| Hal Canary | f107a2f | 2018-07-25 16:52:48 -0400 | [diff] [blame^] | 1 | // Copyright 2018 Google LLC. |
| 2 | // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file. |
| 3 | #ifndef SkUTF_DEFINED |
| 4 | #define SkUTF_DEFINED |
| 5 | |
| 6 | #include <cstddef> |
| 7 | #include <cstdint> |
| 8 | |
| 9 | typedef int32_t SkUnichar; |
| 10 | |
| 11 | namespace SkUTF { |
| 12 | |
| 13 | /** Given a sequence of UTF-8 bytes, return the number of unicode codepoints. |
| 14 | If the sequence is invalid UTF-8, return -1. |
| 15 | */ |
| 16 | int CountUTF8(const char* utf8, size_t byteLength); |
| 17 | |
| 18 | /** Given a sequence of aligned UTF-16 characters in machine-endian form, |
| 19 | return the number of unicode codepoints. If the sequence is invalid |
| 20 | UTF-16, return -1. |
| 21 | */ |
| 22 | int CountUTF16(const uint16_t* utf16, size_t byteLength); |
| 23 | |
| 24 | /** Given a sequence of aligned UTF-32 characters in machine-endian form, |
| 25 | return the number of unicode codepoints. If the sequence is invalid |
| 26 | UTF-32, return -1. |
| 27 | */ |
| 28 | int CountUTF32(const int32_t* utf32, size_t byteLength); |
| 29 | |
| 30 | /** Given a sequence of UTF-8 bytes, return the first unicode codepoint. |
| 31 | The pointer will be incremented to point at the next codepoint's start. If |
| 32 | invalid UTF-8 is encountered, set *ptr to end and return -1. |
| 33 | */ |
| 34 | SkUnichar NextUTF8(const char** ptr, const char* end); |
| 35 | |
| 36 | /** Given a sequence of aligned UTF-16 characters in machine-endian form, |
| 37 | return the first unicode codepoint. The pointer will be incremented to |
| 38 | point at the next codepoint's start. If invalid UTF-16 is encountered, |
| 39 | set *ptr to end and return -1. |
| 40 | */ |
| 41 | SkUnichar NextUTF16(const uint16_t** ptr, const uint16_t* end); |
| 42 | |
| 43 | /** Given a sequence of aligned UTF-32 characters in machine-endian form, |
| 44 | return the first unicode codepoint. The pointer will be incremented to |
| 45 | point at the next codepoint's start. If invalid UTF-32 is encountered, |
| 46 | set *ptr to end and return -1. |
| 47 | */ |
| 48 | SkUnichar NextUTF32(const int32_t** ptr, const int32_t* end); |
| 49 | |
| 50 | constexpr unsigned kMaxBytesInUTF8Sequence = 4; |
| 51 | |
| 52 | /** Convert the unicode codepoint into UTF-8. If `utf8` is non-null, place the |
| 53 | result in that array. Return the number of bytes in the result. If `utf8` |
| 54 | is null, simply return the number of bytes that would be used. For invalid |
| 55 | unicode codepoints, return 0. |
| 56 | */ |
| 57 | size_t ToUTF8(SkUnichar uni, char utf8[kMaxBytesInUTF8Sequence] = nullptr); |
| 58 | |
| 59 | /** Convert the unicode codepoint into UTF-16. If `utf16` is non-null, place |
| 60 | the result in that array. Return the number of UTF-16 code units in the |
| 61 | result (1 or 2). If `utf16` is null, simply return the number of code |
| 62 | units that would be used. For invalid unicode codepoints, return 0. |
| 63 | */ |
| 64 | size_t ToUTF16(SkUnichar uni, uint16_t utf16[2] = nullptr); |
| 65 | |
| 66 | } // namespace SkUTF |
| 67 | |
| 68 | #endif // SkUTF_DEFINED |