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boolean.cpp
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1049 lines (908 loc) · 38.1 KB
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//-----------------------------------------------------------------------------
// Top-level functions to compute the Boolean union, difference or intersection
// between two shells of rational polynomial surfaces.
//
// Copyright 2008-2013 Jonathan Westhues.
//-----------------------------------------------------------------------------
#include "solvespace.h"
namespace SolveSpace {
static int I;
void SShell::MakeFromUnionOf(SShell *a, SShell *b) {
MakeFromBoolean(a, b, SSurface::CombineAs::UNION);
}
void SShell::MakeFromDifferenceOf(SShell *a, SShell *b) {
MakeFromBoolean(a, b, SSurface::CombineAs::DIFFERENCE);
}
void SShell::MakeFromIntersectionOf(SShell *a, SShell *b) {
MakeFromBoolean(a, b, SSurface::CombineAs::INTERSECTION);
}
void SCurve::GetAxisAlignedBounding(Vector *ptMax, Vector *ptMin) const {
*ptMax = {VERY_NEGATIVE, VERY_NEGATIVE, VERY_NEGATIVE};
*ptMin = {VERY_POSITIVE, VERY_POSITIVE, VERY_POSITIVE};
for(int i = 0; i <= exact.deg; i++) {
exact.ctrl[i].MakeMaxMin(ptMax, ptMin);
}
}
// We will be inserting other curve vertices into our curves to split them.
// This is helpful when curved surfaces become tangent along a trim and the
// usual tests for curve-surface intersection don't split the curve at a vertex.
// This is faster than the previous version that split at surface corners and
// handles more buggy cases. It's not clear this is the best way but it works ok.
static void FindVertsOnCurve(List<SInter> *l, const SCurve *curve, SShell *sh) {
Vector amax, amin;
curve->GetAxisAlignedBounding(&amax, &amin);
for(const auto &sc : sh->curve) {
if(!sc.isExact) continue;
Vector cmax, cmin;
sc.GetAxisAlignedBounding(&cmax, &cmin);
if(Vector::BoundingBoxesDisjoint(amax, amin, cmax, cmin)) {
// They cannot possibly intersect, no curves to generate
continue;
}
for(int i=0; i<2; i++) {
Vector pt = sc.exact.ctrl[ i==0 ? 0 : sc.exact.deg ];
double t;
curve->exact.ClosestPointTo(pt, &t, /*must converge=*/ false);
double d = pt.Minus(curve->exact.PointAt(t)).Magnitude();
if((t>LENGTH_EPS) && (t<(1.0-LENGTH_EPS)) && (d < LENGTH_EPS)) {
SInter inter;
inter.p = pt;
l->Add(&inter);
}
}
}
}
//-----------------------------------------------------------------------------
// Take our original pwl curve. Wherever an edge intersects a surface within
// either agnstA or agnstB, split the piecewise linear element. Then refine
// the intersection so that it lies on all three relevant surfaces: the
// intersecting surface, srfA, and srfB. (So the pwl curve should lie at
// the intersection of srfA and srfB.) Return a new pwl curve with everything
// split.
//-----------------------------------------------------------------------------
SCurve SCurve::MakeCopySplitAgainst(SShell *agnstA, SShell *agnstB,
SSurface *srfA, SSurface *srfB) const
{
SCurve ret;
ret = *this;
ret.pts = {};
// First find any vertex that lies on our curve.
List<SInter> vertpts = {};
if(isExact) {
if(agnstA)
FindVertsOnCurve(&vertpts, this, agnstA);
if(agnstB)
FindVertsOnCurve(&vertpts, this, agnstB);
}
const SCurvePt *p = pts.First();
ssassert(p != NULL, "Cannot split an empty curve");
SCurvePt prev = *p;
ret.pts.Add(p);
p = pts.NextAfter(p);
for(; p; p = pts.NextAfter(p)) {
List<SInter> il = {};
// Find all the intersections with the two passed shells
if(agnstA)
agnstA->AllPointsIntersecting(prev.p, p->p, &il,
/*asSegment=*/true, /*trimmed=*/false, /*inclTangent=*/true);
if(agnstB)
agnstB->AllPointsIntersecting(prev.p, p->p, &il,
/*asSegment=*/true, /*trimmed=*/false, /*inclTangent=*/true);
if(!il.IsEmpty()) {
// The intersections were generated by intersecting the pwl
// edge against a surface; so they must be refined to lie
// exactly on the original curve.
il.ClearTags();
SInter *pi;
for(pi = il.First(); pi; pi = il.NextAfter(pi)) {
if(pi->srf == srfA || pi->srf == srfB) {
// The edge certainly intersects the surfaces that it
// trims (at its endpoints), but those ones don't count.
