solvespace/constraint.cpp

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#include "solvespace.h"
const hConstraint Constraint::NO_CONSTRAINT = { 0 };
char *Constraint::DescriptionString(void) {
static char ret[1024];
char *s;
switch(type) {
case POINTS_COINCIDENT: s = "pts-coincident"; break;
case PT_PT_DISTANCE: s = "pt-pt-distance"; break;
case PT_LINE_DISTANCE: s = "pt-line-distance"; break;
case PT_PLANE_DISTANCE: s = "pt-plane-distance"; break;
case PT_FACE_DISTANCE: s = "pt-face-distance"; break;
case PT_IN_PLANE: s = "pt-in-plane"; break;
case PT_ON_LINE: s = "pt-on-line"; break;
case PT_ON_FACE: s = "pt-on-face"; break;
case EQUAL_LENGTH_LINES:s = "eq-length"; break;
case EQ_LEN_PT_LINE_D: s = "eq-length-and-pt-ln-dist"; break;
case EQ_PT_LN_DISTANCES:s = "eq-pt-line-distances"; break;
case LENGTH_RATIO: s = "length-ratio"; break;
case SYMMETRIC: s = "symmetric"; break;
case SYMMETRIC_HORIZ: s = "symmetric-h"; break;
case SYMMETRIC_VERT: s = "symmetric-v"; break;
case AT_MIDPOINT: s = "at-midpoint"; break;
case HORIZONTAL: s = "horizontal"; break;
case VERTICAL: s = "vertical"; break;
case DIAMETER: s = "diameter"; break;
case PT_ON_CIRCLE: s = "pt-on-circle"; break;
case SAME_ORIENTATION: s = "same-orientation"; break;
case ANGLE: s = "angle"; break;
case PARALLEL: s = "parallel"; break;
case EQUAL_RADIUS: s = "eq-radius"; break;
case COMMENT: s = "comment"; break;
default: s = "???"; break;
}
sprintf(ret, "c%03x-%s", h.v, s);
return ret;
}
void Constraint::AddConstraint(Constraint *c) {
AddConstraint(c, true);
}
void Constraint::AddConstraint(Constraint *c, bool rememberForUndo) {
if(rememberForUndo) SS.UndoRemember();
SS.constraint.AddAndAssignId(c);
SS.MarkGroupDirty(c->group);
SS.later.generateAll = true;
}
void Constraint::Constrain(int type, hEntity ptA, hEntity ptB, hEntity entityA)
{
Constraint c;
memset(&c, 0, sizeof(c));
c.group = SS.GW.activeGroup;
c.workplane = SS.GW.ActiveWorkplane();
c.type = type;
c.ptA = ptA;
c.ptB = ptB;
c.entityA = entityA;
AddConstraint(&c, false);
}
void Constraint::ConstrainCoincident(hEntity ptA, hEntity ptB) {
Constrain(POINTS_COINCIDENT, ptA, ptB, Entity::NO_ENTITY);
}
void Constraint::MenuConstrain(int id) {
Constraint c;
memset(&c, 0, sizeof(c));
c.group = SS.GW.activeGroup;
c.workplane = SS.GW.ActiveWorkplane();
SS.GW.GroupSelection();
#define gs (SS.GW.gs)
switch(id) {
case GraphicsWindow::MNU_DISTANCE_DIA: {
if(gs.points == 2 && gs.n == 2) {
c.type = PT_PT_DISTANCE;
c.ptA = gs.point[0];
c.ptB = gs.point[1];
} else if(gs.lineSegments == 1 && gs.n == 1) {
c.type = PT_PT_DISTANCE;
Entity *e = SS.GetEntity(gs.entity[0]);
c.ptA = e->point[0];
c.ptB = e->point[1];
} else if(gs.workplanes == 1 && gs.points == 1 && gs.n == 2) {
c.type = PT_PLANE_DISTANCE;
c.ptA = gs.point[0];
c.entityA = gs.entity[0];
} else if(gs.lineSegments == 1 && gs.points == 1 && gs.n == 2) {
c.type = PT_LINE_DISTANCE;
c.ptA = gs.point[0];
c.entityA = gs.entity[0];
} else if(gs.faces == 1 && gs.points == 1 && gs.n == 2) {
c.type = PT_FACE_DISTANCE;
c.ptA = gs.point[0];
c.entityA = gs.face[0];
} else if(gs.circlesOrArcs == 1 && gs.n == 1) {
c.type = DIAMETER;
c.entityA = gs.entity[0];
} else {
Error("Bad selection for distance / diameter constraint.");
return;
}
if(c.type == PT_PT_DISTANCE) {
Vector n = SS.GW.projRight.Cross(SS.GW.projUp);
Vector a = SS.GetEntity(c.ptA)->PointGetNum();
Vector b = SS.GetEntity(c.ptB)->PointGetNum();
c.disp.offset = n.Cross(a.Minus(b));
c.disp.offset = (c.disp.offset).WithMagnitude(50/SS.GW.scale);
} else {
c.disp.offset = Vector::From(0, 0, 0);
}
c.valA = 0;
c.ModifyToSatisfy();
AddConstraint(&c);
break;
}
case GraphicsWindow::MNU_ON_ENTITY:
