/**
* Attempts to locate a corner of the barcode by scanning up, down, left or right from a center
* point which should be within the barcode.
*
* @param centerX center's x component (horizontal)
* @param deltaX same as deltaY but change in x per step instead
* @param left minimum value of x
* @param right maximum value of x
* @param centerY center's y component (vertical)
* @param deltaY change in y per step. If scanning up this is negative; down, positive; left or
* right, 0
* @param top minimum value of y to search through (meaningless when di == 0)
* @param bottom maximum value of y
* @param maxWhiteRun maximum run of white pixels that can still be considered to be within the
* barcode
* @return a {@link com.managed.zxing.ResultPoint} encapsulating the corner that was found
* @throws NotFoundException if such a point cannot be found
*/
private ResultPoint findCornerFromCenter(
int centerX,
int deltaX,
int left,
int right,
int centerY,
int deltaY,
int top,
int bottom,
int maxWhiteRun)
throws NotFoundException {
int[] lastRange = null;
for (int y = centerY, x = centerX;
y < bottom && y >= top && x < right && x >= left;
y += deltaY, x += deltaX) {
int[] range;
if (deltaX == 0) {
// horizontal slices, up and down
range = blackWhiteRange(y, maxWhiteRun, left, right, true);
} else {
// vertical slices, left and right
range = blackWhiteRange(x, maxWhiteRun, top, bottom, false);
}
if (range == null) {
if (lastRange == null) {
throw NotFoundException.getNotFoundInstance();
}
// lastRange was found
if (deltaX == 0) {
int lastY = y - deltaY;
if (lastRange[0] < centerX) {
if (lastRange[1] > centerX) {
// straddle, choose one or the other based on direction
return new ResultPoint(deltaY > 0 ? lastRange[0] : lastRange[1], lastY);
}
return new ResultPoint(lastRange[0], lastY);
} else {
return new ResultPoint(lastRange[1], lastY);
}
} else {
int lastX = x - deltaX;
if (lastRange[0] < centerY) {
if (lastRange[1] > centerY) {
return new ResultPoint(lastX, deltaX < 0 ? lastRange[0] : lastRange[1]);
}
return new ResultPoint(lastX, lastRange[0]);
} else {
return new ResultPoint(lastX, lastRange[1]);
}
}
}
lastRange = range;
}
throw NotFoundException.getNotFoundInstance();
}
public String parseInformation() throws NotFoundException {
if (this.information.size != headerSize + gtinSize + weightSize + dateSize) {
throw NotFoundException.getNotFoundInstance();
}
StringBuffer buf = new StringBuffer();
encodeCompressedGtin(buf, headerSize);
encodeCompressedWeight(buf, headerSize + gtinSize, weightSize);
encodeCompressedDate(buf, headerSize + gtinSize + weightSize);
return buf.toString();
}
