// Embed type information. On success, modify the matrix.
public static void embedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix)
throws WriterException {
BitArray typeInfoBits = new BitArray();
makeTypeInfoBits(ecLevel, maskPattern, typeInfoBits);
for (int i = 0; i < typeInfoBits.getSize(); ++i) {
// Place bits in LSB to MSB order. LSB (least significant bit) is the last value in
// "typeInfoBits".
boolean bit = typeInfoBits.get(typeInfoBits.getSize() - 1 - i);
// Type info bits at the left top corner. See 8.9 of JISX0510:2004 (p.46).
int x1 = TYPE_INFO_COORDINATES[i][0];
int y1 = TYPE_INFO_COORDINATES[i][1];
matrix.set(x1, y1, bit);
if (i < 8) {
// Right top corner.
int x2 = matrix.getWidth() - i - 1;
int y2 = 8;
matrix.set(x2, y2, bit);
} else {
// Left bottom corner.
int x2 = 8;
int y2 = matrix.getHeight() - 7 + (i - 8);
matrix.set(x2, y2, bit);
}
}
}
// Make bit vector of version information. On success, store the result in "bits" and return true.
// See 8.10 of JISX0510:2004 (p.45) for details.
public static void makeVersionInfoBits(int version, BitArray bits) throws WriterException {
bits.appendBits(version, 6);
int bchCode = calculateBCHCode(version, VERSION_INFO_POLY);
bits.appendBits(bchCode, 12);
if (bits.getSize() != 18) { // Just in case.
throw new WriterException("should not happen but we got: " + bits.getSize());
}
}
// Embed "dataBits" using "getMaskPattern". On success, modify the matrix and return true.
// For debugging purposes, it skips masking process if "getMaskPattern" is -1.
// See 8.7 of JISX0510:2004 (p.38) for how to embed data bits.
public static void embedDataBits(BitArray dataBits, int maskPattern, ByteMatrix matrix)
throws WriterException {
int bitIndex = 0;
int direction = -1;
// Start from the right bottom cell.
int x = matrix.getWidth() - 1;
int y = matrix.getHeight() - 1;
while (x > 0) {
// Skip the vertical timing pattern.
if (x == 6) {
x -= 1;
}
while (y >= 0 && y < matrix.getHeight()) {
for (int i = 0; i < 2; ++i) {
int xx = x - i;
// Skip the cell if it's not empty.
if (!isEmpty(matrix.get(xx, y))) {
continue;
}
boolean bit;
if (bitIndex < dataBits.getSize()) {
bit = dataBits.get(bitIndex);
++bitIndex;
} else {
// Padding bit. If there is no bit left, we'll fill the left cells with 0, as described
// in 8.4.9 of JISX0510:2004 (p. 24).
bit = false;
}
// Skip masking if mask_pattern is -1.
if (maskPattern != -1) {
if (MaskUtil.getDataMaskBit(maskPattern, xx, y)) {
bit = !bit;
}
}
matrix.set(xx, y, bit);
}
y += direction;
}
direction = -direction; // Reverse the direction.
y += direction;
x -= 2; // Move to the left.
}
// All bits should be consumed.
if (bitIndex != dataBits.getSize()) {
throw new WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.getSize());
}
}
// Embed version information if need be. On success, modify the matrix and return true.
// See 8.10 of JISX0510:2004 (p.47) for how to embed version information.
public static void maybeEmbedVersionInfo(int version, ByteMatrix matrix) throws WriterException {
if (version < 7) { // Version info is necessary if version >= 7.
return; // Don't need version info.
}
BitArray versionInfoBits = new BitArray();
makeVersionInfoBits(version, versionInfoBits);
int bitIndex = 6 * 3 - 1; // It will decrease from 17 to 0.
for (int i = 0; i < 6; ++i) {
for (int j = 0; j < 3; ++j) {
// Place bits in LSB (least significant bit) to MSB order.
boolean bit = versionInfoBits.get(bitIndex);
bitIndex--;
// Left bottom corner.
matrix.set(i, matrix.getHeight() - 11 + j, bit);
// Right bottom corner.
matrix.set(matrix.getHeight() - 11 + j, i, bit);
}
}
}
// 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, BitArray bits)
throws WriterException {
if (!QRCode.isValidMaskPattern(maskPattern)) {
throw new WriterException("Invalid mask pattern");
}
int typeInfo = (ecLevel.getBits() << 3) | maskPattern;
bits.appendBits(typeInfo, 5);
int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY);
bits.appendBits(bchCode, 10);
BitArray maskBits = new BitArray();
maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15);
bits.xor(maskBits);
if (bits.getSize() != 15) { // Just in case.
throw new WriterException("should not happen but we got: " + bits.getSize());
}
}