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 SkUtils_DEFINED
9#define SkUtils_DEFINED
10
11#include "SkTypes.h"
12#include "SkMath.h"
13#include "SkOpts.h"
14
15/** Similar to memset(), but it assigns a 16, 32, or 64-bit value into the buffer.
16    @param buffer   The memory to have value copied into it
17    @param value    The value to be copied into buffer
18    @param count    The number of times value should be copied into the buffer.
19*/
20static inline void sk_memset16(uint16_t buffer[], uint16_t value, int count) {
21    SkOpts::memset16(buffer, value, count);
22}
23static inline void sk_memset32(uint32_t buffer[], uint32_t value, int count) {
24    SkOpts::memset32(buffer, value, count);
25}
26static inline void sk_memset64(uint64_t buffer[], uint64_t value, int count) {
27    SkOpts::memset64(buffer, value, count);
28}
29///////////////////////////////////////////////////////////////////////////////
30
31#define kMaxBytesInUTF8Sequence     4
32
33#ifdef SK_DEBUG
34    int SkUTF8_LeadByteToCount(unsigned c);
35#else
36    #define SkUTF8_LeadByteToCount(c)   ((((0xE5 << 24) >> ((unsigned)c >> 4 << 1)) & 3) + 1)
37#endif
38
39inline int SkUTF8_CountUTF8Bytes(const char utf8[]) {
40    SkASSERT(utf8);
41    return SkUTF8_LeadByteToCount(*(const uint8_t*)utf8);
42}
43
44int         SkUTF8_CountUnichars(const char utf8[]);
45
46/** These functions are safe: invalid sequences will return -1; */
47int SkUTF8_CountUnichars(const void* utf8, size_t byteLength);
48int SkUTF16_CountUnichars(const void* utf16, size_t byteLength);
49int SkUTF32_CountUnichars(const void* utf32, size_t byteLength);
50
51/** This function is safe: invalid UTF8 sequences will return -1
52 *  When -1 is returned, ptr is unchanged.
53 *  Precondition: *ptr < end;
54 */
55SkUnichar SkUTF8_NextUnicharWithError(const char** ptr, const char* end);
56
57/** this version replaces invalid utf-8 sequences with code point U+FFFD. */
58inline SkUnichar SkUTF8_NextUnichar(const char** ptr, const char* end) {
59    SkUnichar val = SkUTF8_NextUnicharWithError(ptr, end);
60    if (val < 0) {
61        *ptr = end;
62        return 0xFFFD;  // REPLACEMENT CHARACTER
63    }
64    return val;
65}
66
67SkUnichar   SkUTF8_ToUnichar(const char utf8[]);
68SkUnichar   SkUTF8_NextUnichar(const char**);
69SkUnichar   SkUTF8_PrevUnichar(const char**);
70
71/** Return the number of bytes need to convert a unichar
72    into a utf8 sequence. Will be 1..kMaxBytesInUTF8Sequence,
73    or 0 if uni is illegal.
74*/
75size_t      SkUTF8_FromUnichar(SkUnichar uni, char utf8[] = nullptr);
76
77///////////////////////////////////////////////////////////////////////////////
78
79#define SkUTF16_IsHighSurrogate(c)  (((c) & 0xFC00) == 0xD800)
80#define SkUTF16_IsLowSurrogate(c)   (((c) & 0xFC00) == 0xDC00)
81
82int SkUTF16_CountUnichars(const uint16_t utf16[]);
83// returns the current unichar and then moves past it (*p++)
84SkUnichar SkUTF16_NextUnichar(const uint16_t**);
85// this guy backs up to the previus unichar value, and returns it (*--p)
86SkUnichar SkUTF16_PrevUnichar(const uint16_t**);
87size_t SkUTF16_FromUnichar(SkUnichar uni, uint16_t utf16[] = nullptr);
88
89size_t SkUTF16_ToUTF8(const uint16_t utf16[], int numberOf16BitValues,
90                      char utf8[] = nullptr);
91
92inline bool SkUnichar_IsVariationSelector(SkUnichar uni) {
93/*  The 'true' ranges are:
94 *      0x180B  <= uni <=  0x180D
95 *      0xFE00  <= uni <=  0xFE0F
96 *      0xE0100 <= uni <= 0xE01EF
97 */
98    if (uni < 0x180B || uni > 0xE01EF) {
99        return false;
100    }
101    if ((uni > 0x180D && uni < 0xFE00) || (uni > 0xFE0F && uni < 0xE0100)) {
102        return false;
103    }
104    return true;
105}
106
107namespace SkHexadecimalDigits {
108    extern const char gUpper[16];  // 0-9A-F
109    extern const char gLower[16];  // 0-9a-f
110}
111
112#endif
113