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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 "include/core/SkData.h"
9 #include "include/core/SkStream.h"
10 #include "src/core/SkFontDescriptor.h"
11 
12 enum {
13     kInvalid        = 0x00,
14 
15     // Related to a font request.
16     kFontFamilyName = 0x01, // int length, data[length]
17     kFullName       = 0x04, // int length, data[length]
18     kPostscriptName = 0x06, // int length, data[length]
19     kWeight         = 0x10, // scalar (1 - 1000)
20     kWidth          = 0x11, // scalar (percentage, 100 is 'normal')
21     kSlant          = 0x12, // scalar (cw angle, 14 is a normal right leaning oblique)
22     kItalic         = 0x13, // scalar (0 is Roman, 1 is fully Italic)
23 
24     // Related to font data. Can also be used with a requested font.
25     kPaletteIndex   = 0xF8, // int
26     kPaletteEntryOverrides = 0xF9, // int count, (int, u32)[count]
27     kFontVariation  = 0xFA, // int count, (u32, scalar)[count]
28 
29     // Related to font data.
30     kFontIndex      = 0xFD, // int
31     kSentinel       = 0xFF, // no data
32 };
33 
SkFontDescriptor()34 SkFontDescriptor::SkFontDescriptor() { }
35 
read_string(SkStream * stream,SkString * string)36 static bool SK_WARN_UNUSED_RESULT read_string(SkStream* stream, SkString* string) {
37     size_t length;
38     if (!stream->readPackedUInt(&length)) { return false; }
39     if (length > 0) {
40         string->resize(length);
41         if (stream->read(string->writable_str(), length) != length) { return false; }
42     }
43     return true;
44 }
45 
write_string(SkWStream * stream,const SkString & string,uint32_t id)46 static bool write_string(SkWStream* stream, const SkString& string, uint32_t id) {
47     if (string.isEmpty()) { return true; }
48     return stream->writePackedUInt(id) &&
49            stream->writePackedUInt(string.size()) &&
50            stream->write(string.c_str(), string.size());
51 }
52 
write_uint(SkWStream * stream,size_t n,uint32_t id)53 static bool write_uint(SkWStream* stream, size_t n, uint32_t id) {
54     return stream->writePackedUInt(id) &&
55            stream->writePackedUInt(n);
56 }
57 
write_scalar(SkWStream * stream,SkScalar n,uint32_t id)58 static bool write_scalar(SkWStream* stream, SkScalar n, uint32_t id) {
59     return stream->writePackedUInt(id) &&
60            stream->writeScalar(n);
61 }
62 
read_id(SkStream * stream)63 static size_t SK_WARN_UNUSED_RESULT read_id(SkStream* stream) {
64     size_t i;
65     if (!stream->readPackedUInt(&i)) { return kInvalid; }
66     return i;
67 }
68 
69 static constexpr SkScalar usWidths[9] {
70     1, 2, 3, 4, 5, 6, 7, 8, 9
71 };
72 static constexpr SkScalar width_for_usWidth[0x10] = {
73     50,
74     50, 62.5, 75, 87.5, 100, 112.5, 125, 150, 200,
75     200, 200, 200, 200, 200, 200
76 };
77 
Deserialize(SkStream * stream,SkFontDescriptor * result)78 bool SkFontDescriptor::Deserialize(SkStream* stream, SkFontDescriptor* result) {
79     size_t coordinateCount;
80     using CoordinateCountType = decltype(result->fCoordinateCount);
81 
82     size_t index;
83     using CollectionIndexType = decltype(result->fCollectionIndex);
84 
85     size_t paletteIndex;
86     using PaletteIndexType = decltype(result->fPaletteIndex);
87 
88     size_t paletteEntryOverrideCount;
89     using PaletteEntryOverrideCountType = decltype(result->fPaletteEntryOverrideCount);
90 
91     size_t paletteEntryOverrideIndex;
92     using PaletteEntryOverrideIndexType = decltype(result->fPaletteEntryOverrides[0].index);
93 
94     SkScalar weight = SkFontStyle::kNormal_Weight;
95     SkScalar width = SkFontStyle::kNormal_Width;
