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      1 /*
      2  * Copyright 2012 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkFontDescriptor.h"
      9 #include "SkMakeUnique.h"
     10 #include "SkStream.h"
     11 #include "SkData.h"
     12 
     13 enum {
     14     // these must match the sfnt 'name' enums
     15     kFontFamilyName = 0x01,
     16     kFullName       = 0x04,
     17     kPostscriptName = 0x06,
     18 
     19     // These count backwards from 0xFF, so as not to collide with the SFNT
     20     // defines for names in its 'name' table.
     21     kFontAxes       = 0xFC,
     22     kFontIndex      = 0xFD,
     23     kFontFileName   = 0xFE,  // Remove when MIN_PICTURE_VERSION > 41
     24     kSentinel       = 0xFF,
     25 };
     26 
     27 SkFontDescriptor::SkFontDescriptor() { }
     28 
     29 static void read_string(SkStream* stream, SkString* string) {
     30     const uint32_t length = SkToU32(stream->readPackedUInt());
     31     if (length > 0) {
     32         string->resize(length);
     33         stream->read(string->writable_str(), length);
     34     }
     35 }
     36 
     37 // Remove when MIN_PICTURE_VERSION > 41
     38 static void skip_string(SkStream* stream) {
     39     const uint32_t length = SkToU32(stream->readPackedUInt());
     40     if (length > 0) {
     41         stream->skip(length);
     42     }
     43 }
     44 
     45 static void write_string(SkWStream* stream, const SkString& string, uint32_t id) {
     46     if (!string.isEmpty()) {
     47         stream->writePackedUInt(id);
     48         stream->writePackedUInt(string.size());
     49         stream->write(string.c_str(), string.size());
     50     }
     51 }
     52 
     53 static size_t read_uint(SkStream* stream) {
     54     return stream->readPackedUInt();
     55 }
     56 
     57 static void write_uint(SkWStream* stream, size_t n, uint32_t id) {
     58     stream->writePackedUInt(id);
     59     stream->writePackedUInt(n);
     60 }
     61 
     62 bool SkFontDescriptor::Deserialize(SkStream* stream, SkFontDescriptor* result) {
     63     size_t styleBits = stream->readPackedUInt();
     64     if (styleBits <= 2) {
     65         // Remove this branch when MIN_PICTURE_VERSION > 45
     66         result->fStyle = SkFontStyle::FromOldStyle(styleBits);
     67     } else {
     68         result->fStyle = SkFontStyle((styleBits >> 16) & 0xFFFF,
     69                                      (styleBits >> 8 ) & 0xFF,
     70                                      static_cast<SkFontStyle::Slant>(styleBits & 0xFF));
     71     }
     72 
     73     SkAutoSTMalloc<4, SkFixed> axis;
     74     size_t axisCount = 0;
     75     size_t index = 0;
     76     for (size_t id; (id = stream->readPackedUInt()) != kSentinel;) {
     77         switch (id) {
     78             case kFontFamilyName:
     79                 read_string(stream, &result->fFamilyName);
     80                 break;
     81             case kFullName:
     82                 read_string(stream, &result->fFullName);
     83                 break;
     84             case kPostscriptName:
     85                 read_string(stream, &result->fPostscriptName);
     86                 break;
     87             case kFontAxes:
     88                 axisCount = read_uint(stream);
     89                 axis.reset(axisCount);
     90                 for (size_t i = 0; i < axisCount; ++i) {
     91                     axis[i] = read_uint(stream);
     92                 }
     93                 break;
     94             case kFontIndex:
     95                 index = read_uint(stream);
     96                 break;
     97             case kFontFileName:  // Remove when MIN_PICTURE_VERSION > 41
     98                 skip_string(stream);
     99                 break;
    100             default:
    101                 SkDEBUGFAIL("Unknown id used by a font descriptor");
    102                 return false;
    103         }
    104     }
    105 
    106     size_t length = stream->readPackedUInt();
    107     if (length > 0) {
    108         sk_sp<SkData> data(SkData::MakeUninitialized(length));
    109         if (stream->read(data->writable_data(), length) == length) {
    110             result->fFontData = skstd::make_unique<SkFontData>(
    111                 skstd::make_unique<SkMemoryStream>(data), index, axis, axisCount);
    112         } else {
    113             SkDEBUGFAIL("Could not read font data");
    114             return false;
    115         }
    116     }
    117     return true;
    118 }
    119 
    120 void SkFontDescriptor::serialize(SkWStream* stream) {
    121     uint32_t styleBits = (fStyle.weight() << 16) | (fStyle.width() << 8) | (fStyle.slant());
    122     stream->writePackedUInt(styleBits);
    123 
    124     write_string(stream, fFamilyName, kFontFamilyName);
    125     write_string(stream, fFullName, kFullName);
    126     write_string(stream, fPostscriptName, kPostscriptName);
    127     if (fFontData.get()) {
    128         if (fFontData->getIndex()) {
    129             write_uint(stream, fFontData->getIndex(), kFontIndex);
    130         }
    131         if (fFontData->getAxisCount()) {
    132             write_uint(stream, fFontData->getAxisCount(), kFontAxes);
    133             for (int i = 0; i < fFontData->getAxisCount(); ++i) {
    134                 stream->writePackedUInt(fFontData->getAxis()[i]);
    135             }
    136         }
    137     }
    138 
    139     stream->writePackedUInt(kSentinel);
    140 
    141     if (fFontData.get() && fFontData->hasStream()) {
    142         std::unique_ptr<SkStreamAsset> fontStream = fFontData->detachStream();
    143         size_t length = fontStream->getLength();
    144         stream->writePackedUInt(length);
    145         stream->writeStream(fontStream.get(), length);
    146     } else {
    147         stream->writePackedUInt(0);
    148     }
    149 }
    150