solvespace/constraint.cpp

94 lines
2.6 KiB
C++

#include "solvespace.h"
hConstraint Constraint::AddConstraint(Constraint *c) {
SS.constraint.AddAndAssignId(c);
return c->h;
}
void Constraint::MenuConstrain(int id) {
Constraint c;
memset(&c, 0, sizeof(c));
c.group = SS.GW.activeGroup;
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->assoc[0];
c.ptB = e->assoc[1];
} else {
Error("Bad selection for distance / diameter constraint.");
return;
}
c.disp.offset = Vector::MakeFrom(50, 50, 50);
c.exprA = Expr::FromString("300")->DeepCopyKeep();
AddConstraint(&c);
break;
case GraphicsWindow::MNU_SOLVE_NOW:
SS.Solve();
return;
default: oops();
}
SS.GW.ClearSelection();
InvalidateGraphics();
}
Expr *Constraint::Distance(hEntity hpa, hEntity hpb) {
Entity *pa = SS.GetEntity(hpa);
Entity *pb = SS.GetEntity(hpb);
if(!(pa->IsPoint() && pb->IsPoint())) oops();
if(pa->type == Entity::POINT_IN_2D &&
pb->type == Entity::POINT_IN_2D &&
pa->csys.v == pb->csys.v)
{
// A nice case; they are both in the same 2d csys, so I can write
// the equation in terms of the basis vectors in that csys.
Expr *du = Expr::FromParam(pa->param.h[0])->Minus(
Expr::FromParam(pb->param.h[0]));
Expr *dv = Expr::FromParam(pa->param.h[1])->Minus(
Expr::FromParam(pb->param.h[1]));
return ((du->Square())->Plus(dv->Square()))->Sqrt();
}
Expr *ax, *ay, *az;
Expr *bx, *by, *bz;
pa->PointGetExprs(&ax, &ay, &az);
pb->PointGetExprs(&bx, &by, &bz);
Expr *dx2 = (ax->Minus(bx))->Square();
Expr *dy2 = (ay->Minus(by))->Square();
Expr *dz2 = (az->Minus(bz))->Square();
return (dx2->Plus(dy2->Plus(dz2)))->Sqrt();
}
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) {
switch(type) {
case PT_PT_DISTANCE:
AddEq(l, Distance(ptA, ptB)->Minus(exprA), 0);
break;
default: oops();
}
}