1 /* 2 * Copyright 2006 The Android Open Source Project 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 #ifndef SkTypeface_DEFINED 9 #define SkTypeface_DEFINED 10 11 #include "include/core/SkFontArguments.h" 12 #include "include/core/SkFontParameters.h" 13 #include "include/core/SkFontStyle.h" 14 #include "include/core/SkFontTypes.h" 15 #include "include/core/SkRect.h" 16 #include "include/core/SkString.h" 17 #include "include/private/SkOnce.h" 18 #include "include/private/SkWeakRefCnt.h" 19 20 class SkData; 21 class SkDescriptor; 22 class SkFontData; 23 class SkFontDescriptor; 24 class SkScalerContext; 25 class SkStream; 26 class SkStreamAsset; 27 class SkWStream; 28 struct SkAdvancedTypefaceMetrics; 29 struct SkScalerContextEffects; 30 struct SkScalerContextRec; 31 32 typedef uint32_t SkFontID; 33 /** Machine endian. */ 34 typedef uint32_t SkFontTableTag; 35 36 /** \class SkTypeface 37 38 The SkTypeface class specifies the typeface and intrinsic style of a font. 39 This is used in the paint, along with optionally algorithmic settings like 40 textSize, textSkewX, textScaleX, kFakeBoldText_Mask, to specify 41 how text appears when drawn (and measured). 42 43 Typeface objects are immutable, and so they can be shared between threads. 44 */ 45 class SK_API SkTypeface : public SkWeakRefCnt { 46 public: 47 /** Returns the typeface's intrinsic style attributes. */ fontStyle()48 SkFontStyle fontStyle() const { 49 return fStyle; 50 } 51 52 /** Returns true if style() has the kBold bit set. */ isBold()53 bool isBold() const { return fStyle.weight() >= SkFontStyle::kSemiBold_Weight; } 54 55 /** Returns true if style() has the kItalic bit set. */ isItalic()56 bool isItalic() const { return fStyle.slant() != SkFontStyle::kUpright_Slant; } 57 58 /** Returns true if the typeface claims to be fixed-pitch. 59 * This is a style bit, advance widths may vary even if this returns true. 60 */ isFixedPitch()61 bool isFixedPitch() const { return fIsFixedPitch; } 62 63 /** Copy into 'coordinates' (allocated by the caller) the design variation coordinates. 64 * 65 * @param coordinates the buffer into which to write the design variation coordinates. 66 * @param coordinateCount the number of entries available through 'coordinates'. 67 * 68 * @return The number of axes, or -1 if there is an error. 69 * If 'coordinates != nullptr' and 'coordinateCount >= numAxes' then 'coordinates' will be 70 * filled with the variation coordinates describing the position of this typeface in design 71 * variation space. It is possible the number of axes can be retrieved but actual position 72 * cannot. 73 */ 74 int getVariationDesignPosition(SkFontArguments::VariationPosition::Coordinate coordinates[], 75 int coordinateCount) const; 76 77 /** Copy into 'parameters' (allocated by the caller) the design variation parameters. 78 * 79 * @param parameters the buffer into which to write the design variation parameters. 80 * @param coordinateCount the number of entries available through 'parameters'. 81 * 82 * @return The number of axes, or -1 if there is an error. 83 * If 'parameters != nullptr' and 'parameterCount >= numAxes' then 'parameters' will be 84 * filled with the variation parameters describing the position of this typeface in design 85 * variation space. It is possible the number of axes can be retrieved but actual parameters 86 * cannot. 87 */ 88 int getVariationDesignParameters(SkFontParameters::Variation::Axis parameters[], 89 int parameterCount) const; 90 91 /** Return a 32bit value for this typeface, unique for the underlying font 92 data. Will never return 0. 93 */ uniqueID()94 SkFontID uniqueID() const { return fUniqueID; } 95 96 /** Return the uniqueID for the specified typeface. If the face is null, 97 resolve it to the default font and return its uniqueID. Will never 98 return 0. 