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 "include/core/SkTypes.h"
7#include <cstddef>
8#include <cstdint>
9
10typedef int32_t SkUnichar;
11
12namespace SkUTF {
13
14/** Given a sequence of UTF-8 bytes, return the number of unicode codepoints.
15 If the sequence is invalid UTF-8, return -1.
16*/
17SK_SPI int CountUTF8(const char* utf8, size_t byteLength);
18
19/** Given a sequence of aligned UTF-16 characters in machine-endian form,
20 return the number of unicode codepoints. If the sequence is invalid
21 UTF-16, return -1.
22*/
23SK_SPI int CountUTF16(const uint16_t* utf16, size_t byteLength);
24
25/** Given a sequence of aligned UTF-32 characters in machine-endian form,
26 return the number of unicode codepoints. If the sequence is invalid
27 UTF-32, return -1.
28*/
29SK_SPI int CountUTF32(const int32_t* utf32, size_t byteLength);
30
31/** Given a sequence of UTF-8 bytes, return the first unicode codepoint.
32 The pointer will be incremented to point at the next codepoint's start. If
33 invalid UTF-8 is encountered, set *ptr to end and return -1.
34*/
35SK_SPI SkUnichar NextUTF8(const char** ptr, const char* end);
36
37/** Given a sequence of aligned UTF-16 characters in machine-endian form,
38 return the first unicode codepoint. The pointer will be incremented to
39 point at the next codepoint's start. If invalid UTF-16 is encountered,
40 set *ptr to end and return -1.
41*/
42SK_SPI SkUnichar NextUTF16(const uint16_t** ptr, const uint16_t* end);
43
44/** Given a sequence of aligned UTF-32 characters in machine-endian form,
45 return the first unicode codepoint. The pointer will be incremented to
46 point at the next codepoint's start. If invalid UTF-32 is encountered,
47 set *ptr to end and return -1.
48*/
49SK_SPI SkUnichar NextUTF32(const int32_t** ptr, const int32_t* end);
50
51constexpr unsigned kMaxBytesInUTF8Sequence = 4;
52
53/** Convert the unicode codepoint into UTF-8. If `utf8` is non-null, place the
54 result in that array. Return the number of bytes in the result. If `utf8`
55 is null, simply return the number of bytes that would be used. For invalid
56 unicode codepoints, return 0.
57*/
58SK_SPI size_t ToUTF8(SkUnichar uni, char utf8[kMaxBytesInUTF8Sequence] = nullptr);
59
60/** Convert the unicode codepoint into UTF-16. If `utf16` is non-null, place
61 the result in that array. Return the number of UTF-16 code units in the
62 result (1 or 2). If `utf16` is null, simply return the number of code
63 units that would be used. For invalid unicode codepoints, return 0.
64*/
65SK_SPI size_t ToUTF16(SkUnichar uni, uint16_t utf16[2] = nullptr);
66
67/** Returns the number of resulting UTF16 values needed to convert the src utf8 sequence.
68 * If dst is not null, it is filled with the corresponding values up to its capacity.
69 * If there is an error, -1 is returned and the dst[] buffer is undefined.
70 */
71SK_SPI int UTF8ToUTF16(uint16_t dst[], int dstCapacity, const char src[], size_t srcByteLength);
72
73} // namespace SkUTF
74
75#endif // SkUTF_DEFINED
76