solvespace/constrainteq.cpp
Jonathan Westhues 9f7ff34b98 Add option to treat all dimensions as reference dimensions. This is
useful because it makes it possible to add cosmetic dimensions to
an existing model, without REF appended.

[git-p4: depot-paths = "//depot/solvespace/": change = 2140]
2010-05-09 17:06:09 -08:00

736 lines
26 KiB
C++

#include "solvespace.h"
const hConstraint ConstraintBase::NO_CONSTRAINT = { 0 };
bool ConstraintBase::HasLabel(void) {
switch(type) {
case PT_LINE_DISTANCE:
case PT_PLANE_DISTANCE:
case PT_FACE_DISTANCE:
case PT_PT_DISTANCE:
case PROJ_PT_DISTANCE:
case DIAMETER:
case LENGTH_RATIO:
case ANGLE:
case COMMENT:
return true;
default:
return false;
}
}
Expr *ConstraintBase::VectorsParallel(int eq, ExprVector a, ExprVector b) {
ExprVector r = a.Cross(b);
// Hairy ball theorem screws me here. There's no clean solution that I
// know, so let's pivot on the initial numerical guess. Our caller
// has ensured that if one of our input vectors is already known (e.g.
// it's from a previous group), then that one's in a; so that one's
// not going to move, and we should pivot on that one.
double mx = fabs((a.x)->Eval());
double my = fabs((a.y)->Eval());
double mz = fabs((a.z)->Eval());
// The basis vector in which the vectors have the LEAST energy is the
// one that we should look at most (e.g. if both vectors lie in the xy
// plane, then the z component of the cross product is most important).
// So find the strongest component of a and b, and that's the component
// of the cross product to ignore.
Expr *e0, *e1;
if(mx > my && mx > mz) {
e0 = r.y; e1 = r.z;
} else if(my > mz) {
e0 = r.z; e1 = r.x;
} else {
e0 = r.x; e1 = r.y;
}
if(eq == 0) return e0;
if(eq == 1) return e1;
oops();
}
Expr *ConstraintBase::PointLineDistance(hEntity wrkpl, hEntity hpt, hEntity hln)
{
EntityBase *ln = SK.GetEntity(hln);
EntityBase *a = SK.GetEntity(ln->point[0]);
EntityBase *b = SK.GetEntity(ln->point[1]);
EntityBase *p = SK.GetEntity(hpt);
if(wrkpl.v == EntityBase::FREE_IN_3D.v) {
ExprVector ep = p->PointGetExprs();
ExprVector ea = a->PointGetExprs();
ExprVector eb = b->PointGetExprs();
ExprVector eab = ea.Minus(eb);
Expr *m = eab.Magnitude();
return ((eab.Cross(ea.Minus(ep))).Magnitude())->Div(m);
} else {
Expr *ua, *va, *ub, *vb;
a->PointGetExprsInWorkplane(wrkpl, &ua, &va);
b->PointGetExprsInWorkplane(wrkpl, &ub, &vb);
Expr *du = ua->Minus(ub);
Expr *dv = va->Minus(vb);
Expr *u, *v;
p->PointGetExprsInWorkplane(wrkpl, &u, &v);
Expr *m = ((du->Square())->Plus(dv->Square()))->Sqrt();
Expr *proj = (dv->Times(ua->Minus(u)))->Minus(
(du->Times(va->Minus(v))));
return proj->Div(m);
}
}
Expr *ConstraintBase::PointPlaneDistance(ExprVector p, hEntity hpl) {
ExprVector n;
Expr *d;
SK.GetEntity(hpl)->WorkplaneGetPlaneExprs(&n, &d);
return (p.Dot(n))->Minus(d);
}
Expr *ConstraintBase::Distance(hEntity wrkpl, hEntity hpa, hEntity hpb) {
EntityBase *pa = SK.GetEntity(hpa);
EntityBase *pb = SK.GetEntity(hpb);
if(!(pa->IsPoint() && pb->IsPoint())) oops();
if(wrkpl.v == EntityBase::FREE_IN_3D.v) {
// This is true distance
ExprVector ea, eb, eab;
ea = pa->PointGetExprs();
eb = pb->PointGetExprs();
eab = ea.Minus(eb);
return eab.Magnitude();
} else {
// This is projected distance, in the given workplane.
