void TraceOutlineCcw(Remaining toReadNext, RawOutline output, bool outside)
{
output.BeginContour(outside);
//if we starts on left-side of the column
ColumnWalkerCcw ccw = new ColumnWalkerCcw(_verticalGroupList);
ccw.Bind(output);
//-------------------------------
for (; ;)
{
switch (toReadNext.unreadSide)
{
default:
throw new System.NotSupportedException();
case ReadSide.Left:
ccw.Bind(toReadNext.column);
ccw.ReadLeftSide();
break;
case ReadSide.Right:
ccw.Bind(toReadNext.column);
ccw.ReadRightSide();
break;
case ReadSide.None:
//complete
output.EndContour();
return;
}
toReadNext = ccw.FindReadNextColumn();
}
}
/// <summary>
/// trace outline counter-clockwise
/// </summary>
/// <param name="output"></param>
void TraceOutline(HSpan[] sortedHSpans, RawOutline output)
{
if (sortedHSpans == null)
{
return;
}
//
var sep = new VerticalGroupSeparator(_verticalGroupList);
sep.Separate(sortedHSpans);
int vertGroupCount = _verticalGroupList.Count;
if (vertGroupCount == 0)
{
return;
}
_verticalGroupList.EvaluateCorners();
List <Remaining> incompleteReadList = new List <Remaining>();
TraceOutlineCcw(new Remaining(_verticalGroupList.GetGroup(0).GetColumn(0), ReadSide.Left), output, true);
TRACE_AGAIN: //**
//check if the shape have hole(s)
_verticalGroupList.CollectIncompleteColumns(incompleteReadList);
if (incompleteReadList.Count > 0)
{
//this should be a hole
Remaining incompleteRead = incompleteReadList[0];
switch (incompleteRead.unreadSide)
{
//?should not occur
case ReadSide.LeftAndRight:
{
TraceOutlineCcw(new Remaining(incompleteRead.column, ReadSide.Left), output, false);
incompleteReadList.Clear();
goto TRACE_AGAIN;
}
case ReadSide.Left:
case ReadSide.Right:
{
TraceOutlineCcw(incompleteRead, output, false);
incompleteReadList.Clear();
goto TRACE_AGAIN;
}
}
}
else
{
//complete all
}
}