void Constraint::DrawOrGetDistance(Vector *labelPos) {
    if(!SS.GW.showConstraints) return;
    Group *g = SK.GetGroup(group);
    // If the group is hidden, then the constraints are hidden and not
    // able to be selected.
    if(!(g->visible)) return;
    // And likewise if the group is not the active group; except for comments
    // with an assigned style.
    if(g->h.v != SS.GW.activeGroup.v && !(type == COMMENT && disp.style.v)) {
        return;
    }
    if(disp.style.v) {
        Style *s = Style::Get(disp.style);
        if(!s->visible) return;
    }

    // Unit vectors that describe our current view of the scene. One pixel
    // long, not one actual unit.
    Vector gr = SS.GW.projRight.ScaledBy(1/SS.GW.scale);
    Vector gu = SS.GW.projUp.ScaledBy(1/SS.GW.scale);
    Vector gn = (gr.Cross(gu)).WithMagnitude(1/SS.GW.scale);

    switch(type) {
        case PT_PT_DISTANCE: {
            Vector ap = SK.GetEntity(ptA)->PointGetNum();
            Vector bp = SK.GetEntity(ptB)->PointGetNum();

            if(workplane.v != Entity::FREE_IN_3D.v) {
                DoProjectedPoint(&ap);
                DoProjectedPoint(&bp);
            }

            Vector ref = ((ap.Plus(bp)).ScaledBy(0.5)).Plus(disp.offset);

            DoLineWithArrows(ref, ap, bp, false);
            DoLabel(ref, labelPos, gr, gu);
            break;
        }

        case PROJ_PT_DISTANCE: {
            Vector ap = SK.GetEntity(ptA)->PointGetNum(),
                   bp = SK.GetEntity(ptB)->PointGetNum(),
                   dp = (bp.Minus(ap)),
                   pp = SK.GetEntity(entityA)->VectorGetNum();

            Vector ref = ((ap.Plus(bp)).ScaledBy(0.5)).Plus(disp.offset);

            pp = pp.WithMagnitude(1);
            double d = dp.Dot(pp);
            Vector bpp = ap.Plus(pp.ScaledBy(d));
            StippledLine(ap, bpp);
            StippledLine(bp, bpp);

            DoLineWithArrows(ref, ap, bpp, false);
            DoLabel(ref, labelPos, gr, gu);
            break;
        }

        case PT_FACE_DISTANCE:
        case PT_PLANE_DISTANCE: {
            Vector pt = SK.GetEntity(ptA)->PointGetNum();
            Entity *enta = SK.GetEntity(entityA);
            Vector n, p;
            if(type == PT_PLANE_DISTANCE) {
                n = enta->Normal()->NormalN();
                p = enta->WorkplaneGetOffset();
            } else {
                n = enta->FaceGetNormalNum();
                p = enta->FaceGetPointNum();
            }

            double d = (p.Minus(pt)).Dot(n);
            Vector closest = pt.Plus(n.WithMagnitude(d));

            Vector ref = ((closest.Plus(pt)).ScaledBy(0.5)).Plus(disp.offset);

            if(!pt.Equals(closest)) {
                DoLineWithArrows(ref, pt, closest, true);
            }

            DoLabel(ref, labelPos, gr, gu);
            break;
        }

        case PT_LINE_DISTANCE: {
            Vector pt = SK.GetEntity(ptA)->PointGetNum();
            Entity *line = SK.GetEntity(entityA);
            Vector lA = SK.GetEntity(line->point[0])->PointGetNum();
            Vector lB = SK.GetEntity(line->point[1])->PointGetNum();
            Vector dl = lB.Minus(lA);

            if(workplane.v != Entity::FREE_IN_3D.v) {
                lA = lA.ProjectInto(workplane);
                lB = lB.ProjectInto(workplane);
                DoProjectedPoint(&pt);
            }

            // Find the closest point on the line
            Vector closest = pt.ClosestPointOnLine(lA, dl);

            Vector ref = ((closest.Plus(pt)).ScaledBy(0.5)).Plus(disp.offset);
            DoLabel(ref, labelPos, gr, gu);

            if(!pt.Equals(closest)) {
                DoLineWithArrows(ref, pt, closest, true);
            }

            if(workplane.v != Entity::FREE_IN_3D.v) {
                // Draw the projection marker from the closest point on the
                // projected line to the projected point on the real line.
                Vector lAB = (lA.Minus(lB));
                double t = (lA.Minus(closest)).DivPivoting(lAB);

                Vector lA = SK.GetEntity(line->point[0])->PointGetNum();
                Vector lB = SK.GetEntity(line->point[1])->PointGetNum();

                Vector c2 = (lA.ScaledBy(1-t)).Plus(lB.ScaledBy(t));
                DoProjectedPoint(&c2);
            }
            break;
        }

        case DIAMETER: {
            Entity *circle = SK.GetEntity(entityA);
            Vector center = SK.GetEntity(circle->point[0])->PointGetNum();
            Quaternion q = SK.GetEntity(circle->normal)->NormalGetNum();
            Vector n = q.RotationN().WithMagnitude(1);
            double r = circle->CircleGetRadiusNum();

            Vector ref = center.Plus(disp.offset);
            // Force the label into the same plane as the circle.
            ref = ref.Minus(n.ScaledBy(n.Dot(ref) - n.Dot(center)));

            Vector mark = ref.Minus(center);
            mark = mark.WithMagnitude(mark.Magnitude()-r);
            DoLineTrimmedAgainstBox(ref, ref, ref.Minus(mark));

            Vector topLeft;
            DoLabel(ref, &topLeft, gr, gu);
            if(labelPos) *labelPos = topLeft;