99 */ 100 static SkFontID UniqueID(const SkTypeface* face); 101 102 /** Returns true if the two typefaces reference the same underlying font, 103 handling either being null (treating null as the default font) 104 */ 105 static bool Equal(const SkTypeface* facea, const SkTypeface* faceb); 106 107 /** Returns the default normal typeface, which is never nullptr. */ 108 static sk_sp<SkTypeface> MakeDefault(); 109 110 /** Creates a new reference to the typeface that most closely matches the 111 requested familyName and fontStyle. This method allows extended font 112 face specifiers as in the SkFontStyle type. Will never return null. 113 114 @param familyName May be NULL. The name of the font family. 115 @param fontStyle The style of the typeface. 116 @return reference to the closest-matching typeface. Call must call 117 unref() when they are done. 118 */ 119 static sk_sp<SkTypeface> MakeFromName(const char familyName[], SkFontStyle fontStyle); 120 121 /** Return a new typeface given a file. If the file does not exist, or is 122 not a valid font file, returns nullptr. 123 */ 124 static sk_sp<SkTypeface> MakeFromFile(const char path[], int index = 0); 125 126 /** Return a new typeface given a stream. If the stream is 127 not a valid font file, returns nullptr. Ownership of the stream is 128 transferred, so the caller must not reference it again. 129 */ 130 static sk_sp<SkTypeface> MakeFromStream(std::unique_ptr<SkStreamAsset> stream, int index = 0); 131 132 /** Return a new typeface given a SkData. If the data is null, or is not a valid font file, 133 * returns nullptr. 134 */ 135 static sk_sp<SkTypeface> MakeFromData(sk_sp<SkData>, int index = 0); 136 137 /** Return a new typeface given font data and configuration. If the data 138 is not valid font data, returns nullptr. 139 */ 140 static sk_sp<SkTypeface> MakeFromFontData(std::unique_ptr<SkFontData>); 141 142 /** Return a new typeface based on this typeface but parameterized as specified in the 143 SkFontArguments. If the SkFontArguments does not supply an argument for a parameter 144 in the font then the value from this typeface will be used as the value for that 145 argument. If the cloned typeface would be exaclty the same as this typeface then 146 this typeface may be ref'ed and returned. May return nullptr on failure. 147 */ 148 sk_sp<SkTypeface> makeClone(const SkFontArguments&) const; 149 150 /** 151 * A typeface can serialize just a descriptor (names, etc.), or it can also include the 152 * actual font data (which can be large). This enum controls how serialize() decides what 153 * to serialize. 154 */ 155 enum class SerializeBehavior { 156 kDoIncludeData, 157 kDontIncludeData, 158 kIncludeDataIfLocal, 159 }; 160 161 /** Write a unique signature to a stream, sufficient to reconstruct a 162 typeface referencing the same font when Deserialize is called. 163 */ 164 void serialize(SkWStream*, SerializeBehavior = SerializeBehavior::kIncludeDataIfLocal) const; 165 166 /** 167 * Same as serialize(SkWStream*, ...) but returns the serialized data in SkData, instead of 168 * writing it to a stream. 169 */ 170 sk_sp<SkData> serialize(SerializeBehavior = SerializeBehavior::kIncludeDataIfLocal) const; 171 172 /** Given the data previously written by serialize(), return a new instance 173 of a typeface referring to the same font. If that font is not available, 174 return nullptr. 175 Does not affect ownership of SkStream. 176 */ 177 static sk_sp<SkTypeface> MakeDeserialize(SkStream*); 178 179 /** 180 * Given an array of UTF32 character codes, return their corresponding glyph IDs. 181 * 182 * @param chars pointer to the array of UTF32 chars 183 * @param number of chars and glyphs 184 * @param glyphs returns the corresponding glyph IDs for each character. 