bool *allCoplanar,

bool *allNonZeroLen)

{

SBezierList sbl = {};

int i;

for(auto &e : SK.entity) {

if(e.group != h)

continue;

if(e.construction)

continue;

if(e.forceHidden)

continue;

e.GenerateBezierCurves(&sbl);

}

SBezier *sb;

*allNonZeroLen = true;

for(sb = sbl.l.First(); sb; sb = sbl.l.NextAfter(sb)) {

for(i = 1; i <= sb->deg; i++) {

if(!(sb->ctrl[i]).Equals(sb->ctrl[0])) {

break;

}

}

if(i > sb->deg) {

// This is a zero-length edge.

*allNonZeroLen = false;

polyError.errorPointAt = sb->ctrl[0];

goto done;

}

}

// Try to assemble all these Beziers into loops. The closed loops go into

// bezierLoops, with the outer loops grouped with their holes. The

// leftovers, if any, go in bezierOpens.

bezierLoops.FindOuterFacesFrom(&sbl, &polyLoops, NULL,

SS.ChordTolMm(),

allClosed, &(polyError.notClosedAt),

allCoplanar, &(polyError.errorPointAt),

&bezierOpens);

done:

sbl.Clear();

polyLoops.Clear();

bezierLoops.Clear();

bezierOpens.Clear();

if(type == Type::DRAWING_3D || type == Type::DRAWING_WORKPLANE ||

type == Type::ROTATE || type == Type::TRANSLATE || type == Type::LINKED)

{

bool allClosed = false, allCoplanar = false, allNonZeroLen = false;

AssembleLoops(&allClosed, &allCoplanar, &allNonZeroLen);

if(!allNonZeroLen) {

polyError.how = PolyError::ZERO_LEN_EDGE;

} else if(!allCoplanar) {

polyError.how = PolyError::NOT_COPLANAR;

} else if(!allClosed) {

polyError.how = PolyError::NOT_CLOSED;

} else {

polyError.how = PolyError::GOOD;

// The self-intersecting check is kind of slow, so don't run it

// unless requested.

if(SS.checkClosedContour) {

if(polyLoops.SelfIntersecting(&(polyError.errorPointAt))) {

polyError.how = PolyError::SELF_INTERSECTING;

}

}

}

}

for(SSurface &ss : surface){

hEntity face = { ss.face };

if(face == Entity::NO_ENTITY) continue;

face = g->Remap(face, remap);

ss.face = face.v;

}

STriangle *tr;

for(tr = l.First(); tr; tr = l.NextAfter(tr)) {

hEntity face = { tr->meta.face };

if(face == Entity::NO_ENTITY) continue;

face = g->Remap(face, remap);

tr->meta.face = face.v;

}

int n = (int)valA, a0 = 0;

if(subtype == Subtype::ONE_SIDED && skipFirst) {

a0++; n++;

}

int a;

// create all the transformed copies

std::vector <T> transd(n);

std::vector <T> workA(n);

workA[0] = {};

// first generate a shell/mesh with each transformed copy

#pragma omp parallel for

for(a = a0; a < n; a++) {

transd[a] = {};

workA[a] = {};

int ap = a*2 - (subtype == Subtype::ONE_SIDED ? 0 : (n-1));

if(type == Type::TRANSLATE) {

Vector trans = Vector::From(h.param(0), h.param(1), h.param(2));

trans = trans.ScaledBy(ap);

transd[a].MakeFromTransformationOf(steps,

trans, Quaternion::IDENTITY, 1.0);

} else {

Vector trans = Vector::From(h.param(0), h.param(1), h.param(2));

double theta = ap * SK.GetParam(h.param(3))->val;

double c = cos(theta), s = sin(theta);

Vector axis = Vector::From(h.param(4), h.param(5), h.param(6));

Quaternion q = Quaternion::From(c, s*axis.x, s*axis.y, s*axis.z);

// Rotation is centered at t; so A(x - t) + t = Ax + (t - At)

transd[a].MakeFromTransformationOf(steps,

trans.Minus(q.Rotate(trans)), q, 1.0);