96     SkScalar slant = 0;
97     SkScalar italic = 0;
98 
99     size_t styleBits;
100     if (!stream->readPackedUInt(&styleBits)) { return false; }
101     weight = ((styleBits >> 16) & 0xFFFF);
102     width  = ((styleBits >>  8) & 0x000F)[width_for_usWidth];
103     slant  = ((styleBits >>  0) & 0x000F) != SkFontStyle::kUpright_Slant ? 14 : 0;
104     italic = ((styleBits >>  0) & 0x000F) == SkFontStyle::kItalic_Slant ? 1 : 0;
105 
106     for (size_t id; (id = read_id(stream)) != kSentinel;) {
107         switch (id) {
108             case kFontFamilyName:
109                 if (!read_string(stream, &result->fFamilyName)) { return false; }
110                 break;
111             case kFullName:
112                 if (!read_string(stream, &result->fFullName)) { return false; }
113                 break;
114             case kPostscriptName:
115                 if (!read_string(stream, &result->fPostscriptName)) { return false; }
116                 break;
117             case kWeight:
118                 if (!stream->readScalar(&weight)) { return false; }
119                 break;
120             case kWidth:
121                 if (!stream->readScalar(&width)) { return false; }
122                 break;
123             case kSlant:
124                 if (!stream->readScalar(&slant)) { return false; }
125                 break;
126             case kItalic:
127                 if (!stream->readScalar(&italic)) { return false; }
128                 break;
129             case kFontVariation:
130                 if (!stream->readPackedUInt(&coordinateCount)) { return false; }
131                 if (!SkTFitsIn<CoordinateCountType>(coordinateCount)) { return false; }
132                 result->fCoordinateCount = SkTo<CoordinateCountType>(coordinateCount);
133 
134                 result->fVariation.reset(coordinateCount);
135                 for (size_t i = 0; i < coordinateCount; ++i) {
136                     if (!stream->readU32(&result->fVariation[i].axis)) { return false; }
137                     if (!stream->readScalar(&result->fVariation[i].value)) { return false; }
138                 }
139                 break;
140             case kFontIndex:
141                 if (!stream->readPackedUInt(&index)) { return false; }
142                 if (!SkTFitsIn<CollectionIndexType>(index)) { return false; }
143                 result->fCollectionIndex = SkTo<CollectionIndexType>(index);
144                 break;
145             case kPaletteIndex:
146                 if (!stream->readPackedUInt(&paletteIndex)) { return false; }
147                 if (!SkTFitsIn<PaletteIndexType>(paletteIndex)) { return false; }
148                 result->fPaletteIndex = SkTo<PaletteIndexType>(paletteIndex);
149                 break;
150             case kPaletteEntryOverrides:
151                 if (!stream->readPackedUInt(&paletteEntryOverrideCount)) { return false; }
152                 if (!SkTFitsIn<PaletteEntryOverrideCountType>(paletteEntryOverrideCount)) {
153                     return false;
154                 }
155                 result->fPaletteEntryOverrideCount =
156                         SkTo<PaletteEntryOverrideCountType>(paletteEntryOverrideCount);
157 
158                 result->fPaletteEntryOverrides.reset(paletteEntryOverrideCount);
159                 for (size_t i = 0; i < paletteEntryOverrideCount; ++i) {
160                     if (!stream->readPackedUInt(&paletteEntryOverrideIndex)) { return false; }
161                     if (!SkTFitsIn<PaletteEntryOverrideIndexType>(paletteEntryOverrideIndex)) {
162                         return false;
163                     }
