/**
* Flip TriangleList(I) with TriangleList(J).
*/
private bool FlipTriangles(int TriangleIndexOne, int TriangleIndexTwo)
{
BSTriangle A = TriangleList[TriangleIndexOne];
BSTriangle B = TriangleList[TriangleIndexTwo];
// if already optimized, don't have to do any
BSPoint TestPt = A.FindNonSharingPoint(B);
// If it's not inside, we don't have to do any
if (GetCircumcircleState(A, TestPt) != ECircumCircleState.Inside)
{
return(false);
}
BSTriangle[] NewTriangles = new BSTriangle[2];
int TrianglesMade = 0;
for (int VertexIndexOne = 0; VertexIndexOne < 2; ++VertexIndexOne)
{
for (int VertexIndexTwo = VertexIndexOne + 1; VertexIndexTwo < 3; ++VertexIndexTwo)
{
// Check if these vertices form a valid triangle (should be non-colinear)
if (IsEligibleForTriangulation(A.Vertices[VertexIndexOne], A.Vertices[VertexIndexTwo], TestPt))
{
// Create the new triangle and check if the final (original) vertex falls inside or outside of it's circumcircle
BSTriangle NewTriangle = new BSTriangle(A.Vertices[VertexIndexOne], A.Vertices[VertexIndexTwo], TestPt);
int VertexIndexThree = 3 - (VertexIndexTwo + VertexIndexOne);
if (GetCircumcircleState(NewTriangle, A.Vertices[VertexIndexThree]) == ECircumCircleState.Outside)
{
// If so store the triangle and increment the number of triangles
//checkf(TrianglesMade < 2, TEXT("Incorrect number of triangles created"));
NewTriangles[TrianglesMade] = NewTriangle;
++TrianglesMade;
}
}
}
}
// In case two triangles were generated the flip was successful so we can add them to the list
if (TrianglesMade == 2)
{
AddTriangle(NewTriangles[0], false);
AddTriangle(NewTriangles[1], false);
}
return(TrianglesMade == 2);
}
