if(h.isFromRequest()) {

Request *r = SK.GetRequest(h.request());

return r->DescriptionString();

} else {

Group *g = SK.GetGroup(h.group());

return g->DescriptionString();

}

if(dogd.drawing) {

// Draw lines from active group in front of those from previous

ssglDepthRangeOffset((group.v == SS.GW.activeGroup.v) ? 4 : 3);

// Narrow lines are drawn as lines, but fat lines must be drawn as

// filled polygons, to get the line join style right.

ssglStippledLine(a, b, dogd.lineWidth, dogd.stippleType, dogd.stippleScale, maybeFat);

ssglDepthRangeOffset(0);

} else {

Point2d ap = SS.GW.ProjectPoint(a);

Point2d bp = SS.GW.ProjectPoint(b);

double d = dogd.mp.DistanceToLine(ap, bp.Minus(ap), true);

// A little bit easier to select in the active group

if(group.v == SS.GW.activeGroup.v) d -= 1;

if(d < dogd.dmin) {

dogd.dmin = d;

dogd.data = data;

}

}

dogd.refp = (a.Plus(b)).ScaledBy(0.5);

// This handles points as a special case, because I seem to be able

// to get a huge speedup that way, by consolidating stuff to gl.

int i;

if(SS.GW.showPoints) {

double s = 3.5/SS.GW.scale;

Vector r = SS.GW.projRight.ScaledBy(s);

Vector d = SS.GW.projUp.ScaledBy(s);

ssglColorRGB(Style::Color(Style::DATUM));

ssglDepthRangeOffset(6);

glBegin(GL_QUADS);

for(i = 0; i < SK.entity.n; i++) {

Entity *e = &(SK.entity.elem[i]);

if(!e->IsPoint()) continue;

if(!(SK.GetGroup(e->group)->IsVisible())) continue;

if(e->forceHidden) continue;

Vector v = e->PointGetNum();

// If we're analyzing the sketch to show the degrees of freedom,

// then we draw big colored squares over the points that are

// free to move.

bool free = false;

if(e->type == POINT_IN_3D) {

Param *px = SK.GetParam(e->param[0]),

*py = SK.GetParam(e->param[1]),

*pz = SK.GetParam(e->param[2]);

free = (px->free) || (py->free) || (pz->free);

} else if(e->type == POINT_IN_2D) {

Param *pu = SK.GetParam(e->param[0]),

*pv = SK.GetParam(e->param[1]);

free = (pu->free) || (pv->free);

}

if(free) {

Vector re = r.ScaledBy(2.5), de = d.ScaledBy(2.5);

ssglColorRGB(Style::Color(Style::ANALYZE));

ssglVertex3v(v.Plus (re).Plus (de));

ssglVertex3v(v.Plus (re).Minus(de));

ssglVertex3v(v.Minus(re).Minus(de));

ssglVertex3v(v.Minus(re).Plus (de));

ssglColorRGB(Style::Color(Style::DATUM));

}

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);

}

for(i = 0; i < SK.entity.n; i++) {

Entity *e = &(SK.entity.elem[i]);

if(e->IsPoint()) {

continue; // already handled

}

e->Draw(drawAsHidden);

}

hStyle hs = Style::ForEntity(h);

dogd.lineWidth = Style::Width(hs);

if(drawAsHidden) {

dogd.stippleType = Style::PatternType({ Style::HIDDEN_EDGE });

dogd.stippleScale = Style::StippleScaleMm({ Style::HIDDEN_EDGE });

} else {

dogd.stippleType = Style::PatternType(hs);

dogd.stippleScale = Style::StippleScaleMm(hs);

}

ssglLineWidth((float)dogd.lineWidth);

ssglColorRGB(Style::Color(hs));

dogd.drawing = true;

DrawOrGetDistance();

if(construction && !includingConstruction) return;

SBezierList *sbl = GetOrGenerateBezierCurves();

int i, j;

for(i = 0; i < sbl->l.n; i++) {

SBezier *sb = &(sbl->l.elem[i]);

List<Vector> lv = {};

sb->MakePwlInto(&lv);

for(j = 1; j < lv.n; j++) {

el->AddEdge(lv.elem[j-1], lv.elem[j], style.v, i);

}

lv.Clear();

}

SBezierList *sbl = GetOrGenerateBezierCurves();

// We don't bother with bounding boxes for normals, workplanes, etc.

