/// <summary>
/// Returns true if coordinate (x,y) is inside element
/// </summary>
public static bool Includes(this MeshElement element, double x, double y, double tolerance)
{
bool isQuad = element.IsQuadrilateral();
List <MeshNode> elementNodes = element.Nodes;
if (!isQuad)
{
return
(LeftDistance(x, y, elementNodes[0], elementNodes[1]) >= -tolerance &&
LeftDistance(x, y, elementNodes[1], elementNodes[2]) >= -tolerance &&
LeftDistance(x, y, elementNodes[2], elementNodes[0]) >= -tolerance);
}
return
(LeftDistance(x, y, elementNodes[0], elementNodes[1]) >= -tolerance &&
LeftDistance(x, y, elementNodes[1], elementNodes[2]) >= -tolerance &&
LeftDistance(x, y, elementNodes[2], elementNodes[3]) >= -tolerance &&
LeftDistance(x, y, elementNodes[3], elementNodes[0]) >= -tolerance);
}
/// <summary>
/// Add a target, by specifying its (x,y) coordinate.
/// </summary>
public void AddTarget(double x, double y)
{
if (_targets == null)
{
_targets = new List <InterPData>();
}
if (_searcher == null)
{
_searcher = new MeshSearcher(_mesh);
_searcher.SetupElementSearch();
}
InterPData interpData = new InterPData();
// Setting "out-of-bounds" index
interpData.Element1Index = -1;
// Find element that includes the (x,y) coordinate
MeshElement element = _searcher.FindElement(x, y);
// Check if element has been found, i.e. includes the (x,y) point
if (element != null)
{
bool found = false;
interpData.Element1Index = element.Index;
// Check which face the point belongs to, and which "side" of the face
bool isQuad = element.IsQuadrilateral();
int numFaces = isQuad ? 4 : 3;
for (int j = 0; j < numFaces; j++)
{
MeshFace elementFace = element.Faces[j];
// From the element (x,y), looking towards the face,
// figure out wich node is right and which is left.
MeshNode rightNode, leftNode;
if (elementFace.LeftElement == element)
{
rightNode = elementFace.FromNode;
leftNode = elementFace.ToNode;
}
else
{
rightNode = elementFace.ToNode;
leftNode = elementFace.FromNode;
}
// Find also the element on the other side of the face
double otherElementX, otherElementY;
MeshElement otherElement = elementFace.OtherElement(element);
if (otherElement != null)
{
otherElementX = otherElement.XCenter;
otherElementY = otherElement.YCenter;
interpData.Element2Index = otherElement.Index;
}
else
{
// No other element - boundary face, use center of face.
otherElementX = 0.5 * (rightNode.X + leftNode.X);
otherElementY = 0.5 * (rightNode.Y + leftNode.Y);
// Use "itself" as element-2
interpData.Element2Index = element.Index;
}
// Check if point is on the right side of the line between element and other-element
if (MeshExtensions.IsPointInsideLines(x, y, element.XCenter, element.YCenter, rightNode.X, rightNode.Y, otherElementX, otherElementY))
{
(double w1, double w2, double w3) = MeshExtensions.InterpolationWeights(x, y, element.XCenter, element.YCenter, rightNode.X, rightNode.Y, otherElementX, otherElementY);
interpData.NodeIndex = rightNode.Index;
interpData.Element1Weight = w1;
interpData.NodeWeight = w2;
interpData.Element2Weight = w3;
found = true;
break;
}
// Check if point is on the left side of the line between element and other-element
if (MeshExtensions.IsPointInsideLines(x, y, element.XCenter, element.YCenter, otherElementX, otherElementY, leftNode.X, leftNode.Y))
{
(double w1, double w2, double w3) = MeshExtensions.InterpolationWeights(x, y, element.XCenter, element.YCenter, otherElementX, otherElementY, leftNode.X, leftNode.Y);
interpData.NodeIndex = leftNode.Index;
interpData.Element1Weight = w1;
interpData.Element2Weight = w2;
interpData.NodeWeight = w3;
found = true;
break;
}
}
if (!found) // Should never happen, but just in case
{
interpData.Element1Weight = 1;
interpData.Element2Weight = 0;
interpData.NodeWeight = 0;
interpData.Element2Index = element.Index;
interpData.NodeIndex = element.Nodes[0].Index;
}
}
_targets.Add(interpData);
}