void
PolylineCollection::chained_path_from(Point start_near, PolylineCollection* retval, bool no_reverse) const
{
Polylines my_paths = this->polylines;
Points endpoints; //里面存储所有polyline里面的第一个点和允许翻转时的最后一个点的坐标
for (Polylines::const_iterator it = my_paths.begin(); it != my_paths.end(); ++it) {
endpoints.push_back(it->first_point());
if (no_reverse) {
endpoints.push_back(it->first_point());
} else {
endpoints.push_back(it->last_point());
}
}
while (!my_paths.empty()) {
// find nearest point
int start_index = start_near.nearest_point_index(endpoints);
int path_index = start_index/2;
if (start_index % 2 && !no_reverse) {
my_paths.at(path_index).reverse();
}
retval->polylines.push_back(my_paths.at(path_index));
my_paths.erase(my_paths.begin() + path_index);
endpoints.erase(endpoints.begin() + 2*path_index, endpoints.begin() + 2*path_index + 2);
start_near = retval->polylines.back().last_point();
}
}
Point
PolylineCollection::leftmost_point() const
{
if (this->polylines.empty()) qDebug("leftmost_point() called on empty PolylineCollection");
Point p = this->polylines.front().leftmost_point();
for (Polylines::const_iterator it = this->polylines.begin() + 1; it != this->polylines.end(); ++it) {
Point p2 = it->leftmost_point();
if (p2.x < p.x) p = p2;
}
return p;
}
Point PolylineCollection::leftmost_point(const Polylines &polylines)
{
if (polylines.empty()) CONFESS("leftmost_point() called on empty PolylineCollection");
Polylines::const_iterator it = polylines.begin();
Point p = it->leftmost_point();
for (++ it; it != polylines.end(); ++it) {
Point p2 = it->leftmost_point();
if (p2.x < p.x)
p = p2;
}
return p;
}
ExtrusionEntityCollection
PerimeterGenerator::_fill_gaps(double min, double max, double w,
const Polygons &gaps) const
{
ExtrusionEntityCollection coll;
min *= (1 - INSET_OVERLAP_TOLERANCE);
ExPolygons curr = diff_ex(
offset2(gaps, -min/2, +min/2),
offset2(gaps, -max/2, +max/2),
true
);
Polylines polylines;
for (ExPolygons::const_iterator ex = curr.begin(); ex != curr.end(); ++ex)
ex->medial_axis(max, min/2, &polylines);
if (polylines.empty())
return coll;
#ifdef SLIC3R_DEBUG
if (!curr.empty())
printf(" %zu gaps filled with extrusion width = %f\n", curr.size(), w);
#endif
//my $flow = $layerm->flow(FLOW_ROLE_SOLID_INFILL, 0, $w);
Flow flow(
w, this->layer_height, this->solid_infill_flow.nozzle_diameter
);
double mm3_per_mm = flow.mm3_per_mm();
for (Polylines::const_iterator p = polylines.begin(); p != polylines.end(); ++p) {
ExtrusionPath path(erGapFill);
path.polyline = *p;
path.mm3_per_mm = mm3_per_mm;
path.width = flow.width;
path.height = this->layer_height;
if (p->is_valid() && p->first_point().coincides_with(p->last_point())) {
// since medial_axis() now returns only Polyline objects, detect loops here
ExtrusionLoop loop;
loop.paths.push_back(path);
coll.append(loop);
} else {
coll.append(path);
}
}
return coll;
}
void
BridgeDetector::unsupported_edges(double angle, Polylines* unsupported) const
{
// get bridge edges (both contour and holes)
Polylines bridge_edges;
{
Polygons pp = this->expolygon;
bridge_edges.insert(bridge_edges.end(), pp.begin(), pp.end()); // this uses split_at_first_point()
}
// get unsupported edges
Polygons grown_lower;
offset(this->lower_slices, &grown_lower, +this->extrusion_width);
Polylines _unsupported;
diff(bridge_edges, grown_lower, &_unsupported);
/* Split into individual segments and filter out edges parallel to the bridging angle
TODO: angle tolerance should probably be based on segment length and flow width,
so that we build supports whenever there's a chance that at least one or two bridge
extrusions would be anchored within such length (i.e. a slightly non-parallel bridging
direction might still benefit from anchors if long enough) */
double angle_tolerance = PI / 180.0 * 5.0;
for (Polylines::const_iterator polyline = _unsupported.begin(); polyline != _unsupported.end(); ++polyline) {