*hasBBox = (IsPoint() || sbl->l.n > 0);

if(!*hasBBox) return {};

if(screenBBoxValid)

return screenBBox;

if(IsPoint()) {

Vector proj = SS.GW.ProjectPoint3(PointGetNum());

screenBBox = BBox::From(proj, proj);

} else if(sbl->l.n > 0) {

Vector first = SS.GW.ProjectPoint3(sbl->l.elem[0].ctrl[0]);

screenBBox = BBox::From(first, first);

for(int i = 0; i < sbl->l.n; i++) {

SBezier *sb = &sbl->l.elem[i];

for(int i = 0; i <= sb->deg; i++) {

screenBBox.Include(SS.GW.ProjectPoint3(sb->ctrl[i]));

}

}

} else oops();

// Enlarge the bounding box to consider selection radius.

screenBBox.minp.x -= SELECTION_RADIUS;

screenBBox.minp.y -= SELECTION_RADIUS;

screenBBox.maxp.x += SELECTION_RADIUS;

screenBBox.maxp.y += SELECTION_RADIUS;

screenBBoxValid = true;

return screenBBox;

dogd.drawing = false;

dogd.mp = mp;

dogd.dmin = 1e12;

DrawOrGetDistance();

return dogd.dmin;

dogd.drawing = false;

dogd.refp = SS.GW.offset.ScaledBy(-1);

DrawOrGetDistance();

return dogd.refp;

if(IsPoint()) return false;

if(IsWorkplane()) return false;

if(IsNormal()) return false;

return true;

Group *g = SK.GetGroup(group);

if(g->h.v == Group::HGROUP_REFERENCES.v && IsNormal()) {

// The reference normals are always shown

return true;

}

if(!(g->IsVisible())) return false;

// Don't check if points are hidden; this gets called only for

// selected or hovered points, and those should always be shown.

if(IsNormal() && !SS.GW.showNormals) return false;

if(!SS.GW.showWorkplanes) {

if(IsWorkplane() && !h.isFromRequest()) {

if(g->h.v != SS.GW.activeGroup.v) {

// The group-associated workplanes are hidden outside

// their group.

return false;

}

}

}

if(style.v) {

Style *s = Style::Get(style);

if(!s->visible) return false;

}

if(forceHidden) return false;

return true;

if(IsPoint()) actPoint = PointGetNum();

if(IsNormal()) actNormal = NormalGetNum();

if(type == DISTANCE || type == DISTANCE_N_COPY) {

actDistance = DistanceGetNum();

}

if(IsFace()) {

actPoint = FaceGetPointNum();

Vector n = FaceGetNormalNum();

actNormal = Quaternion::From(0, n.x, n.y, n.z);

}

if(forExport) {

// Visibility in copied linked entities follows source file

actVisible = IsVisible();

} else {

// Copied entities within a file are always visible

actVisible = true;

}

static const int MAX_N = BandedMatrix::MAX_UNKNOWNS;

int ep = extraPoints;

// The number of unknowns to solve for.

int n = periodic ? 3 + ep : ep;

if(n >= MAX_N) oops();

// The number of on-curve points, one more than the number of segments.

int pts = periodic ? 4 + ep : 2 + ep;

int i, j, a;

// The starting and finishing control points that define our end tangents

// (if the spline isn't periodic), and the on-curve points.

Vector ctrl_s = Vector::From(0, 0, 0);

Vector ctrl_f = Vector::From(0, 0, 0);

Vector pt[MAX_N+4];

if(periodic) {

for(i = 0; i < ep + 3; i++) {

pt[i] = SK.GetEntity(point[i])->PointGetNum();

}

pt[i++] = SK.GetEntity(point[0])->PointGetNum();

} else {

ctrl_s = SK.GetEntity(point[1])->PointGetNum();

ctrl_f = SK.GetEntity(point[ep+2])->PointGetNum();

j = 0;

pt[j++] = SK.GetEntity(point[0])->PointGetNum();

for(i = 2; i <= ep + 1; i++) {

pt[j++] = SK.GetEntity(point[i])->PointGetNum();

}

pt[j++] = SK.GetEntity(point[ep+3])->PointGetNum();

}

// The unknowns that we will be solving for, a set for each coordinate.

double Xx[MAX_N], Xy[MAX_N], Xz[MAX_N];

// For a cubic Bezier section f(t) as t goes from 0 to 1,

// f' (0) = 3*(P1 - P0)

// f' (1) = 3*(P3 - P2)

// f''(0) = 6*(P0 - 2*P1 + P2)

// f''(1) = 6*(P3 - 2*P2 + P1)

for(a = 0; a < 3; a++) {

BandedMatrix bm = {};

bm.n = n;

for(i = 0; i < n; i++) {

int im, it, ip;

if(periodic) {

im = WRAP(i - 1, n);

it = i;

ip = WRAP(i + 1, n);

