/// <summary>Static method to construct the convex hull of a Multi_vertex_geometry.</summary>
/// <remarks>
/// Static method to construct the convex hull of a Multi_vertex_geometry.
/// Returns a Geometry.
/// \param mvg The geometry used to create the convex hull.
/// </remarks>
internal static com.epl.geometry.Geometry Construct(com.epl.geometry.MultiVertexGeometry mvg)
{
if (mvg.IsEmpty())
{
return(new com.epl.geometry.Polygon(mvg.GetDescription()));
}
com.epl.geometry.MultiVertexGeometryImpl mvg_impl = (com.epl.geometry.MultiVertexGeometryImpl)mvg._getImpl();
int N = mvg_impl.GetPointCount();
if (N <= 2)
{
if (N == 1 || mvg_impl.GetXY(0).Equals(mvg_impl.GetXY(1)))
{
com.epl.geometry.Point point = new com.epl.geometry.Point(mvg_impl.GetDescription());
mvg_impl.GetPointByVal(0, point);
return(point);
}
else
{
com.epl.geometry.Point pt = new com.epl.geometry.Point();
com.epl.geometry.Polyline polyline = new com.epl.geometry.Polyline(mvg_impl.GetDescription());
mvg_impl.GetPointByVal(0, pt);
polyline.StartPath(pt);
mvg_impl.GetPointByVal(1, pt);
polyline.LineTo(pt);
return(polyline);
}
}
com.epl.geometry.AttributeStreamOfDbl stream = (com.epl.geometry.AttributeStreamOfDbl)mvg_impl.GetAttributeStreamRef(com.epl.geometry.VertexDescription.Semantics.POSITION);
com.epl.geometry.ConvexHull convex_hull = new com.epl.geometry.ConvexHull(stream, N);
int t0 = 0;
int tm = 1;
com.epl.geometry.Point2D pt_0 = new com.epl.geometry.Point2D();
com.epl.geometry.Point2D pt_m = new com.epl.geometry.Point2D();
com.epl.geometry.Point2D pt_p = new com.epl.geometry.Point2D();
stream.Read(t0 << 1, pt_0);
while (true)
{
if (tm >= N)
{
break;
}
stream.Read(tm << 1, pt_m);
if (!pt_m.IsEqual(pt_0, com.epl.geometry.NumberUtils.DoubleEps()))
{
break;
}
tm++;
}
// We don't want to close the gap between t0 and tm.
convex_hull.m_tree_hull.AddElement(t0, -1);
if (tm < N)
{
convex_hull.m_tree_hull.AddBiggestElement(tm, -1);
for (int tp = tm + 1; tp < mvg_impl.GetPointCount(); tp++)
{
// Dynamically insert into the current convex hull
stream.Read(tp << 1, pt_p);
int p = convex_hull.TreeHull_(pt_p);
if (p != -1)
{
convex_hull.m_tree_hull.SetElement(p, tp);
}
}
}
// reset the place holder to the point index.
// Extracts the convex hull from the tree. Reading the tree in order from first to last is the resulting convex hull.