if(gs.points == 2 && gs.n == 2) {
c.type = POINTS_COINCIDENT;
c.ptA = gs.point[0];
c.ptB = gs.point[1];
} else if(gs.points == 1 && gs.workplanes == 1 && gs.n == 2) {
c.type = PT_IN_PLANE;
c.ptA = gs.point[0];
c.entityA = gs.entity[0];
} else if(gs.points == 1 && gs.lineSegments == 1 && gs.n == 2) {
c.type = PT_ON_LINE;
c.ptA = gs.point[0];
c.entityA = gs.entity[0];
} else if(gs.points == 1 && gs.circlesOrArcs == 1 && gs.n == 2) {
c.type = PT_ON_CIRCLE;
c.ptA = gs.point[0];
c.entityA = gs.entity[0];
} else if(gs.points == 1 && gs.faces == 1 && gs.n == 2) {
c.type = PT_ON_FACE;
c.ptA = gs.point[0];
c.entityA = gs.face[0];
} else {
Error("Bad selection for on point / curve / plane constraint.");
return;
}
AddConstraint(&c);
break;
case GraphicsWindow::MNU_EQUAL:
if(gs.lineSegments == 2 && gs.n == 2) {
c.type = EQUAL_LENGTH_LINES;
c.entityA = gs.entity[0];
c.entityB = gs.entity[1];
} else if(gs.lineSegments == 2 && gs.points == 2 && gs.n == 4) {
c.type = EQ_PT_LN_DISTANCES;
c.entityA = gs.entity[0];
c.ptA = gs.point[0];
c.entityB = gs.entity[1];
c.ptB = gs.point[1];
} else if(gs.lineSegments == 1 && gs.points == 2 && gs.n == 3) {
// The same line segment for the distances, but different
// points.
c.type = EQ_PT_LN_DISTANCES;
c.entityA = gs.entity[0];
c.ptA = gs.point[0];
c.entityB = gs.entity[0];
c.ptB = gs.point[1];
} else if(gs.lineSegments == 2 && gs.points == 1 && gs.n == 3) {
c.type = EQ_LEN_PT_LINE_D;
c.entityA = gs.entity[0];
c.entityB = gs.entity[1];
c.ptA = gs.point[0];
} else if(gs.circlesOrArcs == 2 && gs.n == 2) {
c.type = EQUAL_RADIUS;
c.entityA = gs.entity[0];
c.entityB = gs.entity[1];
} else {
Error("Bad selection for equal length / radius constraint.");
return;
}
AddConstraint(&c);
break;
case GraphicsWindow::MNU_RATIO:
if(gs.lineSegments == 2 && gs.n == 2) {
c.type = LENGTH_RATIO;
c.entityA = gs.entity[0];
c.entityB = gs.entity[1];
} else {
Error("Bad selection for length ratio constraint.");
return;
}
c.valA = 0;
c.ModifyToSatisfy();
AddConstraint(&c);
break;
case GraphicsWindow::MNU_AT_MIDPOINT:
if(gs.lineSegments == 1 && gs.points == 1 && gs.n == 2) {
c.type = AT_MIDPOINT;
c.entityA = gs.entity[0];
c.ptA = gs.point[0];
} else if(gs.lineSegments == 1 && gs.workplanes == 1 && gs.n == 2) {
c.type = AT_MIDPOINT;
int i = SS.GetEntity(gs.entity[0])->IsWorkplane() ? 1 : 0;
c.entityA = gs.entity[i];
c.entityB = gs.entity[1-i];
} else {
Error("Bad selection for at midpoint constraint.");
return;
}
AddConstraint(&c);
break;
case GraphicsWindow::MNU_SYMMETRIC:
if(gs.points == 2 &&
((gs.workplanes == 1 && gs.n == 3) ||
(gs.n == 2)))
{
c.entityA = gs.entity[0];
c.ptA = gs.point[0];
c.ptB = gs.point[1];
} else if(gs.lineSegments == 1 &&
((gs.workplanes == 1 && gs.n == 2) ||
(gs.n == 1)))
{
int i = SS.GetEntity(gs.entity[0])->IsWorkplane() ? 1 : 0;
Entity *line = SS.GetEntity(gs.entity[i]);
c.entityA = gs.entity[1-i];
c.ptA = line->point[0];
c.ptB = line->point[1];
} else {
Error("Bad selection for symmetric constraint.");
return;
}
if(c.entityA.v == Entity::NO_ENTITY.v) {
if(c.workplane.v == Entity::FREE_IN_3D.v) {
Error("Must be locked in to workplane when constraining "
"symmetric without an explicit symmetry plane.");
return;
}
Vector pa = SS.GetEntity(c.ptA)->PointGetNum();
Vector pb = SS.GetEntity(c.ptB)->PointGetNum();
Vector dp = pa.Minus(pb);
Entity *norm = SS.GetEntity(c.workplane)->Normal();;
Vector u = norm->NormalU(), v = norm->NormalV();
if(fabs(dp.Dot(u)) > fabs(dp.Dot(v))) {
c.type = SYMMETRIC_HORIZ;
} else {
c.type = SYMMETRIC_VERT;
}
if(gs.lineSegments == 1) {
// If this line segment is already constrained horiz or
// vert, then auto-remove that redundant constraint.
