/* approximates a bezier curve with a set of circular arcs by dividing where
* the bezier's deviation from its approximating biarc is at a maximum, then
* recursively calling on the subsections until it is approximated to
* tolerance by the biarc
*/
HIDDEN void
approx_bezier(const ON_BezierCurve& bezier, const ON_Arc& biarc, const struct bn_tol *tol, std::vector<ON_Arc>& approx)
{
fastf_t t = 0.0, step = 0.0;
fastf_t crv = 0.0, err = 0.0, max_t = 0.0, max_err = 0.0;
ON_3dPoint test;
ON_3dVector d1, d2;
// walk the bezier curve at interval given by step
for (t = 0; t <= 1.0; t += step) {
bezier.Ev2Der(t, test, d1, d2);
err = fabs((test - biarc.Center()).Length() - biarc.Radius());
// find the maximum point of deviation
if (err > max_err) {
max_t = t;
max_err = err;
}
crv = CURVATURE(d1, d2);
// step size decreases as |crv| -> 1
step = GETSTEPSIZE(1.0 - fabs(crv));
}
if (max_err + VDIVIDE_TOL < tol->dist) {
// max deviation is less than the given tolerance, add the biarc approximation
approx.push_back(biarc);
} else {
ON_BezierCurve head, tail;
// split bezier at point of maximum deviation and recurse on the new subsections
bezier.Split(max_t, head, tail);
approx_bezier(head, make_biarc(head), tol, approx);
approx_bezier(tail, make_biarc(tail), tol, approx);
}
}
/**
* \return List of bezier spline segments which together represent this curve.
*/
QList<RSpline> RSpline::getBezierSegments() const {
// spline is a single bezier segment:
if (countControlPoints()==getDegree()+1) {
return QList<RSpline>() << *this;
}
updateInternal();
QList<RSpline> ret;
#ifndef R_NO_OPENNURBS
ON_NurbsCurve* dup = dynamic_cast<ON_NurbsCurve*>(curve.DuplicateCurve());
if (dup==NULL) {
return ret;
}
dup->MakePiecewiseBezier();
for (int i=0; i<=dup->CVCount() - dup->Order(); ++i) {
ON_BezierCurve bc;
if (!dup->ConvertSpanToBezier(i, bc)) {
continue;
}
QList<RVector> ctrlPts;
for (int cpi=0; cpi<bc.CVCount(); cpi++) {
ON_3dPoint onp;
bc.GetCV(cpi, onp);
ctrlPts.append(RVector(onp.x, onp.y, onp.z));
}
ret.append(RSpline(ctrlPts, degree));
}
delete dup;
#endif
return ret;
}
/* find a point of inflection on a bezier curve, if it exists, by finding the
* value of parameter 't' where the signed curvature of the bezier changes
* signs. Returns true if an inflection point is found.
*/
HIDDEN bool
bezier_inflection(const ON_BezierCurve& bezier, fastf_t& inflection_pt)
{
int sign;
fastf_t t, step, crv;
ON_3dVector d1, d2; // first derivative, second derivative
ON_3dPoint tmp; // not used, but needed by Ev2Der
// calculate curvature at t=0
bezier.Ev2Der(0, tmp, d1, d2);
crv = CURVATURE(d1, d2);
// step size decreases as |crv| -> 0
step = GETSTEPSIZE(fabs(crv));
sign = SIGN(crv);
for (t = step; t <= 1.0; t += step) {
bezier.Ev2Der(t, tmp, d1, d2);
crv = CURVATURE(d1, d2);
// if sign changes, t is an inflection point
if (sign != SIGN(crv)) {
inflection_pt = t;
return true;
}
step = GETSTEPSIZE(fabs(crv));
}
return false;
}
/* create a biarc for a bezier curve.
*
* extends the tangent lines to the bezier curve at its first and last control
* points, and intersects them to find a third point.
* the biarc passes through the first and last control points, and the incenter
* of the circle defined by the first, last and intersection points.