185 */ 186 void unicharsToGlyphs(const SkUnichar uni[], int count, SkGlyphID glyphs[]) const; 187 188 /** 189 * Return the glyphID that corresponds to the specified unicode code-point 190 * (in UTF32 encoding). If the unichar is not supported, returns 0. 191 * 192 * This is a short-cut for calling unicharsToGlyphs(). 193 */ 194 SkGlyphID unicharToGlyph(SkUnichar unichar) const; 195 196 /** 197 * Return the number of glyphs in the typeface. 198 */ 199 int countGlyphs() const; 200 201 // Table getters -- may fail if the underlying font format is not organized 202 // as 4-byte tables. 203 204 /** Return the number of tables in the font. */ 205 int countTables() const; 206 207 /** Copy into tags[] (allocated by the caller) the list of table tags in 208 * the font, and return the number. This will be the same as CountTables() 209 * or 0 if an error occured. If tags == NULL, this only returns the count 210 * (the same as calling countTables()). 211 */ 212 int getTableTags(SkFontTableTag tags[]) const; 213 214 /** Given a table tag, return the size of its contents, or 0 if not present 215 */ 216 size_t getTableSize(SkFontTableTag) const; 217 218 /** Copy the contents of a table into data (allocated by the caller). Note 219 * that the contents of the table will be in their native endian order 220 * (which for most truetype tables is big endian). If the table tag is 221 * not found, or there is an error copying the data, then 0 is returned. 222 * If this happens, it is possible that some or all of the memory pointed 223 * to by data may have been written to, even though an error has occured. 224 * 225 * @param tag The table tag whose contents are to be copied 226 * @param offset The offset in bytes into the table's contents where the 227 * copy should start from. 228 * @param length The number of bytes, starting at offset, of table data 229 * to copy. 230 * @param data storage address where the table contents are copied to 231 * @return the number of bytes actually copied into data. If offset+length 232 * exceeds the table's size, then only the bytes up to the table's 233 * size are actually copied, and this is the value returned. If 234 * offset > the table's size, or tag is not a valid table, 235 * then 0 is returned. 236 */ 237 size_t getTableData(SkFontTableTag tag, size_t offset, size_t length, 238 void* data) const; 239 240 /** 241 * Return an immutable copy of the requested font table, or nullptr if that table was 242 * not found. This can sometimes be faster than calling getTableData() twice: once to find 243 * the length, and then again to copy the data. 244 * 245 * @param tag The table tag whose contents are to be copied 246 * @return an immutable copy of the table's data, or nullptr. 247 */ 248 sk_sp<SkData> copyTableData(SkFontTableTag tag) const; 249 250 /** 251 * Return the units-per-em value for this typeface, or zero if there is an 252 * error. 253 */ 254 int getUnitsPerEm() const; 255 256 /** 257 * Given a run of glyphs, return the associated horizontal adjustments. 258 * Adjustments are in "design units", which are integers relative to the 259 * typeface's units per em (see getUnitsPerEm). 260 * 261 * Some typefaces are known to never support kerning. Calling this method 262 * with all zeros (e.g. getKerningPairAdustments(NULL, 0, NULL)) returns 263 * a boolean indicating if the typeface might support kerning. If it 264 * returns false, then it will always return false (no kerning) for all 265 * possible glyph runs. If it returns true, then it *may* return true for 266 * somne glyph runs. 267 * 268 * If count is non-zero, then the glyphs parameter must point to at least 269 * [count] valid glyph IDs, and the adjustments parameter must be 270 * sized to at least [count - 1] entries. If the method returns true, then 271 * [count-1] entries in the adjustments array will be set. If the method 272 * returns false, then no kerning should be applied, and the adjustments 273 * array will be in an undefined state (possibly some values may have been 274 * written, but none of them should be interpreted as valid values). 