void SPolygon::UvGridTriangulateInto(SMesh *mesh, SSurface *srf) {
SEdgeList orig;
ZERO(&orig);
MakeEdgesInto(&orig);
SEdgeList holes;
ZERO(&holes);
normal = Vector::From(0, 0, 1);
FixContourDirections();
// Build a rectangular grid, with horizontal and vertical lines in the
// uv plane. The spacing of these lines is adaptive, so calculate that.
List<double> li, lj;
ZERO(&li);
ZERO(&lj);
double v = 0;
li.Add(&v);
srf->MakeTriangulationGridInto(&li, 0, 1, true);
lj.Add(&v);
srf->MakeTriangulationGridInto(&lj, 0, 1, false);
// Now iterate over each quad in the grid. If it's outside the polygon,
// or if it intersects the polygon, then we discard it. Otherwise we
// generate two triangles in the mesh, and cut it out of our polygon.
int i, j;
for(i = 0; i < (li.n - 1); i++) {
for(j = 0; j < (lj.n - 1); j++) {
double us = li.elem[i], uf = li.elem[i+1],
vs = lj.elem[j], vf = lj.elem[j+1];
Vector a = Vector::From(us, vs, 0),
b = Vector::From(us, vf, 0),
c = Vector::From(uf, vf, 0),
d = Vector::From(uf, vs, 0);
if(orig.AnyEdgeCrossings(a, b, NULL) ||
orig.AnyEdgeCrossings(b, c, NULL) ||
orig.AnyEdgeCrossings(c, d, NULL) ||
orig.AnyEdgeCrossings(d, a, NULL))
{
continue;
}
// There's no intersections, so it doesn't matter which point
// we decide to test.
if(!this->ContainsPoint(a)) {
continue;
}
// Add the quad to our mesh
STriangle tr;
ZERO(&tr);
tr.a = a;
tr.b = b;
tr.c = c;
mesh->AddTriangle(&tr);
tr.a = a;
tr.b = c;
tr.c = d;
mesh->AddTriangle(&tr);
holes.AddEdge(a, b);
holes.AddEdge(b, c);
holes.AddEdge(c, d);
holes.AddEdge(d, a);
}
}
holes.CullExtraneousEdges();
SPolygon hp;
ZERO(&hp);
holes.AssemblePolygon(&hp, NULL, true);
SContour *sc;
for(sc = hp.l.First(); sc; sc = hp.l.NextAfter(sc)) {
l.Add(sc);
}
orig.Clear();
holes.Clear();
li.Clear();
lj.Clear();
hp.l.Clear();
UvTriangulateInto(mesh, srf);
}
void SolveSpace::ExportSectionTo(char *filename) {
Vector gn = (SS.GW.projRight).Cross(SS.GW.projUp);
gn = gn.WithMagnitude(1);
Group *g = SK.GetGroup(SS.GW.activeGroup);
g->GenerateDisplayItems();
if(g->displayMesh.IsEmpty()) {
Error("No solid model present; draw one with extrudes and revolves, "
"or use Export 2d View to export bare lines and curves.");
return;
}
// The plane in which the exported section lies; need this because we'll
// reorient from that plane into the xy plane before exporting.
Vector origin, u, v, n;
double d;
SS.GW.GroupSelection();
#define gs (SS.GW.gs)
if((gs.n == 0 && g->activeWorkplane.v != Entity::FREE_IN_3D.v)) {
Entity *wrkpl = SK.GetEntity(g->activeWorkplane);
origin = wrkpl->WorkplaneGetOffset();
n = wrkpl->Normal()->NormalN();
u = wrkpl->Normal()->NormalU();
v = wrkpl->Normal()->NormalV();
} else if(gs.n == 1 && gs.faces == 1) {
Entity *face = SK.GetEntity(gs.entity[0]);
origin = face->FaceGetPointNum();
n = face->FaceGetNormalNum();
if(n.Dot(gn) < 0) n = n.ScaledBy(-1);
u = n.Normal(0);
v = n.Normal(1);
} else if(gs.n == 3 && gs.vectors == 2 && gs.points == 1) {
Vector ut = SK.GetEntity(gs.entity[0])->VectorGetNum(),
vt = SK.GetEntity(gs.entity[1])->VectorGetNum();
ut = ut.WithMagnitude(1);
vt = vt.WithMagnitude(1);
if(fabs(SS.GW.projUp.Dot(vt)) < fabs(SS.GW.projUp.Dot(ut))) {
SWAP(Vector, ut, vt);
}
if(SS.GW.projRight.Dot(ut) < 0) ut = ut.ScaledBy(-1);
if(SS.GW.projUp. Dot(vt) < 0) vt = vt.ScaledBy(-1);
origin = SK.GetEntity(gs.point[0])->PointGetNum();
n = ut.Cross(vt);
u = ut.WithMagnitude(1);
v = (n.Cross(u)).WithMagnitude(1);
} else {
Error("Bad selection for export section. Please select:\n\n"
" * nothing, with an active workplane "
"(workplane is section plane)\n"
" * a face (section plane through face)\n"
" * a point and two line segments "
"(plane through point and parallel to lines)\n");
return;
}
SS.GW.ClearSelection();
n = n.WithMagnitude(1);
d = origin.Dot(n);
SEdgeList el;
ZERO(&el);
SBezierList bl;
ZERO(&bl);
// If there's a mesh, then grab the edges from it.
g->runningMesh.MakeEdgesInPlaneInto(&el, n, d);
// If there's a shell, then grab the edges and possibly Beziers.
g->runningShell.MakeSectionEdgesInto(n, d,
&el,
(SS.exportPwlCurves || fabs(SS.exportOffset) > LENGTH_EPS) ? NULL : &bl);
// All of these are solid model edges, so use the appropriate style.
SEdge *se;
for(se = el.l.First(); se; se = el.l.NextAfter(se)) {
se->auxA = Style::SOLID_EDGE;
}
SBezier *sb;
for(sb = bl.l.First(); sb; sb = bl.l.NextAfter(sb)) {
sb->auxA = Style::SOLID_EDGE;
}
el.CullExtraneousEdges();
bl.CullIdenticalBeziers();
// And write the edges.
VectorFileWriter *out = VectorFileWriter::ForFile(filename);
if(out) {
// parallel projection (no perspective), and no mesh
ExportLinesAndMesh(&el, &bl, NULL,
u, v, n, origin, 0,
out);
}
el.Clear();
bl.Clear();
}
