SkFontStream.cpp File Reference

#include "include/core/SkStream.h"
#include "include/core/SkTypes.h"
#include "include/private/base/SkMalloc.h"
#include "src/base/SkAutoMalloc.h"
#include "src/base/SkEndian.h"
#include "src/core/SkFontStream.h"
#include <cstdint>

Go to the source code of this file.

Classes
struct	SkSFNTHeader
struct	SkTTCFHeader
union	SkSharedTTHeader
struct	SkSFNTDirEntry
struct	SfntHeader

Functions
static bool	read (SkStream *stream, void *buffer, size_t amount)
static bool	skip (SkStream *stream, size_t amount)
static int	count_tables (SkStream *stream, int ttcIndex, size_t *offsetToDir)

Function Documentation

count_tables()

static int count_tables ( SkStream *  stream, int  ttcIndex, size_t *  offsetToDir  )

static

Return the number of tables, or if this is a TTC (collection), return the number of tables in the first element of the collection. In either case, if offsetToDir is not-null, set it to the offset to the beginning of the table headers (SkSFNTDirEntry), relative to the start of the stream.

On an error, return 0 for number of tables, and ignore offsetToDir

Definition at line 59 of file SkFontStream.cpp.

                                                                             {
    SkASSERT(ttcIndex >= 0);
 
    SkAutoSMalloc<1024> storage(sizeof(SkSharedTTHeader));
    SkSharedTTHeader* header = (SkSharedTTHeader*)storage.get();
 
    if (!read(stream, header, sizeof(SkSharedTTHeader))) {
        return 0;
    }
 
    // by default, SkSFNTHeader is at the start of the stream
    size_t offset = 0;
 
    // if we're really a collection, the first 4-bytes will be 'ttcf'
    uint32_t tag = SkEndian_SwapBE32(header->fCollection.fTag);
    if (SkSetFourByteTag('t', 't', 'c', 'f') == tag) {
        unsigned count = SkEndian_SwapBE32(header->fCollection.fNumOffsets);
        if ((unsigned)ttcIndex >= count) {
            return 0;
        }
 
        if (ttcIndex > 0) { // need to read more of the shared header
            stream->rewind();
            size_t amount = sizeof(SkSharedTTHeader) + ttcIndex * sizeof(uint32_t);
            header = (SkSharedTTHeader*)storage.reset(amount);
            if (!read(stream, header, amount)) {
                return 0;
            }
        }
        // this is the offset to the local SkSFNTHeader
        offset = SkEndian_SwapBE32((&header->fCollection.fOffset0)[ttcIndex]);
        stream->rewind();
        if (!skip(stream, offset)) {
            return 0;
        }
        if (!read(stream, header, sizeof(SkSFNTHeader))) {
            return 0;
        }
    }
 
    if (offsetToDir) {
        // add the size of the header, so we will point to the DirEntries
        *offsetToDir = offset + sizeof(SkSFNTHeader);
    }
    return SkEndian_SwapBE16(header->fSingle.fNumTables);
}

read()

static bool read ( SkStream *  stream, void *  buffer, size_t  amount  )

static

Definition at line 44 of file SkFontStream.cpp.

                                                                {
    return stream->read(buffer, amount) == amount;
}

skip()

static bool skip ( SkStream *  stream, size_t  amount  )

static

Definition at line 48 of file SkFontStream.cpp.

                                                  {
    return stream->skip(amount) == amount;
}