public static Polygons MakeCloseSegmentsMergable(this Polygons polygonsToSplit, long distanceNeedingAdd, bool pathsAreClosed = true)
{
Polygons splitPolygons = new Polygons();
for (int i = 0; i < polygonsToSplit.Count; i++)
{
Polygon accumulatedSplits = polygonsToSplit[i];
for (int j = 0; j < polygonsToSplit.Count; j++)
{
accumulatedSplits = QTPolygonExtensions.MakeCloseSegmentsMergable(accumulatedSplits, polygonsToSplit[j], distanceNeedingAdd, pathsAreClosed);
}
splitPolygons.Add(accumulatedSplits);
}
return(splitPolygons);
}
public static bool MergePerimeterOverlaps(this Polygon perimeter, long overlapMergeAmount_um, out Polygons separatedPolygons, bool pathIsClosed = true)
{
// if the path is wound CW
separatedPolygons = new Polygons();
long cleanDistance_um = overlapMergeAmount_um / 40;
Polygons cleanedPolygs = Clipper.CleanPolygons(new Polygons()
{
perimeter
}, cleanDistance_um);
perimeter = cleanedPolygs[0];
if (perimeter.Count == 0)
{
return(false);
}
bool pathWasOptimized = false;
for (int i = 0; i < perimeter.Count; i++)
{
perimeter[i] = new IntPoint(perimeter[i])
{
Width = overlapMergeAmount_um
};
}
perimeter = QTPolygonExtensions.MakeCloseSegmentsMergable(perimeter, overlapMergeAmount_um * 3 / 4, pathIsClosed);
// make a copy that has every point duplicated (so that we have them as segments).
List <Segment> polySegments = Segment.ConvertToSegments(perimeter, pathIsClosed);
var markedAltered = new Altered[polySegments.Count];
var minimumLengthToCreateSquared = overlapMergeAmount_um / 10;
minimumLengthToCreateSquared *= minimumLengthToCreateSquared;
var touchingEnumerator = new CloseSegmentsIterator(polySegments, overlapMergeAmount_um);
int segmentCount = polySegments.Count;
// now walk every segment and check if there is another segment that is similar enough to merge them together
for (int firstSegmentIndex = 0; firstSegmentIndex < segmentCount; firstSegmentIndex++)
{
foreach (int checkSegmentIndex in touchingEnumerator.GetTouching(firstSegmentIndex, segmentCount))
{
// The first point of start and the last point of check (the path will be coming back on itself).
long startDelta = (polySegments[firstSegmentIndex].Start - polySegments[checkSegmentIndex].End).Length();
// if the segments are similar enough
if (startDelta < overlapMergeAmount_um)
{
// The last point of start and the first point of check (the path will be coming back on itself).
long endDelta = (polySegments[firstSegmentIndex].End - polySegments[checkSegmentIndex].Start).Length();
if (endDelta < overlapMergeAmount_um)
{
// only consider the merge if the directions of the lines are towards each other
var firstSegmentDirection = polySegments[firstSegmentIndex].End - polySegments[firstSegmentIndex].Start;
var checkSegmentDirection = polySegments[checkSegmentIndex].End - polySegments[checkSegmentIndex].Start;
if (firstSegmentDirection.Dot(checkSegmentDirection) > 0)
{
continue;
}
// get the line width
long startEndWidth = (polySegments[firstSegmentIndex].Start - polySegments[checkSegmentIndex].End).Length();
long endStartWidth = (polySegments[firstSegmentIndex].End - polySegments[checkSegmentIndex].Start).Length();
long width = Math.Min(startEndWidth, endStartWidth) + overlapMergeAmount_um;
// check if we extrude enough to consider doing this merge
var segmentStart = (polySegments[firstSegmentIndex].Start + polySegments[checkSegmentIndex].End) / 2;
var segmentEnd = (polySegments[firstSegmentIndex].End + polySegments[checkSegmentIndex].Start) / 2;
if ((segmentStart - segmentEnd).LengthSquared() < minimumLengthToCreateSquared)
{
continue;
}
pathWasOptimized = true;
// move the first segments points to the average of the merge positions
polySegments[firstSegmentIndex].Start = segmentStart;
polySegments[firstSegmentIndex].Start.Width = width;
polySegments[firstSegmentIndex].End = segmentEnd;
polySegments[firstSegmentIndex].End.Width = width;
markedAltered[firstSegmentIndex] = Altered.Merged;
// mark this segment for removal
markedAltered[checkSegmentIndex] = Altered.Remove;
// We only expect to find one match for each segment, so move on to the next segment
break;
}
}
}
}
// remove the marked segments
for (int segmentIndex = segmentCount - 1; segmentIndex >= 0; segmentIndex--)
{
if (markedAltered[segmentIndex] == Altered.Remove)
{
polySegments.RemoveAt(segmentIndex);
}
}
// go through the polySegments and create a new polygon for every connected set of segments
var currentPolygon = new Polygon();
separatedPolygons.Add(currentPolygon);
// put in the first point
for (int segmentIndex = 0; segmentIndex < polySegments.Count; segmentIndex++)
{
// add the start point
currentPolygon.Add(polySegments[segmentIndex].Start);
// if the next segment is not connected to this one
if (segmentIndex < polySegments.Count - 1 &&
polySegments[segmentIndex].End != polySegments[segmentIndex + 1].Start)
{
// add the end point
currentPolygon.Add(polySegments[segmentIndex].End);
// create a new polygon
currentPolygon = new Polygon();
separatedPolygons.Add(currentPolygon);
}
}
// add the end point
currentPolygon.Add(polySegments[polySegments.Count - 1].End);
if (pathWasOptimized &&
Math.Abs(perimeter.PolygonLength() - separatedPolygons.PolygonLength(false)) < overlapMergeAmount_um * 2)
{
return(false);
}
return(pathWasOptimized);
}