}
bool CharIsNewline() const {
return !IsSimpleGlyph() && (mValue & FLAG_CHAR_IS_NEWLINE) != 0;
}
bool CharMayHaveEmphasisMark() const {
return !CharIsSpace() &&
(IsSimpleGlyph() || !(mValue & FLAG_CHAR_NO_EMPHASIS_MARK));
}
uint32_t CharTypeFlags() const {
return IsSimpleGlyph() ? 0 : (mValue & CHAR_TYPE_FLAGS_MASK);
}
void SetClusterStart(bool aIsClusterStart) {
NS_ASSERTION(!IsSimpleGlyph(),
"can't call SetClusterStart on simple glyphs");
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) {
NS_ASSERTION(aCanBreakBefore <= 2,
"Bogus break-before value!");
uint32_t breakMask = (uint32_t(aCanBreakBefore) << FLAGS_CAN_BREAK_SHIFT);
uint32_t toggle = breakMask ^ (mValue & FLAGS_CAN_BREAK_BEFORE);
mValue ^= toggle;
return toggle;
}
CompressedGlyph& SetSimpleGlyph(uint32_t aAdvanceAppUnits, uint32_t aGlyph) {
NS_ASSERTION(IsSimpleAdvance(aAdvanceAppUnits), "Advance overflow");
NS_ASSERTION(IsSimpleGlyphID(aGlyph), "Glyph overflow");
NS_ASSERTION(!CharTypeFlags(), "Char type flags lost");
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_CHAR_IS_SPACE)) |
FLAG_IS_SIMPLE_GLYPH |
(aAdvanceAppUnits << ADVANCE_SHIFT) | aGlyph;
return *this;
}
CompressedGlyph& SetComplex(bool aClusterStart, bool aLigatureStart,
uint32_t aGlyphCount) {
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_CHAR_IS_SPACE)) |
FLAG_NOT_MISSING |
CharTypeFlags() |
(aClusterStart ? 0 : FLAG_NOT_CLUSTER_START) |
(aLigatureStart ? 0 : FLAG_NOT_LIGATURE_GROUP_START) |
(aGlyphCount << GLYPH_COUNT_SHIFT);
return *this;
}
/**
* Missing glyphs are treated as ligature group starts; don't mess with
* the cluster-start flag (see bugs 618870 and 619286).
*/
CompressedGlyph& SetMissing(uint32_t aGlyphCount) {
mValue = (mValue & (FLAGS_CAN_BREAK_BEFORE | FLAG_NOT_CLUSTER_START |
FLAG_CHAR_IS_SPACE)) |
CharTypeFlags() |
(aGlyphCount << GLYPH_COUNT_SHIFT);
return *this;
}
uint32_t GetGlyphCount() const {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
return (mValue & GLYPH_COUNT_MASK) >> GLYPH_COUNT_SHIFT;
}
void SetIsSpace() {
mValue |= FLAG_CHAR_IS_SPACE;
}
void SetIsTab() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_IS_TAB;
}
void SetIsNewline() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_IS_NEWLINE;
}
void SetNoEmphasisMark() {
NS_ASSERTION(!IsSimpleGlyph(), "Expected non-simple-glyph");
mValue |= FLAG_CHAR_NO_EMPHASIS_MARK;
}
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, x-offset and y-offset of the glyph, in appunits
* mAdvance is in the text direction (RTL or LTR)
* mXOffset is always from left to right
* mYOffset is always from top to bottom */
int32_t mAdvance;
float mXOffset, mYOffset;
};
void SetGlyphs(uint32_t aCharIndex, CompressedGlyph aGlyph,
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 AdjustAdvancesForSyntheticBold(float aSynBoldOffset,
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);
uint32_t GetFlags() const {
return mFlags;
}
bool IsVertical() const {
return (GetFlags() & gfxTextRunFactory::TEXT_ORIENT_MASK) !=
gfxTextRunFactory::TEXT_ORIENT_HORIZONTAL;
}
bool UseCenterBaseline() const {
uint32_t orient = GetFlags() & gfxTextRunFactory::TEXT_ORIENT_MASK;
return orient == gfxTextRunFactory::TEXT_ORIENT_VERTICAL_MIXED ||
orient == gfxTextRunFactory::TEXT_ORIENT_VERTICAL_UPRIGHT;
}
bool IsRightToLeft() const {
return (GetFlags() & gfxTextRunFactory::TEXT_IS_RTL) != 0;
}
bool IsSidewaysLeft() const {
return (GetFlags() & gfxTextRunFactory::TEXT_ORIENT_MASK) ==
gfxTextRunFactory::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() &
gfxTextRunFactory::TEXT_DISABLE_OPTIONAL_LIGATURES) != 0;
}