SS.constraint.ClearTags();
for(int i = 0; i < SS.constraint.n; i++) {
Constraint *ct = &(SS.constraint.elem[i]);
if(ct->type != HORIZONTAL && ct->type != VERTICAL) {
continue;
}
if(ct->entityA.v != (gs.entity[0]).v) continue;
ct->tag = 1;
}
SS.constraint.RemoveTagged();
// And no need to do anything special, since nothing
// ever depends on a constraint.
}
} else {
// Symmetry with a symmetry plane specified explicitly.
c.type = SYMMETRIC;
}
AddConstraint(&c);
break;
case GraphicsWindow::MNU_VERTICAL:
case GraphicsWindow::MNU_HORIZONTAL: {
hEntity ha, hb;
if(c.workplane.v == Entity::FREE_IN_3D.v) {
Error("Select workplane before constraining horiz/vert.");
return;
}
if(gs.lineSegments == 1 && gs.n == 1) {
c.entityA = gs.entity[0];
Entity *e = SS.GetEntity(c.entityA);
ha = e->point[0];
hb = e->point[1];
} else if(gs.points == 2 && gs.n == 2) {
ha = c.ptA = gs.point[0];
hb = c.ptB = gs.point[1];
} else {
Error("Bad selection for horizontal / vertical constraint.");
return;
}
if(id == GraphicsWindow::MNU_HORIZONTAL) {
c.type = HORIZONTAL;
} else {
c.type = VERTICAL;
}
AddConstraint(&c);
break;
}
case GraphicsWindow::MNU_ORIENTED_SAME: {
if(gs.anyNormals == 2 && gs.n == 2) {
c.type = SAME_ORIENTATION;
c.entityA = gs.anyNormal[0];
c.entityB = gs.anyNormal[1];
} else {
Error("Bad selection for same orientation constraint.");
return;
}
SS.UndoRemember();
Entity *nfree = SS.GetEntity(c.entityA);
Entity *nref = SS.GetEntity(c.entityB);
if(nref->group.v == SS.GW.activeGroup.v) {
SWAP(Entity *, nref, nfree);
}
if(nfree->group.v == SS.GW.activeGroup.v &&
nref ->group.v != SS.GW.activeGroup.v)
{
// nfree is free, and nref is locked (since it came from a
// previous group); so let's force nfree aligned to nref,
// and make convergence easy
Vector ru = nref ->NormalU(), rv = nref ->NormalV();
Vector fu = nfree->NormalU(), fv = nfree->NormalV();
if(fabs(fu.Dot(ru)) < fabs(fu.Dot(rv))) {
// There might be an odd*90 degree rotation about the
// normal vector; allow that, since the numerical
// constraint does
SWAP(Vector, ru, rv);
}
fu = fu.Dot(ru) > 0 ? ru : ru.ScaledBy(-1);
fv = fv.Dot(rv) > 0 ? rv : rv.ScaledBy(-1);
nfree->NormalForceTo(Quaternion::From(fu, fv));
}
AddConstraint(&c, false);
break;
}
case GraphicsWindow::MNU_OTHER_ANGLE:
if(gs.constraints == 1 && gs.n == 0) {
Constraint *c = SS.GetConstraint(gs.constraint[0]);
if(c->type == ANGLE) {
c->otherAngle = !(c->otherAngle);
c->ModifyToSatisfy();
break;
}
}
Error("Must select an angle constraint.");
return;
case GraphicsWindow::MNU_REFERENCE:
if(gs.constraints == 1 && gs.n == 0) {
Constraint *c = SS.GetConstraint(gs.constraint[0]);
if(c->HasLabel() && c->type != COMMENT) {
(c->reference) = !(c->reference);
SS.GetGroup(c->group)->clean = false;
SS.GenerateAll();
break;
}
}
Error("Must select a constraint with associated label.");
return;
case GraphicsWindow::MNU_ANGLE:
if(gs.vectors == 2 && gs.n == 2) {
c.type = ANGLE;
c.entityA = gs.vector[0];
c.entityB = gs.vector[1];
c.valA = 0;
c.otherAngle = true;
} else {
Error("Bad selection for angle constraint.");
return;
}
c.ModifyToSatisfy();
AddConstraint(&c);
break;
case GraphicsWindow::MNU_PARALLEL:
if(gs.vectors == 2 && gs.n == 2) {
c.type = PARALLEL;
c.entityA = gs.vector[0];
c.entityB = gs.vector[1];
} else {