}

}

for(a = a0; a < n; a++) {

// We need to rewrite any plane face entities to the transformed ones.

int remap = (a == (n - 1)) ? REMAP_LAST : a;

transd[a].RemapFaces(this, remap);

}

std::vector<T> *soFar = &transd;

std::vector<T> *scratch = &workA;

// do the boolean operations on pairs of equal size

while(n > 1) {

for(a = 0; a < n; a+=2) {

scratch->at(a/2).Clear();

// combine a pair of shells

if((a==0) && (a0==1)) { // if the first was skipped just copy the 2nd

scratch->at(a/2).MakeFromCopyOf(&(soFar->at(a+1)));

(soFar->at(a+1)).Clear();

a0 = 0;

} else if (a == n-1) { // for an odd number just copy the last one

scratch->at(a/2).MakeFromCopyOf(&(soFar->at(a)));

(soFar->at(a)).Clear();

} else if(forWhat == CombineAs::ASSEMBLE) {

scratch->at(a/2).MakeFromAssemblyOf(&(soFar->at(a)), &(soFar->at(a+1)));

(soFar->at(a)).Clear();

(soFar->at(a+1)).Clear();

} else {

scratch->at(a/2).MakeFromUnionOf(&(soFar->at(a)), &(soFar->at(a+1)));

(soFar->at(a)).Clear();

(soFar->at(a+1)).Clear();

}

}

swap(scratch, soFar);

n = (n+1)/2;

}

outs->Clear();

*outs = soFar->at(0);

// If this group contributes no new mesh, then our running mesh is the

// same as last time, no combining required. Likewise if we have a mesh

// but it's suppressed.

if(thiss->IsEmpty() || suppress) {

outs->MakeFromCopyOf(prevs);

return;

}

// So our group's shell appears in thisShell. Combine this with the

// previous group's shell, using the requested operation.

switch(how) {

case CombineAs::UNION:

outs->MakeFromUnionOf(prevs, thiss);

break;

case CombineAs::DIFFERENCE:

outs->MakeFromDifferenceOf(prevs, thiss);

break;

case CombineAs::INTERSECTION:

outs->MakeFromIntersectionOf(prevs, thiss);

break;

case CombineAs::ASSEMBLE:

outs->MakeFromAssemblyOf(prevs, thiss);

break;

}

bool prevBooleanFailed = booleanFailed;

booleanFailed = false;

Group *srcg = this;

thisShell.Clear();

thisMesh.Clear();

runningShell.Clear();

runningMesh.Clear();

// Don't attempt a lathe or extrusion unless the source section is good:

// planar and not self-intersecting.

bool haveSrc = true;

if(type == Type::EXTRUDE || type == Type::LATHE || type == Type::REVOLVE) {

Group *src = SK.GetGroup(opA);

if(src->polyError.how != PolyError::GOOD) {

haveSrc = false;

}

}

if(type == Type::TRANSLATE || type == Type::ROTATE) {

// A step and repeat gets merged against the group's previous group,

// not our own previous group.

srcg = SK.GetGroup(opA);

if(!srcg->suppress) {

if(!IsForcedToMesh()) {

GenerateForStepAndRepeat<SShell>(&(srcg->thisShell), &thisShell, srcg->meshCombine);

} else {

SMesh prevm = {};

prevm.MakeFromCopyOf(&srcg->thisMesh);

srcg->thisShell.TriangulateInto(&prevm);

GenerateForStepAndRepeat<SMesh> (&prevm, &thisMesh, srcg->meshCombine);

}

}

} else if(type == Type::EXTRUDE && haveSrc) {

Group *src = SK.GetGroup(opA);

Vector translate = Vector::From(h.param(0), h.param(1), h.param(2));

Vector tbot, ttop;

if(subtype == Subtype::ONE_SIDED || subtype == Subtype::ONE_SKEWED) {

tbot = {}; ttop = translate.ScaledBy(2);

} else {

tbot = translate.ScaledBy(-1); ttop = translate.ScaledBy(1);

}

SBezierLoopSetSet *sblss = &(src->bezierLoops);

SBezierLoopSet *sbls;

for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {

int is = thisShell.surface.n;

// Extrude this outer contour (plus its inner contours, if present)

thisShell.MakeFromExtrusionOf(sbls, tbot, ttop, color);

// And for any plane faces, annotate the model with the entity for

// that face, so that the user can select them with the mouse.