Expr *au, *av, *bu, *bv;
pa->PointGetExprsInWorkplane(wrkpl, &au, &av);
pb->PointGetExprsInWorkplane(wrkpl, &bu, &bv);
Expr *du = au->Minus(bu);
Expr *dv = av->Minus(bv);
return ((du->Square())->Plus(dv->Square()))->Sqrt();
}
}
//-----------------------------------------------------------------------------
// Return the cosine of the angle between two vectors. If a workplane is
// specified, then it's the cosine of their projections into that workplane.
//-----------------------------------------------------------------------------
Expr *ConstraintBase::DirectionCosine(hEntity wrkpl,
ExprVector ae, ExprVector be)
{
if(wrkpl.v == EntityBase::FREE_IN_3D.v) {
Expr *mags = (ae.Magnitude())->Times(be.Magnitude());
return (ae.Dot(be))->Div(mags);
} else {
EntityBase *w = SK.GetEntity(wrkpl);
ExprVector u = w->Normal()->NormalExprsU();
ExprVector v = w->Normal()->NormalExprsV();
Expr *ua = u.Dot(ae);
Expr *va = v.Dot(ae);
Expr *ub = u.Dot(be);
Expr *vb = v.Dot(be);
Expr *maga = (ua->Square()->Plus(va->Square()))->Sqrt();
Expr *magb = (ub->Square()->Plus(vb->Square()))->Sqrt();
Expr *dot = (ua->Times(ub))->Plus(va->Times(vb));
return dot->Div(maga->Times(magb));
}
}
ExprVector ConstraintBase::PointInThreeSpace(hEntity workplane,
Expr *u, Expr *v)
{
EntityBase *w = SK.GetEntity(workplane);
ExprVector ub = w->Normal()->NormalExprsU();
ExprVector vb = w->Normal()->NormalExprsV();
ExprVector ob = w->WorkplaneGetOffsetExprs();
return (ub.ScaledBy(u)).Plus(vb.ScaledBy(v)).Plus(ob);
}
void ConstraintBase::ModifyToSatisfy(void) {
if(type == ANGLE) {
Vector a = SK.GetEntity(entityA)->VectorGetNum();
Vector b = SK.GetEntity(entityB)->VectorGetNum();
if(other) a = a.ScaledBy(-1);
if(workplane.v != EntityBase::FREE_IN_3D.v) {
a = a.ProjectVectorInto(workplane);
b = b.ProjectVectorInto(workplane);
}
double c = (a.Dot(b))/(a.Magnitude() * b.Magnitude());
valA = acos(c)*180/PI;
} else {
// We'll fix these ones up by looking at their symbolic equation;
// that means no extra work.
IdList<Equation,hEquation> l;
// An uninit IdList could lead us to free some random address, bad.
ZERO(&l);
// Generate the equations even if this is a reference dimension
GenerateReal(&l);
if(l.n != 1) oops();
// These equations are written in the form f(...) - d = 0, where
// d is the value of the valA.