bool TextIs8Bit() const {
return (GetFlags() & gfxTextRunFactory::TEXT_IS_8BIT) != 0;
}
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(),
0, 0
};
SetGlyphs(aIndex, CompressedGlyph().SetComplex(true, true, 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()
: mLastUsed(0)
{ }
// 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;
};
mozilla::UniquePtr<DetailedGlyphStore> mDetailedGlyphs;
// Number of char16_t characters and CompressedGlyph glyph records
uint32_t mLength;
// Shaping flags (direction, ligature-suppression)
uint32_t mFlags;
int32_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::unicode::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,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags) {
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,
aAppUnitsPerDevUnit, aFlags);
}
static gfxShapedWord* Create(const char16_t *aText, uint32_t aLength,
Script aRunScript,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags) {
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 & gfxTextRunFactory::TEXT_IS_8BIT) {
nsAutoCString narrowText;
LossyAppendUTF16toASCII(nsDependentSubstring(aText, aLength),
narrowText);
return Create((const uint8_t*)(narrowText.BeginReading()),
aLength, aRunScript, aAppUnitsPerDevUnit, aFlags);
}
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,
aAppUnitsPerDevUnit, aFlags);
}
// Override operator delete to properly free the object that was
// allocated via malloc.
void operator delete(void* p) {
free(p);
}
virtual const CompressedGlyph *GetCharacterGlyphs() const override {
return &mCharGlyphsStorage[0];
}
virtual 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;
}
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;
}
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,
int32_t aAppUnitsPerDevUnit, uint32_t aFlags)
: gfxShapedText(aLength, aFlags | gfxTextRunFactory::TEXT_IS_8BIT,
aAppUnitsPerDevUnit)
, mScript(aRunScript)
, mAgeCounter(0)
{
memset(mCharGlyphsStorage, 0, aLength * sizeof(CompressedGlyph));
uint8_t *text = reinterpret_cast<uint8_t*>(&mCharGlyphsStorage[aLength]);
memcpy(text, aText, aLength * sizeof(uint8_t));
}
gfxShapedWord(const char16_t *aText, uint32_t aLength,
Script aRunScript,
int32_t aAppUnitsPerDevUnit, uint32_t aFlags)
: gfxShapedText(aLength, aFlags, aAppUnitsPerDevUnit)
, mScript(aRunScript)
, 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);
}
Script mScript;
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:
typedef mozilla::gfx::DrawTarget DrawTarget;
typedef mozilla::unicode::Script Script;
public:
nsrefcnt AddRef(void) {
NS_PRECONDITION(int32_t(mRefCnt) >= 0, "illegal refcnt");
if (mExpirationState.IsTracked()) {
gfxFontCache::GetCache()->RemoveObject(this);
}
++mRefCnt;
NS_LOG_ADDREF(this, mRefCnt, "gfxFont", sizeof(*this));
return mRefCnt;
}
nsrefcnt Release(void) {
NS_PRECONDITION(0 != mRefCnt, "dup release");
--mRefCnt;
NS_LOG_RELEASE(this, mRefCnt, "gfxFont");
if (mRefCnt == 0) {
NotifyReleased();
// |this| may have been deleted.
return 0;
}
return mRefCnt;
}
int32_t GetRefCount() { return mRefCnt; }
// options to specify the kind of AA to be used when creating a font
typedef enum {
kAntialiasDefault,
kAntialiasNone,
kAntialiasGrayscale,
kAntialiasSubpixel
} AntialiasOption;
protected:
nsAutoRefCnt mRefCnt;
cairo_scaled_font_t *mScaledFont;
void NotifyReleased() {
gfxFontCache *cache = gfxFontCache::GetCache();
if (cache) {
// Don't delete just yet; return the object to the cache for
// possibly recycling within some time limit
cache->NotifyReleased(this);
} else {
// The cache may have already been shut down.