            // Show this as diameter or radius?
            if(!other) {
                // Draw the diameter symbol
                Vector dc = topLeft;
                dc = dc.Plus(gu.WithMagnitude(5/SS.GW.scale));
                dc = dc.Plus(gr.WithMagnitude(9/SS.GW.scale));
                double dr = 5/SS.GW.scale;
                double theta, dtheta = (2*PI)/12;
                for(theta = 0; theta < 2*PI-0.01; theta += dtheta) {
                    LineDrawOrGetDistance(
                        dc.Plus(gu.WithMagnitude(cos(theta)*dr)).Plus(
                                gr.WithMagnitude(sin(theta)*dr)),
                        dc.Plus(gu.WithMagnitude(cos(theta+dtheta)*dr)).Plus(
                                gr.WithMagnitude(sin(theta+dtheta)*dr)));
                }
                theta = 25*(PI/180);
                dr *= 1.7;
                dtheta = PI;
                LineDrawOrGetDistance(
                    dc.Plus(gu.WithMagnitude(cos(theta)*dr)).Plus(
                            gr.WithMagnitude(sin(theta)*dr)),
                    dc.Plus(gu.WithMagnitude(cos(theta+dtheta)*dr)).Plus(
                            gr.WithMagnitude(sin(theta+dtheta)*dr)));
            }
            break;
        }

        case POINTS_COINCIDENT: {
            if(!dogd.drawing) {
                for(int i = 0; i < 2; i++) {
                    Vector p = SK.GetEntity(i == 0 ? ptA : ptB)-> PointGetNum();
                    Point2d pp = SS.GW.ProjectPoint(p);
                    // The point is selected within a radius of 7, from the
                    // same center; so if the point is visible, then this
                    // constraint cannot be selected. But that's okay.
                    dogd.dmin = min(dogd.dmin, pp.DistanceTo(dogd.mp) - 3);
                    dogd.refp = p;
                }
                break;
            }

            if(dogd.drawing) {
                // Let's adjust the color of this constraint to have the same
                // rough luma as the point color, so that the constraint does not
                // stand out in an ugly way.
                RgbaColor cd = Style::Color(Style::DATUM),
                         cc = Style::Color(Style::CONSTRAINT);
                // convert from 8-bit color to a vector
                Vector vd = Vector::From(cd.redF(), cd.greenF(), cd.blueF()),
                       vc = Vector::From(cc.redF(), cc.greenF(), cc.blueF());
                // and scale the constraint color to have the same magnitude as
                // the datum color, maybe a bit dimmer
                vc = vc.WithMagnitude(vd.Magnitude()*0.9);
                // and set the color to that.
                ssglColorRGB(RGBf(vc.x, vc.y, vc.z));

                for(int a = 0; a < 2; a++) {
                    Vector r = SS.GW.projRight.ScaledBy((a+1)/SS.GW.scale);
                    Vector d = SS.GW.projUp.ScaledBy((2-a)/SS.GW.scale);
                    for(int i = 0; i < 2; i++) {
                        Vector p = SK.GetEntity(i == 0 ? ptA : ptB)-> PointGetNum();
                        glBegin(GL_QUADS);
                            ssglVertex3v(p.Plus (r).Plus (d));
                            ssglVertex3v(p.Plus (r).Minus(d));
                            ssglVertex3v(p.Minus(r).Minus(d));
                            ssglVertex3v(p.Minus(r).Plus (d));
                        glEnd();
                    }

                }
            }
            break;
        }

        case PT_ON_CIRCLE:
        case PT_ON_LINE:
        case PT_ON_FACE:
        case PT_IN_PLANE: {
            double s = 8/SS.GW.scale;
            Vector p = SK.GetEntity(ptA)->PointGetNum();
            Vector r, d;
            if(type == PT_ON_FACE) {
                Vector n = SK.GetEntity(entityA)->FaceGetNormalNum();
                r = n.Normal(0);
                d = n.Normal(1);
            } else if(type == PT_IN_PLANE) {
                EntityBase *n = SK.GetEntity(entityA)->Normal();
                r = n->NormalU();
                d = n->NormalV();
            } else {
                r = gr;
                d = gu;
                s *= (6.0/8); // draw these a little smaller
            }
            r = r.WithMagnitude(s); d = d.WithMagnitude(s);
            LineDrawOrGetDistance(p.Plus (r).Plus (d), p.Plus (r).Minus(d));
            LineDrawOrGetDistance(p.Plus (r).Minus(d), p.Minus(r).Minus(d));
            LineDrawOrGetDistance(p.Minus(r).Minus(d), p.Minus(r).Plus (d));
            LineDrawOrGetDistance(p.Minus(r).Plus (d), p.Plus (r).Plus (d));
            break;
        }

        case WHERE_DRAGGED: {
            Vector p = SK.GetEntity(ptA)->PointGetNum(),
                   u = p.Plus(gu.WithMagnitude(8/SS.GW.scale)).Plus(
                              gr.WithMagnitude(8/SS.GW.scale)),
                   uu = u.Minus(gu.WithMagnitude(5/SS.GW.scale)),
                   ur = u.Minus(gr.WithMagnitude(5/SS.GW.scale));
            // Draw four little crop marks, uniformly spaced (by ninety
            // degree rotations) around the point.
            int i;
            for(i = 0; i < 4; i++) {
                LineDrawOrGetDistance(u, uu);
                LineDrawOrGetDistance(u, ur);
                u = u.RotatedAbout(p, gn, PI/2);
                ur = ur.RotatedAbout(p, gn, PI/2);
                uu = uu.RotatedAbout(p, gn, PI/2);
            }
            break;
        }

        case SAME_ORIENTATION: {
            for(int i = 0; i < 2; i++) {
                Entity *e = SK.GetEntity(i == 0 ? entityA : entityB);
                Quaternion q = e->NormalGetNum();
                Vector n = q.RotationN().WithMagnitude(25/SS.GW.scale);
                Vector u = q.RotationU().WithMagnitude(6/SS.GW.scale);
                Vector p = SK.GetEntity(e->point[0])->PointGetNum();
                p = p.Plus(n.WithMagnitude(10/SS.GW.scale));

                LineDrawOrGetDistance(p.Plus(u), p.Minus(u).Plus(n));
                LineDrawOrGetDistance(p.Minus(u), p.Plus(u).Plus(n));
            }
            break;
        }

        case EQUAL_ANGLE: {
            Vector ref;
            Entity *a = SK.GetEntity(entityA);
            Entity *b = SK.GetEntity(entityB);
            Entity *c = SK.GetEntity(entityC);
            Entity *d = SK.GetEntity(entityD);