valA += (l.elem[0].e)->Eval();
l.Clear();
}
}
void ConstraintBase::AddEq(IdList<Equation,hEquation> *l, Expr *expr, int index)
{
Equation eq;
eq.e = expr;
eq.h = h.equation(index);
l->Add(&eq);
}
void ConstraintBase::Generate(IdList<Equation,hEquation> *l) {
if(!reference) {
GenerateReal(l);
}
}
void ConstraintBase::GenerateReal(IdList<Equation,hEquation> *l) {
Expr *exA = Expr::From(valA);
switch(type) {
case PT_PT_DISTANCE:
AddEq(l, Distance(workplane, ptA, ptB)->Minus(exA), 0);
break;
case PROJ_PT_DISTANCE: {
ExprVector pA = SK.GetEntity(ptA)->PointGetExprs(),
pB = SK.GetEntity(ptB)->PointGetExprs(),
dp = pB.Minus(pA);
ExprVector pp = SK.GetEntity(entityA)->VectorGetExprs();
pp = pp.WithMagnitude(Expr::From(1.0));
AddEq(l, (dp.Dot(pp))->Minus(exA), 0);
break;
}
case PT_LINE_DISTANCE:
AddEq(l,
PointLineDistance(workplane, ptA, entityA)->Minus(exA), 0);
break;
case PT_PLANE_DISTANCE: {
ExprVector pt = SK.GetEntity(ptA)->PointGetExprs();
AddEq(l, (PointPlaneDistance(pt, entityA))->Minus(exA), 0);
break;
}
case PT_FACE_DISTANCE: {
ExprVector pt = SK.GetEntity(ptA)->PointGetExprs();
EntityBase *f = SK.GetEntity(entityA);
ExprVector p0 = f->FaceGetPointExprs();
ExprVector n = f->FaceGetNormalExprs();
AddEq(l, (pt.Minus(p0)).Dot(n)->Minus(exA), 0);
break;
}
case EQUAL_LENGTH_LINES: {
EntityBase *a = SK.GetEntity(entityA);
EntityBase *b = SK.GetEntity(entityB);
AddEq(l, Distance(workplane, a->point[0], a->point[1])->Minus(
Distance(workplane, b->point[0], b->point[1])), 0);
break;
}
// These work on distance squared, since the pt-line distances are
// signed, and we want the absolute value.
case EQ_LEN_PT_LINE_D: {
EntityBase *forLen = SK.GetEntity(entityA);
Expr *d1 = Distance(workplane, forLen->point[0], forLen->point[1]);
Expr *d2 = PointLineDistance(workplane, ptA, entityB);
AddEq(l, (d1->Square())->Minus(d2->Square()), 0);
break;
}
case EQ_PT_LN_DISTANCES: {
Expr *d1 = PointLineDistance(workplane, ptA, entityA);
Expr *d2 = PointLineDistance(workplane, ptB, entityB);
AddEq(l, (d1->Square())->Minus(d2->Square()), 0);
break;
}
case LENGTH_RATIO: {
EntityBase *a = SK.GetEntity(entityA);
EntityBase *b = SK.GetEntity(entityB);
Expr *la = Distance(workplane, a->point[0], a->point[1]);
Expr *lb = Distance(workplane, b->point[0], b->point[1]);
AddEq(l, (la->Div(lb))->Minus(exA), 0);
break;
}
case DIAMETER: {
EntityBase *circle = SK.GetEntity(entityA);
Expr *r = circle->CircleGetRadiusExpr();
AddEq(l, (r->Times(Expr::From(2)))->Minus(exA), 0);
break;
}
case EQUAL_RADIUS: {
EntityBase *c1 = SK.GetEntity(entityA);
EntityBase *c2 = SK.GetEntity(entityB);
AddEq(l, (c1->CircleGetRadiusExpr())->Minus(
c2->CircleGetRadiusExpr()), 0);
break;
}
case EQUAL_LINE_ARC_LEN: {
EntityBase *line = SK.GetEntity(entityA),
*arc = SK.GetEntity(entityB);
// Get the line length
ExprVector l0 = SK.GetEntity(line->point[0])->PointGetExprs(),
l1 = SK.GetEntity(line->point[1])->PointGetExprs();
Expr *ll = (l1.Minus(l0)).Magnitude();