delete this;
}
}
gfxFont(gfxFontEntry *aFontEntry, const gfxFontStyle *aFontStyle,
AntialiasOption anAAOption = kAntialiasDefault,
cairo_scaled_font_t *aScaledFont = nullptr);
public:
virtual ~gfxFont();
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 nsString& GetName() const { return mFontEntry->Name(); }
const gfxFontStyle *GetStyle() const { return &mStyle; }
virtual cairo_scaled_font_t* GetCairoScaledFont() { return mScaledFont; }
virtual gfxFont* CopyWithAntialiasOption(AntialiasOption anAAOption) {
// platforms where this actually matters should override
return nullptr;
}
virtual gfxFloat GetAdjustedSize() const {
return mAdjustedSize > 0.0
? mAdjustedSize
: (mStyle.sizeAdjust == 0.0 ? 0.0 : mStyle.size);
}
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() {
return mFontEntry->HasCmapTable();
}
// check whether this is an sfnt we can potentially use with Graphite
bool FontCanSupportGraphite() {
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() {
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);
// 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 horizontal advance of a glyph.
gfxFloat GetGlyphHAdvance(DrawTarget* aDrawTarget, uint16_t aGID);
// Return Azure GlyphRenderingOptions for drawing this font.
virtual already_AddRefed<mozilla::gfx::GlyphRenderingOptions>
GetGlyphRenderingOptions(const TextRunDrawParams* aRunParams = nullptr)
{ return nullptr; }
gfxFloat SynthesizeSpaceWidth(uint32_t aCh);
// Font metrics
struct Metrics {
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 zeroOrAveCharWidth; // width of '0', or if there is
// no '0' glyph in this font,
// equal to .aveCharWidth
};
enum Orientation {
eHorizontal,
eVertical
};
const Metrics& GetMetrics(Orientation aOrientation)
{
if (aOrientation == eHorizontal) {
return GetHorizontalMetrics();
}
if (!mVerticalMetrics) {
mVerticalMetrics.reset(CreateVerticalMetrics());
}
return *mVerticalMetrics;
}
/**
* 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,
gfxPoint *aPt, const TextRunDrawParams& aRunParams,
uint16_t 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, gfxPoint* 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, uint16_t 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
virtual uint32_t GetSpaceGlyph() = 0;
gfxGlyphExtents *GetOrCreateGlyphExtents(int32_t aAppUnitsPerDevUnit);
// You need to call SetupCairoFont on aDrawTarget just before calling this.
virtual void SetupGlyphExtents(DrawTarget* aDrawTarget, uint32_t aGlyphID,
bool aNeedTight, gfxGlyphExtents *aExtents);
// This is called by the default Draw() implementation above.
virtual bool SetupCairoFont(DrawTarget* aDrawTarget) = 0;
virtual bool AllowSubpixelAA() { return true; }
bool IsSyntheticBold() { return mApplySyntheticBold; }
// 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() {
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) {
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) {
if (!mIsValid) {
return 0;
}
return mFontEntry->GetUVSGlyph(aCh, aVS);
}
template<typename T>
bool InitFakeSmallCapsRun(DrawTarget *aDrawTarget,
gfxTextRun *aTextRun,
const T *aText,
uint32_t aOffset,
uint32_t aLength,
uint8_t aMatchType,
uint16_t aOrientation,
Script aScript,
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,
bool aVertical);
// Get a ShapedWord representing the given text (either 8- or 16-bit)
// for use in setting up a gfxTextRun.
template<typename T>
gfxShapedWord* GetShapedWord(DrawTarget *aDrawTarget,
const T *aText,
uint32_t aLength,
uint32_t aHash,
Script aRunScript,
bool aVertical,
int32_t aAppUnitsPerDevUnit,
uint32_t aFlags,
gfxTextPerfMetrics *aTextPerf);
// Ensure the ShapedWord cache is initialized. This MUST be called before
// any attempt to use GetShapedWord().
void InitWordCache() {
if (!mWordCache) {
mWordCache = mozilla::MakeUnique<nsTHashtable<CacheHashEntry>>();
}
}
// 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
void AgeCachedWords();
// Discard all cached word records; called on memory-pressure notification.
void ClearCachedWords() {
if (mWordCache) {
mWordCache->Clear();
}
}
// Glyph rendering/geometry has changed, so invalidate data as necessary.