// They are culled later, but no sense calculating them
// and they will cause numerical problems (since two
// of the three surfaces they're refined to lie on will
// be identical, so the matrix will be singular).
pi->tag = 1;
continue;
}
Point2d puv;
(pi->srf)->ClosestPointTo(pi->p, &puv, /*mustConverge=*/false);
// Split the edge if the intersection lies within the surface's
// trim curves, or within the chord tol of the trim curve; want
// some slop if points are close to edge and pwl is too coarse,
// and it doesn't hurt to split unnecessarily.
Point2d dummy = { 0, 0 };
SBspUv::Class c = (pi->srf->bsp) ? pi->srf->bsp->ClassifyPoint(puv, dummy, pi->srf) : SBspUv::Class::OUTSIDE;
if(c == SBspUv::Class::OUTSIDE) {
double d = VERY_POSITIVE;
if(pi->srf->bsp) d = pi->srf->bsp->MinimumDistanceToEdge(puv, pi->srf);
if(d > SS.ChordTolMm()) {
pi->tag = 1;
continue;
}
}
// We're keeping the intersection, so actually refine it. Finding the intersection
// to within EPS is important to match the ends of different chopped trim curves.
// The general 3-surface intersection fails to refine for trims where surfaces
// are tangent at the curve, but those trims are usually exact, so…
if(isExact) {
(pi->srf)->PointOnCurve(&exact, &(puv.x), &(puv.y));
} else {
(pi->srf)->PointOnSurfaces(srfA, srfB, &(puv.x), &(puv.y));
}
pi->p = (pi->srf)->PointAt(puv);
}
il.RemoveTagged();
}
// Now add any vertex that is on this segment
const Vector lineStart = prev.p;
const Vector lineDirection = (p->p).Minus(prev.p);
for(const auto &vtx : vertpts) {
double t = (vtx.p.Minus(lineStart)).DivProjected(lineDirection);
if((0.0 < t) && (t < 1.0)) {
il.Add(&vtx);
}
}
if(!il.IsEmpty()) {
SInter *pi;
// And now sort them in order along the line. Note that we must
// do that after refining, in case the refining would make two
// points switch places.
std::sort(il.begin(), il.end(), [&](const SInter &a, const SInter &b) {
double ta = (a.p.Minus(lineStart)).DivProjected(lineDirection);
double tb = (b.p.Minus(lineStart)).DivProjected(lineDirection);
return (ta < tb);
});
// And now uses the intersections to generate our split pwl edge(s)
Vector prev = Vector::From(VERY_POSITIVE, 0, 0);
for(pi = il.First(); pi; pi = il.NextAfter(pi)) {
// On-edge intersection will generate same split point for
// both surfaces, so don't create zero-length edge.
if(!prev.Equals(pi->p)) {
SCurvePt scpt;
scpt.tag = 0;
scpt.p = pi->p;
scpt.vertex = true;
ret.pts.Add(&scpt);
}
prev = pi->p;
}
}
il.Clear();
ret.pts.Add(p);
prev = *p;
}
vertpts.Clear();
return ret;
}
void SShell::CopyCurvesSplitAgainst(bool opA, SShell *agnst, SShell *into) {
#pragma omp parallel for
for(int i=0; i<curve.n; i++) {
SCurve *sc = &curve[i];
SCurve scn = sc->MakeCopySplitAgainst(agnst, NULL,
surface.FindById(sc->surfA),
surface.FindById(sc->surfB));
scn.source = opA ? SCurve::Source::A : SCurve::Source::B;
#pragma omp critical
{
hSCurve hsc = into->curve.AddAndAssignId(&scn);
// And note the new ID so that we can rewrite the trims appropriately
sc->newH = hsc;
}
}
}
void SSurface::TrimFromEdgeList(SEdgeList *el, bool asUv) {
el->l.ClearTags();
STrimBy stb = {};
for(;;) {
// Find an edge, any edge; we'll start from there.