// And get the arc radius, and the cosine of its angle
EntityBase *ao = SK.GetEntity(arc->point[0]),
*as = SK.GetEntity(arc->point[1]),
*af = SK.GetEntity(arc->point[2]);
ExprVector aos = (as->PointGetExprs()).Minus(ao->PointGetExprs()),
aof = (af->PointGetExprs()).Minus(ao->PointGetExprs());
Expr *r = aof.Magnitude();
ExprVector n = arc->Normal()->NormalExprsN();
ExprVector u = aos.WithMagnitude(Expr::From(1.0));
ExprVector v = n.Cross(u);
// so in our new csys, we start at (1, 0, 0)
Expr *costheta = aof.Dot(u)->Div(r);
Expr *sintheta = aof.Dot(v)->Div(r);
double thetas, thetaf, dtheta;
arc->ArcGetAngles(&thetas, &thetaf, &dtheta);
Expr *theta;
if(dtheta < 3*PI/4) {
theta = costheta->ACos();
} else if(dtheta < 5*PI/4) {
// As the angle crosses pi, cos theta is not invertible;
// so use the sine to stop blowing up
theta = Expr::From(PI)->Minus(sintheta->ASin());
} else {
theta = (Expr::From(2*PI))->Minus(costheta->ACos());
}
// And write the equation; r*theta = L
AddEq(l, (r->Times(theta))->Minus(ll), 0);
break;
}
case POINTS_COINCIDENT: {
EntityBase *a = SK.GetEntity(ptA);
EntityBase *b = SK.GetEntity(ptB);
if(workplane.v == EntityBase::FREE_IN_3D.v) {
ExprVector pa = a->PointGetExprs();
ExprVector pb = b->PointGetExprs();
AddEq(l, pa.x->Minus(pb.x), 0);
AddEq(l, pa.y->Minus(pb.y), 1);
AddEq(l, pa.z->Minus(pb.z), 2);
} else {
Expr *au, *av;
Expr *bu, *bv;
a->PointGetExprsInWorkplane(workplane, &au, &av);
b->PointGetExprsInWorkplane(workplane, &bu, &bv);
AddEq(l, au->Minus(bu), 0);
AddEq(l, av->Minus(bv), 1);
}
break;
}
case PT_IN_PLANE:
// This one works the same, whether projected or not.
AddEq(l, PointPlaneDistance(
SK.GetEntity(ptA)->PointGetExprs(), entityA), 0);
break;
case PT_ON_FACE: {
// a plane, n dot (p - p0) = 0
ExprVector p = SK.GetEntity(ptA)->PointGetExprs();
EntityBase *f = SK.GetEntity(entityA);
ExprVector p0 = f->FaceGetPointExprs();
ExprVector n = f->FaceGetNormalExprs();
AddEq(l, (p.Minus(p0)).Dot(n), 0);
break;
}
case PT_ON_LINE:
if(workplane.v == EntityBase::FREE_IN_3D.v) {
EntityBase *ln = SK.GetEntity(entityA);
EntityBase *a = SK.GetEntity(ln->point[0]);
EntityBase *b = SK.GetEntity(ln->point[1]);
EntityBase *p = SK.GetEntity(ptA);
ExprVector ep = p->PointGetExprs();
ExprVector ea = a->PointGetExprs();
ExprVector eb = b->PointGetExprs();
ExprVector eab = ea.Minus(eb);
// Construct a vector from the point to either endpoint of
// the line segment, and choose the longer of these.
ExprVector eap = ea.Minus(ep);
ExprVector ebp = eb.Minus(ep);
ExprVector elp =
(ebp.Magnitude()->Eval() > eap.Magnitude()->Eval()) ?
ebp : eap;
if(p->group.v == group.v) {
AddEq(l, VectorsParallel(0, eab, elp), 0);
AddEq(l, VectorsParallel(1, eab, elp), 1);
} else {
AddEq(l, VectorsParallel(0, elp, eab), 0);
AddEq(l, VectorsParallel(1, elp, eab), 1);
}
} else {
AddEq(l, PointLineDistance(workplane, ptA, entityA), 0);
}
break;
case PT_ON_CIRCLE: {
// This actually constrains the point to lie on the cylinder.
