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 
SkFontDescriptor()27 SkFontDescriptor::SkFontDescriptor() { }
28 
read_string(SkStream * stream,SkString * string)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
skip_string(SkStream * stream)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 
write_string(SkWStream * stream,const SkString & string,uint32_t id)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 
read_uint(SkStream * stream)53 static size_t read_uint(SkStream* stream) {
54     return stream->readPackedUInt();
55 }
56 
write_uint(SkWStream * stream,size_t n,uint32_t id)57 static void write_uint(SkWStream* stream, size_t n, uint32_t id) {
58     stream->writePackedUInt(id);
59     stream->writePackedUInt(n);
60 }
61 
Deserialize(SkStream * stream,SkFontDescriptor * result)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 
serialize(SkWStream * stream)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