Lines lines = polyline->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
if (!xd::Geometry::directions_parallel(line->direction(), angle))
unsupported->push_back(*line);
}
}
/*
if (0) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output(
"unsupported_" . rad2deg($angle) . ".svg",
expolygons => [$self->expolygon],
green_expolygons => $self->_anchors,
red_expolygons => union_ex($grown_lower),
no_arrows => 1,
polylines => \@bridge_edges,
red_polylines => $unsupported,
);
}
*/
}
void
PerimeterGenerator::process()
{
// other perimeters
this->_mm3_per_mm = this->perimeter_flow.mm3_per_mm();
coord_t pwidth = this->perimeter_flow.scaled_width();
coord_t pspacing = this->perimeter_flow.scaled_spacing();
// external perimeters
this->_ext_mm3_per_mm = this->ext_perimeter_flow.mm3_per_mm();
coord_t ext_pwidth = this->ext_perimeter_flow.scaled_width();
coord_t ext_pspacing = this->ext_perimeter_flow.scaled_spacing();
coord_t ext_pspacing2 = this->ext_perimeter_flow.scaled_spacing(this->perimeter_flow);
// overhang perimeters
this->_mm3_per_mm_overhang = this->overhang_flow.mm3_per_mm();
// solid infill
coord_t ispacing = this->solid_infill_flow.scaled_spacing();
coord_t gap_area_threshold = pwidth * pwidth;
// Calculate the minimum required spacing between two adjacent traces.
// This should be equal to the nominal flow spacing but we experiment
// with some tolerance in order to avoid triggering medial axis when
// some squishing might work. Loops are still spaced by the entire
// flow spacing; this only applies to collapsing parts.
// For ext_min_spacing we use the ext_pspacing calculated for two adjacent
// external loops (which is the correct way) instead of using ext_pspacing2
// which is the spacing between external and internal, which is not correct
// and would make the collapsing (thus the details resolution) dependent on
// internal flow which is unrelated.
coord_t min_spacing = pspacing * (1 - INSET_OVERLAP_TOLERANCE);
coord_t ext_min_spacing = ext_pspacing * (1 - INSET_OVERLAP_TOLERANCE);
// prepare grown lower layer slices for overhang detection
if (this->lower_slices != NULL && this->config->overhangs) {
// We consider overhang any part where the entire nozzle diameter is not supported by the
// lower layer, so we take lower slices and offset them by half the nozzle diameter used
// in the current layer
double nozzle_diameter = this->print_config->nozzle_diameter.get_at(this->config->perimeter_extruder-1);
this->_lower_slices_p = offset(*this->lower_slices, scale_(+nozzle_diameter/2));
}
// we need to process each island separately because we might have different
// extra perimeters for each one
for (Surfaces::const_iterator surface = this->slices->surfaces.begin();
surface != this->slices->surfaces.end(); ++surface) {
// detect how many perimeters must be generated for this island
signed short loop_number = this->config->perimeters + surface->extra_perimeters;
loop_number--; // 0-indexed loops
Polygons gaps;
Polygons last = surface->expolygon.simplify_p(SCALED_RESOLUTION);
if (loop_number >= 0) { // no loops = -1
std::vector<PerimeterGeneratorLoops> contours(loop_number+1); // depth => loops
std::vector<PerimeterGeneratorLoops> holes(loop_number+1); // depth => loops
Polylines thin_walls;
// we loop one time more than needed in order to find gaps after the last perimeter was applied
for (signed short i = 0; i <= loop_number+1; ++i) { // outer loop is 0
Polygons offsets;
if (i == 0) {
// the minimum thickness of a single loop is:
// ext_width/2 + ext_spacing/2 + spacing/2 + width/2
if (this->config->thin_walls) {
offsets = offset2(
last,
-(ext_pwidth/2 + ext_min_spacing/2 - 1),
+(ext_min_spacing/2 - 1)
);
} else {
offsets = offset(last, -ext_pwidth/2);
}
// look for thin walls
if (this->config->thin_walls) {
Polygons diffpp = diff(
