/// \brief drop cutter at (cl.x, cl.y) against facet of Triangle t
/// calls xy_normal_length(), normal_length(), and center_height() on the subclass.
/// if cl.z is too low, updates cl.z so that cutter does not cut the facet.
/// CompositeCutter may be the only sub-class that needs to reimplement this function.
// general purpose facet-drop which calls xy_normal_length(), normal_length(),
// and center_height() on the subclass
//C++ TO C# CONVERTER WARNING: 'const' methods are not available in C#:
//ORIGINAL LINE: virtual bool facetDrop(CLPoint &cl, const Triangle &t) const
public virtual bool facetDrop(CLPoint cl, Triangle t)
{ // Drop cutter at (cl.x, cl.y) against facet of Triangle t
Point normal = t.upNormal(); // facet surface normal
if (GlobalMembers.isZero_tol(normal.z)) // vertical surface
{
return(false); //can't drop against vertical surface
}
Debug.Assert(GlobalMembers.isPositive(normal.z));
if ((GlobalMembers.isZero_tol(normal.x)) && (GlobalMembers.isZero_tol(normal.y)))
{ // horizontal plane special case
CCPoint cc_tmp = new CCPoint(cl.x, cl.y, t.p[0].z, CCType.FACET);
return(cl.liftZ_if_inFacet(cc_tmp.z, cc_tmp, t));
}
else
{ // general case
// plane containing facet: a*x + b*y + c*z + d = 0, so
// d = -a*x - b*y - c*z, where (a,b,c) = surface normal
double d = -normal.dot(t.p[0]);
normal.normalize(); // make length of normal == 1.0
Point xyNormal = new Point(normal.x, normal.y, 0.0);
xyNormal.xyNormalize();
// define the radiusvector which points from the cc-point to the cutter-center
Point radiusvector = this.xy_normal_length * xyNormal + this.normal_length * normal;
CCPoint cc_tmp = new CCPoint(cl - radiusvector); // NOTE xy-coords right, z-coord is not.
cc_tmp.z = (1.0 / normal.z) * (-d - normal.x * cc_tmp.x - normal.y * cc_tmp.y); // cc-point lies in the plane.
cc_tmp.type = CCType.FACET;
double tip_z = cc_tmp.z + radiusvector.z - this.center_height;
return(cl.liftZ_if_inFacet(tip_z, cc_tmp, t));
}
}
/// Cone facet-drop is special, since we can make contact with either the tip or the circular rim
// because this checks for contact with both the tip and the circular edge it is hard to move to the base-class
// we either hit the tip, when the slope of the plane is smaller than angle
// or when the slope is steep, the circular edge between the cone and the cylindrical shaft
//C++ TO C# CONVERTER WARNING: 'const' methods are not available in C#:
//ORIGINAL LINE: bool facetDrop(CLPoint &cl, const Triangle &t) const
public new bool facetDrop(CLPoint cl, Triangle t)
{
bool result = false;
Point normal = t.upNormal(); // facet surface normal
if (GlobalMembers.isZero_tol(normal.z)) // vertical surface
{
return(false); //can't drop against vertical surface
}
if ((GlobalMembers.isZero_tol(normal.x)) && (GlobalMembers.isZero_tol(normal.y)))
{ // horizontal plane special case
CCPoint cc_tmp = new CCPoint(cl.x, cl.y, t.p[0].z, CCType.FACET_TIP); // so any vertex is at the correct height
return(cl.liftZ_if_inFacet(cc_tmp.z, cc_tmp, t));
}
else
{
// define plane containing facet
// a*x + b*y + c*z + d = 0, so
// d = -a*x - b*y - c*z, where (a,b,c) = surface normal
double a = normal.x;
double b = normal.y;
double c = normal.z;
double d = -normal.dot(t.p[0]);
normal.xyNormalize(); // make xy length of normal == 1.0
// cylindrical contact point case
// find the xy-coordinates of the cc-point
CCPoint cyl_cc_tmp = new CCPoint(cl - radius * normal);
cyl_cc_tmp.z = (1.0 / c) * (-d - a * cyl_cc_tmp.x - b * cyl_cc_tmp.y);
double cyl_cl_z = cyl_cc_tmp.z - length; // tip positioned here
cyl_cc_tmp.type = CCType.FACET_CYL;
// tip contact with facet
CCPoint tip_cc_tmp = new CCPoint(cl.x, cl.y, 0.0);
tip_cc_tmp.z = (1.0 / c) * (-d - a * tip_cc_tmp.x - b * tip_cc_tmp.y);
double tip_cl_z = tip_cc_tmp.z;
tip_cc_tmp.type = CCType.FACET_TIP;
result = result || cl.liftZ_if_inFacet(tip_cl_z, tip_cc_tmp, t);
result = result || cl.liftZ_if_inFacet(cyl_cl_z, cyl_cc_tmp, t);
return(result);
}
}