void NotifyGlyphsChanged();
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;
virtual already_AddRefed<mozilla::gfx::ScaledFont> GetScaledFont(DrawTarget* aTarget)
{ return gfxPlatform::GetPlatform()->GetScaledFontForFont(aTarget, this); }
bool KerningDisabled() {
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()
{
// Currently only fonts with SVG glyphs can have animated glyphs
return mFontEntry->TryGetSVGData(this);
}
static void DestroySingletons() {
delete sScriptTagToCode;
delete sDefaultFeatures;
}
// Get a font dimension from the MATH table, scaled to appUnits;
// may only be called if mFontEntry->TryGetMathTable has succeeded
// (i.e. the font is known to be a valid OpenType math font).
nscoord GetMathConstant(gfxFontEntry::MathConstant aConstant,
uint32_t aAppUnitsPerDevPixel)
{
return NSToCoordRound(mFontEntry->GetMathConstant(aConstant) *
GetAdjustedSize() * aAppUnitsPerDevPixel);
}
// Get a dimensionless math constant (e.g. a percentage);
// may only be called if mFontEntry->TryGetMathTable has succeeded
// (i.e. the font is known to be a valid OpenType math font).
float GetMathConstant(gfxFontEntry::MathConstant aConstant)
{
return mFontEntry->GetMathConstant(aConstant);
}
// return a cloned font resized and offset to simulate sub/superscript glyphs
virtual already_AddRefed<gfxFont>
GetSubSuperscriptFont(int32_t aAppUnitsPerDevPixel);
/**
* Return the reference cairo_t object from aDT.
*/
static cairo_t* RefCairo(mozilla::gfx::DrawTarget* aDT);
protected:
virtual const Metrics& GetHorizontalMetrics() = 0;
const Metrics* CreateVerticalMetrics();
// Output a single glyph at *aPt, which is updated by the glyph's advance.
// 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).
void DrawOneGlyph(uint32_t aGlyphID,
double aAdvance,
gfxPoint *aPt,
GlyphBufferAzure& aBuffer,
bool *aEmittedGlyphs) const;
// 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.
bool DrawGlyphs(const gfxShapedText *aShapedText,
uint32_t aOffset, // offset in the textrun
uint32_t aCount, // length of run to draw
gfxPoint *aPt,
const TextRunDrawParams& aRunParams,
const FontDrawParams& aFontParams);
// 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).
// Default implementation relies on gfxFontEntry::CreateFontInstance;
// backends that don't implement that will need to override this and use
// an alternative technique. (gfxFontconfigFonts, I'm looking at you...)
virtual already_AddRefed<gfxFont> GetSmallCapsFont();
// 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(DrawTarget& aDrawTarget, uint16_t aGID) {
return -1;
}
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);
// do spaces participate in shaping rules? if so, can't used word cache
bool SpaceMayParticipateInShaping(Script aRunScript);
// 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,
bool aVertical,
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,
bool aVertical,
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,
bool aVertical,
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,
bool aVertical,
gfxTextRun *aTextRun);
void CheckForFeaturesInvolvingSpace();
// 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 nsDataHashtable<nsUint32HashKey,Script> *sScriptTagToCode;
static nsTHashtable<nsUint32HashKey> *sDefaultFeatures;
RefPtr<gfxFontEntry> mFontEntry;
struct CacheHashKey {
union {
const uint8_t *mSingle;
const char16_t *mDouble;
} mText;
uint32_t mLength;
uint32_t mFlags;
Script mScript;
int32_t mAppUnitsPerDevUnit;
PLDHashNumber mHashKey;
bool mTextIs8Bit;
CacheHashKey(const uint8_t *aText, uint32_t aLength,
uint32_t aStringHash,
Script aScriptCode, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: mLength(aLength),
mFlags(aFlags),
mScript(aScriptCode),
mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
mHashKey(aStringHash + static_cast<int32_t>(aScriptCode) +
aAppUnitsPerDevUnit * 0x100 + aFlags * 0x10000),
mTextIs8Bit(true)
{
NS_ASSERTION(aFlags & gfxTextRunFactory::TEXT_IS_8BIT,
"8-bit flag should have been set");
mText.mSingle = aText;
}
CacheHashKey(const char16_t *aText, uint32_t aLength,
uint32_t aStringHash,
Script aScriptCode, int32_t aAppUnitsPerDevUnit,
uint32_t aFlags)
: mLength(aLength),
mFlags(aFlags),
mScript(aScriptCode),
mAppUnitsPerDevUnit(aAppUnitsPerDevUnit),
mHashKey(aStringHash + static_cast<int32_t>(aScriptCode) +
aAppUnitsPerDevUnit * 0x100 + aFlags * 0x10000),
mTextIs8Bit(false)
{
// 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;
}
};
class CacheHashEntry : public PLDHashEntryHdr {
public:
typedef const CacheHashKey &KeyType;
typedef const CacheHashKey *KeyTypePointer;
// When constructing a new entry in the hashtable, the caller of Put()
// will fill us in.
