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skia / skia.git / b5e1f7558052cc60deaf23ccc2c898d1c6c94c09 / . / src / ports / SkFontHost_FreeType.cpp
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/*
* Copyright 2006 The Android Open Source Project
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkAdvancedTypefaceMetrics.h"
#include "SkBitmap.h"
#include "SkCanvas.h"
#include "SkColorData.h"
#include "SkDescriptor.h"
#include "SkFDot6.h"
#include "SkFontDescriptor.h"
#include "SkFontHost_FreeType_common.h"
#include "SkGlyph.h"
#include "SkMakeUnique.h"
#include "SkMask.h"
#include "SkMaskGamma.h"
#include "SkMatrix22.h"
#include "SkMalloc.h"
#include "SkMutex.h"
#include "SkOTUtils.h"
#include "SkPath.h"
#include "SkScalerContext.h"
#include "SkStream.h"
#include "SkString.h"
#include "SkTemplates.h"
#include <memory>
#include <ft2build.h>
#include FT_ADVANCES_H
#include FT_BITMAP_H
#include FT_FREETYPE_H
#include FT_LCD_FILTER_H
#include FT_MODULE_H
#include FT_MULTIPLE_MASTERS_H
#include FT_OUTLINE_H
#include FT_SIZES_H
#include FT_SYSTEM_H
#include FT_TRUETYPE_TABLES_H
#include FT_TYPE1_TABLES_H
#include FT_XFREE86_H
// SK_FREETYPE_MINIMUM_RUNTIME_VERSION 0x<major><minor><patch><flags>
// Flag SK_FREETYPE_DLOPEN: also try dlopen to get newer features.
#define SK_FREETYPE_DLOPEN (0x1)
#ifndef SK_FREETYPE_MINIMUM_RUNTIME_VERSION
# if defined(SK_BUILD_FOR_ANDROID_FRAMEWORK) || defined (SK_BUILD_FOR_GOOGLE3)
# define SK_FREETYPE_MINIMUM_RUNTIME_VERSION (((FREETYPE_MAJOR) << 24) | ((FREETYPE_MINOR) << 16) | ((FREETYPE_PATCH) << 8))
# else
# define SK_FREETYPE_MINIMUM_RUNTIME_VERSION ((2 << 24) | (3 << 16) | (11 << 8) | (SK_FREETYPE_DLOPEN))
# endif
#endif
#if SK_FREETYPE_MINIMUM_RUNTIME_VERSION & SK_FREETYPE_DLOPEN
# include <dlfcn.h>
#endif
// FT_LOAD_COLOR and the corresponding FT_Pixel_Mode::FT_PIXEL_MODE_BGRA
// were introduced in FreeType 2.5.0.
// The following may be removed once FreeType 2.5.0 is required to build.
#ifndef FT_LOAD_COLOR
# define FT_LOAD_COLOR ( 1L << 20 )
# define FT_PIXEL_MODE_BGRA 7
#endif
// FT_LOAD_BITMAP_METRICS_ONLY was introduced in FreeType 2.7.1
// The following may be removed once FreeType 2.7.1 is required to build.
#ifndef FT_LOAD_BITMAP_METRICS_ONLY
# define FT_LOAD_BITMAP_METRICS_ONLY ( 1L << 22 )
#endif
//#define ENABLE_GLYPH_SPEW // for tracing calls
//#define DUMP_STRIKE_CREATION
//#define SK_FONTHOST_FREETYPE_RUNTIME_VERSION
//#define SK_GAMMA_APPLY_TO_A8
static bool isLCD(const SkScalerContextRec& rec) {
return SkMask::kLCD16_Format == rec.fMaskFormat;
}
//////////////////////////////////////////////////////////////////////////
extern "C" {
static void* sk_ft_alloc(FT_Memory, long size) {
return sk_malloc_throw(size);
}
static void sk_ft_free(FT_Memory, void* block) {
sk_free(block);
}
static void* sk_ft_realloc(FT_Memory, long cur_size, long new_size, void* block) {
return sk_realloc_throw(block, new_size);
}
};
FT_MemoryRec_ gFTMemory = { nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc };
class FreeTypeLibrary : SkNoncopyable {
public:
FreeTypeLibrary()
: fGetVarDesignCoordinates(nullptr)
, fLibrary(nullptr)
, fIsLCDSupported(false)
, fLCDExtra(0)
{
if (FT_New_Library(&gFTMemory, &fLibrary)) {
return;
}
FT_Add_Default_Modules(fLibrary);
// When using dlsym
// *(void**)(&procPtr) = dlsym(self, "proc");
// is non-standard, but safe for POSIX. Cannot write
// *reinterpret_cast<void**>(&procPtr) = dlsym(self, "proc");
// because clang has not implemented DR573. See http://clang.llvm.org/cxx_dr_status.html .
FT_Int major, minor, patch;
FT_Library_Version(fLibrary, &major, &minor, &patch);
#if SK_FREETYPE_MINIMUM_RUNTIME_VERSION >= 0x02070100
fGetVarDesignCoordinates = FT_Get_Var_Design_Coordinates;
#elif SK_FREETYPE_MINIMUM_RUNTIME_VERSION & SK_FREETYPE_DLOPEN
if (major > 2 || ((major == 2 && minor > 7) || (major == 2 && minor == 7 && patch >= 0))) {
//The FreeType library is already loaded, so symbols are available in process.
void* self = dlopen(nullptr, RTLD_LAZY);
if (self) {
*(void**)(&fGetVarDesignCoordinates) = dlsym(self, "FT_Get_Var_Design_Coordinates");
dlclose(self);
}
}
#endif
#if SK_FREETYPE_MINIMUM_RUNTIME_VERSION >= 0x02070200
FT_Set_Default_Properties(fLibrary);
#elif SK_FREETYPE_MINIMUM_RUNTIME_VERSION & SK_FREETYPE_DLOPEN
if (major > 2 || ((major == 2 && minor > 7) || (major == 2 && minor == 7 && patch >= 1))) {
//The FreeType library is already loaded, so symbols are available in process.
void* self = dlopen(nullptr, RTLD_LAZY);
if (self) {
FT_Set_Default_PropertiesProc setDefaultProperties;
*(void**)(&setDefaultProperties) = dlsym(self, "FT_Set_Default_Properties");
dlclose(self);
if (setDefaultProperties) {
setDefaultProperties(fLibrary);
}
}
}
#endif
// Setup LCD filtering. This reduces color fringes for LCD smoothed glyphs.
// The default has changed over time, so this doesn't mean the same thing to all users.
if (FT_Library_SetLcdFilter(fLibrary, FT_LCD_FILTER_DEFAULT) == 0) {
fIsLCDSupported = true;
fLCDExtra = 2; //Using a filter adds one full pixel to each side.
}
}
~FreeTypeLibrary() {
if (fLibrary) {
FT_Done_Library(fLibrary);
}
}
FT_Library library() { return fLibrary; }
bool isLCDSupported() { return fIsLCDSupported; }
int lcdExtra() { return fLCDExtra; }
// FT_Get_{MM,Var}_{Blend,Design}_Coordinates were added in FreeType 2.7.1.
// Prior to this there was no way to get the coordinates out of the FT_Face.
// This wasn't too bad because you needed to specify them anyway, and the clamp was provided.
// However, this doesn't work when face_index specifies named variations as introduced in 2.6.1.
using FT_Get_Var_Blend_CoordinatesProc = FT_Error (*)(FT_Face, FT_UInt, FT_Fixed*);
FT_Get_Var_Blend_CoordinatesProc fGetVarDesignCoordinates;
private:
FT_Library fLibrary;
bool fIsLCDSupported;
int fLCDExtra;
// FT_Library_SetLcdFilterWeights was introduced in FreeType 2.4.0.
// The following platforms provide FreeType of at least 2.4.0.
// Ubuntu >= 11.04 (previous deprecated April 2013)
// Debian >= 6.0 (good)
// OpenSuse >= 11.4 (previous deprecated January 2012 / Nov 2013 for Evergreen 11.2)
// Fedora >= 14 (good)
// Android >= Gingerbread (good)
// RHEL >= 7 (6 has 2.3.11, EOL Nov 2020, Phase 3 May 2017)
using FT_Library_SetLcdFilterWeightsProc = FT_Error (*)(FT_Library, unsigned char*);
// FreeType added the ability to read global properties in 2.7.0. After 2.7.1 a means for users
// of FT_New_Library to request these global properties to be read was added.
using FT_Set_Default_PropertiesProc = void (*)(FT_Library);
};
struct SkFaceRec;
SK_DECLARE_STATIC_MUTEX(gFTMutex);
static FreeTypeLibrary* gFTLibrary;
static SkFaceRec* gFaceRecHead;
// Private to ref_ft_library and unref_ft_library
static int gFTCount;
// Caller must lock gFTMutex before calling this function.
static bool ref_ft_library() {
gFTMutex.assertHeld();
SkASSERT(gFTCount >= 0);
if (0 == gFTCount) {
SkASSERT(nullptr == gFTLibrary);
gFTLibrary = new FreeTypeLibrary;
}
++gFTCount;
return gFTLibrary->library();
}
// Caller must lock gFTMutex before calling this function.
static void unref_ft_library() {
gFTMutex.assertHeld();
SkASSERT(gFTCount > 0);
--gFTCount;
if (0 == gFTCount) {
SkASSERT(nullptr == gFaceRecHead);
SkASSERT(nullptr != gFTLibrary);
delete gFTLibrary;
SkDEBUGCODE(gFTLibrary = nullptr;)
}
}
///////////////////////////////////////////////////////////////////////////
struct SkFaceRec {
SkFaceRec* fNext;
std::unique_ptr<FT_FaceRec, SkFunctionWrapper<FT_Error, FT_FaceRec, FT_Done_Face>> fFace;
FT_StreamRec fFTStream;
std::unique_ptr<SkStreamAsset> fSkStream;
uint32_t fRefCnt;
uint32_t fFontID;
// FreeType prior to 2.7.1 does not implement retreiving variation design metrics.
