bool ContainsPoint(ref Triangle3d triangle, ref Plane3d plane, Vector3d point)
{
// Generate a coordinate system for the plane. The incoming triangle has
// vertices <V0,V1,V2>. The incoming plane has unit-length normal N.
// The incoming point is P. V0 is chosen as the origin for the plane. The
// coordinate axis directions are two unit-length vectors, U0 and U1,
// constructed so that {U0,U1,N} is an orthonormal set. Any point Q
// in the plane may be written as Q = V0 + x0*U0 + x1*U1. The coordinates
// are computed as x0 = Dot(U0,Q-V0) and x1 = Dot(U1,Q-V0).
Vector3d U0 = Vector3d.Zero, U1 = Vector3d.Zero;
Vector3d.GenerateComplementBasis(ref U0, ref U1, plane.Normal);
// Compute the planar coordinates for the points P, V1, and V2. To
// simplify matters, the origin is subtracted from the points, in which
// case the planar coordinates are for P-V0, V1-V0, and V2-V0.
Vector3d PmV0 = point - triangle[0];
Vector3d V1mV0 = triangle[1] - triangle[0];
Vector3d V2mV0 = triangle[2] - triangle[0];
// The planar representation of P-V0.
Vector2d ProjP = new Vector2d(U0.Dot(PmV0), U1.Dot(PmV0));
// The planar representation of the triangle <V0-V0,V1-V0,V2-V0>.
Vector2dTuple3 ProjV = new Vector2dTuple3(
Vector2d.Zero,
new Vector2d(U0.Dot(V1mV0), U1.Dot(V1mV0)),
new Vector2d(U0.Dot(V2mV0), U1.Dot(V2mV0)));
// Test whether P-V0 is in the triangle <0,V1-V0,V2-V0>.
QueryTuple2d query = new QueryTuple2d(ProjV);
if (query.ToTriangle(ProjP, 0, 1, 2) <= 0)
{
Result = IntersectionResult.Intersects;
Type = IntersectionType.Point;
Quantity = 1;
Points[0] = point;
return(true);
}
return(false);
}
public QueryTuple2d(Vector2dTuple3 tuple)
{
mVertices = tuple;
}
public QueryTuple2d(Vector2d v0, Vector2d v1, Vector2d v2)
{
mVertices = new Vector2dTuple3(v0, v1, v2);
}
Circle UpdateSupport3(int i, int[] permutation, Support support)
{
var point = new Vector2dTuple3(
Points[permutation[support.Index[0]]], // P0
Points[permutation[support.Index[1]]], // P1
Points[permutation[support.Index[2]]] // P2
);
Vector2d P3 = Points[permutation[i]];
// Permutations of type 2, used for calling ExactCircle2(..).
int numType2 = 3;
// Permutations of type 2, used for calling ExactCircle3(..).
int numType3 = 3;
Circle[] circle = circle_buf;
int indexCircle = 0;
double minRSqr = double.MaxValue;
int indexMinRSqr = -1;
double distDiff = 0, minDistDiff = double.MaxValue;
int indexMinDistDiff = -1;
// Permutations of type 2.
int j;
for (j = 0; j < numType2; ++j, ++indexCircle)
{
circle[indexCircle] = ExactCircle2(point[type2_3[j, 0]], ref P3);
if (circle[indexCircle].Radius < minRSqr)
{
if (Contains(point[type2_3[j, 1]], ref circle[indexCircle], ref distDiff) &&
Contains(point[type2_3[j, 2]], ref circle[indexCircle], ref distDiff))
{
minRSqr = circle[indexCircle].Radius;
indexMinRSqr = indexCircle;
}
else if (distDiff < minDistDiff)
{
minDistDiff = distDiff;
indexMinDistDiff = indexCircle;
}
}
}
// Permutations of type 3.
for (j = 0; j < numType3; ++j, ++indexCircle)
{
circle[indexCircle] = ExactCircle3(point[type3_3[j, 0]], point[type3_3[j, 1]], ref P3);
if (circle[indexCircle].Radius < minRSqr)
{
if (Contains(point[type3_3[j, 2]], ref circle[indexCircle], ref distDiff))
{
minRSqr = circle[indexCircle].Radius;
indexMinRSqr = indexCircle;
}
else if (distDiff < minDistDiff)
{
minDistDiff = distDiff;
indexMinDistDiff = indexCircle;
}
}
}
// Theoreticaly, indexMinRSqr >= 0, but floating-point round-off errors
// can lead to indexMinRSqr == -1. When this happens, the minimal circle
// is chosen to be the one that has the minimum absolute errors between
// the circle and points (barely) outside the circle.
if (indexMinRSqr == -1)
{
indexMinRSqr = indexMinDistDiff;
}
Circle minimal = circle[indexMinRSqr];
switch (indexMinRSqr)
{
case 0:
support.Quantity = 2;
support.Index[1] = i;
break;
case 1:
support.Quantity = 2;
support.Index[0] = i;
break;
case 2:
support.Quantity = 2;
support.Index[0] = support.Index[2];
support.Index[1] = i;
break;
case 3:
support.Index[2] = i;
break;
case 4:
support.Index[1] = i;
break;
case 5:
support.Index[0] = i;
break;
}
return(minimal);
}
