PrusaSlicer-NonPlainar/xs/src/libslic3r/PerimeterGenerator.cpp
2015-07-07 01:17:31 +02:00

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#include "PerimeterGenerator.hpp"
namespace Slic3r {
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 = scale_(this->ext_perimeter_flow.spacing_to(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.
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
unsigned 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); // depth => loops
std::vector<PerimeterGeneratorLoops> holes(loop_number); // depth => loops
Polylines thin_walls;
// we loop one time more than needed in order to find gaps after the last perimeter was applied
for (unsigned 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,
-(0.5*ext_pwidth + 0.5*ext_min_spacing - 1),
+(0.5*ext_min_spacing - 1)
);
} else {
offsets = offset(last, -0.5*ext_pwidth);
}
// look for thin walls
if (this->config->thin_walls) {
Polygons diff = diff(
last,
offset(offsets, +0.5*ext_pwidth),
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(diff, -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_pspacing, min_width, &pp);
double threshold = ext_pwidth * ext_pwidth;
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_pspacing : pspacing;
if (this->config->thin_walls) {
offsets = offset2(
last,
-(distance + 0.5*min_spacing - 1),
+(0.5*min_spacing - 1),
);
} else {
offsets = offset(
last,
-distance,
);
}
// look for gaps
if (this->config->gap_fill_speed > 0 && this->config->fill_density > 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 = diff_ex(
offset(last, -0.5*distance),
offset(offsets, +0.5*distance + 10), // safety offset
);
for (ExPolygons::const_iterator ex = diff.begin(); ex != diff.end(); ++ex) {
if (fabs(ex->area()) >= gap_area_threshold)
gaps.push_back(*ex);
}
}
}
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 (unsigned short d = 0; <= loop_number; ++d) {
PerimeterGeneratorLoops &holes_d = holes[d];
// loop through all holes having depth == d
for (unsigned 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 (unsigned short t = d+1; t <= loop_number; ++t) {
for (unsigned short j = 0; j < holes_d.size(); ++j) {
PerimeterGeneratorLoop &candidate_parent = holes[t][j];
if (candidate_parent.polygon.contains(loop.polygon.first_point())) {
candidate_parent.add_child(loop);
holes_d.erase(holes_d.begin() + i);
--i;
goto NEXT_HOLE;
}
}
}
// if no hole contains this hole, find the contour loop that contains it
for (unsigned short t = loop_number; t >= 0; --t) {
for (unsigned 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.add_child(loop);
holes_d.erase(holes_d.begin() + i);
--i;
goto NEXT_HOLE;
}
}
}
}
NEXT_HOLE:
}
// nest contour loops
for (unsigned short d = loop_number; d >= 1; --d) {
PerimeterGeneratorLoops &contours_d = contours[d];
// loop through all contours having depth == d
for (unsigned short i = 0; i < contours_d.size(); ++i) {
const PerimeterGeneratorLoop &loop = contours_d[i];
// find the contour loop that contains it
for (unsigned short t = d-1; t >= 0; --t) {
for (unsigned short j = 0; j < contours_d[t].size(); ++j) {
PerimeterGeneratorLoop &candidate_parent = contours[t][j];
if (candidate_parent.polygon.contains(loop.polygon.first_point())) {
candidate_parent.add_child(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 > 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, unscale(2*pwidth)));
gap_sizes.push_back(PerimeterGeneratorGapSize(0.1*pwidth, pwidth, unscale(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, gap_size.width);
this->gap_fill->append(gap_fill);
// 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).
double dist = scale_(gap_size->width/2);
Polygons filled;
for (ExtrusionEntitiesPtr::const_iterator it = gap_fill.entities.begin();
it != gap_fill.entities.end(); ++it)
offset((*it)->as_polyline(), &filled, dist);
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_pspacing/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_(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(
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
}
}
}
ExtrusionEntityCollection
PerimeterGenerator::_traverse_loops(const PerimeterGeneratorLoops &loops,
const Polylines &thin_walls) const
{
// loops is an arrayref of ::Loop objects
// turn each one into an ExtrusionLoop object
ExtrusionEntityCollection coll;
for (PerimeterGeneratorLoops::const_iterator loop = loops.begin();
loop != loops.end(); ++loop) {
bool is_external = loop->is_external();
ExtrusionRole role;
ExtrusionLoopRole loop_role;
role = is_external ? erExternalPerimeter : erPerimeter;
if (loop->is_internal_contour()) {
// Note that we set loop role to ContourInternalPerimeter
// also when loop is both internal and external (i.e.