// Cache the variation design metrics used to create the font if the user specifies them.
SkAutoSTMalloc<4, SkFixed> fAxes;
int fAxesCount;
// FreeType from 2.6.1 (14d6b5d7) until 2.7.0 (ee3f36f6b38) uses font_index for both font index
// and named variation index on input, but masks the named variation index part on output.
// Manually keep track of when a named variation is requested for 2.6.1 until 2.7.1.
bool fNamedVariationSpecified;
SkFaceRec(std::unique_ptr<SkStreamAsset> stream, uint32_t fontID);
};
extern "C" {
static unsigned long sk_ft_stream_io(FT_Stream ftStream,
unsigned long offset,
unsigned char* buffer,
unsigned long count)
{
SkStreamAsset* stream = static_cast<SkStreamAsset*>(ftStream->descriptor.pointer);
if (count) {
if (!stream->seek(offset)) {
return 0;
}
count = stream->read(buffer, count);
}
return count;
}
static void sk_ft_stream_close(FT_Stream) {}
}
SkFaceRec::SkFaceRec(std::unique_ptr<SkStreamAsset> stream, uint32_t fontID)
: fNext(nullptr), fSkStream(std::move(stream)), fRefCnt(1), fFontID(fontID)
, fAxesCount(0), fNamedVariationSpecified(false)
{
sk_bzero(&fFTStream, sizeof(fFTStream));
fFTStream.size = fSkStream->getLength();
fFTStream.descriptor.pointer = fSkStream.get();
fFTStream.read = sk_ft_stream_io;
fFTStream.close = sk_ft_stream_close;
}
static void ft_face_setup_axes(SkFaceRec* rec, const SkFontData& data) {
if (!(rec->fFace->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) {
return;
}
// If a named variation is requested, don't overwrite the named variation's position.
if (data.getIndex() > 0xFFFF) {
rec->fNamedVariationSpecified = true;
return;
}
SkDEBUGCODE(
FT_MM_Var* variations = nullptr;
if (FT_Get_MM_Var(rec->fFace.get(), &variations)) {
SkDEBUGF(("INFO: font %s claims variations, but none found.\n",
rec->fFace->family_name));
return;
}
SkAutoFree autoFreeVariations(variations);
if (static_cast<FT_UInt>(data.getAxisCount()) != variations->num_axis) {
SkDEBUGF(("INFO: font %s has %d variations, but %d were specified.\n",
rec->fFace->family_name, variations->num_axis, data.getAxisCount()));
return;
}
)
SkAutoSTMalloc<4, FT_Fixed> coords(data.getAxisCount());
for (int i = 0; i < data.getAxisCount(); ++i) {
coords[i] = data.getAxis()[i];
}
if (FT_Set_Var_Design_Coordinates(rec->fFace.get(), data.getAxisCount(), coords.get())) {
SkDEBUGF(("INFO: font %s has variations, but specified variations could not be set.\n",
rec->fFace->family_name));
return;
}
rec->fAxesCount = data.getAxisCount();
rec->fAxes.reset(rec->fAxesCount);
for (int i = 0; i < rec->fAxesCount; ++i) {
rec->fAxes[i] = data.getAxis()[i];
}
}
// Will return nullptr on failure
// Caller must lock gFTMutex before calling this function.
static SkFaceRec* ref_ft_face(const SkTypeface* typeface) {
gFTMutex.assertHeld();
const SkFontID fontID = typeface->uniqueID();
SkFaceRec* cachedRec = gFaceRecHead;
while (cachedRec) {
if (cachedRec->fFontID == fontID) {
SkASSERT(cachedRec->fFace);
cachedRec->fRefCnt += 1;
return cachedRec;
}
cachedRec = cachedRec->fNext;
}
std::unique_ptr<SkFontData> data = typeface->makeFontData();
if (nullptr == data || !data->hasStream()) {
return nullptr;
}
std::unique_ptr<SkFaceRec> rec(new SkFaceRec(data->detachStream(), fontID));
FT_Open_Args args;
memset(&args, 0, sizeof(args));
const void* memoryBase = rec->fSkStream->getMemoryBase();
if (memoryBase) {
args.flags = FT_OPEN_MEMORY;
args.memory_base = (const FT_Byte*)memoryBase;
args.memory_size = rec->fSkStream->getLength();
} else {
args.flags = FT_OPEN_STREAM;
args.stream = &rec->fFTStream;
}
{
FT_Face rawFace;
FT_Error err = FT_Open_Face(gFTLibrary->library(), &args, data->getIndex(), &rawFace);
if (err) {
SK_TRACEFTR(err, "unable to open font '%x'", fontID);
return nullptr;
}
rec->fFace.reset(rawFace);
}
SkASSERT(rec->fFace);
ft_face_setup_axes(rec.get(), *data);
// FreeType will set the charmap to the "most unicode" cmap if it exists.
// If there are no unicode cmaps, the charmap is set to nullptr.
// However, "symbol" cmaps should also be considered "fallback unicode" cmaps
// because they are effectively private use area only (even if they aren't).
// This is the last on the fallback list at
// https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6cmap.html
if (!rec->fFace->charmap) {
FT_Select_Charmap(rec->fFace.get(), FT_ENCODING_MS_SYMBOL);
}
rec->fNext = gFaceRecHead;
gFaceRecHead = rec.get();
return rec.release();
}
// Caller must lock gFTMutex before calling this function.
// Marked extern because vc++ does not support internal linkage template parameters.
extern /*static*/ void unref_ft_face(SkFaceRec* faceRec) {
gFTMutex.assertHeld();
SkFaceRec* rec = gFaceRecHead;
SkFaceRec* prev = nullptr;
while (rec) {
SkFaceRec* next = rec->fNext;
if (rec->fFace == faceRec->fFace) {
if (--rec->fRefCnt == 0) {
if (prev) {
prev->fNext = next;
} else {
gFaceRecHead = next;
}
delete rec;
}
return;
}
prev = rec;
rec = next;
}
SkDEBUGFAIL("shouldn't get here, face not in list");
}
class AutoFTAccess {
public:
AutoFTAccess(const SkTypeface* tf) : fFaceRec(nullptr) {
gFTMutex.acquire();
SkASSERT_RELEASE(ref_ft_library());
fFaceRec = ref_ft_face(tf);
}
~AutoFTAccess() {
if (fFaceRec) {
unref_ft_face(fFaceRec);
}
unref_ft_library();
gFTMutex.release();
}
FT_Face face() { return fFaceRec ? fFaceRec->fFace.get() : nullptr; }
int getAxesCount() { return fFaceRec ? fFaceRec->fAxesCount : 0; }
SkFixed* getAxes() { return fFaceRec ? fFaceRec->fAxes.get() : nullptr; }
bool isNamedVariationSpecified() {
return fFaceRec ? fFaceRec->fNamedVariationSpecified : false;
}
private:
SkFaceRec* fFaceRec;
};
///////////////////////////////////////////////////////////////////////////
class SkScalerContext_FreeType : public SkScalerContext_FreeType_Base {
public:
SkScalerContext_FreeType(sk_sp<SkTypeface>,
const SkScalerContextEffects&,
const SkDescriptor* desc);
~SkScalerContext_FreeType() override;
bool success() const {
return fFTSize != nullptr && fFace != nullptr;
}
protected:
unsigned generateGlyphCount() override;
uint16_t generateCharToGlyph(SkUnichar uni) override;
void generateAdvance(SkGlyph* glyph) override;
void generateMetrics(SkGlyph* glyph) override;
void generateImage(const SkGlyph& glyph) override;
void generatePath(SkGlyphID glyphID, SkPath* path) override;
void generateFontMetrics(SkPaint::FontMetrics*) override;
SkUnichar generateGlyphToChar(uint16_t glyph) override;
private:
using UnrefFTFace = SkFunctionWrapper<void, SkFaceRec, unref_ft_face>;
std::unique_ptr<SkFaceRec, UnrefFTFace> fFaceRec;
FT_Face fFace; // Borrowed face from gFaceRecHead.
