/// <summary>
/// Merge overlapping <see cref="TimeWindow"/>s. For use by merging <see cref="WindowAssigner{TElement,TWindow}"/>.
/// </summary>
/// <param name="windows"></param>
/// <param name="callback"></param>
public static void MergeWindows(IEnumerable <TimeWindow> windows, IMergeWindowCallback <TimeWindow> callback)
{
// sort the windows by the start time and then merge overlapping windows
var sortedWindows = windows.OrderBy(it => it.Start);
var merged = new List <MergedItem>();
MergedItem currentMerge = null;
foreach (var candidate in sortedWindows)
{
if (currentMerge == null)
{
currentMerge = new MergedItem(candidate, candidate);
}
else if (currentMerge.MergeResult.Intersects(candidate))
{ // 两个窗口的时间段相互重叠，则属于同一会话，因此会话窗口策略把这两个窗口合并成一个新的、更长的会话窗口。
currentMerge.MergeResult = currentMerge.MergeResult.Cover(candidate);
currentMerge.ToBeMerged.Add(candidate);
}
else
{
merged.Add(currentMerge);
currentMerge = new MergedItem(candidate, candidate);
}
}
if (currentMerge != null)
{
merged.Add(currentMerge);
}
foreach (var mergeItem in merged)
{
if (mergeItem.ToBeMerged.Count > 0)
{
callback.Merge(mergeItem.ToBeMerged, mergeItem.MergeResult);
}
}
}
static void TransformVertices(List <Vector3> verticesOut, List <Vector3> normalsOut, MergedItem item)
{
var mesh = item.mesh;
var vertexCount = mesh.vertexCount;
var vertices = mesh.vertices;
var normals = mesh.normals;
var matrix = item.matrix;
for (int i = 0; i < vertexCount; i++)
{
var v = matrix.MultiplyPoint3x4(vertices[i]);
var n = matrix.MultiplyVector(normals[i]);
verticesOut.Add(v);
normalsOut.Add(n);
}
}