SEdge *se;
for(se = el->l.First(); se; se = el->l.NextAfter(se)) {
if(se->tag) continue;
break;
}
if(!se) break;
se->tag = 1;
stb.start = se->a;
stb.finish = se->b;
stb.curve.v = se->auxA;
stb.backwards = se->auxB ? true : false;
// Find adjoining edges from the same curve; those should be
// merged into a single trim.
bool merged;
do {
merged = false;
for(se = el->l.First(); se; se = el->l.NextAfter(se)) {
if(se->tag) continue;
if(se->auxA != (int)stb.curve.v) continue;
if(( se->auxB && !stb.backwards) ||
(!se->auxB && stb.backwards)) continue;
if((se->a).Equals(stb.finish)) {
stb.finish = se->b;
se->tag = 1;
merged = true;
} else if((se->b).Equals(stb.start)) {
stb.start = se->a;
se->tag = 1;
merged = true;
}
}
} while(merged);
if(asUv) {
stb.start = PointAt(stb.start.x, stb.start.y);
stb.finish = PointAt(stb.finish.x, stb.finish.y);
}
// And add the merged trim, with xyz (not uv like the polygon) pts
trim.Add(&stb);
}
}
C3F7
static bool KeepRegion(SSurface::CombineAs type, bool opA, SShell::Class shell, SShell::Class orig)
{
bool inShell = (shell == SShell::Class::SURF_INSIDE),
outSide = (shell == SShell::Class::SURF_OUTSIDE),
coincSame = (shell == SShell::Class::SURF_COINC_SAME),
coincOpp = (shell == SShell::Class::SURF_COINC_OPP),
inOrig = (orig == SShell::Class::SURF_INSIDE);
// This one line is not really part of this functions logic
if(!inOrig) return false;
switch(type) {
case SSurface::CombineAs::UNION:
if(opA) {
return outSide;
} else {
return outSide || coincSame;
}
case SSurface::CombineAs::DIFFERENCE:
if(opA) {
return outSide || coincOpp;
} else {
return inShell;
}
case SSurface::CombineAs::INTERSECTION:
if(opA) {
return inShell;
} else {
return inShell || coincSame;
}
default: ssassert(false, "Unexpected combine type");
}
}
static bool KeepEdge(SSurface::CombineAs type, bool opA,
SShell::Class indir_shell, SShell::Class outdir_shell,
SShell::Class indir_orig, SShell::Class outdir_orig)
{
bool keepIn = KeepRegion(type, opA, indir_shell, indir_orig),
keepOut = KeepRegion(type, opA, outdir_shell, outdir_orig);
// If the regions to the left and right of this edge are both in or both
// out, then this edge is not useful and should be discarded.
if(keepIn && !keepOut) return true;
return false;
}
static void TagByClassifiedEdge(SBspUv::Class bspclass, SShell::Class *indir, SShell::Class *outdir)
{
switch(bspclass) {
case SBspUv::Class::INSIDE:
*indir = SShell::Class::SURF_INSIDE;
*outdir = SShell::Class::SURF_INSIDE;
break;
case SBspUv::Class::OUTSIDE:
*indir = SShell::Class::SURF_OUTSIDE;
*outdir = SShell::Class::SURF_OUTSIDE;
break;
case SBspUv::Class::EDGE_PARALLEL:
*indir = SShell::Class::SURF_INSIDE;
*outdir = SShell::Class::SURF_OUTSIDE;
break;
case SBspUv::Class::EDGE_ANTIPARALLEL:
*indir = SShell::Class::SURF_OUTSIDE;
*outdir = SShell::Class::SURF_INSIDE;
break;
default:
dbp("TagByClassifiedEdge: fail!");
*indir = SShell::Class::SURF_OUTSIDE;
*outdir = SShell::Class::SURF_OUTSIDE;
break;
}
}
static void DEBUGEDGELIST(SEdgeList *sel, SSurface *surf) {
dbp("print %d edges", sel->l.n);
SEdge *se;
for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
Vector mid = (se->a).Plus(se->b).ScaledBy(0.5);
Vector arrow = (se->b).Minus(se->a);
swap(arrow.x, arrow.y);
arrow.x *= -1;
arrow = arrow.WithMagnitude(0.01);
arrow = arrow.Plus(mid);
SS.nakedEdges.AddEdge(surf->PointAt(se->a.x, se->a.y),
surf->PointAt(se->b.x, se->b.y));
SS.nakedEdges.AddEdge(surf->PointAt(mid.x, mid.y),
surf->PointAt(arrow.x, arrow.y));
}
}
//-----------------------------------------------------------------------------
// We are given src, with at least one edge, and avoid, a list of points to
// avoid. We return a chain of edges (that share endpoints), such that no
// point within the avoid list ever occurs in the middle of a chain. And we
// delete the edges in that chain from our source list.
//-----------------------------------------------------------------------------
void SSurface::FindChainAvoiding(SEdgeList *src, SEdgeList *dest,
SPointList *avoid)
{
ssassert(!src->l.IsEmpty(), "Need at least one edge");
// Start with an arbitrary edge.
dest->l.Add(src->l.First());
src->l.ClearTags();
src->l.First()->tag = 1;
bool added;
do {
added = false;
// The start and finish of the current edge chain
Vector s = dest->l.First()->a,
f = dest->l.Last()->b;
// We can attach a new edge at the start or finish, as long as that
// start or finish point isn't in the list of points to avoid.
bool startOkay = !avoid->ContainsPoint(s),
finishOkay = !avoid->ContainsPoint(f);
// Now look for an unused edge that joins at the start or finish of
// our chain (if permitted by the avoid list).