EntityBase *circle = SK.GetEntity(entityA);
ExprVector center = SK.GetEntity(circle->point[0])->PointGetExprs();
ExprVector pt = SK.GetEntity(ptA)->PointGetExprs();
EntityBase *normal = SK.GetEntity(circle->normal);
ExprVector u = normal->NormalExprsU(),
v = normal->NormalExprsV();
Expr *du = (center.Minus(pt)).Dot(u),
*dv = (center.Minus(pt)).Dot(v);
Expr *r = circle->CircleGetRadiusExpr();
AddEq(l,
((du->Square())->Plus(dv->Square()))->Minus(r->Square()), 0);
break;
}
case AT_MIDPOINT:
if(workplane.v == EntityBase::FREE_IN_3D.v) {
EntityBase *ln = SK.GetEntity(entityA);
ExprVector a = SK.GetEntity(ln->point[0])->PointGetExprs();
ExprVector b = SK.GetEntity(ln->point[1])->PointGetExprs();
ExprVector m = (a.Plus(b)).ScaledBy(Expr::From(0.5));
if(ptA.v) {
ExprVector p = SK.GetEntity(ptA)->PointGetExprs();
AddEq(l, (m.x)->Minus(p.x), 0);
AddEq(l, (m.y)->Minus(p.y), 1);
AddEq(l, (m.z)->Minus(p.z), 2);
} else {
AddEq(l, PointPlaneDistance(m, entityB), 0);
}
} else {
EntityBase *ln = SK.GetEntity(entityA);
EntityBase *a = SK.GetEntity(ln->point[0]);
EntityBase *b = SK.GetEntity(ln->point[1]);
Expr *au, *av, *bu, *bv;
a->PointGetExprsInWorkplane(workplane, &au, &av);
b->PointGetExprsInWorkplane(workplane, &bu, &bv);
Expr *mu = Expr::From(0.5)->Times(au->Plus(bu));
Expr *mv = Expr::From(0.5)->Times(av->Plus(bv));
if(ptA.v) {
EntityBase *p = SK.GetEntity(ptA);
Expr *pu, *pv;
p->PointGetExprsInWorkplane(workplane, &pu, &pv);
AddEq(l, pu->Minus(mu), 0);
AddEq(l, pv->Minus(mv), 1);
} else {
ExprVector m = PointInThreeSpace(workplane, mu, mv);
AddEq(l, PointPlaneDistance(m, entityB), 0);
}
}
break;
case SYMMETRIC:
if(workplane.v == EntityBase::FREE_IN_3D.v) {
EntityBase *plane = SK.GetEntity(entityA);
EntityBase *ea = SK.GetEntity(ptA);
EntityBase *eb = SK.GetEntity(ptB);
ExprVector a = ea->PointGetExprs();
ExprVector b = eb->PointGetExprs();
// The midpoint of the line connecting the symmetric points
// lies on the plane of the symmetry.
ExprVector m = (a.Plus(b)).ScaledBy(Expr::From(0.5));
AddEq(l, PointPlaneDistance(m, plane->h), 0);
// And projected into the plane of symmetry, the points are
// coincident.
Expr *au, *av, *bu, *bv;
ea->PointGetExprsInWorkplane(plane->h, &au, &av);
eb->PointGetExprsInWorkplane(plane->h, &bu, &bv);
AddEq(l, au->Minus(bu), 1);
AddEq(l, av->Minus(bv), 2);
} else {
EntityBase *plane = SK.GetEntity(entityA);
EntityBase *a = SK.GetEntity(ptA);
EntityBase *b = SK.GetEntity(ptB);
Expr *au, *av, *bu, *bv;
a->PointGetExprsInWorkplane(workplane, &au, &av);
b->PointGetExprsInWorkplane(workplane, &bu, &bv);
Expr *mu = Expr::From(0.5)->Times(au->Plus(bu));
Expr *mv = Expr::From(0.5)->Times(av->Plus(bv));
ExprVector m = PointInThreeSpace(workplane, mu, mv);
AddEq(l, PointPlaneDistance(m, plane->h), 0);
// Construct a vector within the workplane that is normal
// to the symmetry pane's normal (i.e., that lies in the
// plane of symmetry). The line connecting the points is
// perpendicular to that constructed vector.
