// Make bit vector of type information. On success, store the result in "bits" and return true.
// Encode error correction level and mask pattern. See 8.9 of
// JISX0510:2004 (p.45) for details.
public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int maskPattern, BitVector bits)
{
if (!QRCode.isValidMaskPattern(maskPattern))
{
throw new WriterException("Invalid mask pattern");
}
int typeInfo = (ecLevel.Bits << 3) | maskPattern;
bits.appendBits(typeInfo, 5);
int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY);
bits.appendBits(bchCode, 10);
BitVector maskBits = new BitVector();
maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15);
bits.xor(maskBits);
if (bits.size() != 15)
{
// Just in case.
throw new WriterException("should not happen but we got: " + bits.size());
}
}
// Return the mask bit for "getMaskPattern" at "x" and "y". See 8.8 of JISX0510:2004 for mask
// pattern conditions.
public static bool getDataMaskBit(int maskPattern, int x, int y)
{
if (!QRCode.isValidMaskPattern(maskPattern))
{
throw new System.ArgumentException("Invalid mask pattern");
}
int intermediate, temp;
switch (maskPattern)
{
case 0:
intermediate = (y + x) & 0x1;
break;
case 1:
intermediate = y & 0x1;
break;
case 2:
intermediate = x % 3;
break;
case 3:
intermediate = (y + x) % 3;
break;
case 4:
intermediate = ((SupportClass.URShift(y, 1)) + (x / 3)) & 0x1;
break;
case 5:
temp = y * x;
intermediate = (temp & 0x1) + (temp % 3);
break;
case 6:
temp = y * x;
intermediate = (((temp & 0x1) + (temp % 3)) & 0x1);
break;
case 7:
temp = y * x;
intermediate = (((temp % 3) + ((y + x) & 0x1)) & 0x1);
break;
default:
throw new System.ArgumentException("Invalid mask pattern: " + maskPattern);
}
return(intermediate == 0);
}