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PrusaSlicer-NonPlainar/src/libslic3r/Fill/FillRectilinear.cpp
Vojtech Bubnik e5b3af0e53 Fix of Monotonic infill leaves gaps in top infill where rectilinear does not #5259 
and Chyba nebo vlastnost výplně Monotonic? #5225
2020-11-25 14:56:11 +01:00

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#include <stdlib.h>
#include <stdint.h>
#include <algorithm>
#include <cmath>
#include <limits>
#include <random>
#include <boost/container/small_vector.hpp>
#include <boost/log/trivial.hpp>
#include <boost/static_assert.hpp>
#include "../ClipperUtils.hpp"
#include "../ExPolygon.hpp"
#include "../Geometry.hpp"
#include "../Surface.hpp"
#include "../ShortestPath.hpp"
#include "FillRectilinear.hpp"
// #define SLIC3R_DEBUG
// #define INFILL_DEBUG_OUTPUT
// Make assert active if SLIC3R_DEBUG
#ifdef SLIC3R_DEBUG
#undef NDEBUG
#include "SVG.hpp"
#endif
#if defined(SLIC3R_DEBUG) || defined(INFILL_DEBUG_OUTPUT)
#include "SVG.hpp"
#endif
#include <cassert>
// We want our version of assert.
#include "../libslic3r.h"
namespace Slic3r {
// Having a segment of a closed polygon, calculate its Euclidian length.
// The segment indices seg1 and seg2 signify an end point of an edge in the forward direction of the loop,
// therefore the point p1 lies on poly.points[seg1-1], poly.points[seg1] etc.
static inline coordf_t segment_length(const Polygon &poly, size_t seg1, const Point &p1, size_t seg2, const Point &p2)
{
#ifdef SLIC3R_DEBUG
// Verify that p1 lies on seg1. This is difficult to verify precisely,
// but at least verify, that p1 lies in the bounding box of seg1.
for (size_t i = 0; i < 2; ++ i) {
size_t seg = (i == 0) ? seg1 : seg2;
Point px = (i == 0) ? p1 : p2;
Point pa = poly.points[((seg == 0) ? poly.points.size() : seg) - 1];
Point pb = poly.points[seg];
if (pa(0) > pb(0))
std::swap(pa(0), pb(0));
if (pa(1) > pb(1))
std::swap(pa(1), pb(1));
assert(px(0) >= pa(0) && px(0) <= pb(0));
assert(px(1) >= pa(1) && px(1) <= pb(1));
}
#endif /* SLIC3R_DEBUG */
const Point *pPrev = &p1;
const Point *pThis = NULL;
coordf_t len = 0;
if (seg1 <= seg2) {
for (size_t i = seg1; i < seg2; ++ i, pPrev = pThis)
len += (*pPrev - *(pThis = &poly.points[i])).cast<double>().norm();
} else {
for (size_t i = seg1; i < poly.points.size(); ++ i, pPrev = pThis)
len += (*pPrev - *(pThis = &poly.points[i])).cast<double>().norm();
for (size_t i = 0; i < seg2; ++ i, pPrev = pThis)
len += (*pPrev - *(pThis = &poly.points[i])).cast<double>().norm();
}
len += (*pPrev - p2).cast<double>().norm();
return len;
}
// Append a segment of a closed polygon to a polyline.
// The segment indices seg1 and seg2 signify an end point of an edge in the forward direction of the loop.
// Only insert intermediate points between seg1 and seg2.
static inline void polygon_segment_append(Points &out, const Polygon &polygon, size_t seg1, size_t seg2)
{
if (seg1 == seg2) {
// Nothing to append from this segment.
} else if (seg1 < seg2) {
// Do not append a point pointed to by seg2.
out.insert(out.end(), polygon.points.begin() + seg1, polygon.points.begin() + seg2);
} else {
out.reserve(out.size() + seg2 + polygon.points.size() - seg1);
out.insert(out.end(), polygon.points.begin() + seg1, polygon.points.end());
// Do not append a point pointed to by seg2.
out.insert(out.end(), polygon.points.begin(), polygon.points.begin() + seg2);
}
}
// Append a segment of a closed polygon to a polyline.
// The segment indices seg1 and seg2 signify an end point of an edge in the forward direction of the loop,
// but this time the segment is traversed backward.
