コード例 #1
0
ファイル: constraint.cpp プロジェクト: astarasikov/solvespace
void Constraint::MenuConstrain(int id) {
    Constraint c;
    ZERO(&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 = SK.GetEntity(gs.entity[0]);
                c.ptA = e->point[0];
                c.ptB = e->point[1];
            } else if(gs.vectors == 1 && gs.points == 2 && gs.n == 3) {
                c.type = PROJ_PT_DISTANCE;
                c.ptA = gs.point[0];
                c.ptB = gs.point[1];
                c.entityA = gs.vector[0];
            } 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. This "
"constraint can apply to:\n\n"
"    * two points (distance between points)\n"
"    * a line segment (length)\n"
"    * two points and a line segment or normal (projected distance)\n"
"    * a workplane and a point (minimum distance)\n"
"    * a line segment and a point (minimum distance)\n"
"    * a plane face and a point (minimum distance)\n"
"    * a circle or an arc (diameter)\n");
                return;
            }
            if(c.type == PT_PT_DISTANCE || c.type == PROJ_PT_DISTANCE) {
                Vector n = SS.GW.projRight.Cross(SS.GW.projUp);
                Vector a = SK.GetEntity(c.ptA)->PointGetNum();
                Vector b = SK.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. "
                      "This constraint can apply to:\n\n"
                      "    * two points (points coincident)\n"
                      "    * a point and a workplane (point in plane)\n"
                      "    * a point and a line segment (point on line)\n"
                      "    * a point and a circle or arc (point on curve)\n"
                      "    * a point and a plane face (point on face)\n");
                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.vectors == 4 && gs.n == 4) {
                c.type = EQUAL_ANGLE;
                c.entityA = gs.vector[0];
                c.entityB = gs.vector[1];
                c.entityC = gs.vector[2];
                c.entityD = gs.vector[3];
            } else if(gs.vectors == 3 && gs.n == 3) {
                c.type = EQUAL_ANGLE;
                c.entityA = gs.vector[0];
                c.entityB = gs.vector[1];
                c.entityC = gs.vector[1];
                c.entityD = gs.vector[2];
            } else if(gs.circlesOrArcs == 2 && gs.n == 2) {
                c.type = EQUAL_RADIUS;
                c.entityA = gs.entity[0];
                c.entityB = gs.entity[1];
            } else if(gs.arcs == 1 && gs.lineSegments == 1 && gs.n == 2) {
                c.type = EQUAL_LINE_ARC_LEN;
                if(SK.GetEntity(gs.entity[0])->type == Entity::ARC_OF_CIRCLE) {
                    c.entityA = gs.entity[1];
                    c.entityB = gs.entity[0];
                } else {
                    c.entityA = gs.entity[0];
                    c.entityB = gs.entity[1];
                }
            } else {
                Error("Bad selection for equal length / radius constraint. "
                      "This constraint can apply to:\n\n"
                      "    * two line segments (equal length)\n"
                      "    * two line segments and two points "
                              "(equal point-line distances)\n"
                      "    * a line segment and two points "
                              "(equal point-line distances)\n"
                      "    * a line segment, and a point and line segment "
                              "(point-line distance equals length)\n"
                      "    * four line segments or normals "
                              "(equal angle between A,B and C,D)\n"
                      "    * three line segments or normals "
                              "(equal angle between A,B and B,C)\n"
                      "    * two circles or arcs (equal radius)\n"
                      "    * a line segment and an arc "
                              "(line segment length equals arc length)\n");
                return;
            }
            if(c.type == EQUAL_ANGLE) {
                // Infer the nearest supplementary angle from the sketch.
                Vector a1 = SK.GetEntity(c.entityA)->VectorGetNum(),
                       b1 = SK.GetEntity(c.entityB)->VectorGetNum(),
                       a2 = SK.GetEntity(c.entityC)->VectorGetNum(),
                       b2 = SK.GetEntity(c.entityD)->VectorGetNum();
                double d1 = a1.Dot(b1), d2 = a2.Dot(b2);

                if(d1*d2 < 0) {
                    c.other = true;
                }
            }
            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. This "
                      "constraint can apply to:\n\n"
                      "    * two line segments\n");
                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];