Vector onOrig = sbls->point;

int i;

// Not using range-for here because we're starting at a different place and using

// indices for meaning.

for(i = is; i < thisShell.surface.n; i++) {

SSurface *ss = &(thisShell.surface[i]);

hEntity face = Entity::NO_ENTITY;

Vector p = ss->PointAt(0, 0),

n = ss->NormalAt(0, 0).WithMagnitude(1);

double d = n.Dot(p);

if(i == is || i == (is + 1)) {

// These are the top and bottom of the shell.

if(fabs((onOrig.Plus(ttop)).Dot(n) - d) < LENGTH_EPS) {

face = Remap(Entity::NO_ENTITY, REMAP_TOP);

ss->face = face.v;

}

if(fabs((onOrig.Plus(tbot)).Dot(n) - d) < LENGTH_EPS) {

face = Remap(Entity::NO_ENTITY, REMAP_BOTTOM);

ss->face = face.v;

}

continue;

}

// So these are the sides

if(ss->degm != 1 || ss->degn != 1) continue;

for(Entity &e : SK.entity) {

if(e.group != opA) continue;

if(e.type != Entity::Type::LINE_SEGMENT) continue;

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

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

a = a.Plus(ttop);

b = b.Plus(ttop);

// Could get taken backwards, so check all cases.

if((a.Equals(ss->ctrl[0][0]) && b.Equals(ss->ctrl[1][0])) ||

(b.Equals(ss->ctrl[0][0]) && a.Equals(ss->ctrl[1][0])) ||

(a.Equals(ss->ctrl[0][1]) && b.Equals(ss->ctrl[1][1])) ||

(b.Equals(ss->ctrl[0][1]) && a.Equals(ss->ctrl[1][1])))

{

face = Remap(e.h, REMAP_LINE_TO_FACE);

ss->face = face.v;

break;

}

}

}

}

} else if(type == Type::LATHE && haveSrc) {

Group *src = SK.GetGroup(opA);

Vector pt = SK.GetEntity(predef.origin)->PointGetNum(),

axis = SK.GetEntity(predef.entityB)->VectorGetNum();

axis = axis.WithMagnitude(1);

SBezierLoopSetSet *sblss = &(src->bezierLoops);

SBezierLoopSet *sbls;

for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {

thisShell.MakeFromRevolutionOf(sbls, pt, axis, color, this);

}

} else if(type == Type::REVOLVE && haveSrc) {

Group *src = SK.GetGroup(opA);

double anglef = SK.GetParam(h.param(3))->val * 4; // why the 4 is needed?

double dists = 0, distf = 0;

double angles = 0.0;

if(subtype != Subtype::ONE_SIDED) {

anglef *= 0.5;

angles = -anglef;

}

Vector pt = SK.GetEntity(predef.origin)->PointGetNum(),

axis = SK.GetEntity(predef.entityB)->VectorGetNum();

axis = axis.WithMagnitude(1);

SBezierLoopSetSet *sblss = &(src->bezierLoops);

SBezierLoopSet *sbls;

for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {

if(fabs(anglef - angles) < 2 * PI) {

thisShell.MakeFromHelicalRevolutionOf(sbls, pt, axis, color, this,

angles, anglef, dists, distf);

} else {

thisShell.MakeFromRevolutionOf(sbls, pt, axis, color, this);

}

}

} else if(type == Type::HELIX && haveSrc) {

Group *src = SK.GetGroup(opA);

double anglef = SK.GetParam(h.param(3))->val * 4; // why the 4 is needed?

double dists = 0, distf = 0;

double angles = 0.0;

distf = SK.GetParam(h.param(7))->val * 2; // dist is applied twice

if(subtype != Subtype::ONE_SIDED) {

anglef *= 0.5;

angles = -anglef;

distf *= 0.5;

dists = -distf;