*/
HIDDEN ON_Arc
make_biarc(const ON_BezierCurve& bezier)
{
ON_2dPoint isect, arc_pt;
ON_2dPoint p_start(bezier.PointAt(0)), p_end(bezier.PointAt(1.0));
ON_2dVector t_start(bezier.TangentAt(0)), t_end(bezier.TangentAt(1.0));
ON_Ray r_start(p_start, t_start), r_end(p_end, t_end);
r_start.IntersectRay(r_end, isect);
arc_pt = incenter(p_start, p_end, isect);
return ON_Arc(p_start, arc_pt, p_end);
}
RH_C_FUNCTION ON_BezierCurve* ON_BezierCurve_Loft2(int count, /*ARRAY*/const ON_2dPoint* points)
{
ON_BezierCurve* rc = NULL;
if( count && points )
{
rc = new ON_BezierCurve();
if( rc->Loft(2, count, 2, &(points->x), 0, 0) )
{
delete rc;
rc = NULL;
}
}
return rc;
}
RH_C_FUNCTION ON_BezierCurve* ON_BezierCurve_Loft(int count, /*ARRAY*/const ON_3dPoint* points)
{
ON_BezierCurve* rc = NULL;
if( count && points )
{
rc = new ON_BezierCurve();
ON_3dPointArray _pts(count);
_pts.Append(count, points);
if( !rc->Loft(_pts) )
{
delete rc;
rc = NULL;
}
}
return rc;
}
/* approximates a bezier curve with a set of circular arcs.
* returns approximation in carcs
*/
HIDDEN void
bezier_to_carcs(const ON_BezierCurve& bezier, const struct bn_tol *tol, std::vector<ON_Arc>& carcs)
{
bool skip_while = true, curvature_changed = false;
fastf_t inflection_pt, biarc_angle;
ON_Arc biarc;
ON_BezierCurve current, next;
std::vector<ON_BezierCurve> rest;
// find inflection point, if it exists
if (bezier_inflection(bezier, inflection_pt)) {
curvature_changed = true;
bezier.Split(inflection_pt, current, next);
rest.push_back(next);
} else {
current = bezier;
}
while (skip_while || !rest.empty()) {
if (skip_while) skip_while = false;
biarc = make_biarc(current);
if ((biarc_angle = biarc.AngleRadians()) <= M_PI_2) {
// approximate the current bezier segment and add its biarc
// approximation to carcs
approx_bezier(current, biarc, tol, carcs);
} else if (biarc_angle <= M_PI) {
// divide the current bezier segment in half
current.Split(0.5, current, next);
// approximate first bezier segment
approx_bezier(current, biarc, tol, carcs);
// approximate second bezier segment
approx_bezier(next, biarc, tol, carcs);
} else {
fastf_t t = 1.0;
ON_Arc test_biarc;
ON_BezierCurve test_bezier;
// divide the current bezier such that the first curve segment would
// have an approximating biarc segment <=90 degrees
do {
t *= 0.5;
current.Split(t, test_bezier, next);
test_biarc = make_biarc(test_bezier);
} while(test_biarc.AngleRadians() > M_PI_2);
approx_bezier(test_bezier, test_biarc, tol, carcs);
current = next;
skip_while = true;
continue;
}
if (curvature_changed) {
curvature_changed = false;
current = rest.back();
rest.pop_back();
// continue even if we just popped the last element
skip_while = true;
}
}
}
/*
* Need to be updated to return bezier objects instead of returning coordinate vectors.
* No external need to cast to bezier and then find intersections.
