private void AddEndIntercept(XYZ point, List <XYZS> intercepts, double station)
{
if (!Index.CalculateIndexOfCellContainingPosition(point.X, point.Y, out int cellX, out int cellY))
{
Log.LogWarning($"No cell address computable for end point location {point.X}:{point.Y}");
return;
}
var subGrid = Index.LocateSubGridContaining(cellX, cellY);
if (subGrid == null) // No triangles in this 'node' sub grid
{
return;
}
if (!(subGrid is TriangleArrayReferenceSubGrid referenceSubGrid))
{
Log.LogCritical($"Sub grid is not a TriangleArrayReferenceSubGrid, is is a {subGrid.GetType()}");
return;
}
// Get the cell representing a leaf sub grid and determine if there is a triangle at the point location
subGrid.GetSubGridCellIndex(cellX, cellY, out byte subGridX, out byte subGridY);
TriangleArrayReference referenceList = referenceSubGrid.Items[subGridX, subGridY];
int endIndex = referenceList.TriangleArrayIndex + referenceList.Count;
for (int i = referenceList.TriangleArrayIndex; i < endIndex; i++)
{
double height = XYZ.GetTriangleHeightEx
(ref TTM.Vertices.Items[TTM.Triangles.Items[Indices[i]].Vertex0],
ref TTM.Vertices.Items[TTM.Triangles.Items[Indices[i]].Vertex1],
ref TTM.Vertices.Items[TTM.Triangles.Items[Indices[i]].Vertex2], point.X, point.Y);
if (height != Common.Consts.NullDouble)
{
intercepts.Add(new XYZS(point.X, point.Y, height, station, Indices[i]));
return;
}
}
}
/// <summary>
/// Computes a profile line across the TIN surface between two points
/// </summary>
/// <param name="startPoint"></param>
/// <param name="endPoint"></param>
/// <param name="startStation"></param>
/// <returns></returns>
private List <XYZS> Compute(XYZ startPoint, XYZ endPoint, double startStation)
{
// 1. Determine the set of sub grids the profile line cross using the same logic used to
// compute cell cross by production data profiling
// ...
var cellProfileBuilder = new OptimisedTTMCellProfileBuilder(Index.CellSize, true);
if (!cellProfileBuilder.Build(new [] { startPoint, endPoint }, startStation))
{
return(null);
}
// 2. Iterate across each sub grid in turn locating all triangles in that sub grid
// that intersect the line and sorting them according to the distance of the closest
// intercept from the start of the line
// Get the resulting vertical and horizontal intercept list
var VtHzIntercepts = cellProfileBuilder.VtHzIntercepts;
// Iterate through the intercepts looking for ones that hit a sub grid in the TTM
// spatial index that contains triangles
var intercepts = new List <XYZS>();
var plane = new Plane();
// Add an initial intercept if the start point is located within a triangle
AddEndIntercept(startPoint, intercepts, startStation);
int prevCellX = int.MinValue, preCellY = int.MinValue;
for (int interceptIndex = 0; interceptIndex < VtHzIntercepts.Count; interceptIndex++)
{
InterceptRec intercept = VtHzIntercepts.Items[interceptIndex];
if (!Index.CalculateIndexOfCellContainingPosition(intercept.MidPointX, intercept.MidPointY, out int cellX, out int cellY))
{
Log.LogWarning($"No cell address computable for location {intercept.MidPointX}:{intercept.MidPointY}");
continue;
}
// Make sure we are not repeating a sub grid (can happen as a result of how the initial HZ/Vt intersects are constructed
if (prevCellX == cellX && preCellY == cellY)
{
// This sub grid has just been processed...
continue;
}
prevCellX = cellX;
preCellY = cellY;
var subGrid = Index.LocateSubGridContaining(cellX, cellY);
if (subGrid == null)
{
// No triangles are present in this 'node' sub grid. Move to the next sub grid, the implicit gap will be
// picked up when triangle intercepts are aggregated together to form the final profile line
continue;
}
if (!(subGrid is TriangleArrayReferenceSubGrid referenceSubGrid))
{
Log.LogCritical($"Sub grid is not a TriangleArrayReferenceSubGrid, is is a {subGrid.GetType()}");
continue;
}
subGrid.GetSubGridCellIndex(cellX, cellY, out byte subGridX, out byte subGridY);
TriangleArrayReference referenceList = referenceSubGrid.Items[subGridX, subGridY];
if (referenceList.Count == 0)
{
// There are no triangles in this 'leaf' sub grid
continue;
}
// Locate all triangles in this sub grid that intersect the profile line
var endIndex = referenceList.TriangleArrayIndex + referenceList.Count;
for (int i = referenceList.TriangleArrayIndex; i < endIndex; i++)
{
int triIndex = Indices[i];
Triangle tri = TTM.Triangles.Items[triIndex];
// Does this triangle intersect the line?