} else {

im = i;

it = i + 1;

ip = i + 2;

}

// All of these are expressed in terms of a constant part, and

// of X[i-1], X[i], and X[i+1]; so let these be the four

// components of that vector;

Vector4 A, B, C, D, E;

// The on-curve interpolated point

C = Vector4::From((pt[it]).Element(a), 0, 0, 0);

// control point one back, C - X[i]

B = C.Plus(Vector4::From(0, 0, -1, 0));

// control point one forward, C + X[i]

D = C.Plus(Vector4::From(0, 0, 1, 0));

// control point two back

if(i == 0 && !periodic) {

A = Vector4::From(ctrl_s.Element(a), 0, 0, 0);

} else {

// pt[im] + X[i-1]

A = Vector4::From(pt[im].Element(a), 1, 0, 0);

}

// control point two forward

if(i == (n - 1) && !periodic) {

E = Vector4::From(ctrl_f.Element(a), 0, 0, 0);

} else {

// pt[ip] - X[i+1]

E = Vector4::From((pt[ip]).Element(a), 0, 0, -1);

}

// Write the second derivatives of each segment, dropping constant

Vector4 fprev_pp = (C.Minus(B.ScaledBy(2))).Plus(A),

fnext_pp = (C.Minus(D.ScaledBy(2))).Plus(E),

eq = fprev_pp.Minus(fnext_pp);

bm.B[i] = -eq.w;

if(periodic) {

bm.A[i][WRAP(i-2, n)] = eq.x;

bm.A[i][WRAP(i-1, n)] = eq.y;

bm.A[i][i] = eq.z;

} else {

// The wrapping would work, except when n = 1 and everything

// wraps to zero...

if(i > 0) bm.A[i][i - 1] = eq.x;

bm.A[i][i] = eq.y;

if(i < (n-1)) bm.A[i][i + 1] = eq.z;

}

}

bm.Solve();

double *X = (a == 0) ? Xx :

(a == 1) ? Xy :

Xz;

memcpy(X, bm.X, n*sizeof(double));

}

for(i = 0; i < pts - 1; i++) {

Vector p0, p1, p2, p3;

if(periodic) {

p0 = pt[i];

int iw = WRAP(i - 1, n);

p1 = p0.Plus(Vector::From(Xx[iw], Xy[iw], Xz[iw]));

} else if(i == 0) {

p0 = pt[0];

p1 = ctrl_s;

} else {

p0 = pt[i];

p1 = p0.Plus(Vector::From(Xx[i-1], Xy[i-1], Xz[i-1]));

}

if(periodic) {

p3 = pt[i+1];

int iw = WRAP(i, n);

p2 = p3.Minus(Vector::From(Xx[iw], Xy[iw], Xz[iw]));

} else if(i == (pts - 2)) {

p3 = pt[pts-1];

p2 = ctrl_f;

} else {

p3 = pt[i+1];

p2 = p3.Minus(Vector::From(Xx[i], Xy[i], Xz[i]));

}

SBezier sb = SBezier::From(p0, p1, p2, p3);

sbl->l.Add(&sb);

}

SBezier sb;

int i = sbl->l.n;

switch(type) {

case LINE_SEGMENT: {

Vector a = SK.GetEntity(point[0])->PointGetNum();

Vector b = SK.GetEntity(point[1])->PointGetNum();

sb = SBezier::From(a, b);

sb.entity = h.v;

sbl->l.Add(&sb);

break;

}

case CUBIC:

ComputeInterpolatingSpline(sbl, false);

break;

case CUBIC_PERIODIC:

ComputeInterpolatingSpline(sbl, true);

break;

case CIRCLE:

case ARC_OF_CIRCLE: {

Vector center = SK.GetEntity(point[0])->PointGetNum();

Quaternion q = SK.GetEntity(normal)->NormalGetNum();

Vector u = q.RotationU(), v = q.RotationV();

double r = CircleGetRadiusNum();

double thetaa, thetab, dtheta;

if(r < LENGTH_EPS) {

// If a circle or an arc gets dragged through zero radius,

// then we just don't generate anything.

break;

}

if(type == CIRCLE) {

thetaa = 0;

thetab = 2*PI;

dtheta = 2*PI;

} else {

ArcGetAngles(&thetaa, &thetab, &dtheta);

}

int i, n;

if(dtheta > (3*PI/2 + 0.01)) {

n = 4;

} else if(dtheta > (PI + 0.01)) {

n = 3;

} else if(dtheta > (PI/2 + 0.01)) {

n = 2;

} else {

n = 1;

}

dtheta /= n;

for(i = 0; i < n; i++) {

double s, c;

c = cos(thetaa);

s = sin(thetaa);

// The start point of the curve, and the tangent vector at

// that start point.

