void
LayerRegion::process_external_surfaces(const Layer* lower_layer)
{
const Surfaces &surfaces = this->fill_surfaces.surfaces;
const double margin = scale_(EXTERNAL_INFILL_MARGIN);
SurfaceCollection bottom;
for (Surfaces::const_iterator surface = surfaces.begin(); surface != surfaces.end(); ++surface) {
if (!surface->is_bottom()) continue;
ExPolygons grown = offset_ex(surface->expolygon, +margin);
/* detect bridge direction before merging grown surfaces otherwise adjacent bridges
would get merged into a single one while they need different directions
also, supply the original expolygon instead of the grown one, because in case
of very thin (but still working) anchors, the grown expolygon would go beyond them */
double angle = -1;
if (lower_layer != NULL) {
BridgeDetector bd(
surface->expolygon,
lower_layer->slices,
this->flow(frInfill, this->layer()->height, true).scaled_width()
);
#ifdef SLIC3R_DEBUG
printf("Processing bridge at layer %zu:\n", this->layer()->id());
#endif
if (bd.detect_angle()) {
angle = bd.angle;
if (this->layer()->object()->config.support_material) {
Polygons coverage = bd.coverage();
this->bridged.insert(this->bridged.end(), coverage.begin(), coverage.end());
this->unsupported_bridge_edges.append(bd.unsupported_edges());
}
}
}
for (ExPolygons::const_iterator it = grown.begin(); it != grown.end(); ++it) {
Surface s = *surface;
s.expolygon = *it;
s.bridge_angle = angle;
bottom.surfaces.push_back(s);
}
}
SurfaceCollection top;
for (Surfaces::const_iterator surface = surfaces.begin(); surface != surfaces.end(); ++surface) {
if (surface->surface_type != stTop) continue;
// give priority to bottom surfaces
ExPolygons grown = diff_ex(
offset(surface->expolygon, +margin),
(Polygons)bottom
);
for (ExPolygons::const_iterator it = grown.begin(); it != grown.end(); ++it) {
Surface s = *surface;
s.expolygon = *it;
top.surfaces.push_back(s);
}
}
/* if we're slicing with no infill, we can't extend external surfaces
over non-existent infill */
SurfaceCollection fill_boundaries;
if (this->region()->config.fill_density.value > 0) {
fill_boundaries = SurfaceCollection(surfaces);
} else {
for (Surfaces::const_iterator it = surfaces.begin(); it != surfaces.end(); ++it) {
if (it->surface_type != stInternal)
fill_boundaries.surfaces.push_back(*it);
}
}
// intersect the grown surfaces with the actual fill boundaries
SurfaceCollection new_surfaces;
{
// merge top and bottom in a single collection
SurfaceCollection tb = top;
tb.append(bottom);
// group surfaces
std::vector<SurfacesConstPtr> groups;
tb.group(&groups);
for (std::vector<SurfacesConstPtr>::const_iterator g = groups.begin(); g != groups.end(); ++g) {
Polygons subject;
for (SurfacesConstPtr::const_iterator s = g->begin(); s != g->end(); ++s)
append_to(subject, (Polygons)**s);
ExPolygons expp = intersection_ex(
subject,
(Polygons)fill_boundaries,
true // to ensure adjacent expolygons are unified
);
for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex) {
Surface s = *g->front();
s.expolygon = *ex;
new_surfaces.surfaces.push_back(s);
}
}
}
/* subtract the new top surfaces from the other non-top surfaces and re-add them */
{
SurfaceCollection other;
for (Surfaces::const_iterator s = surfaces.begin(); s != surfaces.end(); ++s) {
if (s->surface_type != stTop && !s->is_bottom())
other.surfaces.push_back(*s);
}
// group surfaces
std::vector<SurfacesConstPtr> groups;
other.group(&groups);
for (std::vector<SurfacesConstPtr>::const_iterator g = groups.begin(); g != groups.end(); ++g) {
Polygons subject;
for (SurfacesConstPtr::const_iterator s = g->begin(); s != g->end(); ++s)
append_to(subject, (Polygons)**s);
ExPolygons expp = diff_ex(
subject,
(Polygons)new_surfaces
);
for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex) {
Surface s = *g->front();
s.expolygon = *ex;
new_surfaces.surfaces.push_back(s);
}
}
}
this->fill_surfaces = new_surfaces;
}
