StringUtil: Add UTF-8 encode and decode

This commit is contained in:
Connor McLaughlin 2022-09-17 17:44:27 +10:00 committed by refractionpcsx2
parent 1f5d672cbf
commit 22ed71cef4
2 changed files with 92 additions and 1 deletions

View File

@ -370,6 +370,88 @@ namespace StringUtil
}
}
void EncodeAndAppendUTF8(std::string& s, char32_t ch)
{
if (ch <= 0x7F)
{
s.push_back(static_cast<char>(static_cast<u8>(ch)));
}
else if (ch <= 0x07FF)
{
s.push_back(static_cast<char>(static_cast<u8>(0xc0 | static_cast<u8>((ch >> 6) & 0x1f))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>((ch & 0x3f)))));
}
else if (ch <= 0xFFFF)
{
s.push_back(static_cast<char>(static_cast<u8>(0xe0 | static_cast<u8>(((ch >> 12) & 0x0f)))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>(((ch >> 6) & 0x3f)))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>((ch & 0x3f)))));
}
else if (ch <= 0x10FFFF)
{
s.push_back(static_cast<char>(static_cast<u8>(0xf0 | static_cast<u8>(((ch >> 18) & 0x07)))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>(((ch >> 12) & 0x3f)))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>(((ch >> 6) & 0x3f)))));
s.push_back(static_cast<char>(static_cast<u8>(0x80 | static_cast<u8>((ch & 0x3f)))));
}
else
{
s.push_back(static_cast<char>(0xefu));
s.push_back(static_cast<char>(0xbfu));
s.push_back(static_cast<char>(0xbdu));
}
}
size_t DecodeUTF8(const void* bytes, size_t length, char32_t* ch)
{
const u8* s = reinterpret_cast<const u8*>(bytes);
if (s[0] < 0x80)
{
*ch = s[0];
return 1;
}
else if ((s[0] & 0xe0) == 0xc0)
{
if (length < 2)
goto invalid;
*ch = static_cast<char32_t>((static_cast<u32>(s[0] & 0x1f) << 6) | (static_cast<u32>(s[1] & 0x3f) << 0));
return 2;
}
else if ((s[0] & 0xf0) == 0xe0)
{
if (length < 3)
goto invalid;
*ch = static_cast<char32_t>((static_cast<u32>(s[0] & 0x0f) << 12) | (static_cast<u32>(s[1] & 0x3f) << 6) |
(static_cast<u32>(s[2] & 0x3f) << 0));
return 3;
}
else if ((s[0] & 0xf8) == 0xf0 && (s[0] <= 0xf4))
{
if (length < 4)
goto invalid;
*ch = static_cast<char32_t>((static_cast<u32>(s[0] & 0x07) << 18) | (static_cast<u32>(s[1] & 0x3f) << 12) |
(static_cast<u32>(s[2] & 0x3f) << 6) | (static_cast<u32>(s[3] & 0x3f) << 0));
return 4;
}
invalid:
*ch = 0xFFFFFFFFu;
return 1;
}
size_t DecodeUTF8(const std::string_view& str, size_t offset, char32_t* ch)
{
return DecodeUTF8(str.data() + offset, str.length() - offset, ch);
}
size_t DecodeUTF8(const std::string& str, size_t offset, char32_t* ch)
{
return DecodeUTF8(str.data() + offset, str.length() - offset, ch);
}
#ifdef _WIN32
std::wstring UTF8StringToWideString(const std::string_view& str)
{

View File

@ -169,7 +169,7 @@ namespace StringUtil
std::vector<std::string_view> SplitString(const std::string_view& str, char delimiter, bool skip_empty = true);
/// Joins a string together using the specified delimiter.
template<typename T>
template <typename T>
static inline std::string JoinString(const T& start, const T& end, char delimiter)
{
std::string ret;
@ -204,6 +204,15 @@ namespace StringUtil
/// Appends a UTF-16/UTF-32 codepoint to a UTF-8 string.
void AppendUTF16CharacterToUTF8(std::string& s, u16 ch);
/// Appends a UTF-16/UTF-32 codepoint to a UTF-8 string.
void EncodeAndAppendUTF8(std::string& s, char32_t ch);
/// Decodes UTF-8 to a single codepoint, updating the position parameter.
/// Returns the number of bytes the codepoint took in the original string.
size_t DecodeUTF8(const void* bytes, size_t length, char32_t* ch);
size_t DecodeUTF8(const std::string_view& str, size_t offset, char32_t* ch);
size_t DecodeUTF8(const std::string& str, size_t offset, char32_t* ch);
/// Strided memcpy/memcmp.
static inline void StrideMemCpy(void* dst, std::size_t dst_stride, const void* src, std::size_t src_stride,
std::size_t copy_size, std::size_t count)