            Vector a0 = a->VectorGetRefPoint();
            Vector b0 = b->VectorGetRefPoint();
            Vector c0 = c->VectorGetRefPoint();
            Vector d0 = d->VectorGetRefPoint();
            Vector da = a->VectorGetNum();
            Vector db = b->VectorGetNum();
            Vector dc = c->VectorGetNum();
            Vector dd = d->VectorGetNum();

            if(other) da = da.ScaledBy(-1);

            DoArcForAngle(a0, da, b0, db,
                da.WithMagnitude(40/SS.GW.scale), &ref);
            DoArcForAngle(c0, dc, d0, dd,
                dc.WithMagnitude(40/SS.GW.scale), &ref);

            break;
        }

        case ANGLE: {
            Entity *a = SK.GetEntity(entityA);
            Entity *b = SK.GetEntity(entityB);

            Vector a0 = a->VectorGetRefPoint();
            Vector b0 = b->VectorGetRefPoint();
            Vector da = a->VectorGetNum();
            Vector db = b->VectorGetNum();
            if(other) da = da.ScaledBy(-1);

            Vector ref;
            DoArcForAngle(a0, da, b0, db, disp.offset, &ref);
            DoLabel(ref, labelPos, gr, gu);
            break;
        }

        case PERPENDICULAR: {
            Vector u = Vector::From(0, 0, 0), v = Vector::From(0, 0, 0);
            Vector rn, ru;
            if(workplane.v == Entity::FREE_IN_3D.v) {
                rn = gn;
                ru = gu;
            } else {
                EntityBase *normal = SK.GetEntity(workplane)->Normal();
                rn = normal->NormalN();
                ru = normal->NormalV(); // ru meaning r_up, not u/v
            }

            for(int i = 0; i < 2; i++) {
                Entity *e = SK.GetEntity(i == 0 ? entityA : entityB);

                if(i == 0) {
                    // Calculate orientation of perpendicular sign only
                    // once, so that it's the same both times it's drawn
                    u = e->VectorGetNum();
                    u = u.WithMagnitude(16/SS.GW.scale);
                    v = (rn.Cross(u)).WithMagnitude(16/SS.GW.scale);
                    // a bit of bias to stop it from flickering between the
                    // two possibilities
                    if(fabs(u.Dot(ru)) < fabs(v.Dot(ru)) + LENGTH_EPS) {
                        SWAP(Vector, u, v);
                    }
                    if(u.Dot(ru) < 0) u = u.ScaledBy(-1);
                }

                Vector p = e->VectorGetRefPoint();
                Vector s = p.Plus(u).Plus(v);
                LineDrawOrGetDistance(s, s.Plus(v));

                Vector m = s.Plus(v.ScaledBy(0.5));
                LineDrawOrGetDistance(m, m.Plus(u));
            }
            break;
        }

        case CURVE_CURVE_TANGENT:
        case CUBIC_LINE_TANGENT:
        case ARC_LINE_TANGENT: {
            Vector textAt, u, v;

            if(type == ARC_LINE_TANGENT) {
                Entity *arc = SK.GetEntity(entityA);
                Entity *norm = SK.GetEntity(arc->normal);
                Vector c = SK.GetEntity(arc->point[0])->PointGetNum();
                Vector p =
                    SK.GetEntity(arc->point[other ? 2 : 1])->PointGetNum();
                Vector r = p.Minus(c);
                textAt = p.Plus(r.WithMagnitude(14/SS.GW.scale));
                u = norm->NormalU();
                v = norm->NormalV();
            } else if(type == CUBIC_LINE_TANGENT) {
                Vector n;
                if(workplane.v == Entity::FREE_IN_3D.v) {
                    u = gr;
                    v = gu;
                    n = gn;
                } else {
                    EntityBase *wn = SK.GetEntity(workplane)->Normal();
                    u = wn->NormalU();
                    v = wn->NormalV();
                    n = wn->NormalN();
                }

                Entity *cubic = SK.GetEntity(entityA);
                Vector p = other ? cubic->CubicGetFinishNum() :
                                   cubic->CubicGetStartNum();
                Vector dir = SK.GetEntity(entityB)->VectorGetNum();
                Vector out = n.Cross(dir);
                textAt = p.Plus(out.WithMagnitude(14/SS.GW.scale));
            } else {
                Vector n, dir;
                EntityBase *wn = SK.GetEntity(workplane)->Normal();
                u = wn->NormalU();
                v = wn->NormalV();
                n = wn->NormalN();
                EntityBase *eA = SK.GetEntity(entityA);
                // Big pain; we have to get a vector tangent to the curve
                // at the shared point, which could be from either a cubic
                // or an arc.
                if(other) {
                    textAt = eA->EndpointFinish();
                    if(eA->type == Entity::CUBIC) {
                        dir = eA->CubicGetFinishTangentNum();
                    } else {
                        dir = SK.GetEntity(eA->point[0])->PointGetNum().Minus(
                              SK.GetEntity(eA->point[2])->PointGetNum());
                        dir = n.Cross(dir);
                    }
                } else {
                    textAt = eA->EndpointStart();
                    if(eA->type == Entity::CUBIC) {
                        dir = eA->CubicGetStartTangentNum();
                    } else {
                        dir = SK.GetEntity(eA->point[0])->PointGetNum().Minus(
                              SK.GetEntity(eA->point[1])->PointGetNum());
                        dir = n.Cross(dir);
                    }
                }
                dir = n.Cross(dir);
                textAt = textAt.Plus(dir.WithMagnitude(14/SS.GW.scale));
            }

            if(dogd.drawing) {
                ssglWriteTextRefCenter("T", DEFAULT_TEXT_HEIGHT,
                    textAt, u, v, LineCallback, this);
            } else {
                dogd.refp = textAt;
                Point2d ref = SS.GW.ProjectPoint(dogd.refp);
                dogd.dmin = min(dogd.dmin, ref.DistanceTo(dogd.mp)-10);
            }
            break;
        }

        case PARALLEL: {
            for(int i = 0; i < 2; i++) {
                Entity *e = SK.GetEntity(i == 0 ? entityA : entityB);
                Vector n = e->VectorGetNum();
                n = n.WithMagnitude(25/SS.GW.scale);
                Vector u = (gn.Cross(n)).WithMagnitude(4/SS.GW.scale);
                Vector p = e->VectorGetRefPoint();