FT_Size fFTSize; // The size on the fFace for this scaler.
FT_Int fStrikeIndex;
/** The rest of the matrix after FreeType handles the size.
* With outline font rasterization this is handled by FreeType with FT_Set_Transform.
* With bitmap only fonts this matrix must be applied to scale the bitmap.
*/
SkMatrix fMatrix22Scalar;
/** Same as fMatrix22Scalar, but in FreeType units and space. */
FT_Matrix fMatrix22;
/** The actual size requested. */
SkVector fScale;
uint32_t fLoadGlyphFlags;
bool fDoLinearMetrics;
bool fLCDIsVert;
FT_Error setupSize();
void getBBoxForCurrentGlyph(SkGlyph* glyph, FT_BBox* bbox,
bool snapToPixelBoundary = false);
bool getCBoxForLetter(char letter, FT_BBox* bbox);
// Caller must lock gFTMutex before calling this function.
void updateGlyphIfLCD(SkGlyph* glyph);
// Caller must lock gFTMutex before calling this function.
// update FreeType2 glyph slot with glyph emboldened
void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph, SkGlyphID gid);
bool shouldSubpixelBitmap(const SkGlyph&, const SkMatrix&);
};
///////////////////////////////////////////////////////////////////////////
static bool canEmbed(FT_Face face) {
FT_UShort fsType = FT_Get_FSType_Flags(face);
return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING |
FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0;
}
static bool canSubset(FT_Face face) {
FT_UShort fsType = FT_Get_FSType_Flags(face);
return (fsType & FT_FSTYPE_NO_SUBSETTING) == 0;
}
static void populate_glyph_to_unicode(FT_Face& face, SkTDArray<SkUnichar>* glyphToUnicode) {
FT_Long numGlyphs = face->num_glyphs;
glyphToUnicode->setCount(SkToInt(numGlyphs));
sk_bzero(glyphToUnicode->begin(), sizeof((*glyphToUnicode)[0]) * numGlyphs);
FT_UInt glyphIndex;
SkUnichar charCode = FT_Get_First_Char(face, &glyphIndex);
while (glyphIndex) {
SkASSERT(glyphIndex < SkToUInt(numGlyphs));
// Use the first character that maps to this glyphID. https://crbug.com/359065
if (0 == (*glyphToUnicode)[glyphIndex]) {
(*glyphToUnicode)[glyphIndex] = charCode;
}
charCode = FT_Get_Next_Char(face, charCode, &glyphIndex);
}
}
std::unique_ptr<SkAdvancedTypefaceMetrics> SkTypeface_FreeType::onGetAdvancedMetrics() const {
AutoFTAccess fta(this);
FT_Face face = fta.face();
if (!face) {
return nullptr;
}
std::unique_ptr<SkAdvancedTypefaceMetrics> info(new SkAdvancedTypefaceMetrics);
info->fFontName.set(FT_Get_Postscript_Name(face));
if (FT_HAS_MULTIPLE_MASTERS(face)) {
info->fFlags |= SkAdvancedTypefaceMetrics::kMultiMaster_FontFlag;
}
if (!canEmbed(face)) {
info->fFlags |= SkAdvancedTypefaceMetrics::kNotEmbeddable_FontFlag;
}
if (!canSubset(face)) {
info->fFlags |= SkAdvancedTypefaceMetrics::kNotSubsettable_FontFlag;
}
const char* fontType = FT_Get_X11_Font_Format(face);
if (strcmp(fontType, "Type 1") == 0) {
info->fType = SkAdvancedTypefaceMetrics::kType1_Font;
} else if (strcmp(fontType, "CID Type 1") == 0) {
info->fType = SkAdvancedTypefaceMetrics::kType1CID_Font;
} else if (strcmp(fontType, "CFF") == 0) {
info->fType = SkAdvancedTypefaceMetrics::kCFF_Font;
} else if (strcmp(fontType, "TrueType") == 0) {
info->fType = SkAdvancedTypefaceMetrics::kTrueType_Font;
} else {
info->fType = SkAdvancedTypefaceMetrics::kOther_Font;
}
info->fStyle = (SkAdvancedTypefaceMetrics::StyleFlags)0;
if (FT_IS_FIXED_WIDTH(face)) {
info->fStyle |= SkAdvancedTypefaceMetrics::kFixedPitch_Style;
}
if (face->style_flags & FT_STYLE_FLAG_ITALIC) {
info->fStyle |= SkAdvancedTypefaceMetrics::kItalic_Style;
}
PS_FontInfoRec psFontInfo;
TT_Postscript* postTable;
if (FT_Get_PS_Font_Info(face, &psFontInfo) == 0) {
info->fItalicAngle = psFontInfo.italic_angle;
} else if ((postTable = (TT_Postscript*)FT_Get_Sfnt_Table(face, ft_sfnt_post)) != nullptr) {
info->fItalicAngle = SkFixedFloorToInt(postTable->italicAngle);
} else {
info->fItalicAngle = 0;
}
info->fAscent = face->ascender;
info->fDescent = face->descender;
TT_PCLT* pcltTable;
TT_OS2* os2Table;
if ((pcltTable = (TT_PCLT*)FT_Get_Sfnt_Table(face, ft_sfnt_pclt)) != nullptr) {
info->fCapHeight = pcltTable->CapHeight;
uint8_t serif_style = pcltTable->SerifStyle & 0x3F;
if (2 <= serif_style && serif_style <= 6) {
info->fStyle |= SkAdvancedTypefaceMetrics::kSerif_Style;
} else if (9 <= serif_style && serif_style <= 12) {
info->fStyle |= SkAdvancedTypefaceMetrics::kScript_Style;
}
} else if (((os2Table = (TT_OS2*)FT_Get_Sfnt_Table(face, ft_sfnt_os2)) != nullptr) &&
// sCapHeight is available only when version 2 or later.
os2Table->version != 0xFFFF &&
os2Table->version >= 2)
{
info->fCapHeight = os2Table->sCapHeight;
}
info->fBBox = SkIRect::MakeLTRB(face->bbox.xMin, face->bbox.yMax,
face->bbox.xMax, face->bbox.yMin);
bool perGlyphInfo = FT_IS_SCALABLE(face);
if (perGlyphInfo && info->fType == SkAdvancedTypefaceMetrics::kType1_Font) {
// Postscript fonts may contain more than 255 glyphs, so we end up
// using multiple font descriptions with a glyph ordering. Record
// the name of each glyph.
info->fGlyphNames.reset(face->num_glyphs);
for (int gID = 0; gID < face->num_glyphs; gID++) {
char glyphName[128]; // PS limit for names is 127 bytes.
FT_Get_Glyph_Name(face, gID, glyphName, 128);
info->fGlyphNames[gID].set(glyphName);
}
}
if (perGlyphInfo &&
info->fType != SkAdvancedTypefaceMetrics::kType1_Font &&
face->num_charmaps)
{
populate_glyph_to_unicode(face, &(info->fGlyphToUnicode));
}
return info;
}
///////////////////////////////////////////////////////////////////////////
static bool bothZero(SkScalar a, SkScalar b) {
return 0 == a && 0 == b;
}
// returns false if there is any non-90-rotation or skew
static bool isAxisAligned(const SkScalerContextRec& rec) {
return 0 == rec.fPreSkewX &&
(bothZero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) ||
bothZero(rec.fPost2x2[0][0], rec.fPost2x2[1][1]));
}
SkScalerContext* SkTypeface_FreeType::onCreateScalerContext(const SkScalerContextEffects& effects,
const SkDescriptor* desc) const {
auto c = skstd::make_unique<SkScalerContext_FreeType>(
sk_ref_sp(const_cast<SkTypeface_FreeType*>(this)), effects, desc);
if (!c->success()) {
return nullptr;
}
return c.release();
}
void SkTypeface_FreeType::onFilterRec(SkScalerContextRec* rec) const {
//BOGUS: http://code.google.com/p/chromium/issues/detail?id=121119
//Cap the requested size as larger sizes give bogus values.
//Remove when http://code.google.com/p/skia/issues/detail?id=554 is fixed.
//Note that this also currently only protects against large text size requests,
//the total matrix is not taken into account here.
if (rec->fTextSize > SkIntToScalar(1 << 14)) {
rec->fTextSize = SkIntToScalar(1 << 14);
}
if (isLCD(*rec)) {
// TODO: re-work so that FreeType is set-up and selected by the SkFontMgr.