*/
void Spline::generateBeziers() {
std::vector<std::vector<lc::geo::Coordinate>> bezlist;
auto curve = _splineCurve.Duplicate();
curve->MakePiecewiseBezier();
ON_3dPoint p;
int deg = curve->Degree();
int cpcount = curve->CVCount();
for (int i=0; i<deg+cpcount+2; ++i) {
ON_BezierCurve bc;
if (curve->ConvertSpanToBezier(i, bc)) {
std::vector<geo::Coordinate> bez;
for (int j=0; j<bc.CVCount(); j++) {
bc.GetCV(j, p);
bez.push_back(geo::Coordinate(p.x, p.y, p.z));
}
_beziers.push_back(bez);
}
}
}
extern "C" void
rt_hyp_brep(ON_Brep **b, const struct rt_db_internal *ip, const struct bn_tol *)
{
struct rt_hyp_internal *eip;
RT_CK_DB_INTERNAL(ip);
eip = (struct rt_hyp_internal *)ip->idb_ptr;
RT_HYP_CK_MAGIC(eip);
point_t p1_origin, p2_origin;
ON_3dPoint plane1_origin, plane2_origin;
ON_3dVector plane_x_dir, plane_y_dir;
// First, find planes corresponding to the top and bottom faces - initially
vect_t x_dir, y_dir;
VMOVE(x_dir, eip->hyp_A);
VCROSS(y_dir, eip->hyp_A, eip->hyp_Hi);
VREVERSE(y_dir, y_dir);
VMOVE(p1_origin, eip->hyp_Vi);
plane1_origin = ON_3dPoint(p1_origin);
plane_x_dir = ON_3dVector(x_dir);
plane_y_dir = ON_3dVector(y_dir);
const ON_Plane hyp_bottom_plane(plane1_origin, plane_x_dir, plane_y_dir);
VADD2(p2_origin, eip->hyp_Vi, eip->hyp_Hi);
plane2_origin = ON_3dPoint(p2_origin);
const ON_Plane hyp_top_plane(plane2_origin, plane_x_dir, plane_y_dir);
// Next, create ellipses in the planes corresponding to the edges of the hyp
ON_Ellipse b_ell(hyp_bottom_plane, MAGNITUDE(eip->hyp_A), eip->hyp_b);
ON_NurbsCurve* bcurve = ON_NurbsCurve::New();
b_ell.GetNurbForm((*bcurve));
bcurve->SetDomain(0.0, 1.0);
ON_Ellipse t_ell(hyp_top_plane, MAGNITUDE(eip->hyp_A), eip->hyp_b);
ON_NurbsCurve* tcurve = ON_NurbsCurve::New();
t_ell.GetNurbForm((*tcurve));
tcurve->SetDomain(0.0, 1.0);
// Generate the bottom cap
ON_SimpleArray<ON_Curve*> boundary;
boundary.Append(ON_Curve::Cast(bcurve));
ON_PlaneSurface* bp = new ON_PlaneSurface();
bp->m_plane = hyp_bottom_plane;
bp->SetDomain(0, -100.0, 100.0);
bp->SetDomain(1, -100.0, 100.0);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->m_S.Append(bp);
const int bsi = (*b)->m_S.Count() - 1;
ON_BrepFace& bface = (*b)->NewFace(bsi);
(*b)->NewPlanarFaceLoop(bface.m_face_index, ON_BrepLoop::outer, boundary, true);
const ON_BrepLoop* bloop = (*b)->m_L.Last();
bp->SetDomain(0, bloop->m_pbox.m_min.x, bloop->m_pbox.m_max.x);
bp->SetDomain(1, bloop->m_pbox.m_min.y, bloop->m_pbox.m_max.y);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->FlipFace(bface);
(*b)->SetTrimIsoFlags(bface);
boundary.Empty();
delete bcurve;
// Generate the top cap
boundary.Append(ON_Curve::Cast(tcurve));
ON_PlaneSurface* tp = new ON_PlaneSurface();
tp->m_plane = hyp_top_plane;
tp->SetDomain(0, -100.0, 100.0);
tp->SetDomain(1, -100.0, 100.0);
tp->SetExtents(0, bp->Domain(0));
tp->SetExtents(1, bp->Domain(1));
(*b)->m_S.Append(tp);
int tsi = (*b)->m_S.Count() - 1;
ON_BrepFace& tface = (*b)->NewFace(tsi);
(*b)->NewPlanarFaceLoop(tface.m_face_index, ON_BrepLoop::outer, boundary, true);
ON_BrepLoop* tloop = (*b)->m_L.Last();
tp->SetDomain(0, tloop->m_pbox.m_min.x, tloop->m_pbox.m_max.x);
tp->SetDomain(1, tloop->m_pbox.m_min.y, tloop->m_pbox.m_max.y);
tp->SetExtents(0, bp->Domain(0));
tp->SetExtents(1, bp->Domain(1));
(*b)->SetTrimIsoFlags(tface);
delete tcurve;
// Now, the hard part. Need an elliptical hyperbolic NURBS surface.