                LineDrawOrGetDistance(p.Plus(u), p.Plus(u).Plus(n));
                LineDrawOrGetDistance(p.Minus(u), p.Minus(u).Plus(n));
            }
            break;
        }

        case EQUAL_RADIUS: {
            for(int i = 0; i < 2; i++) {
                DoEqualRadiusTicks(i == 0 ? entityA : entityB);
            }
            break;
        }

        case EQUAL_LINE_ARC_LEN: {
            Entity *line = SK.GetEntity(entityA);
            DoEqualLenTicks(
                SK.GetEntity(line->point[0])->PointGetNum(),
                SK.GetEntity(line->point[1])->PointGetNum(),
                gn);

            DoEqualRadiusTicks(entityB);
            break;
        }

        case LENGTH_RATIO:
        case EQUAL_LENGTH_LINES: {
            Vector a, b = Vector::From(0, 0, 0);
            for(int i = 0; i < 2; i++) {
                Entity *e = SK.GetEntity(i == 0 ? entityA : entityB);
                a = SK.GetEntity(e->point[0])->PointGetNum();
                b = SK.GetEntity(e->point[1])->PointGetNum();

                if(workplane.v != Entity::FREE_IN_3D.v) {
                    DoProjectedPoint(&a);
                    DoProjectedPoint(&b);
                }

                DoEqualLenTicks(a, b, gn);
            }
            if(type == LENGTH_RATIO) {
                Vector ref = ((a.Plus(b)).ScaledBy(0.5)).Plus(disp.offset);
                DoLabel(ref, labelPos, gr, gu);
            }
            break;
        }

        case EQ_LEN_PT_LINE_D: {
            Entity *forLen = SK.GetEntity(entityA);
            Vector a = SK.GetEntity(forLen->point[0])->PointGetNum(),
                   b = SK.GetEntity(forLen->point[1])->PointGetNum();
            if(workplane.v != Entity::FREE_IN_3D.v) {
                DoProjectedPoint(&a);
                DoProjectedPoint(&b);
            }
            DoEqualLenTicks(a, b, gn);

            Entity *ln = SK.GetEntity(entityB);
            Vector la = SK.GetEntity(ln->point[0])->PointGetNum(),
                   lb = SK.GetEntity(ln->point[1])->PointGetNum();
            Vector pt = SK.GetEntity(ptA)->PointGetNum();
            if(workplane.v != Entity::FREE_IN_3D.v) {
                DoProjectedPoint(&pt);
                la = la.ProjectInto(workplane);
                lb = lb.ProjectInto(workplane);
            }

            Vector closest = pt.ClosestPointOnLine(la, lb.Minus(la));
            LineDrawOrGetDistance(pt, closest);
            DoEqualLenTicks(pt, closest, gn);
            break;
        }

        case EQ_PT_LN_DISTANCES: {
            for(int i = 0; i < 2; i++) {
                Entity *ln = SK.GetEntity(i == 0 ? entityA : entityB);
                Vector la = SK.GetEntity(ln->point[0])->PointGetNum(),
                       lb = SK.GetEntity(ln->point[1])->PointGetNum();
                Entity *pte = SK.GetEntity(i == 0 ? ptA : ptB);
                Vector pt = pte->PointGetNum();

                if(workplane.v != Entity::FREE_IN_3D.v) {
                    DoProjectedPoint(&pt);
                    la = la.ProjectInto(workplane);
                    lb = lb.ProjectInto(workplane);
                }

                Vector closest = pt.ClosestPointOnLine(la, lb.Minus(la));

                LineDrawOrGetDistance(pt, closest);
                DoEqualLenTicks(pt, closest, gn);
            }
            break;
        }

        {
        case SYMMETRIC:
            Vector n;
            n = SK.GetEntity(entityA)->Normal()->NormalN(); goto s;
        case SYMMETRIC_HORIZ:
            n = SK.GetEntity(workplane)->Normal()->NormalU(); goto s;
        case SYMMETRIC_VERT:
            n = SK.GetEntity(workplane)->Normal()->NormalV(); goto s;
        case SYMMETRIC_LINE: {
            Entity *ln = SK.GetEntity(entityA);
            Vector la = SK.GetEntity(ln->point[0])->PointGetNum(),
                   lb = SK.GetEntity(ln->point[1])->PointGetNum();
            la = la.ProjectInto(workplane);
            lb = lb.ProjectInto(workplane);
            n = lb.Minus(la);
            Vector nw = SK.GetEntity(workplane)->Normal()->NormalN();
            n = n.RotatedAbout(nw, PI/2);
            goto s;
        }
s:
            Vector a = SK.GetEntity(ptA)->PointGetNum();
            Vector b = SK.GetEntity(ptB)->PointGetNum();

            for(int i = 0; i < 2; i++) {
                Vector tail = (i == 0) ? a : b;
                Vector d = (i == 0) ? b : a;
                d = d.Minus(tail);
                // Project the direction in which the arrow is drawn normal
                // to the symmetry plane; for projected symmetry constraints,
                // they might not be in the same direction, even when the
                // constraint is fully solved.
                d = n.ScaledBy(d.Dot(n));
                d = d.WithMagnitude(20/SS.GW.scale);
                Vector tip = tail.Plus(d);

