internal static int[] findStartGuardPattern(BitArray row)
{
bool foundStart = false;
int[] startRange = null;
int nextStart = 0;
while (!foundStart)
{
startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN);
int start = startRange[0];
nextStart = startRange[1];
// Make sure there is a quiet zone at least as big as the start pattern before the barcode.
// If this check would run off the left edge of the image, do not accept this barcode,
// as it is very likely to be a false positive.
int quietStart = start - (nextStart - start);
if (quietStart >= 0)
{
foundStart = row.isRange(quietStart, start, false);
}
}
return startRange;
}
private static int[] findAsteriskPattern(BitArray row)
{
int width = row.Size;
int rowOffset = 0;
while (rowOffset < width)
{
if (row.get_Renamed(rowOffset))
{
break;
}
rowOffset++;
}
int counterPosition = 0;
int[] counters = new int[9];
int patternStart = rowOffset;
bool isWhite = false;
int patternLength = counters.Length;
for (int i = rowOffset; i < width; i++)
{
bool pixel = row.get_Renamed(i);
if (pixel ^ isWhite)
{
counters[counterPosition]++;
}
else
{
if (counterPosition == patternLength - 1)
{
if (toNarrowWidePattern(counters) == ASTERISK_ENCODING)
{
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return new int[]{patternStart, i};
}
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++)
{
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw ReaderException.Instance;
}
/// <summary> <p>Like {@link #decodeRow(int, BitArray, java.util.Hashtable)}, but
/// allows caller to inform method about where the UPC/EAN start pattern is
/// found. This allows this to be computed once and reused across many implementations.</p>
/// </summary>
public virtual Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange, System.Collections.Hashtable hints)
{
ResultPointCallback resultPointCallback = hints == null?null:(ResultPointCallback) hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber));
}
System.Text.StringBuilder result = decodeRowStringBuffer;
result.Length = 0;
int endStart = decodeMiddle(row, startGuardRange, result);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint(endStart, rowNumber));
}
int[] endRange = decodeEnd(row, endStart);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((endRange[0] + endRange[1]) / 2.0f, rowNumber));
}
// Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
// spec might want more whitespace, but in practice this is the maximum we can count on.
int end = endRange[1];
int quietEnd = end + (end - endRange[0]);
if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))
{
throw ReaderException.Instance;
}
System.String resultString = result.ToString();
if (!checkChecksum(resultString))
{
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float) (startGuardRange[1] + startGuardRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float) (endRange[1] + endRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat);
}