last,
offset(offsets, +ext_pwidth/2),
true // medial axis requires non-overlapping geometry
);
// the following offset2 ensures almost nothing in @thin_walls is narrower than $min_width
// (actually, something larger than that still may exist due to mitering or other causes)
coord_t min_width = ext_pwidth / 2;
ExPolygons expp = offset2_ex(diffpp, -min_width/2, +min_width/2);
// the maximum thickness of our thin wall area is equal to the minimum thickness of a single loop
Polylines pp;
for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex)
ex->medial_axis(ext_pwidth + ext_pspacing2, min_width, &pp);
double threshold = ext_pwidth * 2;
for (Polylines::const_iterator p = pp.begin(); p != pp.end(); ++p) {
if (p->length() > threshold) {
thin_walls.push_back(*p);
}
}
#ifdef DEBUG
printf(" %zu thin walls detected\n", thin_walls.size());
#endif
/*
if (false) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output(
"medial_axis.svg",
no_arrows => 1,
#expolygons => \@expp,
polylines => \@thin_walls,
);
}
*/
}
} else {
coord_t distance = (i == 1) ? ext_pspacing2 : pspacing;
if (this->config->thin_walls) {
offsets = offset2(
last,
-(distance + min_spacing/2 - 1),
+(min_spacing/2 - 1)
);
} else {
offsets = offset(
last,
-distance
);
}
// look for gaps
if (this->config->gap_fill_speed.value > 0 && this->config->fill_density.value > 0) {
// not using safety offset here would "detect" very narrow gaps
// (but still long enough to escape the area threshold) that gap fill
// won't be able to fill but we'd still remove from infill area
ExPolygons diff_expp = diff_ex(
offset(last, -0.5*distance),
offset(offsets, +0.5*distance + 10) // safety offset
);
for (ExPolygons::const_iterator ex = diff_expp.begin(); ex != diff_expp.end(); ++ex) {
if (fabs(ex->area()) >= gap_area_threshold) {
Polygons pp = *ex;
gaps.insert(gaps.end(), pp.begin(), pp.end());
}
}
}
}
if (offsets.empty()) break;
if (i > loop_number) break; // we were only looking for gaps this time
last = offsets;
for (Polygons::const_iterator polygon = offsets.begin(); polygon != offsets.end(); ++polygon) {
PerimeterGeneratorLoop loop(*polygon, i);
loop.is_contour = polygon->is_counter_clockwise();
if (loop.is_contour) {
contours[i].push_back(loop);
} else {
holes[i].push_back(loop);
}
}
}
// nest loops: holes first
for (signed short d = 0; d <= loop_number; ++d) {
PerimeterGeneratorLoops &holes_d = holes[d];
// loop through all holes having depth == d
for (signed short i = 0; i < holes_d.size(); ++i) {
const PerimeterGeneratorLoop &loop = holes_d[i];
// find the hole loop that contains this one, if any
for (signed short t = d+1; t <= loop_number; ++t) {
for (signed short j = 0; j < holes[t].size(); ++j) {
PerimeterGeneratorLoop &candidate_parent = holes[t][j];
if (candidate_parent.polygon.contains(loop.polygon.first_point())) {
candidate_parent.children.push_back(loop);
holes_d.erase(holes_d.begin() + i);
--i;
goto NEXT_LOOP;
}
}
}
// if no hole contains this hole, find the contour loop that contains it
for (signed short t = loop_number; t >= 0; --t) {
for (signed short j = 0; j < contours[t].size(); ++j) {
PerimeterGeneratorLoop &candidate_parent = contours[t][j];
if (candidate_parent.polygon.contains(loop.polygon.first_point())) {
candidate_parent.children.push_back(loop);
holes_d.erase(holes_d.begin() + i);
--i;
goto NEXT_LOOP;
}
}
}
NEXT_LOOP: ;
}
}
// nest contour loops
for (signed short d = loop_number; d >= 1; --d) {
PerimeterGeneratorLoops &contours_d = contours[d];
// loop through all contours having depth == d
for (signed short i = 0; i < contours_d.size(); ++i) {
const PerimeterGeneratorLoop &loop = contours_d[i];
// find the contour loop that contains it
for (signed short t = d-1; t >= 0; --t) {
for (signed short j = 0; j < contours[t].size(); ++j) {
PerimeterGeneratorLoop &candidate_parent = contours[t][j];