// Only insert intermediate points between seg1 and seg2.
static inline void polygon_segment_append_reversed(Points &out, const Polygon &polygon, size_t seg1, size_t seg2)
{
if (seg1 >= seg2) {
out.reserve(seg1 - seg2);
for (size_t i = seg1; i > seg2; -- i)
out.push_back(polygon.points[i - 1]);
} else {
// it could be, that seg1 == seg2. In that case, append the complete loop.
out.reserve(out.size() + seg2 + polygon.points.size() - seg1);
for (size_t i = seg1; i > 0; -- i)
out.push_back(polygon.points[i - 1]);
for (size_t i = polygon.points.size(); i > seg2; -- i)
out.push_back(polygon.points[i - 1]);
}
}
// Intersection point of a vertical line with a polygon segment.
struct SegmentIntersection
{
// Index of a contour in ExPolygonWithOffset, with which this vertical line intersects.
size_t iContour { 0 };
// Index of a segment in iContour, with which this vertical line intersects.
size_t iSegment { 0 };
// y position of the intersection, rational number.
int64_t pos_p { 0 };
uint32_t pos_q { 1 };
coord_t pos() const {
// Division rounds both positive and negative down to zero.
// Add half of q for an arithmetic rounding effect.
int64_t p = pos_p;
if (p < 0)
p -= int64_t(pos_q>>1);
else
p += int64_t(pos_q>>1);
return coord_t(p / int64_t(pos_q));
}
// Left vertical line / contour intersection point.
// null if next_on_contour_vertical.
int32_t prev_on_contour { 0 };
// Right vertical line / contour intersection point.
// If next_on_contour_vertical, then then next_on_contour contains next contour point on the same vertical line.
int32_t next_on_contour { 0 };
// Kind of intersection. With the original contour, or with the inner offestted contour?
// A vertical segment will be at least intersected by OUTER_LOW, OUTER_HIGH,
// but it could be intersected with OUTER_LOW, INNER_LOW, INNER_HIGH, OUTER_HIGH,
// and there may be more than one pair of INNER_LOW, INNER_HIGH between OUTER_LOW, OUTER_HIGH.
enum SegmentIntersectionType : char {
UNKNOWN,
OUTER_LOW,
OUTER_HIGH,
INNER_LOW,
INNER_HIGH,
};
SegmentIntersectionType type { UNKNOWN };
enum class LinkType : uint8_t {
// Horizontal link (left or right).
Horizontal,
// Vertical link, up.
Up,
// Vertical link, down.
Down,
// Phony intersection point has no link.
Phony,
};
enum class LinkQuality : uint8_t {
Invalid,
Valid,
// Valid link, but too long to be followed.
TooLong,
};
// Kept grouped with other booleans for smaller memory footprint.
LinkType prev_on_contour_type { LinkType::Horizontal };
LinkType next_on_contour_type { LinkType::Horizontal };
LinkQuality prev_on_contour_quality { LinkQuality::Valid };
LinkQuality next_on_contour_quality { LinkQuality::Valid };
// Was this segment along the y axis consumed?
// Up means up along the vertical segment.
bool consumed_vertical_up { false };
// Was a segment of the inner perimeter contour consumed?
// Right means right from the vertical segment.
bool consumed_perimeter_right { false };
// For the INNER_LOW type, this point may be connected to another INNER_LOW point following a perimeter contour.
// For the INNER_HIGH type, this point may be connected to another INNER_HIGH point following a perimeter contour.
// If INNER_LOW is connected to INNER_HIGH or vice versa,
// one has to make sure the vertical infill line does not overlap with the connecting perimeter line.
