| // Copyright 2018 Google LLC. |
| // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. |
| #ifndef SkUTF_DEFINED |
| #define SkUTF_DEFINED |
| |
| #include "include/private/base/SkAPI.h" |
| |
| #include <cstddef> |
| #include <cstdint> |
| |
| typedef int32_t SkUnichar; |
| |
| namespace SkUTF { |
| |
| /** Given a sequence of UTF-8 bytes, return the number of unicode codepoints. |
| If the sequence is invalid UTF-8, return -1. |
| */ |
| SK_SPI int CountUTF8(const char* utf8, size_t byteLength); |
| |
| /** Given a sequence of aligned UTF-16 characters in machine-endian form, |
| return the number of unicode codepoints. If the sequence is invalid |
| UTF-16, return -1. |
| */ |
| SK_SPI int CountUTF16(const uint16_t* utf16, size_t byteLength); |
| |
| /** Given a sequence of aligned UTF-32 characters in machine-endian form, |
| return the number of unicode codepoints. If the sequence is invalid |
| UTF-32, return -1. |
| */ |
| SK_SPI int CountUTF32(const int32_t* utf32, size_t byteLength); |
| |
| /** Given a sequence of UTF-8 bytes, return the first unicode codepoint. |
| The pointer will be incremented to point at the next codepoint's start. If |
| invalid UTF-8 is encountered, set *ptr to end and return -1. |
| */ |
| SK_SPI SkUnichar NextUTF8(const char** ptr, const char* end); |
| |
| /** Given a sequence of aligned UTF-16 characters in machine-endian form, |
| return the first unicode codepoint. The pointer will be incremented to |
| point at the next codepoint's start. If invalid UTF-16 is encountered, |
| set *ptr to end and return -1. |
| */ |
| SK_SPI SkUnichar NextUTF16(const uint16_t** ptr, const uint16_t* end); |
| |
| /** Given a sequence of aligned UTF-32 characters in machine-endian form, |
| return the first unicode codepoint. The pointer will be incremented to |
| point at the next codepoint's start. If invalid UTF-32 is encountered, |
| set *ptr to end and return -1. |
| */ |
| SK_SPI SkUnichar NextUTF32(const int32_t** ptr, const int32_t* end); |
| |
| constexpr unsigned kMaxBytesInUTF8Sequence = 4; |
| |
| /** Convert the unicode codepoint into UTF-8. If `utf8` is non-null, place the |
| result in that array. Return the number of bytes in the result. If `utf8` |
| is null, simply return the number of bytes that would be used. For invalid |
| unicode codepoints, return 0. |
| */ |
| SK_SPI size_t ToUTF8(SkUnichar uni, char utf8[kMaxBytesInUTF8Sequence] = nullptr); |
| |
| /** Convert the unicode codepoint into UTF-16. If `utf16` is non-null, place |
| the result in that array. Return the number of UTF-16 code units in the |
| result (1 or 2). If `utf16` is null, simply return the number of code |
| units that would be used. For invalid unicode codepoints, return 0. |
| */ |
| SK_SPI size_t ToUTF16(SkUnichar uni, uint16_t utf16[2] = nullptr); |
| |
| /** Returns the number of resulting UTF16 values needed to convert the src utf8 sequence. |
| * If dst is not null, it is filled with the corresponding values up to its capacity. |
| * If there is an error, -1 is returned and the dst[] buffer is undefined. |
| */ |
| SK_SPI int UTF8ToUTF16(uint16_t dst[], int dstCapacity, const char src[], size_t srcByteLength); |
| |
| /** Returns the number of resulting UTF8 values needed to convert the src utf16 sequence. |
| * If dst is not null, it is filled with the corresponding values up to its capacity. |
| * If there is an error, -1 is returned and the dst[] buffer is undefined. |
| */ |
| SK_SPI int UTF16ToUTF8(char dst[], int dstCapacity, const uint16_t src[], size_t srcLength); |
| |
| /** |
| * Given a UTF-16 code point, returns true iff it is a leading surrogate. |
| * https://unicode.org/faq/utf_bom.html#utf16-2 |
| */ |
| static inline bool IsLeadingSurrogateUTF16(uint16_t c) { return ((c) & 0xFC00) == 0xD800; } |
| |
| /** |
| * Given a UTF-16 code point, returns true iff it is a trailing surrogate. |
| * https://unicode.org/faq/utf_bom.html#utf16-2 |
| */ |
| static inline bool IsTrailingSurrogateUTF16(uint16_t c) { return ((c) & 0xFC00) == 0xDC00; } |
| |
| |
| } // namespace SkUTF |
| |
| #endif // SkUTF_DEFINED |