SEdge *se;
for(se = src->l.First(); se; se = src->l.NextAfter(se)) {
if(se->tag) continue;
if(startOkay && s.Equals(se->b)) {
dest->l.AddToBeginning(se);
s = se->a;
se->tag = 1;
startOkay = !avoid->ContainsPoint(s);
} else if(finishOkay && f.Equals(se->a)) {
dest->l.Add(se);
f = se->b;
se->tag = 1;
finishOkay = !avoid->ContainsPoint(f);
} else {
continue;
}
added = true;
}
} while(added);
src->l.RemoveTagged();
}
void SSurface::EdgeNormalsWithinSurface(Point2d auv, Point2d buv,
Vector *pt,
Vector *enin, Vector *enout,
Vector *surfn,
uint32_t auxA,
SShell *shell, SShell *sha, SShell *shb)
{
// the midpoint of the edge
Point2d muv = (auv.Plus(buv)).ScaledBy(0.5);
*pt = PointAt(muv);
// If this edge just approximates a curve, then refine our midpoint so
// so that it actually lies on that curve too. Otherwise stuff like
// point-on-face tests will fail, since the point won't actually lie
// on the other face.
hSCurve hc = { auxA };
SCurve *sc = shell->curve.FindById(hc);
if(sc->isExact && sc->exact.deg != 1) {
double t;
sc->exact.ClosestPointTo(*pt, &t, /*mustConverge=*/false);
*pt = sc->exact.PointAt(t);
} else if(!sc->isExact) {
SSurface *trimmedA = sc->GetSurfaceA(sha, shb),
*trimmedB = sc->GetSurfaceB(sha, shb);
*pt = trimmedA->ClosestPointOnThisAndSurface(trimmedB, *pt);
}
ClosestPointTo(*pt, &muv);
*surfn = NormalAt(muv.x, muv.y);
// Compute the edge's inner normal in xyz space.
Vector ab = (PointAt(auv)).Minus(PointAt(buv)),
enxyz = (ab.Cross(*surfn)).WithMagnitude(SS.ChordTolMm());
// And based on that, compute the edge's inner normal in uv space. This
// vector is perpendicular to the edge in xyz, but not necessarily in uv.
Vector tu, tv, tx, ty;
TangentsAt(muv.x, muv.y, &tu, &tv);
Vector n = tu.Cross(tv);
// since tu and tv may not be orthogonal, use y in place of v, x in place of u.
// |y| = |v|sin(theta) where theta is the angle between tu and t
47C9
v.
ty = n.Cross(tu).ScaledBy(1.0/tu.MagSquared());
tx = tv.Cross(n).ScaledBy(1.0/tv.MagSquared());
Point2d enuv;
enuv.x = enxyz.Dot(tx) / tx.MagSquared();
enuv.y = enxyz.Dot(ty) / ty.MagSquared();
// Compute the inner and outer normals of this edge (within the srf),
// in xyz space. These are not necessarily antiparallel, if the
// surface is curved.
Vector pin = PointAt(muv.Minus(enuv)),
pout = PointAt(muv.Plus(enuv));
*enin = pin.Minus(*pt),
*enout = pout.Minus(*pt);
// ideally this should work (fail screwdriver file)
// *enin = enxyz.ScaledBy(-1.0);
// *enout = enxyz;
}
//-----------------------------------------------------------------------------
// Trim this surface against the specified shell, in the way that's appropriate
// for the specified Boolean operation type (and which operand we are). We
// also need a pointer to the shell that contains our own surface, since that
// contains our original trim curves.
//-----------------------------------------------------------------------------
SSurface SSurface::MakeCopyTrimAgainst(SShell *parent,
SShell *sha, SShell *shb,
SShell *into,
SSurface::CombineAs type,
int dbg_index)
{
bool opA = (parent == sha);
SShell *agnst = opA ? shb : sha;
SSurface ret;
// The returned surface is identical, just the trim curves change
ret = *this;
ret.trim = {};
// First, build a list of the existing trim curves; update them to use
// the split curves.
STrimBy *stb;
for(stb = trim.First(); stb; stb = trim.NextAfter(stb)) {
STrimBy stn = *stb;
stn.curve = (parent->curve.FindById(stn.curve))->newH;
ret.trim.Add(&stn);
}
if(type == SSurface::CombineAs::DIFFERENCE && !opA) {
// The second operand of a Boolean difference gets turned inside out
ret.Reverse();
}
// Build up our original trim polygon; remember the coordinates could
// be changed if we just flipped the surface normal, and we are using
// the split curves (not the original curves).