                LineDrawOrGetDistance(tail, tip);
                d = d.WithMagnitude(9/SS.GW.scale);
                LineDrawOrGetDistance(tip, tip.Minus(d.RotatedAbout(gn,  0.6)));
                LineDrawOrGetDistance(tip, tip.Minus(d.RotatedAbout(gn, -0.6)));
            }
            break;
        }

        case AT_MIDPOINT:
        case HORIZONTAL:
        case VERTICAL:
            if(entityA.v) {
                Vector r, u, n;
                if(workplane.v == Entity::FREE_IN_3D.v) {
                    r = gr; u = gu; n = gn;
                } else {
                    r = SK.GetEntity(workplane)->Normal()->NormalU();
                    u = SK.GetEntity(workplane)->Normal()->NormalV();
                    n = r.Cross(u);
                }
                // For "at midpoint", this branch is always taken.
                Entity *e = SK.GetEntity(entityA);
                Vector a = SK.GetEntity(e->point[0])->PointGetNum();
                Vector b = SK.GetEntity(e->point[1])->PointGetNum();
                Vector m = (a.ScaledBy(0.5)).Plus(b.ScaledBy(0.5));
                Vector offset = (a.Minus(b)).Cross(n);
                offset = offset.WithMagnitude(13/SS.GW.scale);
                // Draw midpoint constraint on other side of line, so that
                // a line can be midpoint and horizontal at same time.
                if(type == AT_MIDPOINT) offset = offset.ScaledBy(-1);

                if(dogd.drawing) {
                    const char *s = (type == HORIZONTAL)  ? "H" : (
                                    (type == VERTICAL)    ? "V" : (
                                    (type == AT_MIDPOINT) ? "M" : NULL));

                    ssglWriteTextRefCenter(s, DEFAULT_TEXT_HEIGHT,
                        m.Plus(offset), r, u, LineCallback, this);
                } else {
                    dogd.refp = m.Plus(offset);
                    Point2d ref = SS.GW.ProjectPoint(dogd.refp);
                    dogd.dmin = min(dogd.dmin, ref.DistanceTo(dogd.mp)-10);
                }
            } else {
                Vector a = SK.GetEntity(ptA)->PointGetNum();
                Vector b = SK.GetEntity(ptB)->PointGetNum();

                Entity *w = SK.GetEntity(workplane);
                Vector cu = w->Normal()->NormalU();
                Vector cv = w->Normal()->NormalV();
                Vector cn = w->Normal()->NormalN();

                int i;
                for(i = 0; i < 2; i++) {
                    Vector o = (i == 0) ? a : b;
                    Vector oo = (i == 0) ? a.Minus(b) : b.Minus(a);
                    Vector d = (type == HORIZONTAL) ? cu : cv;
                    if(oo.Dot(d) < 0) d = d.ScaledBy(-1);

                    Vector dp = cn.Cross(d);
                    d = d.WithMagnitude(14/SS.GW.scale);
                    Vector c = o.Minus(d);
                    LineDrawOrGetDistance(o, c);
                    d = d.WithMagnitude(3/SS.GW.scale);
                    dp = dp.WithMagnitude(2/SS.GW.scale);
                    if(dogd.drawing) {
                        glBegin(GL_QUADS);
                            ssglVertex3v((c.Plus(d)).Plus(dp));
                            ssglVertex3v((c.Minus(d)).Plus(dp));
                            ssglVertex3v((c.Minus(d)).Minus(dp));
                            ssglVertex3v((c.Plus(d)).Minus(dp));
                        glEnd();
                    } else {
                        Point2d ref = SS.GW.ProjectPoint(c);
                        dogd.dmin = min(dogd.dmin, ref.DistanceTo(dogd.mp)-6);
                    }
                }
            }
            break;

        case COMMENT: {
            if(dogd.drawing && disp.style.v) {
                ssglLineWidth(Style::Width(disp.style));
                ssglColorRGB(Style::Color(disp.style));
            }
            Vector u, v;
            if(workplane.v == Entity::FREE_IN_3D.v) {
                u = gr;
                v = gu;
            } else {
                EntityBase *norm = SK.GetEntity(workplane)->Normal();
                u = norm->NormalU();
                v = norm->NormalV();
            }
            DoLabel(disp.offset, labelPos, u, v);
            break;
        }

        default: oops();
    }
}
Beispiel #2
0
void GraphicsWindow::MouseMoved(double x, double y, bool leftDown,
            bool middleDown, bool rightDown, bool shiftDown, bool ctrlDown)
{
    if(GraphicsEditControlIsVisible()) return;
    if(context.active) return;

    SS.extraLine.draw = false;

    if(!orig.mouseDown) {
        // If someone drags the mouse into our window with the left button
        // already depressed, then we don't have our starting point; so
        // don't try.
        leftDown = false;
    }

    if(rightDown) {
        middleDown = true;
        shiftDown = !shiftDown;
    }

    if(SS.showToolbar) {
        if(ToolbarMouseMoved((int)x, (int)y)) {
            hover.Clear();
            return;
        }
    }

    if(!leftDown && (pending.operation == DRAGGING_POINTS ||
                     pending.operation == DRAGGING_MARQUEE))
    {
        ClearPending();
        InvalidateGraphics();
    }

    Point2d mp = Point2d::From(x, y);
    currentMousePosition = mp;

    if(rightDown && orig.mouse.DistanceTo(mp) < 5 && !orig.startedMoving) {
        // Avoid accidentally panning (or rotating if shift is down) if the
        // user wants a context menu.
        return;
    }
    orig.startedMoving = true;

    // If the middle button is down, then mouse movement is used to pan and
    // rotate our view. This wins over everything else.
    if(middleDown) {
        hover.Clear();

        double dx = (x - orig.mouse.x) / scale;
        double dy = (y - orig.mouse.y) / scale;

        if(!(shiftDown || ctrlDown)) {
            double s = 0.3*(PI/180)*scale; // degrees per pixel
            projRight = orig.projRight.RotatedAbout(orig.projUp, -s*dx);
            projUp = orig.projUp.RotatedAbout(orig.projRight, s*dy);

            NormalizeProjectionVectors();
        } else if(ctrlDown) {
            double theta = atan2(orig.mouse.y, orig.mouse.x);
            theta -= atan2(y, x);
            SS.extraLine.draw = true;
            SS.extraLine.ptA = UnProjectPoint(Point2d::From(0, 0));
            SS.extraLine.ptB = UnProjectPoint(mp);

            Vector normal = orig.projRight.Cross(orig.projUp);
            projRight = orig.projRight.RotatedAbout(normal, theta);
            projUp = orig.projUp.RotatedAbout(normal, theta);