if (candidate_parent.polygon.contains(loop.polygon.first_point())) {
candidate_parent.children.push_back(loop);
contours_d.erase(contours_d.begin() + i);
--i;
goto NEXT_CONTOUR;
}
}
}
NEXT_CONTOUR: ;
}
}
// at this point, all loops should be in contours[0]
ExtrusionEntityCollection entities = this->_traverse_loops(contours.front(), thin_walls);
// if brim will be printed, reverse the order of perimeters so that
// we continue inwards after having finished the brim
// TODO: add test for perimeter order
if (this->config->external_perimeters_first
|| (this->layer_id == 0 && this->print_config->brim_width.value > 0))
entities.reverse();
// append perimeters for this slice as a collection
if (!entities.empty())
this->loops->append(entities);
}
// fill gaps
if (!gaps.empty()) {
/*
if (false) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output(
"gaps.svg",
expolygons => union_ex(\@gaps),
);
}
*/
// where $pwidth < thickness < 2*$pspacing, infill with width = 2*$pwidth
// where 0.1*$pwidth < thickness < $pwidth, infill with width = 1*$pwidth
std::vector<PerimeterGeneratorGapSize> gap_sizes;
gap_sizes.push_back(PerimeterGeneratorGapSize(pwidth, 2*pspacing, 2*pwidth));
gap_sizes.push_back(PerimeterGeneratorGapSize(0.1*pwidth, pwidth, 1*pwidth));
for (std::vector<PerimeterGeneratorGapSize>::const_iterator gap_size = gap_sizes.begin();
gap_size != gap_sizes.end(); ++gap_size) {
ExtrusionEntityCollection gap_fill = this->_fill_gaps(gap_size->min,
gap_size->max, unscale(gap_size->width), gaps);
this->gap_fill->append(gap_fill.entities);
// Make sure we don't infill narrow parts that are already gap-filled
// (we only consider this surface's gaps to reduce the diff() complexity).
// Growing actual extrusions ensures that gaps not filled by medial axis
// are not subtracted from fill surfaces (they might be too short gaps
// that medial axis skips but infill might join with other infill regions
// and use zigzag).
coord_t dist = gap_size->width/2;
Polygons filled;
for (ExtrusionEntitiesPtr::const_iterator it = gap_fill.entities.begin();
it != gap_fill.entities.end(); ++it) {
Polygons f;
offset((*it)->as_polyline(), &f, dist);
filled.insert(filled.end(), f.begin(), f.end());
}
last = diff(last, filled);
gaps = diff(gaps, filled); // prevent more gap fill here
}
}
// create one more offset to be used as boundary for fill
// we offset by half the perimeter spacing (to get to the actual infill boundary)
// and then we offset back and forth by half the infill spacing to only consider the
// non-collapsing regions
coord_t inset = 0;
if (loop_number == 0) {
// one loop
inset += ext_pspacing2/2;
} else if (loop_number > 0) {
// two or more loops
inset += pspacing/2;
}
// only apply infill overlap if we actually have one perimeter
if (inset > 0)
inset -= this->config->get_abs_value("infill_overlap", inset + ispacing/2);
{
ExPolygons expp = union_ex(last);
// simplify infill contours according to resolution
Polygons pp;
for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex)
ex->simplify_p(SCALED_RESOLUTION, &pp);
// collapse too narrow infill areas
coord_t min_perimeter_infill_spacing = ispacing * (1 - INSET_OVERLAP_TOLERANCE);
expp = offset2_ex(
pp,
-inset -min_perimeter_infill_spacing/2,
+min_perimeter_infill_spacing/2
);
// append infill areas to fill_surfaces
for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex)
this->fill_surfaces->surfaces.push_back(Surface(stInternal, *ex)); // use a bogus surface type
}
}
}
bool
BridgeDetector::detect_angle()
{
if (this->_edges.empty() || this->_anchors.empty()) return false;
/* Outset the bridge expolygon by half the amount we used for detecting anchors;
we'll use this one to clip our test lines and be sure that their endpoints
are inside the anchors and not on their contours leading to false negatives. */
Polygons clip_area;
offset(this->expolygon, &clip_area, +this->extrusion_width/2);