SEdgeList orig = {};
ret.MakeEdgesInto(into, &orig, MakeAs::UV);
ret.trim.Clear();
// which means that we can't necessarily use the old BSP...
SBspUv *origBsp = SBspUv::From(&orig, &ret);
// And now intersect the other shell against us
SEdgeList inter = {};
SSurface *ss;
for(SCurve &sc : into->curve) {
if(sc.source != SCurve::Source::INTERSECTION) continue;
if(opA) {
if(sc.surfA != h) continue;
ss = shb->surface.FindById(sc.surfB);
} else {
if(sc.surfB != h) continue;
ss = sha->surface.FindById(sc.surfA);
}
int i;
for(i = 1; i < sc.pts.n; i++) {
Vector a = sc.pts[i-1].p,
b = sc.pts[i].p;
Point2d auv, buv;
ss->ClosestPointTo(a, &(auv.x), &(auv.y));
ss->ClosestPointTo(b, &(buv.x), &(buv.y));
SBspUv::Class c = (ss->bsp) ? ss->bsp->ClassifyEdge(auv, buv, ss) : SBspUv::Class::OUTSIDE;
if(c != SBspUv::Class::OUTSIDE) {
Vector ta = Vector::From(0, 0, 0);
Vector tb = Vector::From(0, 0, 0);
ret.ClosestPointTo(a, &(ta.x), &(ta.y));
ret.ClosestPointTo(b, &(tb.x), &(tb.y));
Vector tn = ret.NormalAt(ta.x, ta.y);
Vector sn = ss->NormalAt(auv.x, auv.y);
// We are subtracting the portion of our surface that
// lies in the shell, so the in-plane edge normal should
// point opposite to the surface normal.
bool bkwds = true;
if((tn.Cross(b.Minus(a))).Dot(sn) < 0) bkwds = !bkwds;
if((type == SSurface::CombineAs::DIFFERENCE && !opA) ||
(type == SSurface::CombineAs::INTERSECTION)) { // Invert all newly created edges for intersection
bkwds = !bkwds;
}
if(bkwds) {
inter.AddEdge(tb, ta, sc.h.v, 1);
} else {
inter.AddEdge(ta, tb, sc.h.v, 0);
}
}
}
}
// Record all the points where more than two edges join, which I will call
// the choosing points. If two edges join at a non-choosing point, then
// they must either both be kept or both be discarded (since that would
// otherwise create an open contour).
SPointList choosing = {};
SEdge *se;
for(se = orig.l.First(); se; se = orig.l.NextAfter(se)) {
choosing.IncrementTagFor(se->a);
choosing.IncrementTagFor(se->b);
}
for(se = inter.l.First(); se; se = inter.l.NextAfter(se)) {
choosing.IncrementTagFor(se->a);
choosing.IncrementTagFor(se->b);
}
SPoint *sp;
for(sp = choosing.l.First(); sp; sp = choosing.l.NextAfter(sp)) {
if(sp->tag == 2) {
sp->tag = 1;
} else {
sp->tag = 0;
}
}
choosing.l.RemoveTagged();
// The list of edges to trim our new surface, a combination of edges from
// our original and intersecting edge lists.
SEdgeList final = {};
while(!orig.l.IsEmpty()) {
SEdgeList chain = {};
FindChainAvoiding(&orig, &chain, &choosing);
// Arbitrarily choose an edge within the chain to classify; they
// should all be the same, though.
se = &(chain.l[chain.l.n/2]);
Point2d auv = (se->a).ProjectXy(),
buv = (se->b).ProjectXy();
Vector pt, enin, enout, surfn;
ret.EdgeNormalsWithinSurface(auv, buv, &pt, &enin, &enout, &surfn,
se->auxA, into, sha, shb);
SShell::Class indir_shell, outdir_shell, indir_orig, outdir_orig;
indir_orig = SShell::Class::SURF_INSIDE;
outdir_orig = SShell::Class::SURF_OUTSIDE;
agnst->ClassifyEdge(&indir_shell, &outdir_shell,
ret.PointAt(auv), ret.PointAt(buv), pt,
enin, enout, surfn);
if(KeepEdge(type, opA, indir_shell, outdir_shell,
indir_orig, outdir_orig))
{
for(se = chain.l.First(); se; se = chain.l.NextAfter(se)) {
final.AddEdge(se->a, se->b, se->auxA, se->auxB);
}
}
chain.Clear();
}
while(!inter.l.IsEmpty()) {
SEdgeList chain = {};
FindChainAvoiding(&inter, &chain, &choosing);
// Any edge in the chain, same as above.
