submodule/skia/src/core/SkFontDescriptor.cpp

   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
  34 SkFontDescriptor::SkFontDescriptor() { }
  35
  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
  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
  53 static bool write_uint(SkWStream* stream, size_t n, uint32_t id) {
  54     return stream->writePackedUInt(id) &&
  55            stream->writePackedUInt(n);
  56 }
  57
  58 static bool write_scalar(SkWStream* stream, SkScalar n, uint32_t id) {
  59     return stream->writePackedUInt(id) &&
  60            stream->writeScalar(n);
  61 }
  62
  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
  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
 196 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 > 0) {
 210         write_uint(stream, fCollectionIndex, kFontIndex);
 211     }
 212     if (fPaletteIndex > 0) {
 213         write_uint(stream, fPaletteIndex, kPaletteIndex);
 214     }
 215     if (fCoordinateCount > 0) {
 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 > 0) {
 223         int nonNegativePaletteOverrideIndexes = 0;
 224         for (int i = 0; i < fPaletteEntryOverrideCount; ++i) {
 225             if (0 <= fPaletteEntryOverrides[i].index) {
 226                 ++nonNegativePaletteOverrideIndexes;
 227             }
 228         }
 229         write_uint(stream, nonNegativePaletteOverrideIndexes, kPaletteEntryOverrides);
 230         for (int i = 0; i < fPaletteEntryOverrideCount; ++i) {
 231             if (0 <= fPaletteEntryOverrides[i].index) {
 232                 stream->writePackedUInt(fPaletteEntryOverrides[i].index);
 233                 stream->write32(fPaletteEntryOverrides[i].color);
 234             }
 235         }
 236     }
 237
 238     stream->writePackedUInt(kSentinel);
 239
 240     if (fStream) {
 241         std::unique_ptr<SkStreamAsset> fontStream = fStream->duplicate();
 242         size_t length = fontStream->getLength();
 243         stream->writePackedUInt(length);
 244         stream->writeStream(fontStream.get(), length);
 245     } else {
 246         stream->writePackedUInt(0);
 247     }
 248 }
 249
 250 SkFontStyle::Width SkFontDescriptor::SkFontStyleWidthForWidthAxisValue(SkScalar width) {
 251     int usWidth = SkScalarRoundToInt(SkScalarInterpFunc(width, &width_for_usWidth[1], usWidths, 9));
 252     return static_cast<SkFontStyle::Width>(usWidth);
 253 }