notepad-plus-plus/scintilla/src/UniConversion.cxx

132 lines
3.7 KiB
C++

// Scintilla source code edit control
/** @file UniConversion.cxx
** Functions to handle UTF-8 and UTF-16 strings.
**/
// Copyright 1998-2001 by Neil Hodgson <neilh@scintilla.org>
// The License.txt file describes the conditions under which this software may be distributed.
#include <stdlib.h>
#include "UniConversion.h"
enum { SURROGATE_LEAD_FIRST = 0xD800 };
enum { SURROGATE_TRAIL_FIRST = 0xDC00 };
enum { SURROGATE_TRAIL_LAST = 0xDFFF };
unsigned int UTF8Length(const wchar_t *uptr, unsigned int tlen) {
unsigned int len = 0;
for (unsigned int i = 0; i < tlen && uptr[i];) {
unsigned int uch = uptr[i];
if (uch < 0x80) {
len++;
} else if (uch < 0x800) {
len += 2;
} else if ((uch >= SURROGATE_LEAD_FIRST) &&
(uch <= SURROGATE_TRAIL_LAST)) {
len += 4;
i++;
} else {
len += 3;
}
i++;
}
return len;
}
void UTF8FromUTF16(const wchar_t *uptr, unsigned int tlen, char *putf, unsigned int len) {
int k = 0;
for (unsigned int i = 0; i < tlen && uptr[i];) {
unsigned int uch = uptr[i];
if (uch < 0x80) {
putf[k++] = static_cast<char>(uch);
} else if (uch < 0x800) {
putf[k++] = static_cast<char>(0xC0 | (uch >> 6));
putf[k++] = static_cast<char>(0x80 | (uch & 0x3f));
} else if ((uch >= SURROGATE_LEAD_FIRST) &&
(uch <= SURROGATE_TRAIL_LAST)) {
// Half a surrogate pair
i++;
unsigned int xch = 0x10000 + ((uch & 0x3ff) << 10) + (uptr[i] & 0x3ff);
putf[k++] = static_cast<char>(0xF0 | (xch >> 18));
putf[k++] = static_cast<char>(0x80 | ((xch >> 12) & 0x3f));
putf[k++] = static_cast<char>(0x80 | ((xch >> 6) & 0x3f));
putf[k++] = static_cast<char>(0x80 | (xch & 0x3f));
} else {
putf[k++] = static_cast<char>(0xE0 | (uch >> 12));
putf[k++] = static_cast<char>(0x80 | ((uch >> 6) & 0x3f));
putf[k++] = static_cast<char>(0x80 | (uch & 0x3f));
}
i++;
}
putf[len] = '\0';
}
unsigned int UTF8CharLength(unsigned char ch) {
if (ch < 0x80) {
return 1;
} else if (ch < 0x80 + 0x40 + 0x20) {
return 2;
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
return 3;
} else {
return 4;
}
}
unsigned int UTF16Length(const char *s, unsigned int len) {
unsigned int ulen = 0;
unsigned int charLen;
for (unsigned int i=0; i<len;) {
unsigned char ch = static_cast<unsigned char>(s[i]);
if (ch < 0x80) {
charLen = 1;
} else if (ch < 0x80 + 0x40 + 0x20) {
charLen = 2;
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
charLen = 3;
} else {
charLen = 4;
ulen++;
}
i += charLen;
ulen++;
}
return ulen;
}
unsigned int UTF16FromUTF8(const char *s, unsigned int len, wchar_t *tbuf, unsigned int tlen) {
unsigned int ui=0;
const unsigned char *us = reinterpret_cast<const unsigned char *>(s);
unsigned int i=0;
while ((i<len) && (ui<tlen)) {
unsigned char ch = us[i++];
if (ch < 0x80) {
tbuf[ui] = ch;
} else if (ch < 0x80 + 0x40 + 0x20) {
tbuf[ui] = static_cast<wchar_t>((ch & 0x1F) << 6);
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + (ch & 0x7F));
} else if (ch < 0x80 + 0x40 + 0x20 + 0x10) {
tbuf[ui] = static_cast<wchar_t>((ch & 0xF) << 12);
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + ((ch & 0x7F) << 6));
ch = us[i++];
tbuf[ui] = static_cast<wchar_t>(tbuf[ui] + (ch & 0x7F));
} else {
// Outside the BMP so need two surrogates
int val = (ch & 0x7) << 18;
ch = us[i++];
val += (ch & 0x3F) << 12;
ch = us[i++];
val += (ch & 0x3F) << 6;
ch = us[i++];
val += (ch & 0x3F);
tbuf[ui] = static_cast<wchar_t>(((val - 0x10000) >> 10) + SURROGATE_LEAD_FIRST);
ui++;
tbuf[ui] = static_cast<wchar_t>((val & 0x3ff) + SURROGATE_TRAIL_FIRST);
}
ui++;
}
return ui;
}