// First step is to create a nurbs curve.
double MX = eip->hyp_b * eip->hyp_bnr;
point_t ep1, ep2, ep3;
VSET(ep1, -eip->hyp_b, 0, 0.5*MAGNITUDE(eip->hyp_Hi));
VSET(ep2, -MX*eip->hyp_bnr, 0, 0);
VSET(ep3, -eip->hyp_b, 0, -0.5*MAGNITUDE(eip->hyp_Hi));
ON_3dPoint onp1 = ON_3dPoint(ep1);
ON_3dPoint onp2 = ON_3dPoint(ep2);
ON_3dPoint onp3 = ON_3dPoint(ep3);
ON_3dPointArray cpts(3);
cpts.Append(onp1);
cpts.Append(onp2);
cpts.Append(onp3);
ON_BezierCurve *bezcurve = new ON_BezierCurve(cpts);
bezcurve->MakeRational();
bezcurve->SetWeight(1, bezcurve->Weight(0)/eip->hyp_bnr);
ON_NurbsCurve* tnurbscurve = ON_NurbsCurve::New();
bezcurve->GetNurbForm(*tnurbscurve);
delete bezcurve;
ON_3dPoint revpnt1 = ON_3dPoint(0, 0, -0.5*MAGNITUDE(eip->hyp_Hi));
ON_3dPoint revpnt2 = ON_3dPoint(0, 0, 0.5*MAGNITUDE(eip->hyp_Hi));
ON_Line revaxis = ON_Line(revpnt1, revpnt2);
ON_RevSurface* hyp_surf = ON_RevSurface::New();
hyp_surf->m_curve = tnurbscurve;
hyp_surf->m_axis = revaxis;
hyp_surf->m_angle = ON_Interval(0, 2*ON_PI);
// Get the NURBS form of the surface
ON_NurbsSurface *hypcurvedsurf = ON_NurbsSurface::New();
hyp_surf->GetNurbForm(*hypcurvedsurf, 0.0);
delete hyp_surf;
for (int i = 0; i < hypcurvedsurf->CVCount(0); i++) {
for (int j = 0; j < hypcurvedsurf->CVCount(1); j++) {
point_t cvpt;
ON_4dPoint ctrlpt;
hypcurvedsurf->GetCV(i, j, ctrlpt);
// Scale and shear
vect_t proj_ah;
vect_t proj_ax;
fastf_t factor;
VPROJECT(eip->hyp_A, eip->hyp_Hi, proj_ah, proj_ax);
VSET(cvpt, ctrlpt.x * MAGNITUDE(proj_ax)/eip->hyp_b, ctrlpt.y, ctrlpt.z);
factor = VDOT(eip->hyp_A, eip->hyp_Hi)>0 ? 1.0 : -1.0;
cvpt[2] += factor*cvpt[0]/MAGNITUDE(proj_ax)*MAGNITUDE(proj_ah) + 0.5*MAGNITUDE(eip->hyp_Hi)*ctrlpt.w;
// Rotate
vect_t Au, Bu, Hu;
mat_t R;
point_t new_cvpt;
VSCALE(Bu, y_dir, 1/MAGNITUDE(y_dir));
VSCALE(Hu, eip->hyp_Hi, 1/MAGNITUDE(eip->hyp_Hi));
VCROSS(Au, Bu, Hu);
VUNITIZE(Au);
MAT_IDN(R);
VMOVE(&R[0], Au);
VMOVE(&R[4], Bu);
VMOVE(&R[8], Hu);
VEC3X3MAT(new_cvpt, cvpt, R);
VMOVE(cvpt, new_cvpt);
// Translate
vect_t scale_v;
VSCALE(scale_v, eip->hyp_Vi, ctrlpt.w);
VADD2(cvpt, cvpt, scale_v);
ON_4dPoint newpt = ON_4dPoint(cvpt[0], cvpt[1], cvpt[2], ctrlpt.w);
hypcurvedsurf->SetCV(i, j, newpt);
}
}
(*b)->m_S.Append(hypcurvedsurf);
int surfindex = (*b)->m_S.Count();
ON_BrepFace& face = (*b)->NewFace(surfindex - 1);
(*b)->FlipFace(face);
int faceindex = (*b)->m_F.Count();
(*b)->NewOuterLoop(faceindex-1);
}
extern "C" void