SkAutoMutexAcquire ama(gFTMutex);
ref_ft_library();
if (!gFTLibrary->isLCDSupported()) {
// If the runtime Freetype library doesn't support LCD, disable it here.
rec->fMaskFormat = SkMask::kA8_Format;
}
unref_ft_library();
}
SkPaint::Hinting h = rec->getHinting();
if (SkPaint::kFull_Hinting == h && !isLCD(*rec)) {
// collapse full->normal hinting if we're not doing LCD
h = SkPaint::kNormal_Hinting;
}
// rotated text looks bad with hinting, so we disable it as needed
if (!isAxisAligned(*rec)) {
h = SkPaint::kNo_Hinting;
}
rec->setHinting(h);
#ifndef SK_GAMMA_APPLY_TO_A8
if (!isLCD(*rec)) {
// SRGBTODO: Is this correct? Do we want contrast boost?
rec->ignorePreBlend();
}
#endif
}
int SkTypeface_FreeType::onGetUPEM() const {
AutoFTAccess fta(this);
FT_Face face = fta.face();
return face ? face->units_per_EM : 0;
}
bool SkTypeface_FreeType::onGetKerningPairAdjustments(const uint16_t glyphs[],
int count, int32_t adjustments[]) const {
AutoFTAccess fta(this);
FT_Face face = fta.face();
if (!face || !FT_HAS_KERNING(face)) {
return false;
}
for (int i = 0; i < count - 1; ++i) {
FT_Vector delta;
FT_Error err = FT_Get_Kerning(face, glyphs[i], glyphs[i+1],
FT_KERNING_UNSCALED, &delta);
if (err) {
return false;
}
adjustments[i] = delta.x;
}
return true;
}
/** Returns the bitmap strike equal to or just larger than the requested size. */
static FT_Int chooseBitmapStrike(FT_Face face, FT_F26Dot6 scaleY) {
if (face == nullptr) {
SkDEBUGF(("chooseBitmapStrike aborted due to nullptr face.\n"));
return -1;
}
FT_Pos requestedPPEM = scaleY; // FT_Bitmap_Size::y_ppem is in 26.6 format.
FT_Int chosenStrikeIndex = -1;
FT_Pos chosenPPEM = 0;
for (FT_Int strikeIndex = 0; strikeIndex < face->num_fixed_sizes; ++strikeIndex) {
FT_Pos strikePPEM = face->available_sizes[strikeIndex].y_ppem;
if (strikePPEM == requestedPPEM) {
// exact match - our search stops here
return strikeIndex;
} else if (chosenPPEM < requestedPPEM) {
// attempt to increase chosenPPEM
if (chosenPPEM < strikePPEM) {
chosenPPEM = strikePPEM;
chosenStrikeIndex = strikeIndex;
}
} else {
// attempt to decrease chosenPPEM, but not below requestedPPEM
if (requestedPPEM < strikePPEM && strikePPEM < chosenPPEM) {
chosenPPEM = strikePPEM;
chosenStrikeIndex = strikeIndex;
}
}
}
return chosenStrikeIndex;
}
SkScalerContext_FreeType::SkScalerContext_FreeType(sk_sp<SkTypeface> typeface,
const SkScalerContextEffects& effects,
const SkDescriptor* desc)
: SkScalerContext_FreeType_Base(std::move(typeface), effects, desc)
, fFace(nullptr)
, fFTSize(nullptr)
, fStrikeIndex(-1)
{
SkAutoMutexAcquire ac(gFTMutex);
SkASSERT_RELEASE(ref_ft_library());
fFaceRec.reset(ref_ft_face(this->getTypeface()));
// load the font file
if (nullptr == fFaceRec) {
SkDEBUGF(("Could not create FT_Face.\n"));
return;
}
fRec.computeMatrices(SkScalerContextRec::kFull_PreMatrixScale, &fScale, &fMatrix22Scalar);
FT_F26Dot6 scaleX = SkScalarToFDot6(fScale.fX);
FT_F26Dot6 scaleY = SkScalarToFDot6(fScale.fY);
fMatrix22.xx = SkScalarToFixed(fMatrix22Scalar.getScaleX());
fMatrix22.xy = SkScalarToFixed(-fMatrix22Scalar.getSkewX());
fMatrix22.yx = SkScalarToFixed(-fMatrix22Scalar.getSkewY());
fMatrix22.yy = SkScalarToFixed(fMatrix22Scalar.getScaleY());
fLCDIsVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag);
// compute the flags we send to Load_Glyph
bool linearMetrics = SkToBool(fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag);
{
FT_Int32 loadFlags = FT_LOAD_DEFAULT;
if (SkMask::kBW_Format == fRec.fMaskFormat) {
// See http://code.google.com/p/chromium/issues/detail?id=43252#c24
loadFlags = FT_LOAD_TARGET_MONO;
if (fRec.getHinting() == SkPaint::kNo_Hinting) {
loadFlags = FT_LOAD_NO_HINTING;
linearMetrics = true;
}
} else {
switch (fRec.getHinting()) {
case SkPaint::kNo_Hinting:
loadFlags = FT_LOAD_NO_HINTING;
linearMetrics = true;
break;
case SkPaint::kSlight_Hinting:
loadFlags = FT_LOAD_TARGET_LIGHT; // This implies FORCE_AUTOHINT
break;
case SkPaint::kNormal_Hinting:
if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
loadFlags = FT_LOAD_FORCE_AUTOHINT;
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
} else {
loadFlags = FT_LOAD_NO_AUTOHINT;
#endif
}
break;
case SkPaint::kFull_Hinting:
if (fRec.fFlags & SkScalerContext::kForceAutohinting_Flag) {
loadFlags = FT_LOAD_FORCE_AUTOHINT;
break;
}
loadFlags = FT_LOAD_TARGET_NORMAL;
if (isLCD(fRec)) {
if (fLCDIsVert) {
loadFlags = FT_LOAD_TARGET_LCD_V;
} else {
loadFlags = FT_LOAD_TARGET_LCD;
}
}
break;
default:
SkDebugf("---------- UNKNOWN hinting %d\n", fRec.getHinting());
break;
}
}
if ((fRec.fFlags & SkScalerContext::kEmbeddedBitmapText_Flag) == 0) {
loadFlags |= FT_LOAD_NO_BITMAP;
}
// Always using FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH to get correct
// advances, as fontconfig and cairo do.
// See http://code.google.com/p/skia/issues/detail?id=222.
loadFlags |= FT_LOAD_IGNORE_GLOBAL_ADVANCE_WIDTH;
// Use vertical layout if requested.
if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
loadFlags |= FT_LOAD_VERTICAL_LAYOUT;
}
loadFlags |= FT_LOAD_COLOR;
fLoadGlyphFlags = loadFlags;
}
using DoneFTSize = SkFunctionWrapper<FT_Error, skstd::remove_pointer_t<FT_Size>, FT_Done_Size>;
std::unique_ptr<skstd::remove_pointer_t<FT_Size>, DoneFTSize> ftSize([this]() -> FT_Size {
FT_Size size;
FT_Error err = FT_New_Size(fFaceRec->fFace.get(), &size);
if (err != 0) {
SK_TRACEFTR(err, "FT_New_Size(%s) failed.", fFaceRec->fFace->family_name);
return nullptr;
}
return size;
}());
if (nullptr == ftSize) {
SkDEBUGF(("Could not create FT_Size.\n"));
return;
}
FT_Error err = FT_Activate_Size(ftSize.get());
if (err != 0) {
SK_TRACEFTR(err, "FT_Activate_Size(%s) failed.", fFaceRec->fFace->family_name);
return;
}
if (FT_IS_SCALABLE(fFaceRec->fFace)) {
err = FT_Set_Char_Size(fFaceRec->fFace.get(), scaleX, scaleY, 72, 72);
if (err != 0) {
SK_TRACEFTR(err, "FT_Set_CharSize(%s, %f, %f) failed.",
fFaceRec->fFace->family_name, fScale.fX, fScale.fY);
return;
}
} else if (FT_HAS_FIXED_SIZES(fFaceRec->fFace)) {
fStrikeIndex = chooseBitmapStrike(fFaceRec->fFace.get(), scaleY);
if (fStrikeIndex == -1) {
SkDEBUGF(("No glyphs for font \"%s\" size %f.\n",
fFaceRec->fFace->family_name, fScale.fY));
return;
}
err = FT_Select_Size(fFaceRec->fFace.get(), fStrikeIndex);
if (err != 0) {
SK_TRACEFTR(err, "FT_Select_Size(%s, %d) failed.",
fFaceRec->fFace->family_name, fStrikeIndex);
fStrikeIndex = -1;
return;
}
// A non-ideal size was picked, so recompute the matrix.
// This adjusts for the difference between FT_Set_Char_Size and FT_Select_Size.
fMatrix22Scalar.preScale(fScale.x() / fFaceRec->fFace->size->metrics.x_ppem,
fScale.y() / fFaceRec->fFace->size->metrics.y_ppem);
fMatrix22.xx = SkScalarToFixed(fMatrix22Scalar.getScaleX());
fMatrix22.xy = SkScalarToFixed(-fMatrix22Scalar.getSkewX());
fMatrix22.yx = SkScalarToFixed(-fMatrix22Scalar.getSkewY());
fMatrix22.yy = SkScalarToFixed(fMatrix22Scalar.getScaleY());
// FreeType does not provide linear metrics for bitmap fonts.
linearMetrics = false;
// FreeType documentation says:
// FT_LOAD_NO_BITMAP -- Ignore bitmap strikes when loading.