explicit CacheHashEntry(KeyTypePointer aKey) { }
CacheHashEntry(const CacheHashEntry& toCopy) { NS_ERROR("Should not be called"); }
~CacheHashEntry() { }
bool KeyEquals(const KeyTypePointer aKey) const;
static KeyTypePointer KeyToPointer(KeyType aKey) { return &aKey; }
static PLDHashNumber HashKey(const KeyTypePointer aKey) {
return aKey->mHashKey;
}
size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
{
return aMallocSizeOf(mShapedWord.get());
}
enum { ALLOW_MEMMOVE = true };
mozilla::UniquePtr<gfxShapedWord> mShapedWord;
};
mozilla::UniquePtr<nsTHashtable<CacheHashEntry> > mWordCache;
static const uint32_t kShapedWordCacheMaxAge = 3;
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?
nsExpirationState mExpirationState;
gfxFontStyle mStyle;
nsTArray<mozilla::UniquePtr<gfxGlyphExtents>> mGlyphExtentsArray;
mozilla::UniquePtr<nsTHashtable<nsPtrHashKey<GlyphChangeObserver>>>
mGlyphChangeObservers;
gfxFloat mAdjustedSize;
// 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;
// the AA setting requested for this font - may affect glyph bounds
AntialiasOption mAntialiasOption;
// a copy of the font without antialiasing, if needed for separate
// measurement by mathml code
mozilla::UniquePtr<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::UniquePtr<gfxFontShaper> mHarfBuzzShaper;
mozilla::UniquePtr<gfxFontShaper> mGraphiteShaper;
// if a userfont with unicode-range specified, contains map of *possible*
// ranges supported by font
RefPtr<gfxCharacterMap> mUnicodeRangeMap;
RefPtr<mozilla::gfx::ScaledFont> mAzureScaledFont;
// For vertical metrics, created on demand.
mozilla::UniquePtr<const Metrics> mVerticalMetrics;
// 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, gfxPoint aPoint,
uint32_t aGlyphId, gfxTextContextPaint *aContextPaint) const;
bool RenderSVGGlyph(gfxContext *aContext, gfxPoint aPoint,
uint32_t aGlyphId, gfxTextContextPaint *aContextPaint,
gfxTextRunDrawCallbacks *aCallbacks,
bool& aEmittedGlyphs) const;
bool RenderColorGlyph(DrawTarget* aDrawTarget,
gfxContext* aContext,
mozilla::gfx::ScaledFont* scaledFont,
mozilla::gfx::GlyphRenderingOptions* renderingOptions,
mozilla::gfx::DrawOptions drawOptions,
const mozilla::gfx::Point& aPoint,
uint32_t aGlyphId) const;
// 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 double 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 TextRunDrawParams {
RefPtr<mozilla::gfx::DrawTarget> dt;
gfxContext *context;
gfxFont::Spacing *spacing;
gfxTextRunDrawCallbacks *callbacks;
gfxTextContextPaint *runContextPaint;
mozilla::gfx::Color fontSmoothingBGColor;
gfxFloat direction;
double devPerApp;
nscolor textStrokeColor;
gfxPattern *textStrokePattern;
const mozilla::gfx::StrokeOptions *strokeOpts;
const mozilla::gfx::DrawOptions *drawOpts;
DrawMode drawMode;
bool isVerticalRun;
bool isRTL;
bool paintSVGGlyphs;
};
struct FontDrawParams {
RefPtr<mozilla::gfx::ScaledFont> scaledFont;
RefPtr<mozilla::gfx::GlyphRenderingOptions> renderingOptions;
gfxTextContextPaint *contextPaint;
mozilla::gfx::Matrix *passedInvMatrix;
mozilla::gfx::Matrix matInv;
double synBoldOnePixelOffset;
int32_t extraStrikes;
mozilla::gfx::DrawOptions drawOptions;
bool isVerticalFont;
bool haveSVGGlyphs;
bool haveColorGlyphs;
};
struct EmphasisMarkDrawParams {
gfxContext* context;
gfxFont::Spacing* spacing;
gfxTextRun* mark;
gfxFloat advance;
gfxFloat direction;
bool isVertical;
};
#endif
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