rt_ehy_brep(ON_Brep **b, const struct rt_db_internal *ip, const struct bn_tol *)
{
struct rt_ehy_internal *eip;
RT_CK_DB_INTERNAL(ip);
eip = (struct rt_ehy_internal *)ip->idb_ptr;
RT_EHY_CK_MAGIC(eip);
// Check the parameters
if (!NEAR_ZERO(VDOT(eip->ehy_Au, eip->ehy_H), RT_DOT_TOL)) {
bu_log("rt_ehy_brep: Au and H are not perpendicular!\n");
return;
}
if (!NEAR_EQUAL(MAGNITUDE(eip->ehy_Au), 1.0, RT_LEN_TOL)) {
bu_log("rt_ehy_brep: Au not a unit vector!\n");
return;
}
if (MAGNITUDE(eip->ehy_H) < RT_LEN_TOL
|| eip->ehy_c < RT_LEN_TOL
|| eip->ehy_r1 < RT_LEN_TOL
|| eip->ehy_r2 < RT_LEN_TOL) {
bu_log("rt_ehy_brep: not all dimensions positive!\n");
return;
}
if (eip->ehy_r2 > eip->ehy_r1) {
bu_log("rt_ehy_brep: semi-minor axis cannot be longer than semi-major axis!\n");
return;
}
point_t p1_origin;
ON_3dPoint plane1_origin, plane2_origin;
ON_3dVector plane_x_dir, plane_y_dir;
// First, find plane in 3 space corresponding to the bottom face of the EPA.
vect_t x_dir, y_dir;
VMOVE(x_dir, eip->ehy_Au);
VCROSS(y_dir, eip->ehy_Au, eip->ehy_H);
VUNITIZE(y_dir);
VMOVE(p1_origin, eip->ehy_V);
plane1_origin = ON_3dPoint(p1_origin);
plane_x_dir = ON_3dVector(x_dir);
plane_y_dir = ON_3dVector(y_dir);
const ON_Plane ehy_bottom_plane(plane1_origin, plane_x_dir, plane_y_dir);
// Next, create an ellipse in the plane corresponding to the edge of the ehy.
ON_Ellipse ellipse1(ehy_bottom_plane, eip->ehy_r1, eip->ehy_r2);
ON_NurbsCurve* ellcurve1 = ON_NurbsCurve::New();
ellipse1.GetNurbForm((*ellcurve1));
ellcurve1->SetDomain(0.0, 1.0);
// Generate the bottom cap
ON_SimpleArray<ON_Curve*> boundary;
boundary.Append(ON_Curve::Cast(ellcurve1));
ON_PlaneSurface* bp = new ON_PlaneSurface();
bp->m_plane = ehy_bottom_plane;
bp->SetDomain(0, -100.0, 100.0);
bp->SetDomain(1, -100.0, 100.0);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->m_S.Append(bp);
const int bsi = (*b)->m_S.Count() - 1;
ON_BrepFace& bface = (*b)->NewFace(bsi);
(*b)->NewPlanarFaceLoop(bface.m_face_index, ON_BrepLoop::outer, boundary, true);
const ON_BrepLoop* bloop = (*b)->m_L.Last();
bp->SetDomain(0, bloop->m_pbox.m_min.x, bloop->m_pbox.m_max.x);
bp->SetDomain(1, bloop->m_pbox.m_min.y, bloop->m_pbox.m_max.y);
bp->SetExtents(0, bp->Domain(0));
bp->SetExtents(1, bp->Domain(1));
(*b)->SetTrimIsoFlags(bface);
delete ellcurve1;
// Now, the hard part. Need an elliptical hyperbolic NURBS surface
// First step is to create a nurbs curve.
