/// <summary>
/// { Returns the triangle neighbouring aTriangle which is nearer to
/// aPoint than aTriangle.If aPoint is in aTriangle then aTriangle is
/// returned, and found set to true. If aPoint is outside the model,
/// returns Nil - requires model to be convex. }
/// </summary>
/// <param name="aPoint"></param>
/// <param name="aTriangle"></param>
/// <param name="lastTri"></param>
/// <param name="found"></param>
/// <returns></returns>
protected Triangle GetBestTri(TriVertex aPoint, Triangle aTriangle, Triangle lastTri, out bool found)
{
Triangle Result;
found = false;
TriVertex firstPoint = aTriangle.Vertices[0];
TriVertex secondPoint = aTriangle.Vertices[1];
if (aTriangle.Neighbours[0] != lastTri && TinningUtils.DefinitelyLeftOfBaseLine(aPoint, firstPoint, secondPoint))
{
Result = aTriangle.Neighbours[0];
}
else
{
TriVertex thirdPoint = aTriangle.Vertices[2];
if (aTriangle.Neighbours[1] != lastTri && TinningUtils.DefinitelyLeftOfBaseLine(aPoint, secondPoint, thirdPoint))
{
Result = aTriangle.Neighbours[1];
}
else if (aTriangle.Neighbours[2] != lastTri && TinningUtils.DefinitelyLeftOfBaseLine(aPoint, thirdPoint, firstPoint))
{
Result = aTriangle.Neighbours[2];
}
else // to the right of each line -must be inside aTriangle
{
Result = aTriangle;
found = true;
}
}
return(Result);
}
/// <summary>
/// Returns true if the circumcircle of theTri contains theCoordRec
/// </summary>
/// <param name="theTri"></param>
/// <param name="theCoord"></param>
/// <returns></returns>
protected bool Influenced(Triangle theTri, TriVertex theCoord)
{
var result = false;
double cotan = TinningUtils.Cotangent(theTri.Vertices[2], theTri.Vertices[0], theTri.Vertices[1]);
if (cotan > -1E20)
{
double cNorth = ((theTri.Vertices[1].Y + theTri.Vertices[0].Y) / 2) -
((theTri.Vertices[1].X - theTri.Vertices[0].X) / 2) *
cotan;
double cEast = ((theTri.Vertices[1].X + theTri.Vertices[0].X) / 2) +
((theTri.Vertices[1].Y - theTri.Vertices[0].Y) / 2) *
cotan;
double radSq = Math.Pow(cNorth - theTri.Vertices[0].Y, 2) + Math.Pow(cEast - theTri.Vertices[0].X, 2);
result = Math.Pow(theCoord.X - cEast, 2) + Math.Pow(theCoord.Y - cNorth, 2) < radSq;
}
return(result);
}