XYZ v0 = TTM.Vertices.Items[tri.Vertex0];
XYZ v1 = TTM.Vertices.Items[tri.Vertex1];
XYZ v2 = TTM.Vertices.Items[tri.Vertex2];
bool planeInited = false;
if (LineIntersection.LinesIntersect(startPoint.X, startPoint.Y, endPoint.X, endPoint.Y, v0.X, v0.Y, v1.X, v1.Y, out double intersectX, out double intersectY, true, out bool linesAreColinear))
{
// If the lines are co-linear there is nothing more to do. The two vertices need to be added and no more checking is required
if (linesAreColinear)
{
intercepts.Add(new XYZS(v0.X, v0.Y, v0.Z, startStation + MathUtilities.Hypot(startPoint.X - v0.X, startPoint.Y - v0.Y), triIndex));
intercepts.Add(new XYZS(v1.X, v1.Y, v1.Z, startStation + MathUtilities.Hypot(startPoint.X - v1.X, startPoint.Y - v1.Y), triIndex));
continue;
}
planeInited = true;
plane.Init(v0, v1, v2);
// Otherwise, add the intercept location to the list
intercepts.Add(new XYZS(intersectX, intersectY, plane.Evaluate(intersectX, intersectY), startStation + MathUtilities.Hypot(startPoint.X - intersectX, startPoint.Y - intersectY), triIndex));
}
if (LineIntersection.LinesIntersect(startPoint.X, startPoint.Y, endPoint.X, endPoint.Y, v0.X, v0.Y, v2.X, v2.Y, out intersectX, out intersectY, true, out linesAreColinear))
{
// If the lines are co-linear there is nothing more to do. The two vertices need to be added and no more checking is required
if (linesAreColinear)
{
intercepts.Add(new XYZS(v0.X, v0.Y, v0.Z, startStation + MathUtilities.Hypot(startPoint.X - v0.X, startPoint.Y - v0.Y), triIndex));
intercepts.Add(new XYZS(v2.X, v2.Y, v2.Z, startStation + MathUtilities.Hypot(startPoint.X - v2.X, startPoint.Y - v2.Y), triIndex));
continue;
}
if (!planeInited)
{
planeInited = true;
plane.Init(v0, v1, v2);
}
// Otherwise, add the intercept location to the list
intercepts.Add(new XYZS(intersectX, intersectY, plane.Evaluate(intersectX, intersectY), startStation + MathUtilities.Hypot(startPoint.X - intersectX, startPoint.Y - intersectY), triIndex));
}
if (LineIntersection.LinesIntersect(startPoint.X, startPoint.Y, endPoint.X, endPoint.Y, v1.X, v1.Y, v2.X, v2.Y, out intersectX, out intersectY, true, out linesAreColinear))
{
// If the lines are co-linear there is nothing more to do. The two vertices need to be added and no more checking is required
if (linesAreColinear)
{
intercepts.Add(new XYZS(v1.X, v1.Y, v1.Z, startStation + MathUtilities.Hypot(startPoint.X - v1.X, startPoint.Y - v1.Y), triIndex));
intercepts.Add(new XYZS(v2.X, v2.Y, v2.Z, startStation + MathUtilities.Hypot(startPoint.X - v2.X, startPoint.Y - v2.Y), triIndex));
continue;
}
if (!planeInited)
{
plane.Init(v0, v1, v2);
}
// Otherwise, add the intercept location to the list
intercepts.Add(new XYZS(intersectX, intersectY, plane.Evaluate(intersectX, intersectY), startStation + MathUtilities.Hypot(startPoint.X - intersectX, startPoint.Y - intersectY), triIndex));
}
}
}
// Add an end intercept if the start point is located within a triangle
AddEndIntercept(endPoint, intercepts, startStation + MathUtilities.Hypot(startPoint.X - endPoint.X, startPoint.Y - endPoint.Y));
return(intercepts);
}