com.epl.geometry.VertexDescription description = mvg_impl.GetDescription();
bool b_has_attributes = (description.GetAttributeCount() > 1);
int point_count = convex_hull.m_tree_hull.Size(-1);
com.epl.geometry.Geometry hull;
if (point_count >= 2)
{
if (point_count >= 3)
{
hull = new com.epl.geometry.Polygon(description);
}
else
{
hull = new com.epl.geometry.Polyline(description);
}
com.epl.geometry.MultiPathImpl hull_impl = (com.epl.geometry.MultiPathImpl)hull._getImpl();
hull_impl.AddPath((com.epl.geometry.Point2D[])null, 0, true);
com.epl.geometry.Point point = null;
if (b_has_attributes)
{
point = new com.epl.geometry.Point();
}
for (int i = convex_hull.m_tree_hull.GetFirst(-1); i != -1; i = convex_hull.m_tree_hull.GetNext(i))
{
if (b_has_attributes)
{
mvg_impl.GetPointByVal(convex_hull.m_tree_hull.GetElement(i), point);
hull_impl.InsertPoint(0, -1, point);
}
else
{
stream.Read(convex_hull.m_tree_hull.GetElement(i) << 1, pt_p);
hull_impl.InsertPoint(0, -1, pt_p);
}
}
}
else
{
System.Diagnostics.Debug.Assert((point_count == 1));
if (b_has_attributes)
{
com.epl.geometry.Point point = new com.epl.geometry.Point(description);
mvg_impl.GetPointByVal(convex_hull.m_tree_hull.GetElement(convex_hull.m_tree_hull.GetFirst(-1)), point);
hull = point;
}
else
{
stream.Read(convex_hull.m_tree_hull.GetElement(convex_hull.m_tree_hull.GetFirst(-1)) << 1, pt_p);
hull = new com.epl.geometry.Point(pt_p);
}
}
return(hull);
}
/// <summary>Copies a path from another multipath.</summary>
/// <param name="src">The multipath to copy from.</param>
/// <param name="srcPathIndex">The index of the path in the the source MultiPath.</param>
/// <param name="bForward">When FALSE, the points are inserted in reverse order.</param>
public virtual void AddPath(com.epl.geometry.MultiPath src, int srcPathIndex, bool bForward)
{
m_impl.AddPath((com.epl.geometry.MultiPathImpl)src._getImpl(), srcPathIndex, bForward);
}
private void GeneralizePath(com.epl.geometry.MultiPathImpl mpsrc, int ipath, com.epl.geometry.MultiPathImpl mpdst, com.epl.geometry.Line lineHelper)
{
if (mpsrc.GetPathSize(ipath) < 2)
{
return;
}
int start = mpsrc.GetPathStart(ipath);
int end = mpsrc.GetPathEnd(ipath) - 1;
com.epl.geometry.AttributeStreamOfDbl xy = (com.epl.geometry.AttributeStreamOfDbl)mpsrc.GetAttributeStreamRef(com.epl.geometry.VertexDescription.Semantics.POSITION);
bool bClosed = mpsrc.IsClosedPath(ipath);
com.epl.geometry.AttributeStreamOfInt32 stack = new com.epl.geometry.AttributeStreamOfInt32(0);
stack.Reserve(mpsrc.GetPathSize(ipath) + 1);
com.epl.geometry.AttributeStreamOfInt32 resultStack = new com.epl.geometry.AttributeStreamOfInt32(0);
resultStack.Reserve(mpsrc.GetPathSize(ipath) + 1);
stack.Add(bClosed ? start : end);
stack.Add(start);
com.epl.geometry.Point2D pt = new com.epl.geometry.Point2D();
while (stack.Size() > 1)
{
int i1 = stack.GetLast();
stack.RemoveLast();
int i2 = stack.GetLast();
mpsrc.GetXY(i1, pt);
lineHelper.SetStartXY(pt);
mpsrc.GetXY(i2, pt);
lineHelper.SetEndXY(pt);
int mid = FindGreatestDistance(lineHelper, pt, xy, i1, i2, end);
if (mid >= 0)
{
stack.Add(mid);
stack.Add(i1);
}
else
{
resultStack.Add(i1);
}
}
if (!bClosed)
{
resultStack.Add(stack.Get(0));
}
int rs_size = resultStack.Size();
int path_size = mpsrc.GetPathSize(ipath);
if (rs_size == path_size && rs_size == stack.Size())
{
mpdst.AddPath(mpsrc, ipath, true);
}
else
{
if (resultStack.Size() > 0)
{
if (m_bRemoveDegenerateParts && resultStack.Size() <= 2)
{
if (bClosed || resultStack.Size() == 1)
{
return;
}
double d = com.epl.geometry.Point2D.Distance(mpsrc.GetXY(resultStack.Get(0)), mpsrc.GetXY(resultStack.Get(1)));
if (d <= m_maxDeviation)
{
return;
}
}
com.epl.geometry.Point point = new com.epl.geometry.Point();
for (int i = 0, n = resultStack.Size(); i < n; i++)
{
mpsrc.GetPointByVal(resultStack.Get(i), point);
if (i == 0)
{
mpdst.StartPath(point);
}
else
{
mpdst.LineTo(point);
}
}
if (bClosed)
{
for (int i_1 = resultStack.Size(); i_1 < 3; i_1++)
{
mpdst.LineTo(point);
}
mpdst.ClosePathWithLine();
}
}
}
}