Error("Bad selection for parallel constraint.");
return;
}
AddConstraint(&c);
break;
case GraphicsWindow::MNU_COMMENT:
c.type = COMMENT;
c.comment.strcpy("NEW COMMENT -- DOUBLE-CLICK TO EDIT");
c.disp.offset = SS.GW.offset.ScaledBy(-1);
AddConstraint(&c);
break;
case GraphicsWindow::MNU_SOLVE_NOW:
SS.ReloadAllImported();
SS.GenerateAll(0, INT_MAX);
return;
default: oops();
}
SS.GW.ClearSelection();
InvalidateGraphics();
}
Expr *Constraint::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.
double m = max(mx, max(my, mz));
Expr *e0, *e1;
if(m == mx) { e0 = r.y; e1 = r.z; }
else if(m == my) { e0 = r.z; e1 = r.x; }
else if(m == mz) { e0 = r.x; e1 = r.y; }
else oops();
if(eq == 0) return e0;
if(eq == 1) return e1;
oops();
}
Expr *Constraint::PointLineDistance(hEntity wrkpl, hEntity hpt, hEntity hln) {
Entity *ln = SS.GetEntity(hln);
Entity *a = SS.GetEntity(ln->point[0]);
Entity *b = SS.GetEntity(ln->point[1]);
Entity *p = SS.GetEntity(hpt);
if(wrkpl.v == Entity::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 *Constraint::PointPlaneDistance(ExprVector p, hEntity hpl) {
ExprVector n;
Expr *d;
SS.GetEntity(hpl)->WorkplaneGetPlaneExprs(&n, &d);
return (p.Dot(n))->Minus(d);
}
Expr *Constraint::Distance(hEntity wrkpl, hEntity hpa, hEntity hpb) {
Entity *pa = SS.GetEntity(hpa);
Entity *pb = SS.GetEntity(hpb);
if(!(pa->IsPoint() && pb->IsPoint())) oops();
if(wrkpl.v == Entity::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();
}
}
ExprVector Constraint::PointInThreeSpace(hEntity workplane, Expr *u, Expr *v) {
Entity *w = SS.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 Constraint::ModifyToSatisfy(void) {
if(type == ANGLE) {
Vector a = SS.GetEntity(entityA)->VectorGetNum();
Vector b = SS.GetEntity(entityB)->VectorGetNum();
if(otherAngle) a = a.ScaledBy(-1);
if(workplane.v != Entity::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 Constraint::AddEq(IdList<Equation,hEquation> *l, Expr *expr, int index) {
Equation eq;
eq.e = expr;
eq.h = h.equation(index);
l->Add(&eq);
}
void Constraint::Generate(IdList<Equation,hEquation> *l) {
if(!reference) {
GenerateReal(l);
}
}
void Constraint::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 PT_LINE_DISTANCE:
AddEq(l,
PointLineDistance(workplane, ptA, entityA)->Minus(exA), 0);
break;
case PT_PLANE_DISTANCE: {
ExprVector pt = SS.GetEntity(ptA)->PointGetExprs();
AddEq(l, (PointPlaneDistance(pt, entityA))->Minus(exA), 0);
break;
}
case PT_FACE_DISTANCE: {
ExprVector pt = SS.GetEntity(ptA)->PointGetExprs();
Entity *f = SS.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: {
Entity *a = SS.GetEntity(entityA);
Entity *b = SS.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: {
Entity *forLen = SS.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: {
Entity *a = SS.GetEntity(entityA);
Entity *b = SS.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: {
Entity *circle = SS.GetEntity(entityA);
Expr *r = circle->CircleGetRadiusExpr();
AddEq(l, (r->Times(Expr::From(2)))->Minus(exA), 0);
break;
}
case EQUAL_RADIUS: {
Entity *c1 = SS.GetEntity(entityA);
Entity *c2 = SS.GetEntity(entityB);
AddEq(l, (c1->CircleGetRadiusExpr())->Minus(
c2->CircleGetRadiusExpr()), 0);
break;
}
case POINTS_COINCIDENT: {
Entity *a = SS.GetEntity(ptA);
Entity *b = SS.GetEntity(ptB);