// there's only one contour loop).
loop_role = elrContourInternalPerimeter;
} else {
loop_role = elrDefault;
}
// detect overhanging/bridging perimeters
ExtrusionPaths paths;
if (this->config->overhangs && this->layer_id > 0
&& !(this->object_config->support_material && this->object_config->support_material_contact_distance == 0)) {
// get non-overhang paths by intersecting this loop with the grown lower slices
{
Polylines polylines;
intersection(loop->polygon(), this->_lower_slices_p, &polylines);
for (Polylines::const_iterator polyline = polylines.begin(); polyline != polylines.end(); ++polyline) {
ExtrusionPath path(role);
path.polyline = *polyline;
path.mm3_per_mm = is_external ? this->_ext_mm3_per_mm : this->_mm3_per_mm;
path.width = is_external ? this->ext_perimeter_flow->width : this->perimeter_flow.width;
path.height = this->layer_height;
paths.push_back(path);
}
}
// get overhang paths by checking what parts of this loop fall
// outside the grown lower slices (thus where the distance between
// the loop centerline and original lower slices is >= half nozzle diameter
{
Polylines polylines;
diff(loop->polygon(), this->_lower_slices_p, &polylines);
for (Polylines::const_iterator polyline = polylines.begin(); polyline != polylines.end(); ++polyline) {
ExtrusionPath path(erOverhangPerimeter);
path.polyline = *polyline;
path.mm3_per_mm = this->_mm3_per_mm_overhang;
path.width = this->overhang_flow.width;
path.height = this->overhang_flow.height;
paths.push_back(path);
}
}
// reapply the nearest point search for starting point
// We allow polyline reversal because Clipper may have randomly
// reversed polylines during clipping.
paths = ExtrusionEntityCollection(paths).chained_path();
} else {
ExtrusionPath path(role);
path.polyline = loop.polygon().split_at_first_point();
path.mm3_per_mm = is_external ? this->_ext_mm3_per_mm : this->_mm3_per_mm;
path.width = is_external ? this->ext_perimeter_flow->width : this->perimeter_flow.width;
path.height = this->layer_height;
}
coll.append(ExtrusionLoop(paths, loop_role));
}
// append thin walls to the nearest-neighbor search (only for first iteration)
if (!thin_walls.empty()) {
for (Polylines::const_iterator polyline = thin_walls.begin(); polyline != thin_walls.end(); ++polyline) {
ExtrusionPath path(erExternalPerimeter);
path.polyline = *polyline;
path.mm3_per_mm = this->_mm3_per_mm;
path.width = this->perimeter_flow.width;
path.height = this->layer_height;
coll.append(path);
}
thin_walls.clear();
}
// sort entities
ExtrusionPathCollection sorted_coll;
coll.chained_path(&sorted_coll, false, &sorted_coll.orig_indices);
// traverse children
ExtrusionPathCollection entities;
for (unsigned short i = 0; i < sorted_coll.orig_indices.size(); ++i) {
size_t idx = sorted_coll.orig_indices[i];
if (idx >= loops.size()) {
// this is a thin wall
// let's get it from the sorted collection as it might have been reversed
entities.append(*sorted_coll.entities[i]);
} else {
PerimeterGeneratorLoop &loop = loops[i];
ExtrusionLoop eloop = *coll.entities[idx];
ExtrusionEntityCollection children = this->_traverse_loops(loop->children, thin_walls);
if (loop->is_contour()) {
eloop.make_counter_clockwise();
entities.append(children);
entities.append(elooop);
} else {
eloop.make_clockwise();
push @entities, $eloop, @children;
entities.append(elooop);
entities.append(children);
}
}
}
return entities;
}
ExtrusionEntityCollection
PerimeterGenerator::_fill_gaps(double min, double max, double w,
const Polygons &gaps) const
{
ExtrusionEntityCollection coll;
min *= (1 - INSET_OVERLAP_TOLERANCE);
ExPolygon curr = diff(
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(" %d gaps filled with extrusion width = %zu\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;
}
#ifdef SLIC3RXS
REGISTER_CLASS(PerimeterGenerator, "Layer::PerimeterGenerator");
#endif
bool
PerimeterGeneratorLoop::is_external() const
{
return this->depth == 0;
}
bool
PerimeterGeneratorLoop::is_internal_contour() const
{
if (this->is_contour) {
// an internal contour is a contour containing no other contours
for (std::vector<PerimeterGeneratorLoop>::const_iterator loop = this->children.begin();
loop != this->children.end(); ++loop) {
if (loop->is_contour) {
return false;
}
}
return true;
}
return false;
}
}