            NormalizeProjectionVectors();
        } else {
            offset.x = orig.offset.x + dx*projRight.x + dy*projUp.x;
            offset.y = orig.offset.y + dx*projRight.y + dy*projUp.y;
            offset.z = orig.offset.z + dx*projRight.z + dy*projUp.z;
        }

        orig.projRight = projRight;
        orig.projUp = projUp;
        orig.offset = offset;
        orig.mouse.x = x;
        orig.mouse.y = y;

        if(SS.TW.shown.screen == TextWindow::SCREEN_EDIT_VIEW) {
            if(havePainted) {
                SS.ScheduleShowTW();
            }
        }
        InvalidateGraphics();
        havePainted = false;
        return;
    }

    if(pending.operation == 0) {
        double dm = orig.mouse.DistanceTo(mp);
        // If we're currently not doing anything, then see if we should
        // start dragging something.
        if(leftDown && dm > 3) {
            Entity *e = NULL;
            if(hover.entity.v) e = SK.GetEntity(hover.entity);
            if(e && e->type != Entity::WORKPLANE) {
                Entity *e = SK.GetEntity(hover.entity);
                if(e->type == Entity::CIRCLE && selection.n <= 1) {
                    // Drag the radius.
                    ClearSelection();
                    pending.circle = hover.entity;
                    pending.operation = DRAGGING_RADIUS;
                } else if(e->IsNormal()) {
                    ClearSelection();
                    pending.normal = hover.entity;
                    pending.operation = DRAGGING_NORMAL;
                } else {
                    if(!hoverWasSelectedOnMousedown) {
                        // The user clicked an unselected entity, which
                        // means they're dragging just the hovered thing,
                        // not the full selection. So clear all the selection
                        // except that entity.
                        ClearSelection();
                        MakeSelected(e->h);
                    }
                    StartDraggingBySelection();
                    if(!hoverWasSelectedOnMousedown) {
                        // And then clear the selection again, since they
                        // probably didn't want that selected if they just
                        // were dragging it.
                        ClearSelection();
                    }
                    hover.Clear();
                    pending.operation = DRAGGING_POINTS;
                }
            } else if(hover.constraint.v &&
                            SK.GetConstraint(hover.constraint)->HasLabel())
            {
                ClearSelection();
                pending.constraint = hover.constraint;
                pending.operation = DRAGGING_CONSTRAINT;
            }
            if(pending.operation != 0) {
                // We just started a drag, so remember for the undo before
                // the drag changes anything.
                SS.UndoRemember();
            } else {
                if(!hover.constraint.v) {
                    // That's just marquee selection, which should not cause
                    // an undo remember.
                    if(dm > 10) {
                        if(hover.entity.v) {
                            // Avoid accidentally selecting workplanes when
                            // starting drags.
                            MakeUnselected(hover.entity, false);
                            hover.Clear();
                        }
                        pending.operation = DRAGGING_MARQUEE;
                        orig.marqueePoint =
                            UnProjectPoint(orig.mouseOnButtonDown);
                    }
                }
            }
        } else {
            // Otherwise, just hit test and give up; but don't hit test
            // if the mouse is down, because then the user could hover
            // a point, mouse down (thus selecting it), and drag, in an
            // effort to drag the point, but instead hover a different
            // entity before we move far enough to start the drag.
            if(!leftDown) HitTestMakeSelection(mp);
        }
        return;
    }

    // If the user has started an operation from the menu, but not
    // completed it, then just do the selection.
    if(pending.operation < FIRST_PENDING) {
        HitTestMakeSelection(mp);
        return;
    }

    // We're currently dragging something; so do that. But if we haven't
    // painted since the last time we solved, do nothing, because there's
    // no sense solving a frame and not displaying it.
    if(!havePainted) {
        if(pending.operation == DRAGGING_POINTS && ctrlDown) {
            SS.extraLine.ptA = UnProjectPoint(orig.mouseOnButtonDown);
            SS.extraLine.ptB = UnProjectPoint(mp);
            SS.extraLine.draw = true;
        }
        return;
    }
    switch(pending.operation) {
        case DRAGGING_CONSTRAINT: {
            Constraint *c = SK.constraint.FindById(pending.constraint);
            UpdateDraggedNum(&(c->disp.offset), x, y);
            orig.mouse = mp;
            InvalidateGraphics();
            break;
        }

        case DRAGGING_NEW_LINE_POINT:
        case DRAGGING_NEW_POINT:
            UpdateDraggedPoint(pending.point, x, y);
            HitTestMakeSelection(mp);
            SS.MarkGroupDirtyByEntity(pending.point);
            orig.mouse = mp;
            InvalidateGraphics();
            break;

        case DRAGGING_POINTS:
            if(shiftDown || ctrlDown) {
                // Edit the rotation associated with a POINT_N_ROT_TRANS,
                // either within (ctrlDown) or out of (shiftDown) the plane
                // of the screen. So first get the rotation to apply, in qt.
                Quaternion qt;
                if(ctrlDown) {
                    double d = mp.DistanceTo(orig.mouseOnButtonDown);
                    if(d < 25) {
                        // Don't start dragging the position about the normal
                        // until we're a little ways out, to get a reasonable
                        // reference pos
                        orig.mouse = mp;
                        break;
                    }
                    double theta = atan2(orig.mouse.y-orig.mouseOnButtonDown.y,
                                         orig.mouse.x-orig.mouseOnButtonDown.x);
                    theta -= atan2(y-orig.mouseOnButtonDown.y,
                                   x-orig.mouseOnButtonDown.x);

                    Vector gn = projRight.Cross(projUp);
                    qt = Quaternion::From(gn, -theta);

                    SS.extraLine.draw = true;
                    SS.extraLine.ptA = UnProjectPoint(orig.mouseOnButtonDown);
                    SS.extraLine.ptB = UnProjectPoint(mp);
                } else {
                    double dx = -(x - orig.mouse.x);
                    double dy = -(y - orig.mouse.y);
                    double s = 0.3*(PI/180); // degrees per pixel
                    qt = Quaternion::From(projUp,   -s*dx).Times(
                         Quaternion::From(projRight, s*dy));
                }
                orig.mouse = mp;