double intercept_calc = (eip->ehy_c)*(eip->ehy_c)/(MAGNITUDE(eip->ehy_H) + eip->ehy_c);
double intercept_dist = MAGNITUDE(eip->ehy_H) + eip->ehy_c - intercept_calc;
double intercept_length = intercept_dist - MAGNITUDE(eip->ehy_H);
double MX = MAGNITUDE(eip->ehy_H);
double MP = MX + intercept_length;
double w = (MX/MP)/(1-MX/MP);
point_t ep1, ep2, ep3;
VSET(ep1, -eip->ehy_r1, 0, 0);
VSET(ep2, 0, 0, w*intercept_dist);
VSET(ep3, eip->ehy_r1, 0, 0);
ON_3dPoint onp1 = ON_3dPoint(ep1);
ON_3dPoint onp2 = ON_3dPoint(ep2);
ON_3dPoint onp3 = ON_3dPoint(ep3);
ON_3dPointArray cpts(3);
cpts.Append(onp1);
cpts.Append(onp2);
cpts.Append(onp3);
ON_BezierCurve *bcurve = new ON_BezierCurve(cpts);
bcurve->MakeRational();
bcurve->SetWeight(1, w);
ON_NurbsCurve* tnurbscurve = ON_NurbsCurve::New();
bcurve->GetNurbForm(*tnurbscurve);
ON_NurbsCurve* hypbnurbscurve = ON_NurbsCurve::New();
const ON_Interval subinterval = ON_Interval(0, 0.5);
tnurbscurve->GetNurbForm(*hypbnurbscurve, 0.0, &subinterval);
// Next, rotate that curve around the height vector.
point_t revpoint1, revpoint2;
VSET(revpoint1, 0, 0, 0);
VSET(revpoint2, 0, 0, MX);
ON_3dPoint rpnt1 = ON_3dPoint(revpoint1);
ON_3dPoint rpnt2 = ON_3dPoint(revpoint2);
ON_Line revaxis = ON_Line(rpnt1, rpnt2);
ON_RevSurface* hyp_surf = ON_RevSurface::New();
hyp_surf->m_curve = hypbnurbscurve;
hyp_surf->m_axis = revaxis;
hyp_surf->m_angle = ON_Interval(0, 2*ON_PI);
// Get the NURBS form of the surface
ON_NurbsSurface *ehycurvedsurf = ON_NurbsSurface::New();
hyp_surf->GetNurbForm(*ehycurvedsurf, 0.0);
delete hyp_surf;
delete tnurbscurve;
delete bcurve;
// Transformations
for (int i = 0; i < ehycurvedsurf->CVCount(0); i++) {
for (int j = 0; j < ehycurvedsurf->CVCount(1); j++) {
point_t cvpt;
ON_4dPoint ctrlpt;
ehycurvedsurf->GetCV(i, j, ctrlpt);
// Scale the control points of the
// resulting surface to map to the shorter axis.
