SkFontHost_FreeType.cpp File Reference

#include "include/core/SkBBHFactory.h"
#include "include/core/SkBitmap.h"
#include "include/core/SkCanvas.h"
#include "include/core/SkData.h"
#include "include/core/SkDrawable.h"
#include "include/core/SkFontMetrics.h"
#include "include/core/SkGraphics.h"
#include "include/core/SkPath.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkScalar.h"
#include "include/core/SkStream.h"
#include "include/core/SkString.h"
#include "include/private/SkColorData.h"
#include "include/private/base/SkMalloc.h"
#include "include/private/base/SkMutex.h"
#include "include/private/base/SkTPin.h"
#include "include/private/base/SkTemplates.h"
#include "include/private/base/SkTo.h"
#include "src/base/SkTSearch.h"
#include "src/core/SkAdvancedTypefaceMetrics.h"
#include "src/core/SkDescriptor.h"
#include "src/core/SkFDot6.h"
#include "src/core/SkFontDescriptor.h"
#include "src/core/SkFontScanner.h"
#include "src/core/SkGlyph.h"
#include "src/core/SkMask.h"
#include "src/core/SkMaskGamma.h"
#include "src/core/SkScalerContext.h"
#include "src/ports/SkFontHost_FreeType_common.h"
#include "src/ports/SkTypeface_FreeType.h"
#include "src/sfnt/SkOTUtils.h"
#include "src/sfnt/SkSFNTHeader.h"
#include "src/sfnt/SkTTCFHeader.h"
#include "src/utils/SkCallableTraits.h"
#include "src/utils/SkMatrix22.h"
#include <memory>
#include <optional>
#include <tuple>
#include <ft2build.h>
#include <freetype/ftadvanc.h>
#include <freetype/ftimage.h>
#include <freetype/ftbitmap.h>
#include <freetype/freetype.h>
#include <freetype/ftlcdfil.h>
#include <freetype/ftmodapi.h>
#include <freetype/ftmm.h>
#include <freetype/ftoutln.h>
#include <freetype/ftsizes.h>
#include <freetype/ftsystem.h>
#include <freetype/tttables.h>
#include <freetype/t1tables.h>
#include <freetype/ftfntfmt.h>
#include <dlfcn.h>
#include "src/base/SkUtils.h"

Go to the source code of this file.

Classes
class	FreeTypeLibrary
class	SkTypeface_FreeType::FaceRec
class	AutoFTAccess
class	SkScalerContext_FreeType

Macros
#define	SK_FREETYPE_DLOPEN   (0x1)
#define	SK_FREETYPE_MINIMUM_RUNTIME_VERSION   ((2 << 24) | (8 << 16) | (1 << 8) | (SK_FREETYPE_DLOPEN))
#define	LOG_INFO(...)
#define	SK_OUTLINE_EMBOLDEN_DIVISOR   24

Typedefs
using	FT_Alloc_size_t = SkCallableTraits< FT_Alloc_Func >::argument< 1 >::type

Functions
static bool	isLCD (const SkScalerContextRec &rec)
static SkScalar	SkFT_FixedToScalar (FT_Fixed x)
static void *	sk_ft_alloc (FT_Memory, FT_Alloc_size_t size)
static void	sk_ft_free (FT_Memory, void *block)
static void *	sk_ft_realloc (FT_Memory, FT_Alloc_size_t cur_size, FT_Alloc_size_t new_size, void *block)
static SkMutex &	f_t_mutex ()
static unsigned long	sk_ft_stream_io (FT_Stream ftStream, unsigned long offset, unsigned char *buffer, unsigned long count)
static void	sk_ft_stream_close (FT_Stream)
static bool	canEmbed (FT_Face face)
static bool	canSubset (FT_Face face)
static SkAdvancedTypefaceMetrics::FontType	get_font_type (FT_Face face)
static bool	is_opentype_font_data_standard_format (const SkTypeface &typeface)
static bool	bothZero (SkScalar a, SkScalar b)
static bool	isAxisAligned (const SkScalerContextRec &rec)
static int	GetVariationDesignPosition (AutoFTAccess &fta, SkFontArguments::VariationPosition::Coordinate coordinates[], int coordinateCount)
static FT_Int	chooseBitmapStrike (FT_Face face, FT_F26Dot6 scaleY)

Variables
FT_MemoryRec_	gFTMemory = { nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc }
static FreeTypeLibrary *	gFTLibrary
constexpr int	kMaxC2GCacheCount = 512

Macro Definition Documentation

LOG_INFO

#define LOG_INFO

(

...

)

Definition at line 112 of file SkFontHost_FreeType.cpp.