                // Now apply this rotation to the points being dragged.
                List<hEntity> *lhe = &(pending.points);
                for(hEntity *he = lhe->First(); he; he = lhe->NextAfter(he)) {
                    Entity *e = SK.GetEntity(*he);
                    if(e->type != Entity::POINT_N_ROT_TRANS) {
                        if(ctrlDown) {
                            Vector p = e->PointGetNum();
                            p = p.Minus(SS.extraLine.ptA);
                            p = qt.Rotate(p);
                            p = p.Plus(SS.extraLine.ptA);
                            e->PointForceTo(p);
                            SS.MarkGroupDirtyByEntity(e->h);
                        }
                        continue;
                    }

                    Quaternion q = e->PointGetQuaternion();
                    Vector     p = e->PointGetNum();
                    q = qt.Times(q);
                    e->PointForceQuaternionTo(q);
                    // Let's rotate about the selected point; so fix up the
                    // translation so that that point didn't move.
                    e->PointForceTo(p);
                    SS.MarkGroupDirtyByEntity(e->h);
                }
            } else {
                List<hEntity> *lhe = &(pending.points);
                for(hEntity *he = lhe->First(); he; he = lhe->NextAfter(he)) {
                    UpdateDraggedPoint(*he, x, y);
                    SS.MarkGroupDirtyByEntity(*he);
                }
                orig.mouse = mp;
            }
            break;

        case DRAGGING_NEW_CUBIC_POINT: {
            UpdateDraggedPoint(pending.point, x, y);
            HitTestMakeSelection(mp);

            hRequest hr = pending.point.request();
            if(pending.point.v == hr.entity(4).v) {
                // The very first segment; dragging final point drags both
                // tangent points.
                Vector p0 = SK.GetEntity(hr.entity(1))->PointGetNum(),
                       p3 = SK.GetEntity(hr.entity(4))->PointGetNum(),
                       p1 = p0.ScaledBy(2.0/3).Plus(p3.ScaledBy(1.0/3)),
                       p2 = p0.ScaledBy(1.0/3).Plus(p3.ScaledBy(2.0/3));
                SK.GetEntity(hr.entity(1+1))->PointForceTo(p1);
                SK.GetEntity(hr.entity(1+2))->PointForceTo(p2);
            } else {
                // A subsequent segment; dragging point drags only final
                // tangent point.
                int i = SK.GetEntity(hr.entity(0))->extraPoints;
                Vector pn   = SK.GetEntity(hr.entity(4+i))->PointGetNum(),
                       pnm2 = SK.GetEntity(hr.entity(2+i))->PointGetNum(),
                       pnm1 = (pn.Plus(pnm2)).ScaledBy(0.5);
                SK.GetEntity(hr.entity(3+i))->PointForceTo(pnm1);
            }

            orig.mouse = mp;
            SS.MarkGroupDirtyByEntity(pending.point);
            break;
        }
        case DRAGGING_NEW_ARC_POINT: {
            UpdateDraggedPoint(pending.point, x, y);
            HitTestMakeSelection(mp);

            hRequest hr = pending.point.request();
            Vector ona = SK.GetEntity(hr.entity(2))->PointGetNum();
            Vector onb = SK.GetEntity(hr.entity(3))->PointGetNum();
            Vector center = (ona.Plus(onb)).ScaledBy(0.5);

            SK.GetEntity(hr.entity(1))->PointForceTo(center);

            orig.mouse = mp;
            SS.MarkGroupDirtyByEntity(pending.point);
            break;
        }
        case DRAGGING_NEW_RADIUS:
        case DRAGGING_RADIUS: {
            Entity *circle = SK.GetEntity(pending.circle);
            Vector center = SK.GetEntity(circle->point[0])->PointGetNum();
            Point2d c2 = ProjectPoint(center);
            double r = c2.DistanceTo(mp)/scale;
            SK.GetEntity(circle->distance)->DistanceForceTo(r);

            SS.MarkGroupDirtyByEntity(pending.circle);
            break;
        }

        case DRAGGING_NORMAL: {
            Entity *normal = SK.GetEntity(pending.normal);
            Vector p = SK.GetEntity(normal->point[0])->PointGetNum();
            Point2d p2 = ProjectPoint(p);

            Quaternion q = normal->NormalGetNum();
            Vector u = q.RotationU(), v = q.RotationV();

            if(ctrlDown) {
                double theta = atan2(orig.mouse.y-p2.y, orig.mouse.x-p2.x);
                theta -= atan2(y-p2.y, x-p2.x);

                Vector normal = projRight.Cross(projUp);
                u = u.RotatedAbout(normal, -theta);
                v = v.RotatedAbout(normal, -theta);
            } else {
                double dx = -(x - orig.mouse.x);
                double dy = -(y - orig.mouse.y);
                double s = 0.3*(PI/180); // degrees per pixel
                u = u.RotatedAbout(projUp, -s*dx);
                u = u.RotatedAbout(projRight, s*dy);
                v = v.RotatedAbout(projUp, -s*dx);
                v = v.RotatedAbout(projRight, s*dy);
            }
            orig.mouse = mp;
            normal->NormalForceTo(Quaternion::From(u, v));

            SS.MarkGroupDirtyByEntity(pending.normal);
            break;
        }

        case DRAGGING_MARQUEE:
            orig.mouse = mp;
            InvalidateGraphics();
            break;

        default: oops();
    }

    if(pending.operation != 0 &&
       pending.operation != DRAGGING_CONSTRAINT &&
       pending.operation != DRAGGING_MARQUEE)
    {
        SS.GenerateAll();
    }
    havePainted = false;
}
Beispiel #3
0
void Entity::DrawOrGetDistance(void) {
    if(!IsVisible()) return;

