void PushOutputC40TextWord(ref C40TextState state, int value)
{
if (!(value >= 0 && value < 256))
{
throw new ArgumentException("Invalid value: Exceeds range for conversion to byte");
}
this._output[this._outputIdx] = (byte)value;
if (state.UpperShift == true)
{
if (!(value >= 0 && value < 256))
{
throw new ArgumentException("Invalid value: Exceeds range for conversion to upper case character");
}
this._output[this._outputIdx] += 128;
}
this._outputIdx++;
state.Shift = DmtxConstants.DmtxC40TextBasicSet;
state.UpperShift = false;
}
int DecodeSchemeC40Text(int startIndex, int endIndex, DmtxScheme encScheme)
{
int i;
int packed;
int[] c40Values = new int[3];
C40TextState state = new C40TextState();
state.Shift = DmtxConstants.DmtxC40TextBasicSet;
state.UpperShift = false;
if (!(encScheme == DmtxScheme.DmtxSchemeC40 || encScheme == DmtxScheme.DmtxSchemeText))
{
throw new ArgumentException("Invalid scheme selected for decodind!");
}
while (startIndex < endIndex)
{
/* FIXME Also check that ptr+1 is safe to access */
packed = (((int)this._code[startIndex]) << 8) | (int)this._code[startIndex + 1];
c40Values[0] = ((packed - 1) / 1600);
c40Values[1] = ((packed - 1) / 40) % 40;
c40Values[2] = (packed - 1) % 40;
startIndex += 2;
for (i = 0; i < 3; i++)
{
if (state.Shift == DmtxConstants.DmtxC40TextBasicSet)
{ /* Basic set */
if (c40Values[i] <= 2)
{
state.Shift = c40Values[i] + 1;
}
else if (c40Values[i] == 3)
{
PushOutputC40TextWord(ref state, ' ');
}
else if (c40Values[i] <= 13)
{
PushOutputC40TextWord(ref state, c40Values[i] - 13 + '9'); /* 0-9 */
}
else if (c40Values[i] <= 39)
{
if (encScheme == DmtxScheme.DmtxSchemeC40)
{
PushOutputC40TextWord(ref state, c40Values[i] - 39 + 'Z'); /* A-Z */
}
else if (encScheme == DmtxScheme.DmtxSchemeText)
{
PushOutputC40TextWord(ref state, c40Values[i] - 39 + 'z'); /* a-z */
}
}
}
else if (state.Shift == DmtxConstants.DmtxC40TextShift1)
{ /* Shift 1 set */
PushOutputC40TextWord(ref state, c40Values[i]); /* ASCII 0 - 31 */
}
else if (state.Shift == DmtxConstants.DmtxC40TextShift2)
{ /* Shift 2 set */
if (c40Values[i] <= 14)
{
PushOutputC40TextWord(ref state, c40Values[i] + 33); /* ASCII 33 - 47 */
}
else if (c40Values[i] <= 21)
{
PushOutputC40TextWord(ref state, c40Values[i] + 43); /* ASCII 58 - 64 */
}
else if (c40Values[i] <= 26)
{
PushOutputC40TextWord(ref state, c40Values[i] + 69); /* ASCII 91 - 95 */
}
else if (c40Values[i] == 27)
{
PushOutputC40TextWord(ref state, 0x1d); /* FNC1 -- XXX depends on position? */
}
else if (c40Values[i] == 30)
{
state.UpperShift = true;
state.Shift = DmtxConstants.DmtxC40TextBasicSet;
}
}
else if (state.Shift == DmtxConstants.DmtxC40TextShift3)
{ /* Shift 3 set */
if (encScheme == DmtxScheme.DmtxSchemeC40)
{
PushOutputC40TextWord(ref state, c40Values[i] + 96);
}
else if (encScheme == DmtxScheme.DmtxSchemeText)
{
if (c40Values[i] == 0)
{
PushOutputC40TextWord(ref state, c40Values[i] + 96);
}
else if (c40Values[i] <= 26)
{
PushOutputC40TextWord(ref state, c40Values[i] - 26 + 'Z'); /* A-Z */
}
else
{
PushOutputC40TextWord(ref state, c40Values[i] - 31 + 127); /* { | } ~ DEL */
}
}
}
}
/* Unlatch if codeword 254 follows 2 codewords in C40/Text encodation */
if (_code[startIndex] == DmtxConstants.DmtxCharTripletUnlatch)
{
return(startIndex + 1);
}
/* Unlatch is implied if only one codeword remains */
if (endIndex - startIndex == 1)
{
return(startIndex);
}
}
return(startIndex);
}