/// <summary>
/// Classifies a span with regard to already processed spans
/// </summary>
/// <param name="currentSpan"></param>
/// <param name="currentComponentSet"></param>
static void PlaceSpan(Span currentSpan, ConnectedComponentSet currentComponentSet)
{
if (currentSpan.Y == 0)
{
// for the first row, just accumulate the spans in the Generation 0
currentComponentSet.AddNewComponentFromSpan(currentSpan);
return;
}
// find all spans from Generation 1 that "touch" this span
ConnectedComponentSet componentsToJoin = new ConnectedComponentSet();
componentsToJoin.AddRange(
currentComponentSet.Where(
component => component.FrontalSpans.IntersectsWith(currentSpan)));
// if we "touch" 0 existing components, create a new one
if (componentsToJoin.Count == 0)
{
currentComponentSet.AddNewComponentFromSpan(currentSpan);
}
// if we touch one component, append the current span to its bottom
else if (componentsToJoin.Count == 1)
{
componentsToJoin[0].NewFrontalSpans.Add(currentSpan);
}
// if we touch more than one component, it means they all belong together.
// Now we unite all of these components into one.
else
{
for (int i = 1; i < componentsToJoin.Count; i++)
{
componentsToJoin[0].NewFrontalSpans.Add(currentSpan);
componentsToJoin[0].UnionWith(componentsToJoin[i]);
currentComponentSet.Remove(componentsToJoin[i]);
}
}
}
