private static bool IsConvex(LinkedListNode <EarPoint> ele, EarPolygon poly)
{
LinkedListNode <EarPoint> a = poly.Previous(ele);
LinkedListNode <EarPoint> b = ele;
LinkedListNode <EarPoint> c = poly.Next(ele);
return(GeoPolygonUtils.IsConvex(a.Value.mPoint, b.Value.mPoint, c.Value.mPoint));
}
private static bool IsEdgeRemovable(List<Vector2> vertes, HalfEdge edge)
{
if (edge.mPartner == null)
{
return false;
}
return GeoPolygonUtils.IsConvex(vertes[edge.mIndex], vertes[edge.mPartner.mNext.mNext.mIndex], vertes[edge.mNext.mNext.mIndex]) &&
GeoPolygonUtils.IsConvex(vertes[edge.mPartner.mIndex], vertes[edge.mNext.mNext.mIndex], vertes[edge.mPartner.mNext.mNext.mIndex]);
}
public static float VectorAngleVector(Vector2 v1, Vector2 v2)
{
float angle = Vector2.Angle(v1, v2);
if (GeoPolygonUtils.IsConvex(Vector2.zero, v1, v2)) // v2 在 v1 向量的左边
{
return(angle);
}
else
{
return(-angle);
}
}
private static void UpdateEdge(HalfEdge edgeToRemove, PriorityQueue<int, HalfEdge, float> priorityQueue, HashSet<EdgeID> deletedEdgeSet, List<Vector2> pointList)
{
HalfEdge left = GetUndeletedLeft(edgeToRemove, deletedEdgeSet);
HalfEdge right = GetUndeletedRight(edgeToRemove, deletedEdgeSet);
HalfEdge reLeft = RepresentActive(left);
if (priorityQueue.Contain(reLeft.mKey))
{
// Check if this is still removable
HalfEdge leftOfLeft = GetUndeletedLeft(left.mPartner, deletedEdgeSet);
if ((leftOfLeft.mPartner != null && (leftOfLeft.mPartner.mKey == right.mKey || leftOfLeft.mPartner.mKey == edgeToRemove.mKey)) ||
!GeoPolygonUtils.IsConvex(pointList[edgeToRemove.mIndex], pointList[right.mNext.mIndex], pointList[leftOfLeft.mIndex]))
{
priorityQueue.Remove(reLeft.mKey);
}
else
{
// Need to update the priority
float pri = GetSmallestAdjacentAngleOnEdge(left, deletedEdgeSet, pointList);
priorityQueue.Remove(reLeft.mKey);
priorityQueue.Enqueue(reLeft.mKey, reLeft, pri);
}
}
HalfEdge reRight = RepresentActive(right);
if (priorityQueue.Contain(reRight.mKey))
{
HalfEdge rightOfRight = GetUndeletedRight(right, deletedEdgeSet);
if ((rightOfRight.mPartner != null && (rightOfRight.mPartner.mKey == left.mKey || rightOfRight.mKey == edgeToRemove.mKey)) ||
!GeoPolygonUtils.IsConvex(pointList[edgeToRemove.mIndex], pointList[rightOfRight.mNext.mIndex], pointList[left.mIndex]))
{
priorityQueue.Remove(reRight.mKey);
}
else
{
priorityQueue.Remove(reRight.mKey);
priorityQueue.Enqueue(reRight.mKey, reRight, GetSmallestAdjacentAngleOnEdge(right, deletedEdgeSet, pointList));
}
}
}