se = &(chain.l[chain.l.n/2]);
Point2d auv = (se->a).ProjectXy(),
buv = (se->b).ProjectXy();
Vector pt, enin, enout, surfn;
ret.EdgeNormalsWithinSurface(auv, buv, &pt, &enin, &enout, &surfn,
se->auxA, into, sha, shb);
SShell::Class indir_shell, outdir_shell, indir_orig, outdir_orig;
SBspUv::Class c_this = (origBsp) ? origBsp->ClassifyEdge(auv, buv, &ret) : SBspUv::Class::OUTSIDE;
TagByClassifiedEdge(c_this, &indir_orig, &outdir_orig);
agnst->ClassifyEdge(&indir_shell, &outdir_shell,
ret.PointAt(auv), ret.PointAt(buv), pt,
enin, enout, surfn);
if(KeepEdge(type, opA, indir_shell, outdir_shell,
indir_orig, outdir_orig))
{
for(se = chain.l.First(); se; se = chain.l.NextAfter(se)) {
final.AddEdge(se->a, se->b, se->auxA, se->auxB);
}
}
chain.Clear();
}
// Cull extraneous edges; duplicates or anti-parallel pairs. In particular,
// we can get duplicate edges if our surface intersects the other shell
// at an edge, so that both surfaces intersect coincident (and both
// generate an intersection edge).
final.CullExtraneousEdges(/*both=*/true);
// Use our reassembled edges to trim the new surface.
ret.TrimFromEdgeList(&final, /*asUv=*/true);
SPolygon poly = {};
final.l.ClearTags();
if(!final.AssemblePolygon(&poly, NULL, /*keepDir=*/true))
#pragma omp critical
{
into->booleanFailed = true;
dbp("failed: I=%d, avoid=%d", I+dbg_index, choosing.l.n);
DEBUGEDGELIST(&final, &ret);
}
poly.Clear();
choosing.Clear();
final.Clear();
inter.Clear();
orig.Clear();
return ret;
}
void SShell::CopySurfacesTrimAgainst(SShell *sha, SShell *shb, SShell *into, SSurface::CombineAs type) {
std::vector <SSurface> ssn(surface.n);
#pragma omp parallel for
for (int i = 0; i < surface.n; i++)
{
SSurface *ss = &surface[i];
ssn[i] = ss->MakeCopyTrimAgainst(this, sha, shb, into, type, i);
}
for (int i = 0; i < surface.n; i++)
{
surface[i].newH = into->surface.AddAndAssignId(&ssn[i]);
}
I += surface.n;
}
void SShell::MakeIntersectionCurvesAgainst(SShell *agnst, SShell *into) {
#pragma omp parallel for
for(int i = 0; i< surface.n; i++) {
SSurface *sa = &surface[i];
for(SSurface &sb : agnst->surface){
// Intersect every surface from our shell against every surface
// from agnst; this will add zero or more curves to the curve
// list for into.
sa->IntersectAgainst(&sb, this, agnst, into);
}
}
}
void SShell::CleanupAfterBoolean() {
for(SSurface &ss : surface) {
ss.edges.Clear();
}
}
//-----------------------------------------------------------------------------
// All curves contain handles to the two surfaces that they trim. After a
// Boolean or assembly, we must rewrite those handles to refer to the curves
// by their new IDs.
//-----------------------------------------------------------------------------
void SShell::RewriteSurfaceHandlesForCurves(SShell *a, SShell *b) {
for(SCurve &sc : curve) {
sc.surfA = sc.GetSurfaceA(a, b)->newH,
sc.surfB = sc.GetSurfaceB(a, b)->newH;
}
}
//-----------------------------------------------------------------------------
// Copy all the surfaces and curves from two different shells into a single
// shell. The only difficulty is to rewrite all of their handles; we don't
// look for any surface intersections, so if two objects interfere then the
// result is just self-intersecting. This is used for assembly, since it's
// much faster than merging as union.