                // If a point is at-midpoint, then no reason to also constrain
                // it on-line; so auto-remove that.
                DeleteAllConstraintsFor(PT_ON_LINE, c.entityA, c.ptA);
            } else if(gs.lineSegments == 1 && gs.workplanes == 1 && gs.n == 2) {
                c.type = AT_MIDPOINT;
                int i = SK.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. This "
                      "constraint can apply to:\n\n"
                      "    * a line segment and a point "
                            "(point at midpoint)\n"
                      "    * a line segment and a workplane "
                            "(line's midpoint on plane)\n");
                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 = SK.GetEntity(gs.entity[0])->IsWorkplane() ? 1 : 0;
                Entity *line = SK.GetEntity(gs.entity[i]);
                c.entityA = gs.entity[1-i];
                c.ptA = line->point[0];
                c.ptB = line->point[1];
            } else if(SS.GW.LockedInWorkplane()
                        && gs.lineSegments == 2 && gs.n == 2)
            {
                Entity *l0 = SK.GetEntity(gs.entity[0]),
                       *l1 = SK.GetEntity(gs.entity[1]);

                if((l1->group.v != SS.GW.activeGroup.v) ||
                   (l1->construction && !(l0->construction)))
                {
                    SWAP(Entity *, l0, l1);
                }
                c.ptA = l1->point[0];
                c.ptB = l1->point[1];
                c.entityA = l0->h;
                c.type = SYMMETRIC_LINE;
            } else if(SS.GW.LockedInWorkplane()
                        && gs.lineSegments == 1 && gs.points == 2 && gs.n == 3)
            {
                c.ptA = gs.point[0];
                c.ptB = gs.point[1];
                c.entityA = gs.entity[0];
                c.type = SYMMETRIC_LINE;
            } else {
                Error("Bad selection for symmetric constraint. This constraint "
                      "can apply to:\n\n"
                      "    * two points or a line segment "
                          "(symmetric about workplane's coordinate axis)\n"
                      "    * line segment, and two points or a line segment "
                          "(symmetric about line segment)\n"
                      "    * workplane, and two points or a line segment "
                          "(symmetric about workplane)\n");
                return;
            }
            if(c.type != 0) {
                // Already done, symmetry about a line segment in a workplane
            } else if(c.entityA.v == Entity::NO_ENTITY.v) {
                // Horizontal / vertical symmetry, implicit symmetry plane
                // normal to the workplane
                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 = SK.GetEntity(c.ptA)->PointGetNum();
                Vector pb = SK.GetEntity(c.ptB)->PointGetNum();
                Vector dp = pa.Minus(pb);
                EntityBase *norm = SK.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.
                    DeleteAllConstraintsFor(HORIZONTAL, (gs.entity[0]),
                        Entity::NO_ENTITY);
                    DeleteAllConstraintsFor(VERTICAL, (gs.entity[0]),
                        Entity::NO_ENTITY);

                }
            } 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 = SK.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. "
                      "This constraint can apply to:\n\n"
                      "    * two points\n"
                      "    * a line segment\n");
                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. This "
                      "constraint can apply to:\n\n"
                      "    * two normals\n");
                return;
            }
            SS.UndoRemember();

            Entity *nfree = SK.GetEntity(c.entityA);
            Entity *nref  = SK.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 = SK.GetConstraint(gs.constraint[0]);
                if(c->type == ANGLE) {
                    SS.UndoRemember();
                    c->other = !(c->other);
                    c->ModifyToSatisfy();
                    break;
                }
                if(c->type == EQUAL_ANGLE) {
                    SS.UndoRemember();
                    c->other = !(c->other);
                    SS.MarkGroupDirty(c->group);
                    SS.ScheduleGenerateAll();
                    break;
                }
            }
            Error("Must select an angle constraint.");
            return;

        case GraphicsWindow::MNU_REFERENCE:
            if(gs.constraints == 1 && gs.n == 0) {
                Constraint *c = SK.GetConstraint(gs.constraint[0]);
                if(c->HasLabel() && c->type != COMMENT) {
                    (c->reference) = !(c->reference);
                    SK.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;
            } else {
                Error("Bad selection for angle constraint. This constraint "
                      "can apply to:\n\n"
                      "    * two line segments\n"
                      "    * a line segment and a normal\n"
                      "    * two normals\n");
                return;
            }