EntityBase *w = SK.GetEntity(workplane);
ExprVector u = w->Normal()->NormalExprsU();
ExprVector v = w->Normal()->NormalExprsV();
ExprVector pa = a->PointGetExprs();
ExprVector pb = b->PointGetExprs();
ExprVector n;
Expr *d;
plane->WorkplaneGetPlaneExprs(&n, &d);
AddEq(l, (n.Cross(u.Cross(v))).Dot(pa.Minus(pb)), 1);
}
break;
case SYMMETRIC_HORIZ:
case SYMMETRIC_VERT: {
EntityBase *a = SK.GetEntity(ptA);
EntityBase *b = SK.GetEntity(ptB);
Expr *au, *av, *bu, *bv;
a->PointGetExprsInWorkplane(workplane, &au, &av);
b->PointGetExprsInWorkplane(workplane, &bu, &bv);
if(type == SYMMETRIC_HORIZ) {
AddEq(l, av->Minus(bv), 0);
AddEq(l, au->Plus(bu), 1);
} else {
AddEq(l, au->Minus(bu), 0);
AddEq(l, av->Plus(bv), 1);
}
break;
}
case SYMMETRIC_LINE: {
EntityBase *pa = SK.GetEntity(ptA);
EntityBase *pb = SK.GetEntity(ptB);
Expr *pau, *pav, *pbu, *pbv;
pa->PointGetExprsInWorkplane(workplane, &pau, &pav);
pb->PointGetExprsInWorkplane(workplane, &pbu, &pbv);
EntityBase *ln = SK.GetEntity(entityA);
EntityBase *la = SK.GetEntity(ln->point[0]);
EntityBase *lb = SK.GetEntity(ln->point[1]);
Expr *lau, *lav, *lbu, *lbv;
la->PointGetExprsInWorkplane(workplane, &lau, &lav);
lb->PointGetExprsInWorkplane(workplane, &lbu, &lbv);
Expr *dpu = pbu->Minus(pau), *dpv = pbv->Minus(pav);
Expr *dlu = lbu->Minus(lau), *dlv = lbv->Minus(lav);
// The line through the points is perpendicular to the line
// of symmetry.
AddEq(l, (dlu->Times(dpu))->Plus(dlv->Times(dpv)), 0);
// And the signed distances of the points to the line are
// equal in magnitude and opposite in sign, so sum to zero
Expr *dista = (dlv->Times(lau->Minus(pau)))->Minus(
(dlu->Times(lav->Minus(pav))));
Expr *distb = (dlv->Times(lau->Minus(pbu)))->Minus(
(dlu->Times(lav->Minus(pbv))));
AddEq(l, dista->Plus(distb), 1);
break;
}
case HORIZONTAL:
case VERTICAL: {
hEntity ha, hb;
if(entityA.v) {
EntityBase *e = SK.GetEntity(entityA);
ha = e->point[0];
hb = e->point[1];
} else {
ha = ptA;
hb = ptB;
}
EntityBase *a = SK.GetEntity(ha);
EntityBase *b = SK.GetEntity(hb);
Expr *au, *av, *bu, *bv;
a->PointGetExprsInWorkplane(workplane, &au, &av);
b->PointGetExprsInWorkplane(workplane, &bu, &bv);
AddEq(l, (type == HORIZONTAL) ? av->Minus(bv) : au->Minus(bu), 0);
break;
}
case SAME_ORIENTATION: {
EntityBase *a = SK.GetEntity(entityA);
EntityBase *b = SK.GetEntity(entityB);
if(b->group.v != group.v) {
SWAP(EntityBase *, a, b);
}
ExprVector au = a->NormalExprsU(),
av = a->NormalExprsV(),
an = a->NormalExprsN();
ExprVector bu = b->NormalExprsU(),
bv = b->NormalExprsV(),
bn = b->NormalExprsN();
AddEq(l, VectorsParallel(0, an, bn), 0);
AddEq(l, VectorsParallel(1, an, bn), 1);
Expr *d1 = au.Dot(bv);
Expr *d2 = au.Dot(bu);
// Allow either orientation for the coordinate system, depending
// on how it was drawn.
if(fabs(d1->Eval()) < fabs(d2->Eval())) {
AddEq(l, d1, 2);
} else {
AddEq(l, d2, 2);
}
break;
}
case PERPENDICULAR:
case ANGLE: {
EntityBase *a = SK.GetEntity(entityA);
EntityBase *b = SK.GetEntity(entityB);
ExprVector ae = a->VectorGetExprs();
ExprVector be = b->VectorGetExprs();
if(other) ae = ae.ScaledBy(Expr::From(-1));
Expr *c = DirectionCosine(workplane, ae, be);
if(type == ANGLE) {
// The direction cosine is equal to the cosine of the
// specified angle
Expr *rads = exA->Times(Expr::From(PI/180));
AddEq(l, c->Minus(rads->Cos()), 0);
} else {
// The dot product (and therefore the direction cosine)
// is equal to zero, perpendicular.