/* we'll now try several directions using a rudimentary visibility check:
bridge in several directions and then sum the length of lines having both
endpoints within anchors */
// we test angles according to configured resolution
std::vector<double> angles;
for (int i = 0; i <= PI/this->resolution; ++i)
angles.push_back(i * this->resolution);
// we also test angles of each bridge contour
{
Polygons pp = this->expolygon;
for (Polygons::const_iterator p = pp.begin(); p != pp.end(); ++p) {
Lines lines = p->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line)
angles.push_back(line->direction());
}
}
/* we also test angles of each open supporting edge
(this finds the optimal angle for C-shaped supports) */
for (Polylines::const_iterator edge = this->_edges.begin(); edge != this->_edges.end(); ++edge) {
if (edge->first_point().coincides_with(edge->last_point())) continue;
angles.push_back(Line(edge->first_point(), edge->last_point()).direction());
}
// remove duplicates
double min_resolution = PI/180.0; // 1 degree
std::sort(angles.begin(), angles.end());
for (size_t i = 1; i < angles.size(); ++i) {
if (xd::Geometry::directions_parallel(angles[i], angles[i-1], min_resolution)) {
angles.erase(angles.begin() + i);
--i;
}
}
/* compare first value with last one and remove the greatest one (PI)
in case they are parallel (PI, 0) */
if (xd::Geometry::directions_parallel(angles.front(), angles.back(), min_resolution))
angles.pop_back();
BridgeDirectionComparator bdcomp(this->extrusion_width);
double line_increment = this->extrusion_width;
bool have_coverage = false;
for (std::vector<double>::const_iterator angle = angles.begin(); angle != angles.end(); ++angle) {
Polygons my_clip_area = clip_area;
ExPolygons my_anchors = this->_anchors;
// rotate everything - the center point doesn't matter
for (Polygons::iterator it = my_clip_area.begin(); it != my_clip_area.end(); ++it)
it->rotate(-*angle, Point(0,0));
for (ExPolygons::iterator it = my_anchors.begin(); it != my_anchors.end(); ++it)
it->rotate(-*angle, Point(0,0));
// generate lines in this direction
BoundingBox bb;
for (ExPolygons::const_iterator it = my_anchors.begin(); it != my_anchors.end(); ++it)
bb.merge((Points)*it);
Lines lines;
for (coord_t y = bb.min.y; y <= bb.max.y; y += line_increment)
lines.push_back(Line(Point(bb.min.x, y), Point(bb.max.x, y)));
Lines clipped_lines;
intersection(lines, my_clip_area, &clipped_lines);
// remove any line not having both endpoints within anchors
for (size_t i = 0; i < clipped_lines.size(); ++i) {
Line &line = clipped_lines[i];
if (!xd::Geometry::contains(my_anchors, line.a)
|| !xd::Geometry::contains(my_anchors, line.b)) {
clipped_lines.erase(clipped_lines.begin() + i);
--i;
}
}
std::vector<double> lengths;
double total_length = 0;
for (Lines::const_iterator line = clipped_lines.begin(); line != clipped_lines.end(); ++line) {
double len = line->length();
lengths.push_back(len);
total_length += len;
}
if (total_length) have_coverage = true;
// sum length of bridged lines
bdcomp.dir_coverage[*angle] = total_length;
/* The following produces more correct results in some cases and more broken in others.
TODO: investigate, as it looks more reliable than line clipping. */
// $directions_coverage{$angle} = sum(map $_->area, @{$self->coverage($angle)}) // 0;
// max length of bridged lines
bdcomp.dir_avg_length[*angle] = !lengths.empty()
? *std::max_element(lengths.begin(), lengths.end())
: 0;
}
// if no direction produced coverage, then there's no bridge direction
if (!have_coverage) return false;
// sort directions by score
std::sort(angles.begin(), angles.end(), bdcomp);
this->angle = angles.front();
if (this->angle >= PI) this->angle -= PI;
// #ifdef SLIC3R_DEBUG
// printf(" Optimal infill angle is %d degrees\n", (int)Slic3r::Geometry::rad2deg(this->angle));
// #endif
return true;
}