            Entity *ea = SK.GetEntity(c.entityA),
                   *eb = SK.GetEntity(c.entityB);
            if(ea->type == Entity::LINE_SEGMENT &&
               eb->type == Entity::LINE_SEGMENT)
            {
                Vector a0 = SK.GetEntity(ea->point[0])->PointGetNum(),
                       a1 = SK.GetEntity(ea->point[1])->PointGetNum(),
                       b0 = SK.GetEntity(eb->point[0])->PointGetNum(),
                       b1 = SK.GetEntity(eb->point[1])->PointGetNum();
                if(a0.Equals(b0) || a1.Equals(b1)) {
                    // okay, vectors should be drawn in same sense
                } else if(a0.Equals(b1) || a1.Equals(b0)) {
                    // vectors are in opposite sense
                    c.other = true;
                } else {
                    // no shared point; not clear which intersection to draw
                }
            }
            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 if(gs.lineSegments == 1 && gs.arcs == 1 && gs.n == 2) {
                Entity *line = SK.GetEntity(gs.entity[0]);
                Entity *arc  = SK.GetEntity(gs.entity[1]);
                if(line->type == Entity::ARC_OF_CIRCLE) {
                    SWAP(Entity *, line, arc);
                }
                Vector l0 = SK.GetEntity(line->point[0])->PointGetNum(),
                       l1 = SK.GetEntity(line->point[1])->PointGetNum();
                Vector a1 = SK.GetEntity(arc->point[1])->PointGetNum(),
                       a2 = SK.GetEntity(arc->point[2])->PointGetNum();

                if(l0.Equals(a1) || l1.Equals(a1)) {
                    c.other = false;
                } else if(l0.Equals(a2) || l1.Equals(a2)) {
                    c.other = true;
                } else {
                    Error("The tangent arc and line segment must share an "
                          "endpoint. Constrain them with Constrain -> "
                          "On Point before constraining tangent.");
                    return;
                }
                c.type = ARC_LINE_TANGENT;
                c.entityA = arc->h;
                c.entityB = line->h;
            } else if(gs.lineSegments == 1 && gs.cubics == 1 && gs.n == 2) {
                Entity *line  = SK.GetEntity(gs.entity[0]);
                Entity *cubic = SK.GetEntity(gs.entity[1]);
                if(line->type == Entity::CUBIC) {
                    SWAP(Entity *, line, cubic);
                }
                Vector l0 = SK.GetEntity(line->point[0])->PointGetNum(),
                       l1 = SK.GetEntity(line->point[1])->PointGetNum();
                Vector as = cubic->CubicGetStartNum(),
                       af = cubic->CubicGetFinishNum();

                if(l0.Equals(as) || l1.Equals(as)) {
                    c.other = false;
                } else if(l0.Equals(af) || l1.Equals(af)) {
                    c.other = true;
                } else {
                    Error("The tangent cubic and line segment must share an "
                          "endpoint. Constrain them with Constrain -> "
                          "On Point before constraining tangent.");
                    return;
                }
                c.type = CUBIC_LINE_TANGENT;
                c.entityA = cubic->h;
                c.entityB = line->h;
            } else if(gs.cubics + gs.arcs == 2 && gs.n == 2) {
                if(!SS.GW.LockedInWorkplane()) {
                    Error("Curve-curve tangency must apply in workplane.");
                    return;
                }
                Entity *eA = SK.GetEntity(gs.entity[0]),
                       *eB = SK.GetEntity(gs.entity[1]);
                Vector as = eA->EndpointStart(),
                       af = eA->EndpointFinish(),
                       bs = eB->EndpointStart(),
                       bf = eB->EndpointFinish();
                if(as.Equals(bs)) {
                    c.other = false; c.other2 = false;
                } else if(as.Equals(bf)) {
                    c.other = false; c.other2 = true;
                } else if(af.Equals(bs)) {
                    c.other = true; c.other2 = false;
                } else if(af.Equals(bf)) {
                    c.other = true; c.other2 = true;
                } else {
                    Error("The curves must share an endpoint. Constrain them "
                          "with Constrain -> On Point before constraining "
                          "tangent.");
                    return;
                }
                c.type = CURVE_CURVE_TANGENT;
                c.entityA = eA->h;
                c.entityB = eB->h;
            } else {
                Error("Bad selection for parallel / tangent constraint. This "
                      "constraint can apply to:\n\n"
                      "    * two line segments (parallel)\n"
                      "    * a line segment and a normal (parallel)\n"
                      "    * two normals (parallel)\n"
                      "    * two line segments, arcs, or beziers, that share "
                            "an endpoint (tangent)\n");
                return;
            }
            AddConstraint(&c);
            break;