AddEq(l, c, 0);
}
break;
}
case EQUAL_ANGLE: {
EntityBase *a = SK.GetEntity(entityA);
EntityBase *b = SK.GetEntity(entityB);
EntityBase *c = SK.GetEntity(entityC);
EntityBase *d = SK.GetEntity(entityD);
ExprVector ae = a->VectorGetExprs();
ExprVector be = b->VectorGetExprs();
ExprVector ce = c->VectorGetExprs();
ExprVector de = d->VectorGetExprs();
if(other) ae = ae.ScaledBy(Expr::From(-1));
Expr *cab = DirectionCosine(workplane, ae, be);
Expr *ccd = DirectionCosine(workplane, ce, de);
AddEq(l, cab->Minus(ccd), 0);
break;
}
case ARC_LINE_TANGENT: {
EntityBase *arc = SK.GetEntity(entityA);
EntityBase *line = SK.GetEntity(entityB);
ExprVector ac = SK.GetEntity(arc->point[0])->PointGetExprs();
ExprVector ap =
SK.GetEntity(arc->point[other ? 2 : 1])->PointGetExprs();
ExprVector ld = line->VectorGetExprs();
// The line is perpendicular to the radius
AddEq(l, ld.Dot(ac.Minus(ap)), 0);
break;
}
case CUBIC_LINE_TANGENT: {
EntityBase *cubic = SK.GetEntity(entityA);
EntityBase *line = SK.GetEntity(entityB);
ExprVector a;
if(other) {
a = cubic->CubicGetFinishTangentExprs();
} else {
a = cubic->CubicGetStartTangentExprs();
}
ExprVector b = line->VectorGetExprs();
if(workplane.v == EntityBase::FREE_IN_3D.v) {
AddEq(l, VectorsParallel(0, a, b), 0);
AddEq(l, VectorsParallel(1, a, b), 1);
} else {
EntityBase *w = SK.GetEntity(workplane);
ExprVector wn = w->Normal()->NormalExprsN();
AddEq(l, (a.Cross(b)).Dot(wn), 0);
}
break;
}
case PARALLEL: {
EntityBase *ea = SK.GetEntity(entityA), *eb = SK.GetEntity(entityB);
if(eb->group.v != group.v) {
SWAP(EntityBase *, ea, eb);
}
ExprVector a = ea->VectorGetExprs();
ExprVector b = eb->VectorGetExprs();
if(workplane.v == EntityBase::FREE_IN_3D.v) {
AddEq(l, VectorsParallel(0, a, b), 0);
AddEq(l, VectorsParallel(1, a, b), 1);
} else {
EntityBase *w = SK.GetEntity(workplane);
ExprVector wn = w->Normal()->NormalExprsN();
AddEq(l, (a.Cross(b)).Dot(wn), 0);
}
break;
}
case WHERE_DRAGGED: {
EntityBase *ep = SK.GetEntity(ptA);
if(workplane.v == EntityBase::FREE_IN_3D.v) {
ExprVector ev = ep->PointGetExprs();
Vector v = ep->PointGetNum();
AddEq(l, ev.x->Minus(Expr::From(v.x)), 0);
AddEq(l, ev.y->Minus(Expr::From(v.y)), 1);
AddEq(l, ev.z->Minus(Expr::From(v.z)), 2);
} else {
Expr *u, *v;
ep->PointGetExprsInWorkplane(workplane, &u, &v);
AddEq(l, u->Minus(Expr::From(u->Eval())), 0);
AddEq(l, v->Minus(Expr::From(v->Eval())), 1);
}
break;
}
case COMMENT:
break;
default: oops();
}
}