}

Vector pt = SK.GetEntity(predef.origin)->PointGetNum(),

axis = SK.GetEntity(predef.entityB)->VectorGetNum();

axis = axis.WithMagnitude(1);

SBezierLoopSetSet *sblss = &(src->bezierLoops);

SBezierLoopSet *sbls;

for(sbls = sblss->l.First(); sbls; sbls = sblss->l.NextAfter(sbls)) {

thisShell.MakeFromHelicalRevolutionOf(sbls, pt, axis, color, this,

angles, anglef, dists, distf);

}

} else if(type == Type::LINKED) {

// The imported shell or mesh are copied over, with the appropriate

// transformation applied. We also must remap the face entities.

Vector offset = {

SK.GetParam(h.param(0))->val,

SK.GetParam(h.param(1))->val,

SK.GetParam(h.param(2))->val };

Quaternion q = {

SK.GetParam(h.param(3))->val,

SK.GetParam(h.param(4))->val,

SK.GetParam(h.param(5))->val,

SK.GetParam(h.param(6))->val };

thisMesh.MakeFromTransformationOf(&impMesh, offset, q, scale);

thisMesh.RemapFaces(this, 0);

thisShell.MakeFromTransformationOf(&impShell, offset, q, scale);

thisShell.RemapFaces(this, 0);

}

if(srcg->meshCombine != CombineAs::ASSEMBLE) {

thisShell.MergeCoincidentSurfaces();

}

// So now we've got the mesh or shell for this group. Combine it with

// the previous group's mesh or shell with the requested Boolean, and

// we're done.

Group *prevg = srcg->RunningMeshGroup();

if(!IsForcedToMesh()) {

SShell *prevs = &(prevg->runningShell);

GenerateForBoolean<SShell>(prevs, &thisShell, &runningShell,

srcg->meshCombine);

if(srcg->meshCombine != CombineAs::ASSEMBLE) {

runningShell.MergeCoincidentSurfaces();

}

// If the Boolean failed, then we should note that in the text screen

// for this group.

booleanFailed = runningShell.booleanFailed;

if(booleanFailed != prevBooleanFailed) {

SS.ScheduleShowTW();

}

} else {

SMesh prevm, thism;

prevm = {};

thism = {};

prevm.MakeFromCopyOf(&(prevg->runningMesh));

prevg->runningShell.TriangulateInto(&prevm);

thism.MakeFromCopyOf(&thisMesh);

thisShell.TriangulateInto(&thism);

SMesh outm = {};

GenerateForBoolean<SMesh>(&prevm, &thism, &outm, srcg->meshCombine);

// Remove degenerate triangles; if we don't, they'll get split in SnapToMesh

// in every generated group, resulting in polynomial increase in triangle count,

// and corresponding slowdown.

outm.RemoveDegenerateTriangles();

if(srcg->meshCombine != CombineAs::ASSEMBLE) {

// And make sure that the output mesh is vertex-to-vertex.

SKdNode *root = SKdNode::From(&outm);

root->SnapToMesh(&outm);

root->MakeMeshInto(&runningMesh);

} else {

runningMesh.MakeFromCopyOf(&outm);

}

outm.Clear();

thism.Clear();

prevm.Clear();

}

displayDirty = true;

// This is potentially slow (since we've got to triangulate a shell, or

// to find the emphasized edges for a mesh), so we will run it only

// if its inputs have changed.

if(displayDirty) {

Group *pg = RunningMeshGroup();

if(pg && thisMesh.IsEmpty() && thisShell.IsEmpty()) {

// We don't contribute any new solid model in this group, so our

// display items are identical to the previous group's; which means

// that we can just display those, and stop ourselves from

// recalculating for those every time we get a change in this group.