        case GraphicsWindow::MNU_PERPENDICULAR:
            if(gs.vectors == 2 && gs.n == 2) {
                c.type = PERPENDICULAR;
                c.entityA = gs.vector[0];
                c.entityB = gs.vector[1];
            } else {
                Error("Bad selection for perpendicular constraint. This "
                      "constraint can apply to:\n\n"
                      "    * two line segments\n"
                      "    * a line segment and a normal\n"
                      "    * two normals\n");
                return;
            }
            AddConstraint(&c);
            break;

        case GraphicsWindow::MNU_WHERE_DRAGGED:
            if(gs.points == 1 && gs.n == 1) {
                c.type = WHERE_DRAGGED;
                c.ptA = gs.point[0];
            } else {
                Error("Bad selection for lock point where dragged constraint. "
                      "This constraint can apply to:\n\n"
                      "    * a point\n");
                return;
            }
            AddConstraint(&c);
            break;

        case GraphicsWindow::MNU_COMMENT:
            SS.GW.pending.operation = GraphicsWindow::MNU_COMMENT;
            SS.GW.pending.description = "click center of comment text";
            SS.ScheduleShowTW();
            break;

        default: oops();
    }

    SS.GW.ClearSelection();
    InvalidateGraphics();
}
コード例 #2
0
ファイル: generate.cpp プロジェクト: blondegeek/solvespace-1
void SolveSpaceUI::GenerateAll(Generate type, bool andFindFree, bool genForBBox) {
    int first, last, i, j;

    SK.groupOrder.Clear();
    for(int i = 0; i < SK.group.n; i++)
        SK.groupOrder.Add(&SK.group.elem[i].h);
    std::sort(&SK.groupOrder.elem[0], &SK.groupOrder.elem[SK.groupOrder.n],
        [](const hGroup &ha, const hGroup &hb) {
            return SK.GetGroup(ha)->order < SK.GetGroup(hb)->order;
        });

    switch(type) {
        case Generate::DIRTY: {
            first = INT_MAX;
            last  = 0;

            // Start from the first dirty group, and solve until the active group,
            // since all groups after the active group are hidden.
            for(i = 0; i < SK.groupOrder.n; i++) {
                Group *g = SK.GetGroup(SK.groupOrder.elem[i]);
                if((!g->clean) || !g->IsSolvedOkay()) {
                    first = min(first, i);
                }
                if(g->h.v == SS.GW.activeGroup.v) {
                    last = i;
                }
            }
            if(first == INT_MAX || last == 0) {
                // All clean; so just regenerate the entities, and don't solve anything.
                first = -1;
                last  = -1;
            } else {
                SS.nakedEdges.Clear();
            }
            break;
        }

        case Generate::ALL:
            first = 0;
            last  = INT_MAX;
            break;

        case Generate::REGEN:
            first = -1;
            last  = -1;
            break;

        case Generate::UNTIL_ACTIVE: {
            for(i = 0; i < SK.groupOrder.n; i++) {
                if(SK.groupOrder.elem[i].v == SS.GW.activeGroup.v)
                    break;
            }

            first = 0;
            last  = i;
            break;
        }
    }

    // If we're generating entities for display, first we need to find
    // the bounding box to turn relative chord tolerance to absolute.
    if(!SS.exportMode && !genForBBox) {
        GenerateAll(type, andFindFree, /*genForBBox=*/true);
        BBox box = SK.CalculateEntityBBox(/*includeInvisibles=*/true);
        Vector size = box.maxp.Minus(box.minp);
        double maxSize = std::max({ size.x, size.y, size.z });
        chordTolCalculated = maxSize * chordTol / 100.0;
    }

    // Remove any requests or constraints that refer to a nonexistent
    // group; can check those immediately, since we know what the list
    // of groups should be.
    while(PruneOrphans())
        ;

    // Don't lose our numerical guesses when we regenerate.
    IdList<Param,hParam> prev = {};
    SK.param.MoveSelfInto(&prev);
    SK.entity.Clear();

    for(i = 0; i < SK.groupOrder.n; i++) {
        Group *g = SK.GetGroup(SK.groupOrder.elem[i]);

