ON_Surface::ISO
ON_Surface::IsIsoparametric( const ON_Curve& curve, const ON_Interval* subdomain ) const
{
ISO iso = not_iso;
if ( subdomain )
{
ON_Interval cdom = curve.Domain();
double t0 = cdom.NormalizedParameterAt(subdomain->Min());
double t1 = cdom.NormalizedParameterAt(subdomain->Max());
if ( t0 < t1-ON_SQRT_EPSILON )
{
if ( (t0 > ON_SQRT_EPSILON && t0 < 1.0-ON_SQRT_EPSILON) || (t1 > ON_SQRT_EPSILON && t1 < 1.0-ON_SQRT_EPSILON) )
{
cdom.Intersection(*subdomain);
if ( cdom.IsIncreasing() )
{
ON_NurbsCurve nurbs_curve;
if ( curve.GetNurbForm( nurbs_curve, 0.0,&cdom) )
{
return IsIsoparametric( nurbs_curve, 0 );
}
}
}
}
}
ON_BoundingBox bbox;
double tolerance = 0.0;
const int dim = curve.Dimension();
if ( (dim == 2 || dim==3) && curve.GetBoundingBox(bbox) )
{
iso = IsIsoparametric( bbox );
switch (iso) {
case x_iso:
case W_iso:
case E_iso:
// make sure curve is a (nearly) vertical line
// and weed out vertical scribbles
tolerance = bbox.m_max.x - bbox.m_min.x;
if ( tolerance < ON_ZERO_TOLERANCE && ON_ZERO_TOLERANCE*1024.0 <= (bbox.m_max.y-bbox.m_min.y) )
{
// 26 March 2007 Dale Lear
// If tolerance is tiny, then use ON_ZERO_TOLERANCE
// This fixes cases where iso curves where not getting
// the correct flag because tol=1e-16 and the closest
// point to line had calculation errors of 1e-15.
tolerance = ON_ZERO_TOLERANCE;
}
if ( !curve.IsLinear( tolerance ) )
iso = not_iso;
break;
case y_iso:
case S_iso:
case N_iso:
// make sure curve is a (nearly) horizontal line
// and weed out horizontal scribbles
tolerance = bbox.m_max.y - bbox.m_min.y;
if ( tolerance < ON_ZERO_TOLERANCE && ON_ZERO_TOLERANCE*1024.0 <= (bbox.m_max.x-bbox.m_min.x) )
{
// 26 March 2007 Dale Lear
// If tolerance is tiny, then use ON_ZERO_TOLERANCE
// This fixes cases where iso curves where not getting
// the correct flag because tol=1e-16 and the closest
// point to line had calculation errors of 1e-15.
tolerance = ON_ZERO_TOLERANCE;
}
if ( !curve.IsLinear( tolerance ) )
iso = not_iso;
break;
default:
// nothing here
break;
}
}
return iso;
}
int
main(int, char**)
{
srand(time(0));
ON_3dPoint center(0.0, 0.0, 0.0);
double radius = 10.0;
ON_Sphere sphere(center, radius);
ON_Brep *brep = ON_BrepSphere(sphere);
ON_3dPoint p1(0.0, 0.0, 0.0);
ON_3dPoint p2(0.0, 0.0, radius);
// Point-point intersection
bu_log("*** Point-point intersection ***\n");
test_ppi(p1, p1);
test_ppi(p1, p2);
// Point-curve intersection
bu_log("*** Point-curve intersection ***\n");
// brep->m_C3[0] is an arc curve that starts from (0, 0, -R)
// to (0, 0, R) through (R, 0, 0) which forms a semicircle.
ON_Curve *curve = brep->m_C3[0];
ON_3dPoint mid = curve->PointAt(curve->Domain().Mid());
bu_log("debug: %f %f %f\n", mid[0], mid[1], mid[2]);
bu_log("** Part 1 **\n");
test_pci(p1, *curve);
test_pci(p2, *curve);
// Now we use some randomized points (should intersect)
bu_log("** Part 2 **\n");
for (int i = 0; i < 10; i++) {
double x = rand_f(0.0, radius);
double y = 0.0;
double z = sqrt(radius*radius-x*x);
if (rand() % 2) z = -z; // sometimes we have it negative
ON_3dPoint test_pt(x, y, z);
test_pci(test_pt, *curve);
}
// More randomize points (maybe no intersection)
bu_log("** Part 3 **\n");
for (int i = 0; i < 10; i++) {
// We use test points randomly distributed inside a cube
// from (-R, -R, -R) to (R, R, R)
double x = rand_f(-radius, radius);
double y = rand_f(-radius, radius);
double z = rand_f(-radius, radius);
ON_3dPoint test_pt(x, y, z);
test_pci(test_pt, *curve);
}
// Point-surface intersection
bu_log("*** Point-surface intersection ***\n");
bu_log("** Part 1 **\n");
ON_Surface *surf = brep->m_S[0];
test_psi(p1, *surf);
test_psi(p2, *surf);
// Now we use some randomized points (should intersect)
bu_log("** Part 2 **\n");
for (int i = 0; i < 10; i++) {
double x = rand_f(-radius, radius);
double y_range = sqrt(radius*radius-x*x);
double y = rand_f(-y_range, y_range);
double z = sqrt(y_range*y_range-y*y);
if (rand() % 2) z = -z; // sometimes we have it negative
ON_3dPoint test_pt(x, y, z);
test_psi(test_pt, *surf);
}
// More randomize points (maybe no intersection)
bu_log("** Part 3 **\n");
for (int i = 0; i < 10; i++) {
// We use test points randomly distributed inside a cube
// from (-R, -R, -R) to (R, R, R)
double x = rand_f(-radius, radius);
double y = rand_f(-radius, radius);
double z = rand_f(-radius, radius);
ON_3dPoint test_pt(x, y, z);
test_psi(test_pt, *surf);
}
delete brep;
bu_log("All finished.\n");
return 0;
}
