/// <summary>
/// <p>This is called when a horizontal scan finds a possible alignment pattern. It will
/// cross check with a vertical scan, and if successful, will, ah, cross-cross-check
/// with another horizontal scan. This is needed primarily to locate the real horizontal
/// center of the pattern in cases of extreme skew.
/// And then we cross-cross-cross check with another diagonal scan.</p>
/// If that succeeds the finder pattern location is added to a list that tracks
/// the number of times each location has been nearly-matched as a finder pattern.
/// Each additional find is more evidence that the location is in fact a finder
/// pattern center
/// </summary>
/// <param name="stateCount">reading state module counts from horizontal scan</param>
/// <param name="i">row where finder pattern may be found</param>
/// <param name="j">end of possible finder pattern in row</param>
/// <param name="pureBarcode">true if in "pure barcode" mode</param>
/// <returns>
/// true if a finder pattern candidate was found this time
/// </returns>
bool HandlePossibleCenter(int[] stateCount, int i, int j)
{
int stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] +
stateCount[4];
float?centerJ = CenterFromEnd(stateCount, j);
if (centerJ == null)
{
return(false);
}
float?centerI = CrossCheckVertical(i, (int)centerJ.Value, stateCount[2], stateCountTotal);
if (centerI != null)
{
// Re-cross check
centerJ = CrossCheckHorizontal((int)centerJ.Value, (int)centerI.Value, stateCount[2], stateCountTotal);
if (centerJ != null)
{
float estimatedModuleSize = stateCountTotal / 7.0f;
bool found = false;
for (int index = 0; index < PossibleCenters.Count; index++)
{
var center = PossibleCenters[index];
// Look for about the same center and module size:
if (center.AboutEquals(estimatedModuleSize, centerI.Value, centerJ.Value))
{
PossibleCenters.RemoveAt(index);
PossibleCenters.Insert(index, center.CombineEstimate(centerI.Value, centerJ.Value, estimatedModuleSize));
found = true;
break;
}
}
if (!found)
{
var point = new FinderPattern(centerJ.Value, centerI.Value, estimatedModuleSize);
PossibleCenters.Add(point);
}
return(true);
}
}
return(false);
}
/// <summary> <para>
/// <p>This is called when a horizontal scan finds a possible alignment pattern. It will
/// cross check with a vertical scan, and if successful, will, ah, cross-cross-check
/// with another horizontal scan. This is needed primarily to locate the real horizontal
/// center of the pattern in cases of extreme skew.</p>
/// </para>
/// <para>
/// <p>If that succeeds the finder pattern location is added to a list that tracks
/// the number of times each location has been nearly-matched as a finder pattern.
/// Each additional find is more evidence that the location is in fact a finder
/// pattern center</p>
/// </para>
///
/// </summary>
/// <param name="stateCount">reading state module counts from horizontal scan
/// </param>
/// <param name="i">row where finder pattern may be found
/// </param>
/// <param name="j">end of possible finder pattern in row
/// </param>
/// <returns> true if a finder pattern candidate was found this time
/// </returns>
private bool HandlePossibleCenter(int[] stateCount, int i, int j)
{
int stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] + stateCount[4];
float centerJ = CenterFromEnd(stateCount, j);
//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 centerI = CrossCheckVertical(i, (int)centerJ, stateCount[2], stateCountTotal);
if (!float.IsNaN(centerI))
{
// Re-cross check
//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'"
centerJ = CrossCheckHorizontal((int)centerJ, (int)centerI, stateCount[2], stateCountTotal);
if (!float.IsNaN(centerJ))
{
//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 estimatedModuleSize = stateCountTotal / 7.0f;
bool found = false;
int max = PossibleCenters.Count;
for (int index = 0; index < max; index++)
{
FinderPattern center = (FinderPattern)PossibleCenters[index];
// Look for about the same center and module size:
if (center.AboutEquals(estimatedModuleSize, centerI, centerJ))
{
center.IncrementCount();
found = true;
break;
}
}
if (!found)
{
ResultPoint point = new FinderPattern(centerJ, centerI, estimatedModuleSize);
PossibleCenters.Add(point);
resultPointCallback?.FoundPossibleResultPoint(point);
}
return(true);
}
}
return(false);
}