        // The group may depend on entities or other groups, to define its
        // workplane geometry or for its operands. Those must already exist
        // in a previous group, so check them before generating.
        if(PruneGroups(g->h))
            goto pruned;

        for(j = 0; j < SK.request.n; j++) {
            Request *r = &(SK.request.elem[j]);
            if(r->group.v != g->h.v) continue;

            r->Generate(&(SK.entity), &(SK.param));
        }
        g->Generate(&(SK.entity), &(SK.param));

        // The requests and constraints depend on stuff in this or the
        // previous group, so check them after generating.
        if(PruneRequests(g->h) || PruneConstraints(g->h))
            goto pruned;

        // Use the previous values for params that we've seen before, as
        // initial guesses for the solver.
        for(j = 0; j < SK.param.n; j++) {
            Param *newp = &(SK.param.elem[j]);
            if(newp->known) continue;

            Param *prevp = prev.FindByIdNoOops(newp->h);
            if(prevp) {
                newp->val = prevp->val;
                newp->free = prevp->free;
            }
        }

        if(g->h.v == Group::HGROUP_REFERENCES.v) {
            ForceReferences();
            g->solved.how = SolveResult::OKAY;
            g->clean = true;
        } else {
            if(i >= first && i <= last) {
                // The group falls inside the range, so really solve it,
                // and then regenerate the mesh based on the solved stuff.
                if(genForBBox) {
                    SolveGroup(g->h, andFindFree);
                } else {
                    g->GenerateLoops();
                    g->GenerateShellAndMesh();
                    g->clean = true;
                }
            } else {
                // The group falls outside the range, so just assume that
                // it's good wherever we left it. The mesh is unchanged,
                // and the parameters must be marked as known.
                for(j = 0; j < SK.param.n; j++) {
                    Param *newp = &(SK.param.elem[j]);

                    Param *prevp = prev.FindByIdNoOops(newp->h);
                    if(prevp) newp->known = true;
                }
            }
        }
    }

    // And update any reference dimensions with their new values
    for(i = 0; i < SK.constraint.n; i++) {
        Constraint *c = &(SK.constraint.elem[i]);
        if(c->reference) {
            c->ModifyToSatisfy();
        }
    }

    // Make sure the point that we're tracing exists.
    if(traced.point.v && !SK.entity.FindByIdNoOops(traced.point)) {
        traced.point = Entity::NO_ENTITY;
    }
    // And if we're tracing a point, add its new value to the path
    if(traced.point.v) {
        Entity *pt = SK.GetEntity(traced.point);
        traced.path.AddPoint(pt->PointGetNum());
    }

    prev.Clear();
    InvalidateGraphics();

    // Remove nonexistent selection items, for same reason we waited till
    // the end to put up a dialog box.
    GW.ClearNonexistentSelectionItems();

    if(deleted.requests > 0 || deleted.constraints > 0 || deleted.groups > 0) {
        // All sorts of interesting things could have happened; for example,
        // the active group or active workplane could have been deleted. So
        // clear all that out.
        if(deleted.groups > 0) {
            SS.TW.ClearSuper();
        }
        ScheduleShowTW();
        GW.ClearSuper();

        // People get annoyed if I complain whenever they delete any request,
        // and I otherwise will, since those always come with pt-coincident
        // constraints.
        if(deleted.requests > 0 || deleted.nonTrivialConstraints > 0 ||
           deleted.groups > 0)
        {
            // Don't display any errors until we've regenerated fully. The
            // sketch is not necessarily in a consistent state until we've
            // pruned any orphaned etc. objects, and the message loop for the
            // messagebox could allow us to repaint and crash. But now we must
            // be fine.
            Message("Additional sketch elements were deleted, because they "
                    "depend on the element that was just deleted explicitly. "
                    "These include: \n"
                    "     %d request%s\n"
                    "     %d constraint%s\n"
                    "     %d group%s"
                    "%s",
                       deleted.requests, deleted.requests == 1 ? "" : "s",
                       deleted.constraints, deleted.constraints == 1 ? "" : "s",
                       deleted.groups, deleted.groups == 1 ? "" : "s",
                       undo.cnt > 0 ? "\n\nChoose Edit -> Undo to undelete all elements." : "");
        }

        deleted = {};
    }

    FreeAllTemporary();
    allConsistent = true;
    return;

pruned:
    // Restore the numerical guesses
    SK.param.Clear();
    prev.MoveSelfInto(&(SK.param));
    // Try again
    GenerateAll(type, andFindFree, genForBBox);
}