    Group *g = SK.GetGroup(group);

    switch(type) {
        case POINT_N_COPY:
        case POINT_N_TRANS:
        case POINT_N_ROT_TRANS:
        case POINT_N_ROT_AA:
        case POINT_IN_3D:
        case POINT_IN_2D: {
            Vector v = PointGetNum();
            dogd.refp = v;

            if(dogd.drawing) {
                double s = 3.5;
                Vector r = SS.GW.projRight.ScaledBy(s/SS.GW.scale);
                Vector d = SS.GW.projUp.ScaledBy(s/SS.GW.scale);

                ssglColorRGB(Style::Color(Style::DATUM));
                ssglDepthRangeOffset(6);
                glBegin(GL_QUADS);
                    ssglVertex3v(v.Plus (r).Plus (d));
                    ssglVertex3v(v.Plus (r).Minus(d));
                    ssglVertex3v(v.Minus(r).Minus(d));
                    ssglVertex3v(v.Minus(r).Plus (d));
                glEnd();
                ssglDepthRangeOffset(0);
            } else {
                Point2d pp = SS.GW.ProjectPoint(v);
                dogd.dmin = pp.DistanceTo(dogd.mp) - 6;
            }
            break;
        }

        case NORMAL_N_COPY:
        case NORMAL_N_ROT:
        case NORMAL_N_ROT_AA:
        case NORMAL_IN_3D:
        case NORMAL_IN_2D: {
            int i;
            for(i = 0; i < 2; i++) {
                if(i == 0 && !SS.GW.showNormals) {
                    // When the normals are hidden, we will continue to show
                    // the coordinate axes at the bottom left corner, but
                    // not at the origin.
                    continue;
                }

                hRequest hr = h.request();
                // Always draw the x, y, and z axes in red, green, and blue;
                // brighter for the ones at the bottom left of the screen,
                // dimmer for the ones at the model origin.
                int f = (i == 0 ? 100 : 255);
                if(hr.v == Request::HREQUEST_REFERENCE_XY.v) {
                    ssglColorRGB(RGBi(0, 0, f));
                } else if(hr.v == Request::HREQUEST_REFERENCE_YZ.v) {
                    ssglColorRGB(RGBi(f, 0, 0));
                } else if(hr.v == Request::HREQUEST_REFERENCE_ZX.v) {
                    ssglColorRGB(RGBi(0, f, 0));
                } else {
                    ssglColorRGB(Style::Color(Style::NORMALS));
                    if(i > 0) break;
                }

                Quaternion q = NormalGetNum();
                Vector tail;
                if(i == 0) {
                    tail = SK.GetEntity(point[0])->PointGetNum();
                    glLineWidth(1);
                } else {
                    // Draw an extra copy of the x, y, and z axes, that's
                    // always in the corner of the view and at the front.
                    // So those are always available, perhaps useful.
                    double s = SS.GW.scale;
                    double h = 60 - SS.GW.height/2;
                    double w = 60 - SS.GW.width/2;
                    tail = SS.GW.projRight.ScaledBy(w/s).Plus(
                           SS.GW.projUp.   ScaledBy(h/s)).Minus(SS.GW.offset);
                    ssglDepthRangeLockToFront(true);
                    glLineWidth(2);
                }

                Vector v = (q.RotationN()).WithMagnitude(50/SS.GW.scale);
                Vector tip = tail.Plus(v);
                LineDrawOrGetDistance(tail, tip);

                v = v.WithMagnitude(12/SS.GW.scale);
                Vector axis = q.RotationV();
                LineDrawOrGetDistance(tip,tip.Minus(v.RotatedAbout(axis, 0.6)));
                LineDrawOrGetDistance(tip,tip.Minus(v.RotatedAbout(axis,-0.6)));
            }
            ssglDepthRangeLockToFront(false);
            break;
        }

        case DISTANCE:
        case DISTANCE_N_COPY:
            // These are used only as data structures, nothing to display.
            break;

        case WORKPLANE: {
            Vector p;
            p = SK.GetEntity(point[0])->PointGetNum();

            Vector u = Normal()->NormalU();
            Vector v = Normal()->NormalV();

            double s = (min(SS.GW.width, SS.GW.height))*0.45/SS.GW.scale;

            Vector us = u.ScaledBy(s);
            Vector vs = v.ScaledBy(s);

            Vector pp = p.Plus (us).Plus (vs);
            Vector pm = p.Plus (us).Minus(vs);
            Vector mm = p.Minus(us).Minus(vs), mm2 = mm;
            Vector mp = p.Minus(us).Plus (vs);

            glLineWidth(1);
            ssglColorRGB(Style::Color(Style::NORMALS));
            glEnable(GL_LINE_STIPPLE);
            glLineStipple(3, 0x1111);
            if(!h.isFromRequest()) {
                mm = mm.Plus(v.ScaledBy(60/SS.GW.scale));
                mm2 = mm2.Plus(u.ScaledBy(60/SS.GW.scale));
                LineDrawOrGetDistance(mm2, mm);
            }
            LineDrawOrGetDistance(pp, pm);
            LineDrawOrGetDistance(pm, mm2);
            LineDrawOrGetDistance(mm, mp);
            LineDrawOrGetDistance(mp, pp);
            glDisable(GL_LINE_STIPPLE);

            char *str = DescriptionString()+5;
            double th = DEFAULT_TEXT_HEIGHT;
            if(dogd.drawing) {
                ssglWriteText(str, th, mm2, u, v, NULL, NULL);
            } else {
                Vector pos = mm2.Plus(u.ScaledBy(ssglStrWidth(str, th)/2)).Plus(
                                      v.ScaledBy(ssglStrHeight(th)/2));
                Point2d pp = SS.GW.ProjectPoint(pos);
                dogd.dmin = min(dogd.dmin, pp.DistanceTo(dogd.mp) - 10);
                // If a line lies in a plane, then select the line, not
                // the plane.
                dogd.dmin += 3;
            }
            break;
        }

        case LINE_SEGMENT:
        case CIRCLE:
        case ARC_OF_CIRCLE:
        case CUBIC:
        case CUBIC_PERIODIC:
        case TTF_TEXT:
            // Nothing but the curve(s).
            break;

        case FACE_NORMAL_PT:
        case FACE_XPROD:
        case FACE_N_ROT_TRANS:
        case FACE_N_TRANS:
        case FACE_N_ROT_AA:
            // Do nothing; these are drawn with the triangle mesh
            break;

        default:
            oops();
    }

    // And draw the curves; generate the rational polynomial curves for
    // everything, then piecewise linearize them, and display those.
    SEdgeList sel;
    ZERO(&sel);
    GenerateEdges(&sel, true);
    int i;
    for(i = 0; i < sel.l.n; i++) {
        SEdge *se = &(sel.l.elem[i]);
        LineDrawOrGetDistance(se->a, se->b, true);
    }
    sel.Clear();
}