1 // UTFConvert.cpp

     2 

     3 #include "StdAfx.h"

     4 

     5 #include "UTFConvert.h"

     6 #include "Types.h"

     7 

     8 static Byte kUtf8Limits[5] = { 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };

     9 

    10 // These functions are for UTF8 <-> UTF16 conversion.

    11 

    12 bool ConvertUTF8ToUnicode(const AString &src, UString &dest)

    13 {

    14   dest.Empty();

    15   for(int i = 0; i < src.Length();)

    16   {

    17     Byte c = (Byte)src[i++];

    18     if (c < 0x80)

    19     {

    20       dest += (wchar_t)c;

    21       continue;

    22     }

    23     if(c < 0xC0)

    24       return false;

    25     int numAdds;

    26     for (numAdds = 1; numAdds < 5; numAdds++)

    27       if (c < kUtf8Limits[numAdds])

    28         break;

    29     UInt32 value = (c - kUtf8Limits[numAdds - 1]);

    30     do

    31     {

    32       if (i >= src.Length())

    33         return false;

    34       Byte c2 = (Byte)src[i++];

    35       if (c2 < 0x80 || c2 >= 0xC0)

    36         return false;

    37       value <<= 6;

    38       value |= (c2 - 0x80);

    39       numAdds--;

    40     }

    41     while(numAdds > 0);

    42     if (value < 0x10000)

    43       dest += (wchar_t)(value);

    44     else

    45     {

    46       value -= 0x10000;

    47       if (value >= 0x100000)

    48         return false;

    49       dest += (wchar_t)(0xD800 + (value >> 10));

    50       dest += (wchar_t)(0xDC00 + (value & 0x3FF));

    51     }

    52   }

    53   return true; 

    54 }

    55 

    56 bool ConvertUnicodeToUTF8(const UString &src, AString &dest)

    57 {

    58   dest.Empty();

    59   for(int i = 0; i < src.Length();)

    60   {

    61     UInt32 value = (UInt32)src[i++];

    62     if (value < 0x80)

    63     {

    64       dest += (char)value;

    65       continue;

    66     }

    67     if (value >= 0xD800 && value < 0xE000)

    68     {

    69       if (value >= 0xDC00)

    70         return false;

    71       if (i >= src.Length())

    72         return false;

    73       UInt32 c2 = (UInt32)src[i++];

    74       if (c2 < 0xDC00 || c2 >= 0xE000)

    75         return false;

    76       value = ((value - 0xD800) << 10) | (c2 - 0xDC00);

    77     }

    78     int numAdds;

    79     for (numAdds = 1; numAdds < 5; numAdds++)

    80       if (value < (((UInt32)1) << (numAdds * 5 + 6)))

    81         break;

    82     dest += (char)(kUtf8Limits[numAdds - 1] + (value >> (6 * numAdds)));

    83     do

    84     {

    85       numAdds--;

    86       dest += (char)(0x80 + ((value >> (6 * numAdds)) & 0x3F));

    87     }

    88     while(numAdds > 0);

    89   }

    90   return true;

    91 }