double
SurfaceOverlapFacet::projected_overlap( SurfaceOverlapFacet &other_facet, CubitBoolean draw_overlap )
{
double tmp_double = agt->ProjectedOverlap( t, other_facet.t, draw_overlap );
if( tmp_double > 0.00 )
{
CubitVector edge0(t.e0.x, t.e0.y, t.e0.z);
CubitVector edge1(t.e1.x, t.e1.y, t.e1.z);
CubitVector normal = edge0 * edge1;
double area_facet1 = normal.length() / 2;
edge0.set(other_facet.t.e0.x, other_facet.t.e0.y, other_facet.t.e0.z);
edge1.set(other_facet.t.e1.x, other_facet.t.e1.y, other_facet.t.e1.z);
normal = edge0 * edge1;
double area_facet2 = normal.length() / 2;
//don't report overlapping area between facets unless it is greater
//than one hundredth of the area of the smaller facet
if( area_facet1 < area_facet2 )
{
if( tmp_double < (area_facet1*0.01))
tmp_double = 0.0;
}
else if( tmp_double < (area_facet2*0.01 ))
tmp_double = 0.0;
}
return tmp_double;
}
double CurveOverlapFacet::facet_to_facet_distance( CurveOverlapFacet *other_facet )
{
CubitVector u = p1 - p0;
CubitVector v = other_facet->p1 - other_facet->p0;
CubitVector w = p0 - other_facet->p0;
double a = u%u;
double b = u%v;
double c = v%v;
double d = u%w;
double e = v%w;
double D = a*c - b*b;
double sc, sN, sD = D;
double tc, tN, tD = D;
// compute the line parameters of the two closest points
if( D < GEOMETRY_RESABS ) ///the lines are almost parallel
{
sN = 0.0; // force using point P0 on segment S1
sD = 1.0; // to prevent possible division by 0.0 later
tN = e;
tD = c;
}
else // get the closest points on the infinite lines
{
sN = (b*e - c*d);
tN = (a*e - b*d);
if (sN < 0.0)
{ // sc < 0 => the s=0 edge is visible
sN = 0.0;
tN = e;
tD = c;
}
else if (sN > sD)
{ // sc > 1 => the s=1 edge is visible
sN = sD;
tN = e + b;
tD = c;
}
}
if (tN < 0.0)
{ // tc < 0 => the t=0 edge is visible
tN = 0.0;
// recompute sc for this edge
if (-d < 0.0)
sN = 0.0;
else if (-d > a)
sN = sD;
else
{
sN = -d;
sD = a;
}
}
else if (tN > tD)
{ // tc > 1 => the t=1 edge is visible
tN = tD;
// recompute sc for this edge
if ((-d + b) < 0.0)
sN = 0;
else if ((-d + b) > a)
sN = sD;
else
{
sN = (-d + b);
sD = a;
}
}
// finally do the division to get sc and tc
sc = (fabs(sN) < GEOMETRY_RESABS ? 0.0 : sN / sD);
tc = (fabs(tN) < GEOMETRY_RESABS ? 0.0 : tN / tD);
// get the difference of the two closest points
CubitVector dP = w + (sc * u) - (tc * v); // = S1(sc) - S2(tc)
return dP.length(); // return the closest distance
}