//-----------------------------------------------------------------------------
void SShell::MakeFromAssemblyOf(SShell *a, SShell *b) {
booleanFailed = false;
Vector t = Vector::From(0, 0, 0);
Quaternion q = Quaternion::IDENTITY;
int i = 0;
SShell *ab;
// First, copy over all the curves. Note which shell (a or b) each curve
// came from, but assign it a new ID.
curve.ReserveMore(a->curve.n + b->curve.n);
SCurve cn;
for(i = 0; i < 2; i++) {
ab = (i == 0) ? a : b;
for(SCurve &c : ab->curve) {
cn = SCurve::FromTransformationOf(&c, t, q, 1.0);
cn.source = (i == 0) ? SCurve::Source::A : SCurve::Source::B;
// surfA and surfB are wrong now, and we can't fix them until
// we've assigned IDs to the surfaces. So we'll get that later.
c.newH = curve.AddAndAssignId(&cn);
}
}
// Likewise copy over all the surfaces.
surface.ReserveMore(a->surface.n + b->surface.n);
SSurface sn;
for(i = 0; i < 2; i++) {
ab = (i == 0) ? a : b;
for(SSurface &s : ab->surface) {
sn = SSurface::FromTransformationOf(&s, t, q, 1.0, /*includingTrims=*/true);
// All the trim curve IDs get rewritten; we know the new handles
// to the curves since we recorded them in the previous step.
STrimBy *stb;
for(stb = sn.trim.First(); stb; stb = sn.trim.NextAfter(stb)) {
stb->curve = ab->curve.FindById(stb->curve)->newH;
}
s.newH = surface.AddAndAssignId(&sn);
}
}
// Finally, rewrite the surfaces associated with each curve to use the
// new handles.
RewriteSurfaceHandlesForCurves(a, b);
}
void SShell::MakeFromBoolean(SShell *a, SShell *b, SSurface::CombineAs type) {
booleanFailed = false;
a->MakeClassifyingBsps(NULL);
b->MakeClassifyingBsps(NULL);
// Copy over all the original curves, splitting them so that a
// piecewise linear segment never crosses a surface from the other
// shell.
a->CopyCurvesSplitAgainst(/*opA=*/true, b, this);
b->CopyCurvesSplitAgainst(/*opA=*/false, a, this);
// Generate the intersection curves for each surface in A against all
// the surfaces in B (which is all of the intersection curves).
a->MakeIntersectionCurvesAgainst(b, this);
for(SCurve &sc : curve) {
SSurface *srfA = sc.GetSurfaceA(a, b),
*srfB = sc.GetSurfaceB(a, b);
sc.RemoveShortSegments(srfA, srfB);
}
// And clean up the piecewise linear things we made as a calculation aid
a->CleanupAfterBoolean();
b->CleanupAfterBoolean();
// Remake the classifying BSPs with the split (and short-segment-removed)
// curves
a->MakeClassifyingBsps(this);
b->MakeClassifyingBsps(this);
if(b->surface.IsEmpty() || a->surface.IsEmpty()) {
I = 1000000;
} else {
I = 0;
}
// Then trim and copy the surfaces
a->CopySurfacesTrimAgainst(a, b, this, type);
b->CopySurfacesTrimAgainst(a, b, this, type);
// Now that we've copied the surfaces, we know their new hSurfaces, so
// rewrite the curves to refer to the surfaces by their handles in the
// result.
RewriteSurfaceHandlesForCurves(a, b);
// And clean up the piecewise linear things we made as a calculation aid
a->CleanupAfterBoolean();
b->CleanupAfterBoolean();
}
//-----------------------------------------------------------------------------
// All of the BSP routines that we use to perform and accelerate polygon ops.
//-----------------------------------------------------------------------------
void SShell::MakeClassifyingBsps(SShell *useCurvesFrom) {
#pragma omp parallel for
for(int i = 0; i<surface.n; i++) {
surface[i].MakeClassifyingBsp(this, useCurvesFrom);
}
}
void SSurface::MakeClassifyingBsp(SShell *shell, SShell *useCurvesFrom) {
SEdgeList el = {};
MakeEdgesInto(shell, &el, MakeAs::UV, useCurvesFrom);
bsp = SBspUv::From(&el, this);
el.Clear();
edges = {};
MakeEdgesInto(shell, &edges, MakeAs::XYZ, useCurvesFrom);
}
SBspUv *SBspUv::Alloc() {
return (SBspUv *)Platform::AllocTemporary(sizeof(SBspUv));
}
SBspUv *SBspUv::From(SEdgeList *el, SSurface *srf) {
SEdgeList work = {};
SEdge *se;
for(se = el->l.First(); se; se = el->l.NextAfter(se)) {
work.AddEdge(se->a, se->b, se->auxA, se->auxB);
}
std::sort(work.l.begin(), work.l.end(), [](SEdge const &a, SEdge const &b) {
double la = (a.a).Minus(a.b).Magnitude(), lb = (b.a).Minus(b.b).Magnitude();
// Sort in descending order, longest first. This improves numerical
// stability for the normals.
return la > lb;
});
SBspUv *bsp = NULL;
for(se = work.l.First(); se; se = work.l.NextAfter(se)) {
bsp = InsertOrCreateEdge(bsp, (se->a).ProjectXy(), (se->b).ProjectXy(), srf);
}
work.Clear();
return bsp;
}
//-----------------------------------------------------------------------------
// The points in this BSP are in uv space, but we want to apply our tolerances
// consistently in xyz (i.e., we want to say a point is on-edge if its xyz
// distance to that edge is less than LENGTH_EPS, irrespective of its distance
// in uv). So we linearize the surface about the point we're considering and
// then do the test. That preserves point-on-line relationships, and the only
// time we care about exact correctness is when we're very close to the line,
// which is when the linearization is accurate.