// Bitmap-only fonts ignore this flag.
//
// However, in FreeType 2.5.1 color bitmap only fonts do not ignore this flag.
// Force this flag off for bitmap only fonts.
fLoadGlyphFlags &= ~FT_LOAD_NO_BITMAP;
} else {
SkDEBUGF(("Unknown kind of font \"%s\" size %f.\n", fFaceRec->fFace->family_name, fScale.fY));
return;
}
fFTSize = ftSize.release();
fFace = fFaceRec->fFace.get();
fDoLinearMetrics = linearMetrics;
}
SkScalerContext_FreeType::~SkScalerContext_FreeType() {
SkAutoMutexAcquire ac(gFTMutex);
if (fFTSize != nullptr) {
FT_Done_Size(fFTSize);
}
fFaceRec = nullptr;
unref_ft_library();
}
/* We call this before each use of the fFace, since we may be sharing
this face with other context (at different sizes).
*/
FT_Error SkScalerContext_FreeType::setupSize() {
gFTMutex.assertHeld();
FT_Error err = FT_Activate_Size(fFTSize);
if (err != 0) {
return err;
}
FT_Set_Transform(fFace, &fMatrix22, nullptr);
return 0;
}
unsigned SkScalerContext_FreeType::generateGlyphCount() {
return fFace->num_glyphs;
}
uint16_t SkScalerContext_FreeType::generateCharToGlyph(SkUnichar uni) {
SkAutoMutexAcquire ac(gFTMutex);
return SkToU16(FT_Get_Char_Index( fFace, uni ));
}
SkUnichar SkScalerContext_FreeType::generateGlyphToChar(uint16_t glyph) {
SkAutoMutexAcquire ac(gFTMutex);
// iterate through each cmap entry, looking for matching glyph indices
FT_UInt glyphIndex;
SkUnichar charCode = FT_Get_First_Char( fFace, &glyphIndex );
while (glyphIndex != 0) {
if (glyphIndex == glyph) {
return charCode;
}
charCode = FT_Get_Next_Char( fFace, charCode, &glyphIndex );
}
return 0;
}
static SkScalar SkFT_FixedToScalar(FT_Fixed x) {
return SkFixedToScalar(x);
}
void SkScalerContext_FreeType::generateAdvance(SkGlyph* glyph) {
/* unhinted and light hinted text have linearly scaled advances
* which are very cheap to compute with some font formats...
*/
if (fDoLinearMetrics) {
SkAutoMutexAcquire ac(gFTMutex);
if (this->setupSize()) {
glyph->zeroMetrics();
return;
}
FT_Error error;
FT_Fixed advance;
error = FT_Get_Advance( fFace, glyph->getGlyphID(),
fLoadGlyphFlags | FT_ADVANCE_FLAG_FAST_ONLY,
&advance );
if (0 == error) {
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
const SkScalar advanceScalar = SkFT_FixedToScalar(advance);
glyph->fAdvanceX = SkScalarToFloat(fMatrix22Scalar.getScaleX() * advanceScalar);
glyph->fAdvanceY = SkScalarToFloat(fMatrix22Scalar.getSkewY() * advanceScalar);
return;
}
}
/* otherwise, we need to load/hint the glyph, which is slower */
this->generateMetrics(glyph);
return;
}
void SkScalerContext_FreeType::getBBoxForCurrentGlyph(SkGlyph* glyph,
FT_BBox* bbox,
bool snapToPixelBoundary) {
FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
int dx = SkFixedToFDot6(glyph->getSubXFixed());
int dy = SkFixedToFDot6(glyph->getSubYFixed());
// negate dy since freetype-y-goes-up and skia-y-goes-down
bbox->xMin += dx;
bbox->yMin -= dy;
bbox->xMax += dx;
bbox->yMax -= dy;
}
// outset the box to integral boundaries
if (snapToPixelBoundary) {
bbox->xMin &= ~63;
bbox->yMin &= ~63;
bbox->xMax = (bbox->xMax + 63) & ~63;
bbox->yMax = (bbox->yMax + 63) & ~63;
}
// Must come after snapToPixelBoundary so that the width and height are
// consistent. Otherwise asserts will fire later on when generating the
// glyph image.
if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
FT_Vector vector;
vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
FT_Vector_Transform(&vector, &fMatrix22);
bbox->xMin += vector.x;
bbox->xMax += vector.x;
bbox->yMin += vector.y;
bbox->yMax += vector.y;
}
}
bool SkScalerContext_FreeType::getCBoxForLetter(char letter, FT_BBox* bbox) {
const FT_UInt glyph_id = FT_Get_Char_Index(fFace, letter);
if (!glyph_id) {
return false;
}
if (FT_Load_Glyph(fFace, glyph_id, fLoadGlyphFlags) != 0) {
return false;
}
emboldenIfNeeded(fFace, fFace->glyph, SkTo<SkGlyphID>(glyph_id));
FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
return true;
}
void SkScalerContext_FreeType::updateGlyphIfLCD(SkGlyph* glyph) {
if (isLCD(fRec)) {
if (fLCDIsVert) {
glyph->fHeight += gFTLibrary->lcdExtra();
glyph->fTop -= gFTLibrary->lcdExtra() >> 1;
} else {
glyph->fWidth += gFTLibrary->lcdExtra();
glyph->fLeft -= gFTLibrary->lcdExtra() >> 1;
}
}
}
bool SkScalerContext_FreeType::shouldSubpixelBitmap(const SkGlyph& glyph, const SkMatrix& matrix) {
// If subpixel rendering of a bitmap *can* be done.
bool mechanism = fFace->glyph->format == FT_GLYPH_FORMAT_BITMAP &&
fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag &&
(glyph.getSubXFixed() || glyph.getSubYFixed());
// If subpixel rendering of a bitmap *should* be done.
// 1. If the face is not scalable then always allow subpixel rendering.
// Otherwise, if the font has an 8ppem strike 7 will subpixel render but 8 won't.
// 2. If the matrix is already not identity the bitmap will already be resampled,
// so resampling slightly differently shouldn't make much difference.
bool policy = !FT_IS_SCALABLE(fFace) || !matrix.isIdentity();
return mechanism && policy;
}
void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
SkAutoMutexAcquire ac(gFTMutex);
glyph->fRsbDelta = 0;
glyph->fLsbDelta = 0;
FT_Error err;
if (this->setupSize()) {
glyph->zeroMetrics();
return;
}
err = FT_Load_Glyph( fFace, glyph->getGlyphID(),
fLoadGlyphFlags | FT_LOAD_BITMAP_METRICS_ONLY );
if (err != 0) {
glyph->zeroMetrics();
return;
}
emboldenIfNeeded(fFace, fFace->glyph, glyph->getGlyphID());
switch ( fFace->glyph->format ) {
case FT_GLYPH_FORMAT_OUTLINE:
if (0 == fFace->glyph->outline.n_contours) {
glyph->fWidth = 0;
glyph->fHeight = 0;
glyph->fTop = 0;
glyph->fLeft = 0;
} else {
FT_BBox bbox;
getBBoxForCurrentGlyph(glyph, &bbox, true);
glyph->fWidth = SkToU16(SkFDot6Floor(bbox.xMax - bbox.xMin));
glyph->fHeight = SkToU16(SkFDot6Floor(bbox.yMax - bbox.yMin));
glyph->fTop = -SkToS16(SkFDot6Floor(bbox.yMax));
glyph->fLeft = SkToS16(SkFDot6Floor(bbox.xMin));
updateGlyphIfLCD(glyph);
}
break;
case FT_GLYPH_FORMAT_BITMAP:
if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
FT_Vector vector;
vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
FT_Vector_Transform(&vector, &fMatrix22);
fFace->glyph->bitmap_left += SkFDot6Floor(vector.x);
fFace->glyph->bitmap_top += SkFDot6Floor(vector.y);
}
if (fFace->glyph->bitmap.pixel_mode == FT_PIXEL_MODE_BGRA) {
glyph->fMaskFormat = SkMask::kARGB32_Format;
}
{
SkRect rect = SkRect::MakeXYWH(SkIntToScalar(fFace->glyph->bitmap_left),
-SkIntToScalar(fFace->glyph->bitmap_top),
SkIntToScalar(fFace->glyph->bitmap.width),
SkIntToScalar(fFace->glyph->bitmap.rows));
fMatrix22Scalar.mapRect(&rect);
if (this->shouldSubpixelBitmap(*glyph, fMatrix22Scalar)) {
rect.offset(SkFixedToScalar(glyph->getSubXFixed()),
SkFixedToScalar(glyph->getSubYFixed()));
}
SkIRect irect = rect.roundOut();
glyph->fWidth = SkToU16(irect.width());
glyph->fHeight = SkToU16(irect.height());
glyph->fTop = SkToS16(irect.top());
glyph->fLeft = SkToS16(irect.left());
}
break;
default:
SkDEBUGFAIL("unknown glyph format");
glyph->zeroMetrics();
return;
}
if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
if (fDoLinearMetrics) {
const SkScalar advanceScalar = SkFT_FixedToScalar(fFace->glyph->linearVertAdvance);
glyph->fAdvanceX = SkScalarToFloat(fMatrix22Scalar.getSkewX() * advanceScalar);
glyph->fAdvanceY = SkScalarToFloat(fMatrix22Scalar.getScaleY() * advanceScalar);
} else {
glyph->fAdvanceX = -SkFDot6ToFloat(fFace->glyph->advance.x);
glyph->fAdvanceY = SkFDot6ToFloat(fFace->glyph->advance.y);
}
} else {
if (fDoLinearMetrics) {
const SkScalar advanceScalar = SkFT_FixedToScalar(fFace->glyph->linearHoriAdvance);
glyph->fAdvanceX = SkScalarToFloat(fMatrix22Scalar.getScaleX() * advanceScalar);
glyph->fAdvanceY = SkScalarToFloat(fMatrix22Scalar.getSkewY() * advanceScalar);
} else {
glyph->fAdvanceX = SkFDot6ToFloat(fFace->glyph->advance.x);
glyph->fAdvanceY = -SkFDot6ToFloat(fFace->glyph->advance.y);
if (fRec.fFlags & kDevKernText_Flag) {
glyph->fRsbDelta = SkToS8(fFace->glyph->rsb_delta);
glyph->fLsbDelta = SkToS8(fFace->glyph->lsb_delta);
}
}
}
#ifdef ENABLE_GLYPH_SPEW
SkDEBUGF(("Metrics(glyph:%d flags:0x%x) w:%d\n", glyph->getGlyphID(), fLoadGlyphFlags, glyph->fWidth));
#endif
}
static void clear_glyph_image(const SkGlyph& glyph) {
sk_bzero(glyph.fImage, glyph.rowBytes() * glyph.fHeight);
}
void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) {
SkAutoMutexAcquire ac(gFTMutex);
if (this->setupSize()) {
clear_glyph_image(glyph);
return;
}
FT_Error err = FT_Load_Glyph(fFace, glyph.getGlyphID(), fLoadGlyphFlags);
if (err != 0) {
SK_TRACEFTR(err, "SkScalerContext_FreeType::generateImage: FT_Load_Glyph(glyph:%d "
"width:%d height:%d rb:%d flags:%d) failed.",
glyph.getGlyphID(), glyph.fWidth, glyph.fHeight, glyph.rowBytes(),
fLoadGlyphFlags);
clear_glyph_image(glyph);
return;
}
emboldenIfNeeded(fFace, fFace->glyph, glyph.getGlyphID());
SkMatrix* bitmapMatrix = &fMatrix22Scalar;
SkMatrix subpixelBitmapMatrix;
if (this->shouldSubpixelBitmap(glyph, *bitmapMatrix)) {
subpixelBitmapMatrix = fMatrix22Scalar;
subpixelBitmapMatrix.postTranslate(SkFixedToScalar(glyph.getSubXFixed()),
SkFixedToScalar(glyph.getSubYFixed()));
bitmapMatrix = &subpixelBitmapMatrix;
}
generateGlyphImage(fFace, glyph, *bitmapMatrix);
}
void SkScalerContext_FreeType::generatePath(SkGlyphID glyphID, SkPath* path) {
SkAutoMutexAcquire ac(gFTMutex);
SkASSERT(path);
if (this->setupSize()) {
path->reset();
return;
}
uint32_t flags = fLoadGlyphFlags;
flags |= FT_LOAD_NO_BITMAP; // ignore embedded bitmaps so we're sure to get the outline
flags &= ~FT_LOAD_RENDER; // don't scan convert (we just want the outline)
FT_Error err = FT_Load_Glyph(fFace, glyphID, flags);
if (err != 0) {
SK_TRACEFTR(err, "SkScalerContext_FreeType::generatePath: FT_Load_Glyph(glyph:%d "
"flags:%d) failed.", glyphID, flags);
path->reset();
return;
}
emboldenIfNeeded(fFace, fFace->glyph, glyphID);
generateGlyphPath(fFace, path);
// The path's origin from FreeType is always the horizontal layout origin.
// Offset the path so that it is relative to the vertical origin if needed.
if (fRec.fFlags & SkScalerContext::kVertical_Flag) {
FT_Vector vector;
vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
FT_Vector_Transform(&vector, &fMatrix22);
path->offset(SkFDot6ToScalar(vector.x), -SkFDot6ToScalar(vector.y));
}
}
void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* metrics) {
if (nullptr == metrics) {
return;
}
SkAutoMutexAcquire ac(gFTMutex);
if (this->setupSize()) {
sk_bzero(metrics, sizeof(*metrics));
return;
}
FT_Face face = fFace;
metrics->fFlags = 0;
// fetch units/EM from "head" table if needed (ie for bitmap fonts)
SkScalar upem = SkIntToScalar(face->units_per_EM);
if (!upem) {
TT_Header* ttHeader = (TT_Header*)FT_Get_Sfnt_Table(face, ft_sfnt_head);
if (ttHeader) {
upem = SkIntToScalar(ttHeader->Units_Per_EM);
}
}
// use the os/2 table as a source of reasonable defaults.
SkScalar x_height = 0.0f;
SkScalar avgCharWidth = 0.0f;
SkScalar cap_height = 0.0f;
SkScalar strikeoutThickness = 0.0f, strikeoutPosition = 0.0f;
TT_OS2* os2 = (TT_OS2*) FT_Get_Sfnt_Table(face, ft_sfnt_os2);
if (os2) {
x_height = SkIntToScalar(os2->sxHeight) / upem * fScale.y();
avgCharWidth = SkIntToScalar(os2->xAvgCharWidth) / upem;
strikeoutThickness = SkIntToScalar(os2->yStrikeoutSize) / upem;
strikeoutPosition = -SkIntToScalar(os2->yStrikeoutPosition) / upem;
metrics->fFlags |= SkPaint::FontMetrics::kStrikeoutThicknessIsValid_Flag;
metrics->fFlags |= SkPaint::FontMetrics::kStrikeoutPositionIsValid_Flag;
if (os2->version != 0xFFFF && os2->version >= 2) {
cap_height = SkIntToScalar(os2->sCapHeight) / upem * fScale.y();
}
}
// pull from format-specific metrics as needed
SkScalar ascent, descent, leading, xmin, xmax, ymin, ymax;
SkScalar underlineThickness, underlinePosition;
if (face->face_flags & FT_FACE_FLAG_SCALABLE) { // scalable outline font
// FreeType will always use HHEA metrics if they're not zero.
// It completely ignores the OS/2 fsSelection::UseTypoMetrics bit.
// It also ignores the VDMX tables, which are also of interest here
// (and override everything else when they apply).