SK_FREETYPE_DLOPEN

#define SK_FREETYPE_DLOPEN   (0x1)

Definition at line 77 of file SkFontHost_FreeType.cpp.

SK_FREETYPE_MINIMUM_RUNTIME_VERSION

#define SK_FREETYPE_MINIMUM_RUNTIME_VERSION   ((2 << 24) | (8 << 16) | (1 << 8) | (SK_FREETYPE_DLOPEN))

Definition at line 84 of file SkFontHost_FreeType.cpp.

SK_OUTLINE_EMBOLDEN_DIVISOR

#define SK_OUTLINE_EMBOLDEN_DIVISOR   24

Definition at line 1671 of file SkFontHost_FreeType.cpp.

Typedef Documentation

FT_Alloc_size_t

using FT_Alloc_size_t = SkCallableTraits<FT_Alloc_Func>::argument<1>::type

Definition at line 127 of file SkFontHost_FreeType.cpp.

Function Documentation

bothZero()

static bool bothZero ( SkScalar  a, SkScalar  b  )

static

Definition at line 681 of file SkFontHost_FreeType.cpp.

                                             {
    return 0 == a && 0 == b;
}

canEmbed()

static bool canEmbed ( FT_Face  face )

static

Definition at line 505 of file SkFontHost_FreeType.cpp.

                                   {
    FT_UShort fsType = FT_Get_FSType_Flags(face);
    return (fsType & (FT_FSTYPE_RESTRICTED_LICENSE_EMBEDDING |
                      FT_FSTYPE_BITMAP_EMBEDDING_ONLY)) == 0;
}

canSubset()

static bool canSubset ( FT_Face  face )

static

Definition at line 511 of file SkFontHost_FreeType.cpp.

                                    {
    FT_UShort fsType = FT_Get_FSType_Flags(face);
    return (fsType & FT_FSTYPE_NO_SUBSETTING) == 0;
}

chooseBitmapStrike()

static FT_Int chooseBitmapStrike ( FT_Face  face, FT_F26Dot6  scaleY  )

static

Returns the bitmap strike equal to or just larger than the requested size.

Definition at line 861 of file SkFontHost_FreeType.cpp.

                                                                  {
    if (face == nullptr) {
        LOG_INFO("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;
}

f_t_mutex()

static SkMutex & f_t_mutex ( )

static

Definition at line 193 of file SkFontHost_FreeType.cpp.

                            {
    static SkMutex& mutex = *(new SkMutex);
    return mutex;
}

get_font_type()

static SkAdvancedTypefaceMetrics::FontType get_font_type ( FT_Face  face )

static

Definition at line 516 of file SkFontHost_FreeType.cpp.

                                                                     {
    const char* fontType = FT_Get_X11_Font_Format(face);
    static struct { const char* s; SkAdvancedTypefaceMetrics::FontType t; } values[] = {
        { "Type 1",     SkAdvancedTypefaceMetrics::kType1_Font    },
        { "CID Type 1", SkAdvancedTypefaceMetrics::kType1CID_Font },
        { "CFF",        SkAdvancedTypefaceMetrics::kCFF_Font      },
        { "TrueType",   SkAdvancedTypefaceMetrics::kTrueType_Font },
    };
    for(const auto& v : values) { if (strcmp(fontType, v.s) == 0) { return v.t; } }
    return SkAdvancedTypefaceMetrics::kOther_Font;
}

GetVariationDesignPosition()

static int GetVariationDesignPosition ( AutoFTAccess &  fta, SkFontArguments::VariationPosition::Coordinate  coordinates[], int  coordinateCount  )

static

Copy the design variation coordinates into 'coordinates'.

Parameters

coordinates	the buffer into which to write the design variation coordinates.
coordinateCount	the number of entries available through 'coordinates'.

Returns

The number of axes, or -1 if there is an error. If 'coordinates != nullptr' and 'coordinateCount >= numAxes' then 'coordinates' will be filled with the variation coordinates describing the position of this typeface in design variation space. It is possible the number of axes can be retrieved but actual position cannot.

Definition at line 715 of file SkFontHost_FreeType.cpp.