275 */ 276 bool getKerningPairAdjustments(const SkGlyphID glyphs[], int count, 277 int32_t adjustments[]) const; 278 279 struct LocalizedString { 280 SkString fString; 281 SkString fLanguage; 282 }; 283 class LocalizedStrings { 284 public: 285 LocalizedStrings() = default; ~LocalizedStrings()286 virtual ~LocalizedStrings() { } 287 virtual bool next(LocalizedString* localizedString) = 0; unref()288 void unref() { delete this; } 289 290 private: 291 LocalizedStrings(const LocalizedStrings&) = delete; 292 LocalizedStrings& operator=(const LocalizedStrings&) = delete; 293 }; 294 /** 295 * Returns an iterator which will attempt to enumerate all of the 296 * family names specified by the font. 297 * It is the caller's responsibility to unref() the returned pointer. 298 */ 299 LocalizedStrings* createFamilyNameIterator() const; 300 301 /** 302 * Return the family name for this typeface. It will always be returned 303 * encoded as UTF8, but the language of the name is whatever the host 304 * platform chooses. 305 */ 306 void getFamilyName(SkString* name) const; 307 308 /** 309 * Return a stream for the contents of the font data, or NULL on failure. 310 * If ttcIndex is not null, it is set to the TrueTypeCollection index 311 * of this typeface within the stream, or 0 if the stream is not a 312 * collection. 313 * The caller is responsible for deleting the stream. 314 */ 315 std::unique_ptr<SkStreamAsset> openStream(int* ttcIndex) const; 316 317 /** 318 * Return the font data, or nullptr on failure. 319 */ 320 std::unique_ptr<SkFontData> makeFontData() const; 321 322 /** 323 * Return a scalercontext for the given descriptor. If this fails, then 324 * if allowFailure is true, this returns NULL, else it returns a 325 * dummy scalercontext that will not crash, but will draw nothing. 326 */ 327 std::unique_ptr<SkScalerContext> createScalerContext(const SkScalerContextEffects&, 328 const SkDescriptor*, 329 bool allowFailure = false) const; 330 331 /** 332 * Return a rectangle (scaled to 1-pt) that represents the union of the bounds of all 333 * of the glyphs, but each one positioned at (0,). This may be conservatively large, and 334 * will not take into account any hinting or other size-specific adjustments. 335 */ 336 SkRect getBounds() const; 337 338 // PRIVATE / EXPERIMENTAL -- do not call filterRec(SkScalerContextRec * rec)339 void filterRec(SkScalerContextRec* rec) const { 340 this->onFilterRec(rec); 341 } 342 // PRIVATE / EXPERIMENTAL -- do not call getFontDescriptor(SkFontDescriptor * desc,bool * isLocal)343 void getFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const { 344 this->onGetFontDescriptor(desc, isLocal); 345 } 346 // PRIVATE / EXPERIMENTAL -- do not call internal_private_getCTFontRef()347 void* internal_private_getCTFontRef() const { 348 return this->onGetCTFontRef(); 349 } 350 351 protected: 352 /** uniqueID must be unique and non-zero 353 */ 354 SkTypeface(const SkFontStyle& style, bool isFixedPitch = false); 355 virtual ~SkTypeface(); 356 357 virtual sk_sp<SkTypeface> onMakeClone(const SkFontArguments&) const = 0; 358 359 /** Sets the fixedPitch bit. If used, must be called in the constructor. */ setIsFixedPitch(bool isFixedPitch)360 void setIsFixedPitch(bool isFixedPitch) { fIsFixedPitch = isFixedPitch; } 361 /** Sets the font style. If used, must be called in the constructor. */ setFontStyle(SkFontStyle style)362 void setFontStyle(SkFontStyle style) { fStyle = style; } 363 364 virtual SkScalerContext* onCreateScalerContext(const SkScalerContextEffects&, 365 const SkDescriptor*) const = 0; 366 virtual void onFilterRec(SkScalerContextRec*) const = 0; 367 friend class SkScalerContext; // onFilterRec 368 369 // Subclasses *must* override this method to work with the PDF backend. 