Vector p0 = center.Plus(u.ScaledBy( r*c)).Plus(v.ScaledBy(r*s)),

t0 = u.ScaledBy(-r*s). Plus(v.ScaledBy(r*c));

thetaa += dtheta;

c = cos(thetaa);

s = sin(thetaa);

Vector p2 = center.Plus(u.ScaledBy( r*c)).Plus(v.ScaledBy(r*s)),

t2 = u.ScaledBy(-r*s). Plus(v.ScaledBy(r*c));

// The control point must lie on both tangents.

Vector p1 = Vector::AtIntersectionOfLines(p0, p0.Plus(t0),

p2, p2.Plus(t2),

NULL);

SBezier sb = SBezier::From(p0, p1, p2);

sb.weight[1] = cos(dtheta/2);

sbl->l.Add(&sb);

}

break;

}

case TTF_TEXT: {

Vector topLeft = SK.GetEntity(point[0])->PointGetNum();

Vector botLeft = SK.GetEntity(point[1])->PointGetNum();

Vector n = Normal()->NormalN();

Vector v = topLeft.Minus(botLeft);

Vector u = (v.Cross(n)).WithMagnitude(v.Magnitude());

SS.fonts.PlotString(font, str, sbl, botLeft, u, v);

break;

}

default:

// Not a problem, points and normals and such don't generate curves

break;

}

// Record our style for all of the Beziers that we just created.

for(; i < sbl->l.n; i++) {

sbl->l.elem[i].auxA = style.v;

}

// If we're about to perform hit testing on an entity, consider

// whether the pointer is inside its bounding box first.

if(!dogd.drawing) {

bool hasBBox;

BBox box = GetOrGenerateScreenBBox(&hasBBox);

if(hasBBox && !box.Contains(dogd.mp))

return;

}

if(!IsVisible()) return;

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) {

if(dogd.drawing)

ssglColorRGB(RGBi(0, 0, f));

} else if(hr.v == Request::HREQUEST_REFERENCE_YZ.v) {

if(dogd.drawing)

ssglColorRGB(RGBi(f, 0, 0));

} else if(hr.v == Request::HREQUEST_REFERENCE_ZX.v) {

if(dogd.drawing)

ssglColorRGB(RGBi(0, f, 0));

} else {

if(dogd.drawing)

ssglColorRGB(Style::Color(Style::NORMALS));

if(i > 0) break;

}

Quaternion q = NormalGetNum();

Vector tail;

if(i == 0) {

tail = SK.GetEntity(point[0])->PointGetNum();

if(dogd.drawing)

ssglLineWidth(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);

if(dogd.drawing) {

ssglDepthRangeLockToFront(true);

ssglLineWidth(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)));

}

if(dogd.drawing)

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);

if(dogd.drawing) {

ssglLineWidth(1);

ssglColorRGB(Style::Color(Style::NORMALS));

glEnable(GL_LINE_STIPPLE);

glLineStipple(3, 0x1111);

}

if(!h.isFromRequest()) {

mm = mm.Plus(v.ScaledBy(70/SS.GW.scale));

mm2 = mm2.Plus(u.ScaledBy(70/SS.GW.scale));

LineDrawOrGetDistance(mm2, mm);

}

LineDrawOrGetDistance(pp, pm);

LineDrawOrGetDistance(pm, mm2);

LineDrawOrGetDistance(mp, mm);

LineDrawOrGetDistance(pp, mp);

if(dogd.drawing)

glDisable(GL_LINE_STIPPLE);

std::string str = DescriptionString().substr(5);

double th = Style::DefaultTextHeight();

if(dogd.drawing) {

Vector o = mm2.Plus(u.ScaledBy(3/SS.GW.scale)).Plus(

v.ScaledBy(3/SS.GW.scale));

ssglWriteText(str, th, o, u, v, NULL, NULL);

} else {

Vector pos = mm2.Plus(u.ScaledBy(ssglStrWidth(str, th)/2)).Plus(

v.ScaledBy(ssglStrCapHeight(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 = GetOrGenerateEdges();

dogd.data = -1;

for(int i = 0; i < sel->l.n; i++) {

SEdge *se = &(sel->l.elem[i]);

LineDrawOrGetDistance(se->a, se->b, true, se->auxB);

}