// Embed position adjustment patterns if need be.
private static void maybeEmbedPositionAdjustmentPatterns(int version, ByteMatrix matrix)
{
if (version < 2) { // The patterns appear if version >= 2
return;
}
int index = version - 1;
int[] coordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index];
int numCoordinates = POSITION_ADJUSTMENT_PATTERN_COORDINATE_TABLE[index].Length;
for (int i = 0; i < numCoordinates; ++i) {
for (int j = 0; j < numCoordinates; ++j) {
int y = coordinates[i];
int x = coordinates[j];
if (x == -1 || y == -1) {
continue;
}
// If the cell is unset, we embed the position adjustment pattern here.
if (isEmpty(matrix.get(y, x))) {
// -2 is necessary since the x/y coordinates point to the center of the pattern, not the
// left top corner.
embedPositionAdjustmentPattern(x - 2, y - 2, matrix);
}
}
}
}
private static void embedTimingPatterns(ByteMatrix matrix)
{
// -8 is for skipping position detection patterns (size 7), and two horizontal/vertical
// separation patterns (size 1). Thus, 8 = 7 + 1.
for (int i = 8; i < matrix.width() - 8; ++i) {
int bit = (i + 1) % 2;
// Horizontal line.
if (!isValidValue(matrix.get(6, i))) {
throw new WriterException();
}
if (isEmpty(matrix.get(6, i))) {
matrix.set(6, i, bit);
}
// Vertical line.
if (!isValidValue(matrix.get(i, 6))) {
throw new WriterException();
}
if (isEmpty(matrix.get(i, 6))) {
matrix.set(i, 6, bit);
}
}
}
private static void embedVerticalSeparationPattern(int xStart, int yStart,ByteMatrix matrix)
{
// We know the width and height.
if (VERTICAL_SEPARATION_PATTERN[0].Length != 1 || VERTICAL_SEPARATION_PATTERN.Length != 7) {
throw new WriterException("Bad vertical separation pattern");
}
for (int y = 0; y < 7; ++y) {
if (!isEmpty(matrix.get(yStart + y, xStart))) {
throw new WriterException();
}
matrix.set(yStart + y, xStart, VERTICAL_SEPARATION_PATTERN[y][0]);
}
}
private static void embedPositionDetectionPattern(int xStart, int yStart,ByteMatrix matrix)
{
// We know the width and height.
if (POSITION_DETECTION_PATTERN[0].Length != 7 || POSITION_DETECTION_PATTERN.Length != 7) {
throw new WriterException("Bad position detection pattern");
}
for (int y = 0; y < 7; ++y) {
for (int x = 0; x < 7; ++x) {
if (!isEmpty(matrix.get(yStart + y, xStart + x))) {
throw new WriterException();
}
matrix.set(yStart + y, xStart + x, POSITION_DETECTION_PATTERN[y][x]);
}
}
}
// Note that we cannot unify the function with embedPositionDetectionPattern() despite they are
// almost identical, since we cannot write a function that takes 2D arrays in different sizes in
// C/C++. We should live with the fact.
private static void embedPositionAdjustmentPattern(int xStart, int yStart,ByteMatrix matrix)
{
// We know the width and height.
if (POSITION_ADJUSTMENT_PATTERN[0].Length != 5 || POSITION_ADJUSTMENT_PATTERN.Length != 5) {
throw new WriterException("Bad position adjustment");
}
for (int y = 0; y < 5; ++y) {
for (int x = 0; x < 5; ++x) {
if (!isEmpty(matrix.get(yStart + y, xStart + x))) {
throw new WriterException();
}
matrix.set(yStart + y, xStart + x, POSITION_ADJUSTMENT_PATTERN[y][x]);
}
}
}
private static void embedHorizontalSeparationPattern(int xStart, int yStart,ByteMatrix matrix)
{
// We know the width and height.
if (HORIZONTAL_SEPARATION_PATTERN[0].Length != 8 || HORIZONTAL_SEPARATION_PATTERN.Length != 1) {
throw new WriterException("Bad horizontal separation pattern");
}
for (int x = 0; x < 8; ++x) {
if (!isEmpty(matrix.get(yStart, xStart + x))) {
throw new WriterException();
}
matrix.set(yStart, xStart + x, HORIZONTAL_SEPARATION_PATTERN[0][x]);
}
}
// Embed the lonely dark dot at left bottom corner. JISX0510:2004 (p.46)
private static void embedDarkDotAtLeftBottomCorner(ByteMatrix matrix)
{
if (matrix.get(matrix.height() - 8, 8) == 0) {
throw new WriterException();
}
matrix.set(matrix.height() - 8, 8, 1);
}
// 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(BitVector dataBits, int maskPattern, ByteMatrix matrix)
{
int bitIndex = 0;
int direction = -1;
// Start from the right bottom cell.
int x = matrix.width() - 1;
int y = matrix.height() - 1;
while (x > 0) {
// Skip the vertical timing pattern.
if (x == 6) {
x -= 1;
}
while (y >= 0 && y < matrix.height()) {
for (int i = 0; i < 2; ++i) {
int xx = x - i;
// Skip the cell if it's not empty.
if (!isEmpty(matrix.get(y, xx))) {
continue;
}
int bit;
if (bitIndex < dataBits.size()) {
bit = dataBits.at(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 = 0;
}
// Skip masking if mask_pattern is -1.
if (maskPattern != -1) {
int mask = MaskUtil.getDataMaskBit(maskPattern, xx, y);
bit ^= mask;
}
matrix.set(y, xx, bit);
}
y += direction;
}
direction = -direction; // Reverse the direction.
y += direction;
x -= 2; // Move to the left.
}
// All bits should be consumed.
if (bitIndex != dataBits.size()) {
throw new WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.size());
}
}