{
    FT_Face face = fta.face();
    if (!face) {
        return -1;
    }
 
    if (!(face->face_flags & FT_FACE_FLAG_MULTIPLE_MASTERS)) {
        return 0;
    }
 
    FT_MM_Var* variations = nullptr;
    if (FT_Get_MM_Var(face, &variations)) {
        return -1;
    }
    UniqueVoidPtr autoFreeVariations(variations);
 
    if (!coordinates || coordinateCount < SkToInt(variations->num_axis)) {
        return variations->num_axis;
    }
 
    AutoSTMalloc<4, FT_Fixed> coords(variations->num_axis);
    if (FT_Get_Var_Design_Coordinates(face, variations->num_axis, coords.get())) {
        return -1;
    }
    for (FT_UInt i = 0; i < variations->num_axis; ++i) {
        coordinates[i].axis = variations->axis[i].tag;
        coordinates[i].value = SkFixedToScalar(coords[i]);
    }
 
    return variations->num_axis;
}

is_opentype_font_data_standard_format()

static bool is_opentype_font_data_standard_format ( const SkTypeface &  typeface )

static

Definition at line 528 of file SkFontHost_FreeType.cpp.

                                                                              {
    // FreeType reports TrueType for any data that can be decoded to TrueType or OpenType.
    // However, there are alternate data formats for OpenType, like wOFF and wOF2.
    std::unique_ptr<SkStreamAsset> stream = typeface.openStream(nullptr);
    if (!stream) {
        return false;
    }
    char buffer[4];
    if (stream->read(buffer, 4) < 4) {
        return false;
    }
 
    SkFourByteTag tag = SkSetFourByteTag(buffer[0], buffer[1], buffer[2], buffer[3]);
    SK_OT_ULONG otTag = SkEndian_SwapBE32(tag);
    return otTag == SkSFNTHeader::fontType_WindowsTrueType::TAG ||
           otTag == SkSFNTHeader::fontType_MacTrueType::TAG ||
           otTag == SkSFNTHeader::fontType_PostScript::TAG ||
           otTag == SkSFNTHeader::fontType_OpenTypeCFF::TAG ||
           otTag == SkTTCFHeader::TAG;
}

isAxisAligned()

static bool isAxisAligned ( const SkScalerContextRec &  rec )

static

Definition at line 686 of file SkFontHost_FreeType.cpp.

                                                         {
    return 0 == rec.fPreSkewX &&
           (bothZero(rec.fPost2x2[0][1], rec.fPost2x2[1][0]) ||
            bothZero(rec.fPost2x2[0][0], rec.fPost2x2[1][1]));
}

isLCD()

static bool isLCD ( const SkScalerContextRec &  rec )

static

Definition at line 117 of file SkFontHost_FreeType.cpp.

                                                 {
    return SkMask::kLCD16_Format == rec.fMaskFormat;
}

sk_ft_alloc()

static void * sk_ft_alloc ( FT_Memory  , FT_Alloc_size_t  size  )

static

Definition at line 132 of file SkFontHost_FreeType.cpp.

                                                              {
        return sk_malloc_canfail(size);
    }

sk_ft_free()

static void sk_ft_free ( FT_Memory  , void *  block  )

static

Definition at line 135 of file SkFontHost_FreeType.cpp.

                                                   {
        sk_free(block);
    }

sk_ft_realloc()

static void * sk_ft_realloc ( FT_Memory  , FT_Alloc_size_t  cur_size, FT_Alloc_size_t  new_size, void *  block  )

static

Definition at line 138 of file SkFontHost_FreeType.cpp.

                                                                                 {
        return sk_realloc_throw(block, new_size);
    }

sk_ft_stream_close()

static void sk_ft_stream_close ( FT_Stream  )

static

Definition at line 266 of file SkFontHost_FreeType.cpp.

{}

sk_ft_stream_io()

static unsigned long sk_ft_stream_io ( FT_Stream  ftStream, unsigned long  offset, unsigned char *  buffer, unsigned long  count  )

static

Definition at line 250 of file SkFontHost_FreeType.cpp.

    {
        SkStreamAsset* stream = static_cast<SkStreamAsset*>(ftStream->descriptor.pointer);
 
        if (count) {
            if (!stream->seek(offset)) {
                return 0;
            }
            count = stream->read(buffer, count);
        }
        return count;
    }

SkFT_FixedToScalar()

static SkScalar SkFT_FixedToScalar ( FT_Fixed  x )

static

Definition at line 121 of file SkFontHost_FreeType.cpp.

                                               {
  return SkFixedToScalar(x);
}

Variable Documentation

gFTLibrary

FreeTypeLibrary* gFTLibrary

static

Definition at line 198 of file SkFontHost_FreeType.cpp.

gFTMemory

FT_MemoryRec_ gFTMemory = { nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc }

Definition at line 143 of file SkFontHost_FreeType.cpp.

{ nullptr, sk_ft_alloc, sk_ft_free, sk_ft_realloc };

kMaxC2GCacheCount

constexpr int kMaxC2GCacheCount = 512

constexpr

Definition at line 1718 of file SkFontHost_FreeType.cpp.