//

// Note that this can end up recursing multiple times (if multiple

// groups that contribute no solid model exist in sequence), but

// that's okay.

pg->GenerateDisplayItems();

displayMesh.Clear();

displayMesh.MakeFromCopyOf(&(pg->displayMesh));

displayOutlines.Clear();

if(SS.GW.showEdges || SS.GW.showOutlines) {

displayOutlines.MakeFromCopyOf(&pg->displayOutlines);

}

} else {

// We do contribute new solid model, so we have to triangulate the

// shell, and edge-find the mesh.

displayMesh.Clear();

runningShell.TriangulateInto(&displayMesh);

STriangle *t;

for(t = runningMesh.l.First(); t; t = runningMesh.l.NextAfter(t)) {

STriangle trn = *t;

Vector n = trn.Normal();

trn.an = n;

trn.bn = n;

trn.cn = n;

displayMesh.AddTriangle(&trn);

}

displayOutlines.Clear();

if(SS.GW.showEdges || SS.GW.showOutlines) {

SOutlineList rawOutlines = {};

if(!runningMesh.l.IsEmpty()) {

// Triangle mesh only; no shell or emphasized edges.

runningMesh.MakeOutlinesInto(&rawOutlines, EdgeKind::EMPHASIZED);

} else {

displayMesh.MakeOutlinesInto(&rawOutlines, EdgeKind::SHARP);

}

PolylineBuilder builder;

builder.MakeFromOutlines(rawOutlines);

builder.GenerateOutlines(&displayOutlines);

rawOutlines.Clear();

}

}

// If we render this mesh, we need to know whether it's transparent,

// and we'll want all transparent triangles last, to make the depth test

// work correctly.

displayMesh.PrecomputeTransparency();

// Recalculate mass center if needed

if(SS.centerOfMass.draw && SS.centerOfMass.dirty && h == SS.GW.activeGroup) {

SS.UpdateCenterOfMass();

}

displayDirty = false;

}

switch(type) {

case Group::Type::EXTRUDE:

case Group::Type::LATHE:

case Group::Type::REVOLVE:

case Group::Type::HELIX:

case Group::Type::ROTATE:

case Group::Type::TRANSLATE:

return true;

default:

return false;

}

if(!(SS.GW.showShaded ||

SS.GW.drawOccludedAs != GraphicsWindow::DrawOccludedAs::VISIBLE)) return;

switch(how) {

case DrawMeshAs::DEFAULT: {

// Force the shade color to something dim to not distract from

// the sketch.

Canvas::Fill fillFront = {};

if(!SS.GW.showShaded) {

fillFront.layer = Canvas::Layer::DEPTH_ONLY;

}

if((type == Type::DRAWING_3D || type == Type::DRAWING_WORKPLANE)

&& SS.GW.dimSolidModel) {

fillFront.color = Style::Color(Style::DIM_SOLID);

}

Canvas::hFill hcfFront = canvas->GetFill(fillFront);

// The back faces are drawn in red; should never seem them, since we

// draw closed shells, so that's a debugging aid.

Canvas::hFill hcfBack = {};

if(SS.drawBackFaces && !displayMesh.isTransparent) {

Canvas::Fill fillBack = {};

fillBack.layer = fillFront.layer;

fillBack.color = RgbaColor::FromFloat(1.0f, 0.1f, 0.1f);

hcfBack = canvas->GetFill(fillBack);

} else {

hcfBack = hcfFront;

}

// Draw the shaded solid into the depth buffer for hidden line removal,

// and if we're actually going to display it, to the color buffer too.

canvas->DrawMesh(displayMesh, hcfFront, hcfBack);

// Draw mesh edges, for debugging.

if(SS.GW.showMesh) {

Canvas::Stroke strokeTriangle = {};

strokeTriangle.zIndex = 1;

strokeTriangle.color = RgbaColor::FromFloat(0.0f, 1.0f, 0.0f);

strokeTriangle.width = 1;

strokeTriangle.unit = Canvas::Unit::PX;

Canvas::hStroke hcsTriangle = canvas->GetStroke(strokeTriangle);

SEdgeList edges = {};

for(const STriangle &t : displayMesh.l) {

edges.AddEdge(t.a, t.b);

edges.AddEdge(t.b, t.c);

edges.AddEdge(t.c, t.a);