//-----------------------------------------------------------------------------
void SBspUv::ScalePoints(Point2d *pt, Point2d *a, Point2d *b, SSurface *srf) const {
Vector tu, tv;
srf->TangentsAt(pt->x, pt->y, &tu, &tv);
double mu = tu.Magnitude(), mv = tv.Magnitude();
pt->x *= mu; pt->y *= mv;
a ->x *= mu; a ->y *= mv;
b ->x *= mu; b ->y *= mv;
}
double SBspUv::ScaledSignedDistanceToLine(Point2d pt, Point2d a, Point2d b,
SSurface *srf) const
{
ScalePoints(&pt, &a, &b, srf);
Point2d n = ((b.Minus(a)).Normal()).WithMagnitude(1);
double d = a.Dot(n);
return pt.Dot(n) - d;
}
double SBspUv::ScaledDistanceToLine(Point2d pt, Point2d a, Point2d b, bool asSegment,
SSurface *srf) const
{
ScalePoints(&pt, &a, &b, srf);
return pt.DistanceToLine(a, b, asSegment);
}
SBspUv *SBspUv::InsertOrCreateEdge(SBspUv *where, Point2d ea, Point2d eb, SSurface *srf) {
if(where == NULL) {
SBspUv *ret = Alloc();
ret->a = ea;
ret->b = eb;
return ret;
}
where->InsertEdge(ea, eb, srf);
return where;
}
void SBspUv::InsertEdge(Point2d ea, Point2d eb, SSurface *srf) {
double dea = ScaledSignedDistanceToLine(ea, a, b, srf),
deb = ScaledSignedDistanceToLine(eb, a, b, srf);
if(fabs(dea) < LENGTH_EPS && fabs(deb) < LENGTH_EPS) {
// Line segment is coincident with this one, store in same node
SBspUv *m = Alloc();
m->a = ea;
m->b = eb;
m->more = more;
more = m;
} else if(fabs(dea) < LENGTH_EPS) {
// Point A lies on this line, but point B does not
if(deb > 0) {
pos = InsertOrCreateEdge(pos, ea, eb, srf);
} else {
neg = InsertOrCreateEdge(neg, ea, eb, srf);
}
} else if(fabs(deb) < LENGTH_EPS) {
// Point B lies on this line, but point A does not
if(dea > 0) {
pos = InsertOrCreateEdge(pos, ea, eb, srf);
} else {
neg = InsertOrCreateEdge(neg, ea, eb, srf);
}
} else if(dea > 0 && deb > 0) {
pos = InsertOrCreateEdge(pos, ea, eb, srf);
} else if(dea < 0 && deb < 0) {
neg = InsertOrCreateEdge(neg, ea, eb, srf);
} else {
// New edge crosses this one; we need to split.
Point2d n = ((b.Minus(a)).Normal()).WithMagnitude(1);
double d = a.Dot(n);
double t = (d - n.Dot(ea)) / (n.Dot(eb.Minus(ea)));
Point2d pi = ea.Plus((eb.Minus(ea)).ScaledBy(t));
if(dea > 0) {
pos = InsertOrCreateEdge(pos, ea, pi, srf);
neg = InsertOrCreateEdge(neg, pi, eb, srf);
} else {
neg = InsertOrCreateEdge(neg, ea, pi, srf);
pos = InsertOrCreateEdge(pos, pi, eb, srf);
}
}
return;
}
SBspUv::Class SBspUv::ClassifyPoint(Point2d p, Point2d eb, SSurface *srf) const {
double dp = ScaledSignedDistanceToLine(p, a, b, srf);
if(fabs(dp) < LENGTH_EPS) {
const SBspUv *f = this;
while(f) {
Point2d ba = (f->b).Minus(f->a);
if(ScaledDistanceToLine(p, f->a, ba, /*asSegment=*/true, srf) < LENGTH_EPS) {
if(ScaledDistanceToLine(eb, f->a, ba, /*asSegment=*/false, srf) < LENGTH_EPS){