static const int kUseTypoMetricsMask = (1 << 7);
if (os2 && os2->version != 0xFFFF && (os2->fsSelection & kUseTypoMetricsMask)) {
ascent = -SkIntToScalar(os2->sTypoAscender) / upem;
descent = -SkIntToScalar(os2->sTypoDescender) / upem;
leading = SkIntToScalar(os2->sTypoLineGap) / upem;
} else {
ascent = -SkIntToScalar(face->ascender) / upem;
descent = -SkIntToScalar(face->descender) / upem;
leading = SkIntToScalar(face->height + (face->descender - face->ascender)) / upem;
}
xmin = SkIntToScalar(face->bbox.xMin) / upem;
xmax = SkIntToScalar(face->bbox.xMax) / upem;
ymin = -SkIntToScalar(face->bbox.yMin) / upem;
ymax = -SkIntToScalar(face->bbox.yMax) / upem;
underlineThickness = SkIntToScalar(face->underline_thickness) / upem;
underlinePosition = -SkIntToScalar(face->underline_position +
face->underline_thickness / 2) / upem;
metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThicknessIsValid_Flag;
metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
// we may be able to synthesize x_height and cap_height from outline
if (!x_height) {
FT_BBox bbox;
if (getCBoxForLetter('x', &bbox)) {
x_height = SkIntToScalar(bbox.yMax) / 64.0f;
}
}
if (!cap_height) {
FT_BBox bbox;
if (getCBoxForLetter('H', &bbox)) {
cap_height = SkIntToScalar(bbox.yMax) / 64.0f;
}
}
} else if (fStrikeIndex != -1) { // bitmap strike metrics
SkScalar xppem = SkIntToScalar(face->size->metrics.x_ppem);
SkScalar yppem = SkIntToScalar(face->size->metrics.y_ppem);
ascent = -SkIntToScalar(face->size->metrics.ascender) / (yppem * 64.0f);
descent = -SkIntToScalar(face->size->metrics.descender) / (yppem * 64.0f);
leading = (SkIntToScalar(face->size->metrics.height) / (yppem * 64.0f)) + ascent - descent;
xmin = 0.0f;
xmax = SkIntToScalar(face->available_sizes[fStrikeIndex].width) / xppem;
ymin = descent;
ymax = ascent;
underlineThickness = 0;
underlinePosition = 0;
metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlineThicknessIsValid_Flag;
metrics->fFlags &= ~SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
TT_Postscript* post = (TT_Postscript*) FT_Get_Sfnt_Table(face, ft_sfnt_post);
if (post) {
underlineThickness = SkIntToScalar(post->underlineThickness) / upem;
underlinePosition = -SkIntToScalar(post->underlinePosition) / upem;
metrics->fFlags |= SkPaint::FontMetrics::kUnderlineThicknessIsValid_Flag;
metrics->fFlags |= SkPaint::FontMetrics::kUnderlinePositionIsValid_Flag;
}
} else {
sk_bzero(metrics, sizeof(*metrics));
return;
}
// synthesize elements that were not provided by the os/2 table or format-specific metrics
if (!x_height) {
x_height = -ascent * fScale.y();
}
if (!avgCharWidth) {
avgCharWidth = xmax - xmin;
}
if (!cap_height) {
cap_height = -ascent * fScale.y();
}
// disallow negative linespacing
if (leading < 0.0f) {
leading = 0.0f;
}
metrics->fTop = ymax * fScale.y();
metrics->fAscent = ascent * fScale.y();
metrics->fDescent = descent * fScale.y();
metrics->fBottom = ymin * fScale.y();
metrics->fLeading = leading * fScale.y();
metrics->fAvgCharWidth = avgCharWidth * fScale.y();
metrics->fXMin = xmin * fScale.y();
metrics->fXMax = xmax * fScale.y();
metrics->fMaxCharWidth = metrics->fXMax - metrics->fXMin;
metrics->fXHeight = x_height;
metrics->fCapHeight = cap_height;
metrics->fUnderlineThickness = underlineThickness * fScale.y();
metrics->fUnderlinePosition = underlinePosition * fScale.y();
metrics->fStrikeoutThickness = strikeoutThickness * fScale.y();
metrics->fStrikeoutPosition = strikeoutPosition * fScale.y();
}
///////////////////////////////////////////////////////////////////////////////
// hand-tuned value to reduce outline embolden strength
#ifndef SK_OUTLINE_EMBOLDEN_DIVISOR
#ifdef SK_BUILD_FOR_ANDROID_FRAMEWORK
#define SK_OUTLINE_EMBOLDEN_DIVISOR 34
#else
#define SK_OUTLINE_EMBOLDEN_DIVISOR 24
#endif
#endif
///////////////////////////////////////////////////////////////////////////////
void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph, SkGlyphID gid) {
// check to see if the embolden bit is set
if (0 == (fRec.fFlags & SkScalerContext::kEmbolden_Flag)) {
return;
}
switch (glyph->format) {
case FT_GLYPH_FORMAT_OUTLINE:
FT_Pos strength;
strength = FT_MulFix(face->units_per_EM, face->size->metrics.y_scale)
/ SK_OUTLINE_EMBOLDEN_DIVISOR;
FT_Outline_Embolden(&glyph->outline, strength);
break;
case FT_GLYPH_FORMAT_BITMAP:
if (!fFace->glyph->bitmap.buffer) {
FT_Load_Glyph(fFace, gid, fLoadGlyphFlags);
}
FT_GlyphSlot_Own_Bitmap(glyph);
FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
break;
default:
SkDEBUGFAIL("unknown glyph format");
}
}
///////////////////////////////////////////////////////////////////////////////
#include "SkUtils.h"
static SkUnichar next_utf8(const void** chars) {
return SkUTF8_NextUnichar((const char**)chars);
}
static SkUnichar next_utf16(const void** chars) {
return SkUTF16_NextUnichar((const uint16_t**)chars);
}
static SkUnichar next_utf32(const void** chars) {
const SkUnichar** uniChars = (const SkUnichar**)chars;
SkUnichar uni = **uniChars;
*uniChars += 1;
return uni;
}
typedef SkUnichar (*EncodingProc)(const void**);
static EncodingProc find_encoding_proc(SkTypeface::Encoding enc) {
static const EncodingProc gProcs[] = {
next_utf8, next_utf16, next_utf32
};
SkASSERT((size_t)enc < SK_ARRAY_COUNT(gProcs));
return gProcs[enc];
}
int SkTypeface_FreeType::onCharsToGlyphs(const void* chars, Encoding encoding,
uint16_t glyphs[], int glyphCount) const
{
AutoFTAccess fta(this);
FT_Face face = fta.face();
if (!face) {
if (glyphs) {
sk_bzero(glyphs, glyphCount * sizeof(glyphs[0]));
}
return 0;
}
EncodingProc next_uni_proc = find_encoding_proc(encoding);
if (nullptr == glyphs) {
for (int i = 0; i < glyphCount; ++i) {
if (0 == FT_Get_Char_Index(face, next_uni_proc(&chars))) {
return i;
}
}
return glyphCount;
} else {
int first = glyphCount;
for (int i = 0; i < glyphCount; ++i) {
unsigned id = FT_Get_Char_Index(face, next_uni_proc(&chars));
glyphs[i] = SkToU16(id);
if (0 == id && i < first) {
first = i;
}
}
return first;
}
}
int SkTypeface_FreeType::onCountGlyphs() const {
AutoFTAccess fta(this);
FT_Face face = fta.face();
return face ? face->num_glyphs : 0;
}
SkTypeface::LocalizedStrings* SkTypeface_FreeType::onCreateFamilyNameIterator() const {
SkTypeface::LocalizedStrings* nameIter =
SkOTUtils::LocalizedStrings_NameTable::CreateForFamilyNames(*this);
if (nullptr == nameIter) {
SkString familyName;
this->getFamilyName(&familyName);
SkString language("und"); //undetermined
nameIter = new SkOTUtils::LocalizedStrings_SingleName(familyName, language);
}
return nameIter;
}
int SkTypeface_FreeType::onGetVariationDesignPosition(
SkFontArguments::VariationPosition::Coordinate coordinates[], int coordinateCount) const
{
AutoFTAccess fta(this);
FT_Face face = fta.face();
if (!face || !(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) {
return 0;
}
FT_MM_Var* variations = nullptr;
if (FT_Get_MM_Var(face, &variations)) {
return 0;
}
SkAutoFree autoFreeVariations(variations);
if (!coordinates || coordinateCount < SkToInt(variations->num_axis)) {
return variations->num_axis;
}
SkAutoSTMalloc<4, FT_Fixed> coords(variations->num_axis);
// FT_Get_{MM,Var}_{Blend,Design}_Coordinates were added in FreeType 2.7.1.
if (gFTLibrary->fGetVarDesignCoordinates &&
!gFTLibrary->fGetVarDesignCoordinates(face, variations->num_axis, coords.get()))
{
for (FT_UInt i = 0; i < variations->num_axis; ++i) {
coordinates[i].axis = variations->axis[i].tag;
coordinates[i].value = SkFixedToScalar(coords[i]);
}
} else if (static_cast<FT_UInt>(fta.getAxesCount()) == variations->num_axis) {
for (FT_UInt i = 0; i < variations->num_axis; ++i) {
coordinates[i].axis = variations->axis[i].tag;
coordinates[i].value = SkFixedToScalar(fta.getAxes()[i]);
}
} else if (fta.isNamedVariationSpecified()) {
// The font has axes, they cannot be retrieved, and some named axis was specified.
return -1;
} else {
// The font has axes, they cannot be retrieved, but no named instance was specified.
return 0;
}
return variations->num_axis;
}
int SkTypeface_FreeType::onGetTableTags(SkFontTableTag tags[]) const {
AutoFTAccess fta(this);
FT_Face face = fta.face();
FT_ULong tableCount = 0;
FT_Error error;
// When 'tag' is nullptr, returns number of tables in 'length'.
error = FT_Sfnt_Table_Info(face, 0, nullptr, &tableCount);
if (error) {
return 0;
}
if (tags) {
for (FT_ULong tableIndex = 0; tableIndex < tableCount; ++tableIndex) {
FT_ULong tableTag;
FT_ULong tablelength;
error = FT_Sfnt_Table_Info(face, tableIndex, &tableTag, &tablelength);
if (error) {
return 0;
}
tags[tableIndex] = static_cast<SkFontTableTag>(tableTag);
}
}
return tableCount;
}
size_t SkTypeface_FreeType::onGetTableData(SkFontTableTag tag, size_t offset,
size_t length, void* data) const
{
AutoFTAccess fta(this);
FT_Face face = fta.face();
FT_ULong tableLength = 0;
FT_Error error;
// When 'length' is 0 it is overwritten with the full table length; 'offset' is ignored.