}

canvas->DrawEdges(edges, hcsTriangle);

edges.Clear();

}

break;

}

case DrawMeshAs::HOVERED: {

Canvas::Fill fill = {};

fill.color = Style::Color(Style::HOVERED);

fill.pattern = Canvas::FillPattern::CHECKERED_A;

fill.zIndex = 2;

Canvas::hFill hcf = canvas->GetFill(fill);

std::vector<uint32_t> faces;

hEntity he = SS.GW.hover.entity;

if(he.v != 0 && SK.GetEntity(he)->IsFace()) {

faces.push_back(he.v);

}

canvas->DrawFaces(displayMesh, faces, hcf);

break;

}

case DrawMeshAs::SELECTED: {

Canvas::Fill fill = {};

fill.color = Style::Color(Style::SELECTED);

fill.pattern = Canvas::FillPattern::CHECKERED_B;

fill.zIndex = 1;

Canvas::hFill hcf = canvas->GetFill(fill);

std::vector<uint32_t> faces;

SS.GW.GroupSelection();

auto const &gs = SS.GW.gs;

// See also GraphicsWindow::MakeSelected "if(c >= MAX_SELECTABLE_FACES)"

// and GraphicsWindow::GroupSelection "if(e->IsFace())"

for(auto &fc : gs.face) {

faces.push_back(fc.v);

}

canvas->DrawFaces(displayMesh, faces, hcf);

break;

}

}

// Everything here gets drawn whether or not the group is hidden; we

// can control this stuff independently, with show/hide solids, edges,

// mesh, etc.

GenerateDisplayItems();

DrawMesh(DrawMeshAs::DEFAULT, canvas);

if(SS.GW.showEdges) {

Canvas::Stroke strokeEdge = Style::Stroke(Style::SOLID_EDGE);

strokeEdge.zIndex = 1;

Canvas::hStroke hcsEdge = canvas->GetStroke(strokeEdge);

canvas->DrawOutlines(displayOutlines, hcsEdge,

SS.GW.showOutlines

? Canvas::DrawOutlinesAs::EMPHASIZED_WITHOUT_CONTOUR

: Canvas::DrawOutlinesAs::EMPHASIZED_AND_CONTOUR);

if(SS.GW.drawOccludedAs != GraphicsWindow::DrawOccludedAs::INVISIBLE) {

Canvas::Stroke strokeHidden = Style::Stroke(Style::HIDDEN_EDGE);

if(SS.GW.drawOccludedAs == GraphicsWindow::DrawOccludedAs::VISIBLE) {

strokeHidden.stipplePattern = StipplePattern::CONTINUOUS;

}

strokeHidden.layer = Canvas::Layer::OCCLUDED;

Canvas::hStroke hcsHidden = canvas->GetStroke(strokeHidden);

canvas->DrawOutlines(displayOutlines, hcsHidden,

Canvas::DrawOutlinesAs::EMPHASIZED_AND_CONTOUR);

}

}

if(SS.GW.showOutlines) {

Canvas::Stroke strokeOutline = Style::Stroke(Style::OUTLINE);

strokeOutline.zIndex = 1;

Canvas::hStroke hcsOutline = canvas->GetStroke(strokeOutline);

canvas->DrawOutlines(displayOutlines, hcsOutline,

Canvas::DrawOutlinesAs::CONTOUR_ONLY);

}

const Camera &camera = canvas->GetCamera();

Canvas::Stroke strokeUnclosed = Style::Stroke(Style::DRAW_ERROR);

strokeUnclosed.color = strokeUnclosed.color.WithAlpha(50);

Canvas::hStroke hcsUnclosed = canvas->GetStroke(strokeUnclosed);

Canvas::Stroke strokeError = Style::Stroke(Style::DRAW_ERROR);

strokeError.layer = Canvas::Layer::FRONT;

strokeError.width = 1.0f;

Canvas::hStroke hcsError = canvas->GetStroke(strokeError);

double textHeight = Style::DefaultTextHeight() / camera.scale;

// And finally show the polygons too, and any errors if it's not possible

// to assemble the lines into closed polygons.