if(workplane.v == Entity::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(
SS.GetEntity(ptA)->PointGetExprs(), entityA), 0);
break;
case PT_ON_FACE: {
// a plane, n dot (p - p0) = 0
ExprVector p = SS.GetEntity(ptA)->PointGetExprs();
Entity *f = SS.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 == Entity::FREE_IN_3D.v) {
Entity *ln = SS.GetEntity(entityA);
Entity *a = SS.GetEntity(ln->point[0]);
Entity *b = SS.GetEntity(ln->point[1]);
Entity *p = SS.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: {
Entity *circle = SS.GetEntity(entityA);
hEntity center = circle->point[0];
Expr *radius = circle->CircleGetRadiusExpr();
AddEq(l, Distance(workplane, ptA, center)->Minus(radius), 0);
break;
}
case AT_MIDPOINT:
if(workplane.v == Entity::FREE_IN_3D.v) {
Entity *ln = SS.GetEntity(entityA);
ExprVector a = SS.GetEntity(ln->point[0])->PointGetExprs();
ExprVector b = SS.GetEntity(ln->point[1])->PointGetExprs();
ExprVector m = (a.Plus(b)).ScaledBy(Expr::From(0.5));
if(ptA.v) {
ExprVector p = SS.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 {
Entity *ln = SS.GetEntity(entityA);
Entity *a = SS.GetEntity(ln->point[0]);
Entity *b = SS.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) {
Entity *p = SS.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 == Entity::FREE_IN_3D.v) {
Entity *plane = SS.GetEntity(entityA);
Entity *ea = SS.GetEntity(ptA);
Entity *eb = SS.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 {
Entity *plane = SS.GetEntity(entityA);
Entity *a = SS.GetEntity(ptA);
Entity *b = SS.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.
Entity *w = SS.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: {
Entity *a = SS.GetEntity(ptA);
Entity *b = SS.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 HORIZONTAL:
case VERTICAL: {
hEntity ha, hb;
if(entityA.v) {
Entity *e = SS.GetEntity(entityA);
ha = e->point[0];
hb = e->point[1];
} else {
ha = ptA;
hb = ptB;
}
Entity *a = SS.GetEntity(ha);
Entity *b = SS.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: {
Entity *a = SS.GetEntity(entityA);
Entity *b = SS.GetEntity(entityB);
if(b->group.v != group.v) {
SWAP(Entity *, 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 ANGLE: {
Entity *a = SS.GetEntity(entityA);
Entity *b = SS.GetEntity(entityB);
ExprVector ae = a->VectorGetExprs();
ExprVector be = b->VectorGetExprs();
if(otherAngle) ae = ae.ScaledBy(Expr::From(-1));
Expr *c;
if(workplane.v == Entity::FREE_IN_3D.v) {
Expr *mags = (ae.Magnitude())->Times(be.Magnitude());
c = (ae.Dot(be))->Div(mags);
} else {
Entity *w = SS.GetEntity(workplane);
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));
c = dot->Div(maga->Times(magb));
}
Expr *rads = exA->Times(Expr::From(PI/180));
AddEq(l, c->Minus(rads->Cos()), 0);
break;
}
case PARALLEL: {
Entity *ea = SS.GetEntity(entityA), *eb = SS.GetEntity(entityB);
if(eb->group.v != group.v) {
SWAP(Entity *, ea, eb);
}
ExprVector a = ea->VectorGetExprs();
ExprVector b = eb->VectorGetExprs();
if(workplane.v == Entity::FREE_IN_3D.v) {
AddEq(l, VectorsParallel(0, a, b), 0);
AddEq(l, VectorsParallel(1, a, b), 1);
} else {
Entity *w = SS.GetEntity(workplane);
ExprVector wn = w->Normal()->NormalExprsN();
AddEq(l, (a.Cross(b)).Dot(wn), 0);
}
break;
}
case COMMENT:
break;
default: oops();
}
}