error = FT_Load_Sfnt_Table(face, tag, 0, nullptr, &tableLength);
if (error) {
return 0;
}
if (offset > tableLength) {
return 0;
}
FT_ULong size = SkTMin((FT_ULong)length, tableLength - (FT_ULong)offset);
if (data) {
error = FT_Load_Sfnt_Table(face, tag, offset, reinterpret_cast<FT_Byte*>(data), &size);
if (error) {
return 0;
}
}
return size;
}
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
SkTypeface_FreeType::Scanner::Scanner() : fLibrary(nullptr) {
if (FT_New_Library(&gFTMemory, &fLibrary)) {
return;
}
FT_Add_Default_Modules(fLibrary);
}
SkTypeface_FreeType::Scanner::~Scanner() {
if (fLibrary) {
FT_Done_Library(fLibrary);
}
}
FT_Face SkTypeface_FreeType::Scanner::openFace(SkStreamAsset* stream, int ttcIndex,
FT_Stream ftStream) const
{
if (fLibrary == nullptr) {
return nullptr;
}
FT_Open_Args args;
memset(&args, 0, sizeof(args));
const void* memoryBase = stream->getMemoryBase();
if (memoryBase) {
args.flags = FT_OPEN_MEMORY;
args.memory_base = (const FT_Byte*)memoryBase;
args.memory_size = stream->getLength();
} else {
memset(ftStream, 0, sizeof(*ftStream));
ftStream->size = stream->getLength();
ftStream->descriptor.pointer = stream;
ftStream->read = sk_ft_stream_io;
ftStream->close = sk_ft_stream_close;
args.flags = FT_OPEN_STREAM;
args.stream = ftStream;
}
FT_Face face;
if (FT_Open_Face(fLibrary, &args, ttcIndex, &face)) {
return nullptr;
}
return face;
}
bool SkTypeface_FreeType::Scanner::recognizedFont(SkStreamAsset* stream, int* numFaces) const {
SkAutoMutexAcquire libraryLock(fLibraryMutex);
FT_StreamRec streamRec;
FT_Face face = this->openFace(stream, -1, &streamRec);
if (nullptr == face) {
return false;
}
*numFaces = face->num_faces;
FT_Done_Face(face);
return true;
}
#include "SkTSearch.h"
bool SkTypeface_FreeType::Scanner::scanFont(
SkStreamAsset* stream, int ttcIndex,
SkString* name, SkFontStyle* style, bool* isFixedPitch, AxisDefinitions* axes) const
{
SkAutoMutexAcquire libraryLock(fLibraryMutex);
FT_StreamRec streamRec;
FT_Face face = this->openFace(stream, ttcIndex, &streamRec);
if (nullptr == face) {
return false;
}
int weight = SkFontStyle::kNormal_Weight;
int width = SkFontStyle::kNormal_Width;
SkFontStyle::Slant slant = SkFontStyle::kUpright_Slant;
if (face->style_flags & FT_STYLE_FLAG_BOLD) {
weight = SkFontStyle::kBold_Weight;
}
if (face->style_flags & FT_STYLE_FLAG_ITALIC) {
slant = SkFontStyle::kItalic_Slant;
}
PS_FontInfoRec psFontInfo;
TT_OS2* os2 = static_cast<TT_OS2*>(FT_Get_Sfnt_Table(face, ft_sfnt_os2));
if (os2 && os2->version != 0xffff) {
weight = os2->usWeightClass;
width = os2->usWidthClass;
// OS/2::fsSelection bit 9 indicates oblique.
if (SkToBool(os2->fsSelection & (1u << 9))) {
slant = SkFontStyle::kOblique_Slant;
}
} else if (0 == FT_Get_PS_Font_Info(face, &psFontInfo) && psFontInfo.weight) {
static const struct {
char const * const name;
int const weight;
} commonWeights [] = {
// There are probably more common names, but these are known to exist.
{ "all", SkFontStyle::kNormal_Weight }, // Multiple Masters usually default to normal.
{ "black", SkFontStyle::kBlack_Weight },
{ "bold", SkFontStyle::kBold_Weight },
{ "book", (SkFontStyle::kNormal_Weight + SkFontStyle::kLight_Weight)/2 },
{ "demi", SkFontStyle::kSemiBold_Weight },
{ "demibold", SkFontStyle::kSemiBold_Weight },
{ "extra", SkFontStyle::kExtraBold_Weight },
{ "extrabold", SkFontStyle::kExtraBold_Weight },
{ "extralight", SkFontStyle::kExtraLight_Weight },
{ "hairline", SkFontStyle::kThin_Weight },
{ "heavy", SkFontStyle::kBlack_Weight },
{ "light", SkFontStyle::kLight_Weight },
{ "medium", SkFontStyle::kMedium_Weight },
{ "normal", SkFontStyle::kNormal_Weight },
{ "plain", SkFontStyle::kNormal_Weight },
{ "regular", SkFontStyle::kNormal_Weight },
{ "roman", SkFontStyle::kNormal_Weight },
{ "semibold", SkFontStyle::kSemiBold_Weight },
{ "standard", SkFontStyle::kNormal_Weight },
{ "thin", SkFontStyle::kThin_Weight },
{ "ultra", SkFontStyle::kExtraBold_Weight },
{ "ultrablack", SkFontStyle::kExtraBlack_Weight },
{ "ultrabold", SkFontStyle::kExtraBold_Weight },
{ "ultraheavy", SkFontStyle::kExtraBlack_Weight },
{ "ultralight", SkFontStyle::kExtraLight_Weight },
};
int const index = SkStrLCSearch(&commonWeights[0].name, SK_ARRAY_COUNT(commonWeights),
psFontInfo.weight, sizeof(commonWeights[0]));
if (index >= 0) {
weight = commonWeights[index].weight;
} else {
SkDEBUGF(("Do not know weight for: %s (%s) \n", face->family_name, psFontInfo.weight));
}
}
if (name) {
name->set(face->family_name);
}
if (style) {
*style = SkFontStyle(weight, width, slant);
}
if (isFixedPitch) {
*isFixedPitch = FT_IS_FIXED_WIDTH(face);
}
if (axes && face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS) {
FT_MM_Var* variations = nullptr;
FT_Error err = FT_Get_MM_Var(face, &variations);
if (err) {
SkDEBUGF(("INFO: font %s claims to have variations, but none found.\n",
face->family_name));
return false;
}
SkAutoFree autoFreeVariations(variations);
axes->reset(variations->num_axis);
for (FT_UInt i = 0; i < variations->num_axis; ++i) {
const FT_Var_Axis& ftAxis = variations->axis[i];
(*axes)[i].fTag = ftAxis.tag;
(*axes)[i].fMinimum = ftAxis.minimum;
(*axes)[i].fDefault = ftAxis.def;
(*axes)[i].fMaximum = ftAxis.maximum;
}
}
FT_Done_Face(face);
return true;
}
/*static*/ void SkTypeface_FreeType::Scanner::computeAxisValues(
AxisDefinitions axisDefinitions,
const SkFontArguments::VariationPosition position,
SkFixed* axisValues,
const SkString& name)
{
for (int i = 0; i < axisDefinitions.count(); ++i) {
const Scanner::AxisDefinition& axisDefinition = axisDefinitions[i];
const SkScalar axisMin = SkFixedToScalar(axisDefinition.fMinimum);
const SkScalar axisMax = SkFixedToScalar(axisDefinition.fMaximum);
axisValues[i] = axisDefinition.fDefault;
// The position may be over specified. If there are multiple values for a given axis,
// use the last one since that's what css-fonts-4 requires.
for (int j = position.coordinateCount; j --> 0;) {
const auto& coordinate = position.coordinates[j];
if (axisDefinition.fTag == coordinate.axis) {
const SkScalar axisValue = SkTPin(coordinate.value, axisMin, axisMax);
if (coordinate.value != axisValue) {
SkDEBUGF(("Requested font axis value out of range: "
"%s '%c%c%c%c' %f; pinned to %f.\n",
name.c_str(),
(axisDefinition.fTag >> 24) & 0xFF,
(axisDefinition.fTag >> 16) & 0xFF,
(axisDefinition.fTag >> 8) & 0xFF,
(axisDefinition.fTag ) & 0xFF,
SkScalarToDouble(coordinate.value),
SkScalarToDouble(axisValue)));
}
axisValues[i] = SkScalarToFixed(axisValue);
break;
}
}
// TODO: warn on defaulted axis?
}
SkDEBUGCODE(
// Check for axis specified, but not matched in font.
for (int i = 0; i < position.coordinateCount; ++i) {
SkFourByteTag skTag = position.coordinates[i].axis;
bool found = false;
for (int j = 0; j < axisDefinitions.count(); ++j) {
if (skTag == axisDefinitions[j].fTag) {
found = true;
break;
}
}
if (!found) {
SkDEBUGF(("Requested font axis not found: %s '%c%c%c%c'\n",
name.c_str(),
(skTag >> 24) & 0xFF,
(skTag >> 16) & 0xFF,
(skTag >> 8) & 0xFF,
(skTag) & 0xFF));
}
}
)
}