VSET(cvpt, ctrlpt.x, ctrlpt.y * eip->ehy_r2/eip->ehy_r1, ctrlpt.z);
// Rotate according to the directions of Au and H
vect_t Hu;
mat_t R;
point_t new_cvpt;
VSCALE(Hu, eip->ehy_H, 1/MAGNITUDE(eip->ehy_H));
MAT_IDN(R);
VMOVE(&R[0], eip->ehy_Au);
VMOVE(&R[4], y_dir);
VMOVE(&R[8], Hu);
VEC3X3MAT(new_cvpt, cvpt, R);
VMOVE(cvpt, new_cvpt);
// Translate according to V
vect_t scale_v;
VSCALE(scale_v, eip->ehy_V, ctrlpt.w);
VADD2(cvpt, cvpt, scale_v);
ON_4dPoint newpt = ON_4dPoint(cvpt[0], cvpt[1], cvpt[2], ctrlpt.w);
ehycurvedsurf->SetCV(i, j, newpt);
}
}
(*b)->m_S.Append(ehycurvedsurf);
int surfindex = (*b)->m_S.Count();
ON_BrepFace& face = (*b)->NewFace(surfindex - 1);
(*b)->FlipFace(face);
int faceindex = (*b)->m_F.Count();
(*b)->NewOuterLoop(faceindex-1);
}
bool ON_Arc::GetNurbFormParameterFromRadian(double RadianParameter, double* NurbParameter ) const
{
if(!IsValid() || NurbParameter==NULL)
return false;
ON_Interval ADomain = DomainRadians();
double endtol = 10.0*ON_EPSILON*(fabs(ADomain[0]) + fabs(ADomain[1]));
double del = RadianParameter - ADomain[0];
if(del <= endtol && del >= -ON_SQRT_EPSILON)
{
*NurbParameter=ADomain[0];
return true;
}
else {
del = ADomain[1] - RadianParameter;
if(del <= endtol && del >= -ON_SQRT_EPSILON){
*NurbParameter=ADomain[1];
return true;
}
}
if( !ADomain.Includes(RadianParameter ) )
return false;
ON_NurbsCurve crv;
if( !GetNurbForm(crv))
return false;
//Isolate a bezier that contains the solution
int cnt = crv.SpanCount();
int si =0; //get span index
int ki=0; //knot index
double ang = ADomain[0];
ON_3dPoint cp;
cp = crv.PointAt( crv.Knot(0) ) - Center();
double x = ON_DotProduct(Plane().Xaxis(),cp);
double y = ON_DotProduct(Plane().Yaxis(),cp);
double at = atan2( y, x); //todo make sure we dont go to far
for( si=0, ki=0; si<cnt; si++, ki+=crv.KnotMultiplicity(ki) ){
cp = crv.PointAt( crv.Knot(ki+2)) - Center();
x = ON_DotProduct(Plane().Xaxis(),cp);
y = ON_DotProduct(Plane().Yaxis(),cp);
double at2 = atan2(y,x);
if(at2>at)
ang+=(at2-at);
else
ang += (2*ON_PI + at2 - at);
at = at2;
if( ang>RadianParameter)
break;
}
// Crash Protection trr#55679
if( ki+2>= crv.KnotCount())
{
*NurbParameter=ADomain[1];
return true;
}
ON_Interval BezDomain(crv.Knot(ki), crv.Knot(ki+2));
ON_BezierCurve bez;
if(!crv.ConvertSpanToBezier(ki,bez))
return false;
ON_Xform COC;
COC.ChangeBasis( ON_Plane(),Plane());
bez.Transform(COC); // change coordinates to circles local frame
double a[3]; // Bez coefficients of a quadratic to solve
for(int i=0; i<3; i++)
a[i] = tan(RadianParameter)* bez.CV(i)[0] - bez.CV(i)[1];
//Solve the Quadratic
double descrim = (a[1]*a[1]) - a[0]*a[2];
double squared = a[0]-2*a[1]+a[2];
double tbez;
if(fabs(squared)> ON_ZERO_TOLERANCE){
ON_ASSERT(descrim>=0);
descrim = sqrt(descrim);
tbez = (a[0]-a[1] + descrim)/(a[0]-2*a[1]+a[2]);
if( tbez<0 || tbez>1){
double tbez2 = (a[0]-a[1]-descrim)/(a[0] - 2*a[1] + a[2]);
if( fabs(tbez2 - .5)<fabs(tbez-.5) )
tbez = tbez2;
}
ON_ASSERT(tbez>=-ON_ZERO_TOLERANCE && tbez<=1+ON_ZERO_TOLERANCE);
}
else{
// Quadratic degenerates to linear
tbez = 1.0;
if(a[0]-a[2])
tbez = a[0]/(a[0]-a[2]);
}
if(tbez<0)
tbez=0.0;
else if(tbez>1.0)
tbez=1.0;
//Debug ONLY Code - check the result
// double aa = a[0]*(1-tbez)*(1-tbez) + 2*a[1]*tbez*(1-tbez) + a[2]*tbez*tbez;
// double tantheta= tan(RadianParameter);
// ON_3dPoint bezp;
// bez.Evaluate(tbez, 0, 3, bezp);
// double yx = bezp.y/bezp.x;
*NurbParameter = BezDomain.ParameterAt(tbez);
return true;
}