370 virtual std::unique_ptr<SkAdvancedTypefaceMetrics> onGetAdvancedMetrics() const = 0; 371 // For type1 postscript fonts only, set the glyph names for each glyph. 372 // destination array is non-null, and points to an array of size this->countGlyphs(). 373 // Backends that do not suport type1 fonts should not override. 374 virtual void getPostScriptGlyphNames(SkString*) const = 0; 375 376 // The mapping from glyph to Unicode; array indices are glyph ids. 377 // For each glyph, give the default Unicode value, if it exists. 378 // dstArray is non-null, and points to an array of size this->countGlyphs(). 379 virtual void getGlyphToUnicodeMap(SkUnichar* dstArray) const = 0; 380 381 virtual std::unique_ptr<SkStreamAsset> onOpenStream(int* ttcIndex) const = 0; 382 // TODO: make pure virtual. 383 virtual std::unique_ptr<SkFontData> onMakeFontData() const; 384 385 virtual int onGetVariationDesignPosition( 386 SkFontArguments::VariationPosition::Coordinate coordinates[], 387 int coordinateCount) const = 0; 388 389 virtual int onGetVariationDesignParameters( 390 SkFontParameters::Variation::Axis parameters[], int parameterCount) const = 0; 391 392 virtual void onGetFontDescriptor(SkFontDescriptor*, bool* isLocal) const = 0; 393 394 virtual void onCharsToGlyphs(const SkUnichar* chars, int count, SkGlyphID glyphs[]) const = 0; 395 virtual int onCountGlyphs() const = 0; 396 397 virtual int onGetUPEM() const = 0; 398 virtual bool onGetKerningPairAdjustments(const SkGlyphID glyphs[], int count, 399 int32_t adjustments[]) const; 400 401 /** Returns the family name of the typeface as known by its font manager. 402 * This name may or may not be produced by the family name iterator. 403 */ 404 virtual void onGetFamilyName(SkString* familyName) const = 0; 405 406 /** Returns an iterator over the family names in the font. */ 407 virtual LocalizedStrings* onCreateFamilyNameIterator() const = 0; 408 409 virtual int onGetTableTags(SkFontTableTag tags[]) const = 0; 410 virtual size_t onGetTableData(SkFontTableTag, size_t offset, 411 size_t length, void* data) const = 0; 412 virtual sk_sp<SkData> onCopyTableData(SkFontTableTag) const; 413 414 virtual bool onComputeBounds(SkRect*) const; 415 onGetCTFontRef()416 virtual void* onGetCTFontRef() const { return nullptr; } 417 418 private: 419 /** Retrieve detailed typeface metrics. Used by the PDF backend. */ 420 std::unique_ptr<SkAdvancedTypefaceMetrics> getAdvancedMetrics() const; 421 friend class SkRandomTypeface; // getAdvancedMetrics 422 friend class SkPDFFont; // getAdvancedMetrics 423 424 /** Style specifies the intrinsic style attributes of a given typeface */ 425 enum Style { 426 kNormal = 0, 427 kBold = 0x01, 428 kItalic = 0x02, 429 430 // helpers 431 kBoldItalic = 0x03 432 }; 433 static SkFontStyle FromOldStyle(Style oldStyle); 434 static SkTypeface* GetDefaultTypeface(Style style = SkTypeface::kNormal); 435 436 friend class SkFontPriv; // GetDefaultTypeface 437 friend class SkPaintPriv; // GetDefaultTypeface 438 friend class SkFont; // getGlyphToUnicodeMap 439 440 private: 441 SkFontID fUniqueID; 442 SkFontStyle fStyle; 443 mutable SkRect fBounds; 444 mutable SkOnce fBoundsOnce; 445 bool fIsFixedPitch; 446 447 typedef SkWeakRefCnt INHERITED; 448 }; 449 #endif 450