/**
* Fill up Grid GridPoints using TriangleList input - Grid information should have been set by SetGridInfo
*
* @param SamplePoints : Sample Point List
* @param TriangleList : List of triangles
*/
public void GenerateGridElements(List <BSPoint> SamplePoints, List <BSTriangle> TriangleList)
{
if (!(NumGridDivisions.X > 0 && NumGridDivisions.Y > 0))
{
return;
}
//if(!(GridDimensions.IsValid))
int TotalNumGridPoints = (int)(NumGridPointsForAxis.X * NumGridPointsForAxis.Y);
GridPoints.Clear();
if (SamplePoints.Count == 0 || TriangleList.Count == 0)
{
return;
}
for (int i = 0; i < TotalNumGridPoints; ++i)
{
GridPoints.Add(new GridElement());
}
Vector3 GridPointPosition;
for (int GridPositionX = 0; GridPositionX < NumGridPointsForAxis.X; ++GridPositionX)
{
for (int GridPositionY = 0; GridPositionY < NumGridPointsForAxis.Y; ++GridPositionY)
{
BSTriangle SelectedTriangle = null;
GridElement GridPoint = GridPoints[GridPositionX * (int)NumGridPointsForAxis.Y + GridPositionY];
GridPointPosition = GetPosFromIndex(GridPositionX, GridPositionY);
Vector3 Weights = Vector3.Zero;
if (FindTriangleThisPointBelongsTo(GridPointPosition, ref Weights, ref SelectedTriangle, TriangleList))
{
// found it
GridPoint.Weights[0] = Weights.X;
GridPoint.Weights[1] = Weights.Y;
GridPoint.Weights[2] = Weights.Z;
// need to find sample point index
// @todo fix this with better solution
// lazy me
GridPoint.Indices[0] = SamplePoints.FindIndex((point) => { return(point == SelectedTriangle.Vertices[0]); });
GridPoint.Indices[1] = SamplePoints.FindIndex((point) => { return(point == SelectedTriangle.Vertices[1]); });
GridPoint.Indices[2] = SamplePoints.FindIndex((point) => { return(point == SelectedTriangle.Vertices[2]); });
//check(GridPoint.Indices[0] != INDEX_NONE);
//check(GridPoint.Indices[1] != INDEX_NONE);
//check(GridPoint.Indices[2] != INDEX_NONE);
}
else
{
List <BSSortByDistance> SortedTriangles = new List <BSSortByDistance>();
for (int TriangleIndex = 0; TriangleIndex < TriangleList.Count; ++TriangleIndex)
{
// Check if points are collinear
BSTriangle Triangle = TriangleList[TriangleIndex];
Vector3 EdgeA = Triangle.Vertices[1].Position - Triangle.Vertices[0].Position;
Vector3 EdgeB = Triangle.Vertices[2].Position - Triangle.Vertices[0].Position;
float Result = EdgeA.X * EdgeB.Y - EdgeA.Y * EdgeB.X;
// Only add valid triangles
if (Result > 0.0f)
{
SortedTriangles.Add(new BSSortByDistance(TriangleIndex, Triangle.GetDistance(GridPointPosition)));
}
}
if (SortedTriangles.Count > 0)
{
// SortedTriangles.Sort([](FSortByDistance A, FSortByDistance B) { return A.Distance < B.Distance; });
BSTriangle ClosestTriangle = TriangleList[SortedTriangles[0].Index];
// For the closest triangle, determine which of its edges is closest to the grid point
List <BSSortByDistance> Edges = new List <BSSortByDistance>();
List <Vector3> PointsOnEdges = new List <Vector3>();
for (int EdgeIndex = 0; EdgeIndex < 3; ++EdgeIndex)
{
Vector3 ClosestPoint = ClosestPointOnLine(ClosestTriangle.Edges[EdgeIndex].Vertices[0].Position, ClosestTriangle.Edges[EdgeIndex].Vertices[1].Position, GridPointPosition);
Edges.Add(new BSSortByDistance(EdgeIndex, (ClosestPoint - GridPointPosition).LengthSquared()));
PointsOnEdges.Add(ClosestPoint);
}
//Edges.Sort([](FSortByDistance A, FSortByDistance B) { return A.Distance < B.Distance; });
// Calculate weighting using the closest edge points and the clamped grid position on the line
Vector3 GridWeights = GetBaryCentric2D(PointsOnEdges[Edges[0].Index], ClosestTriangle.Vertices[0].Position, ClosestTriangle.Vertices[1].Position, ClosestTriangle.Vertices[2].Position);
for (int Index = 0; Index < 3; ++Index)
{
GridPoint.Weights[Index] = GridWeights[Index];
GridPoint.Indices[Index] = SamplePoints.FindIndex((point) => { return(point == ClosestTriangle.Vertices[Index]); });
}
}
else
{
// This means that there is either one point, two points or collinear triangles on the grid
if (SamplePoints.Count == 1)
{
// Just one, fill all grid points to the single sample
GridPoint.Weights[0] = 1.0f;
GridPoint.Indices[0] = 0;
}
else
{
// Two points or co-linear triangles, first find the two closest samples
List <BSSortByDistance> SampleDistances = new List <BSSortByDistance>();
for (int PointIndex = 0; PointIndex < SamplePoints.Count; ++PointIndex)
{
var vec = (SamplePoints[PointIndex].Position - GridPointPosition);
Vector2 vector2 = new Vector2(vec.X, vec.Y);
float DistanceFromSampleToPoint = vector2.LengthSquared();
SampleDistances.Add(new BSSortByDistance(PointIndex, DistanceFromSampleToPoint));
}
SampleDistances.Sort((A, B) =>
{
if (A.Distance == B.Distance)
{
return(0);
}
return(A.Distance > B.Distance ? 1 : -1);
});
// Find closest point on line between the two samples (clamping the grid position to the line, just like clamping to the triangle edges)
BSPoint[] Samples = new BSPoint[2];
Samples[0] = SamplePoints[SampleDistances[0].Index];
Samples[1] = SamplePoints[SampleDistances[1].Index];
Vector3 ClosestPointOnTheLine = ClosestPointOnLine(Samples[0].Position, Samples[1].Position, GridPointPosition);
var temp = (Samples[0].Position - Samples[1].Position);
Vector2 tempVector2 = new Vector2(temp.X, temp.Y);
float LineLength = tempVector2.LengthSquared();
// Weight the samples according to the distance from the grid point on the line to the samples
for (int SampleIndex = 0; SampleIndex < 2; ++SampleIndex)
{
var thelength3D = (Samples[SampleIndex].Position - ClosestPointOnTheLine);
var thelength2D = new Vector2(thelength3D.X, thelength3D.Y);
GridPoint.Weights[SampleIndex] = (LineLength - thelength2D.LengthSquared()) / LineLength;
GridPoint.Indices[SampleIndex] = SamplePoints.FindIndex((point) => { return(point == Samples[SampleIndex]); });
}
}
}
}
}
}
}
public void Reset()
{
GridPoints.Clear();
}