if(polyError.how == PolyError::NOT_CLOSED) {

// Report this error only in sketch-in-workplane groups; otherwise

// it's just a nuisance.

if(type == Type::DRAWING_WORKPLANE) {

canvas->DrawVectorText(_("not closed contour, or not all same style!"),

textHeight,

polyError.notClosedAt.b, camera.projRight, camera.projUp,

hcsError);

canvas->DrawLine(polyError.notClosedAt.a, polyError.notClosedAt.b, hcsUnclosed);

}

} else if(polyError.how == PolyError::NOT_COPLANAR ||

polyError.how == PolyError::SELF_INTERSECTING ||

polyError.how == PolyError::ZERO_LEN_EDGE) {

// These errors occur at points, not lines

if(type == Type::DRAWING_WORKPLANE) {

const char *msg;

if(polyError.how == PolyError::NOT_COPLANAR) {

msg = _("points not all coplanar!");

} else if(polyError.how == PolyError::SELF_INTERSECTING) {

msg = _("contour is self-intersecting!");

} else {

msg = _("zero-length edge!");

}

canvas->DrawVectorText(msg, textHeight,

polyError.errorPointAt, camera.projRight, camera.projUp,

hcsError);

}

} else {

// The contours will get filled in DrawFilledPaths.

}

for(const SBezierLoopSet &sbls : bezierLoops.l) {

if(sbls.l.IsEmpty() || sbls.l[0].l.IsEmpty())

continue;

// In an assembled loop, all the styles should be the same; so doesn't

// matter which one we grab.

const SBezier *sb = &(sbls.l[0].l[0]);

Style *s = Style::Get({ (uint32_t)sb->auxA });

Canvas::Fill fill = {};

fill.zIndex = 1;

if(s->filled) {

// This is a filled loop, where the user specified a fill color.

fill.color = s->fillColor;

} else if(h == SS.GW.activeGroup && SS.checkClosedContour &&

polyError.how == PolyError::GOOD) {

// If this is the active group, and we are supposed to check

// for closed contours, and we do indeed have a closed and

// non-intersecting contour, then fill it dimly.

fill.color = Style::Color(Style::CONTOUR_FILL).WithAlpha(127);

} else continue;

Canvas::hFill hcf = canvas->GetFill(fill);

SPolygon sp = {};

sbls.MakePwlInto(&sp);

canvas->DrawPolygon(sp, hcf);

sp.Clear();

}

const Camera &camera = canvas->GetCamera();

Vector gr = camera.projRight.ScaledBy(1 / camera.scale);

Vector gu = camera.projUp.ScaledBy(1 / camera.scale);

for(SBezierLoopSet &sbls : bezierLoops.l) {

if(sbls.l.IsEmpty() || sbls.l[0].l.IsEmpty())

continue;

Vector min = sbls.l[0].l[0].ctrl[0];

Vector max = min;

Vector zero = {};

sbls.GetBoundingProjd({1.0, 0.0, 0.0}, zero, &min.x, &max.x);

sbls.GetBoundingProjd({0.0, 1.0, 0.0}, zero, &min.y, &max.y);

sbls.GetBoundingProjd({0.0, 0.0, 1.0}, zero, &min.z, &max.z);

Vector mid = min.Plus(max).ScaledBy(0.5);

hStyle hs = { Style::CONSTRAINT };

Canvas::Stroke stroke = Style::Stroke(hs);

stroke.layer = Canvas::Layer::FRONT;

std::string label = SS.MmToStringSI(fabs(sbls.SignedArea()), /*dim=*/2);

double fontHeight = Style::TextHeight(hs);

double textWidth = VectorFont::Builtin()->GetWidth(fontHeight, label),

textHeight = VectorFont::Builtin()->GetCapHeight(fontHeight);

Vector pos = mid.Minus(gr.ScaledBy(textWidth / 2.0))

.Minus(gu.ScaledBy(textHeight / 2.0));

canvas->DrawVectorText(label, fontHeight, pos, gr, gu, canvas->GetStroke(stroke));

}