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o3de/Gems/LyShine/Code/Source/StringUtfUtils.h

63 lines
2.0 KiB
C++

/*
* Copyright (c) Contributors to the Open 3D Engine Project.
* For complete copyright and license terms please see the LICENSE at the root of this distribution.
*
* SPDX-License-Identifier: Apache-2.0 OR MIT
*
*/
#pragma once
namespace LyShine
{
//! \brief Returns the number of UTF8 characters in a string.
//!
//! AZStd::string::length() counts individual bytes in the string buffer
//! whereas this function will consider multi-byte chars as one element/
//! character in the string.
inline int GetUtf8StringLength(const AZStd::string& utf8String)
{
int utf8StrLen = 0;
Unicode::CIterator<const char*, false> pChar(utf8String.c_str());
while (uint32_t ch = *pChar)
{
++pChar;
++utf8StrLen;
}
return utf8StrLen;
}
//! \brief Returns the number of bytes of the size of the given multi-byte char.
inline int GetMultiByteCharSize(const uint32_t multiByteChar)
{
// determine the number of bytes that this Unicode code point uses in utf-8 format
// NOTE: this assumes the uint32_t can be interpreted as a wchar_t, it seems to
// work for cases tested but may not in general.
// In the long run it would be better to eliminate
// this function and use Unicode::CIterator<>::Position instead.
wchar_t wcharString[2] = { static_cast<wchar_t>(multiByteChar), 0 };
AZStd::string utf8String;
AZStd::to_string(utf8String, AZStd::wstring(wcharString));
int utf8Length = utf8String.length();
return utf8Length;
}
inline int GetByteLengthOfUtf8Chars(const char* utf8String, int numUtf8Chars)
{
int byteStrlen = 0;
Unicode::CIterator<const char*, false> pChar(utf8String);
for (int i = 0; i < numUtf8Chars; i++)
{
uint32_t ch = *pChar;
if (!ch)
{
break;
}
byteStrlen += GetMultiByteCharSize(ch);
pChar++;
}
return byteStrlen;
}
}