164                     result->fPaletteEntryOverrides[i].index =
165                             SkTo<PaletteEntryOverrideIndexType>(paletteEntryOverrideIndex);
166                     if (!stream->readU32(&result->fPaletteEntryOverrides[i].color)) {
167                         return false;
168                     }
169                 }
170                 break;
171             default:
172                 SkDEBUGFAIL("Unknown id used by a font descriptor");
173                 return false;
174         }
175     }
176 
177     SkFontStyle::Slant slantEnum = SkFontStyle::kUpright_Slant;
178     if (slant != 0) { slantEnum = SkFontStyle::kOblique_Slant; }
179     if (0 < italic) { slantEnum = SkFontStyle::kItalic_Slant; }
180     SkFontStyle::Width widthEnum = SkFontStyleWidthForWidthAxisValue(width);
181     result->fStyle = SkFontStyle(SkScalarRoundToInt(weight), widthEnum, slantEnum);
182 
183     size_t length;
184     if (!stream->readPackedUInt(&length)) { return false; }
185     if (length > 0) {
186         sk_sp<SkData> data(SkData::MakeUninitialized(length));
187         if (stream->read(data->writable_data(), length) != length) {
188             SkDEBUGFAIL("Could not read font data");
189             return false;
190         }
191         result->fStream = SkMemoryStream::Make(std::move(data));
192     }
193     return true;
194 }
195 
serialize(SkWStream * stream) const196 void SkFontDescriptor::serialize(SkWStream* stream) const {
197     uint32_t styleBits = (fStyle.weight() << 16) | (fStyle.width() << 8) | (fStyle.slant());
198     stream->writePackedUInt(styleBits);
199 
200     write_string(stream, fFamilyName, kFontFamilyName);
201     write_string(stream, fFullName, kFullName);
202     write_string(stream, fPostscriptName, kPostscriptName);
203 
204     write_scalar(stream, fStyle.weight(), kWeight);
205     write_scalar(stream, fStyle.width()[width_for_usWidth], kWidth);
206     write_scalar(stream, fStyle.slant() == SkFontStyle::kUpright_Slant ? 0 : 14, kSlant);
207     write_scalar(stream, fStyle.slant() == SkFontStyle::kItalic_Slant ? 1 : 0, kItalic);
208 
209     if (fCollectionIndex) {
210         write_uint(stream, fCollectionIndex, kFontIndex);
211     }
212     if (fPaletteIndex) {
213         write_uint(stream, fPaletteIndex, kPaletteIndex);
214     }
215     if (fCoordinateCount) {
216         write_uint(stream, fCoordinateCount, kFontVariation);
217         for (int i = 0; i < fCoordinateCount; ++i) {
218             stream->write32(fVariation[i].axis);
219             stream->writeScalar(fVariation[i].value);
220         }
221     }
222     if (fPaletteEntryOverrideCount) {
223         write_uint(stream, fPaletteEntryOverrideCount, kPaletteEntryOverrides);
224         for (int i = 0; i < fPaletteEntryOverrideCount; ++i) {
225             stream->writePackedUInt(fPaletteEntryOverrides[i].index);
226             stream->write32(fPaletteEntryOverrides[i].color);
227         }
228     }
229 
230     stream->writePackedUInt(kSentinel);
231 
232     if (fStream) {
233         std::unique_ptr<SkStreamAsset> fontStream = fStream->duplicate();
234         size_t length = fontStream->getLength();
235         stream->writePackedUInt(length);
236         stream->writeStream(fontStream.get(), length);
237     } else {
238         stream->writePackedUInt(0);
239     }
240 }
241 
SkFontStyleWidthForWidthAxisValue(SkScalar width)242 SkFontStyle::Width SkFontDescriptor::SkFontStyleWidthForWidthAxisValue(SkScalar width) {
243     int usWidth = SkScalarRoundToInt(SkScalarInterpFunc(width, &width_for_usWidth[1], usWidths, 9));
244     return static_cast<SkFontStyle::Width>(usWidth);
245 }
246