bool is_inner() const { return type == INNER_LOW || type == INNER_HIGH; }
bool is_outer() const { return type == OUTER_LOW || type == OUTER_HIGH; }
bool is_low () const { return type == INNER_LOW || type == OUTER_LOW; }
bool is_high () const { return type == INNER_HIGH || type == OUTER_HIGH; }
enum class Side {
Left,
Right
};
enum class Direction {
Up,
Down
};
bool has_left_horizontal() const { return this->prev_on_contour_type == LinkType::Horizontal; }
bool has_right_horizontal() const { return this->next_on_contour_type == LinkType::Horizontal; }
bool has_horizontal(Side side) const { return side == Side::Left ? this->has_left_horizontal() : this->has_right_horizontal(); }
bool has_left_vertical_up() const { return this->prev_on_contour_type == LinkType::Up; }
bool has_left_vertical_down() const { return this->prev_on_contour_type == LinkType::Down; }
bool has_left_vertical(Direction dir) const { return dir == Direction::Up ? this->has_left_vertical_up() : this->has_left_vertical_down(); }
bool has_left_vertical() const { return this->has_left_vertical_up() || this->has_left_vertical_down(); }
bool has_left_vertical_outside() const { return this->is_low() ? this->has_left_vertical_down() : this->has_left_vertical_up(); }
bool has_right_vertical_up() const { return this->next_on_contour_type == LinkType::Up; }
bool has_right_vertical_down() const { return this->next_on_contour_type == LinkType::Down; }
bool has_right_vertical(Direction dir) const { return dir == Direction::Up ? this->has_right_vertical_up() : this->has_right_vertical_down(); }
bool has_right_vertical() const { return this->has_right_vertical_up() || this->has_right_vertical_down(); }
bool has_right_vertical_outside() const { return this->is_low() ? this->has_right_vertical_down() : this->has_right_vertical_up(); }
bool has_vertical() const { return this->has_left_vertical() || this->has_right_vertical(); }
bool has_vertical(Side side) const { return side == Side::Left ? this->has_left_vertical() : this->has_right_vertical(); }
bool has_vertical_up() const { return this->has_left_vertical_up() || this->has_right_vertical_up(); }
bool has_vertical_down() const { return this->has_left_vertical_down() || this->has_right_vertical_down(); }
bool has_vertical(Direction dir) const { return dir == Direction::Up ? this->has_vertical_up() : this->has_vertical_down(); }
int left_horizontal() const { return this->has_left_horizontal() ? this->prev_on_contour : -1; }
int right_horizontal() const { return this->has_right_horizontal() ? this->next_on_contour : -1; }
int horizontal(Side side) const { return side == Side::Left ? this->left_horizontal() : this->right_horizontal(); }
LinkQuality horizontal_quality(Side side) const {
assert(this->has_horizontal(side));
return side == Side::Left ? this->prev_on_contour_quality : this->next_on_contour_quality;
}
int left_vertical_up() const { return this->has_left_vertical_up() ? this->prev_on_contour : -1; }
int left_vertical_down() const { return this->has_left_vertical_down() ? this->prev_on_contour : -1; }
int left_vertical(Direction dir) const { return (dir == Direction::Up ? this->has_left_vertical_up() : this->has_left_vertical_down()) ? this->prev_on_contour : -1; }
int left_vertical() const { return this->has_left_vertical() ? this->prev_on_contour : -1; }
int left_vertical_outside() const { return this->is_low() ? this->left_vertical_down() : this->left_vertical_up(); }
int right_vertical_up() const { return this->has_right_vertical_up() ? this->next_on_contour : -1; }
int right_vertical_down() const { return this->has_right_vertical_down() ? this->next_on_contour : -1; }
int right_vertical(Direction dir) const { return (dir == Direction::Up ? this->has_right_vertical_up() : this->has_right_vertical_down()) ? this->next_on_contour : -1; }
int right_vertical() const { return this->has_right_vertical() ? this->next_on_contour : -1; }
int right_vertical_outside() const { return this->is_low() ? this->right_vertical_down() : this->right_vertical_up(); }
int vertical_up(Side side) const { return side == Side::Left ? this->left_vertical_up() : this->right_vertical_up(); }
int vertical_down(Side side) const { return side == Side::Left ? this->left_vertical_down() : this->right_vertical_down(); }
int vertical_outside(Side side) const { return side == Side::Left ? this->left_vertical_outside() : this->right_vertical_outside(); }
// Returns -1 if there is no link up.
int vertical_up() const {
return this->has_left_vertical_up() ? this->left_vertical_up() : this->right_vertical_up();
}
LinkQuality vertical_up_quality() const {
return this->has_left_vertical_up() ? this->prev_on_contour_quality : this->next_on_contour_quality;
}
// Returns -1 if there is no link down.
int vertical_down() const {
// assert(! this->has_left_vertical_down() || ! this->has_right_vertical_down());
return this->has_left_vertical_down() ? this->left_vertical_down() : this->right_vertical_down();
}
LinkQuality vertical_down_quality() const {
return this->has_left_vertical_down() ? this->prev_on_contour_quality : this->next_on_contour_quality;
}
int vertical_outside() const { return this->is_low() ? this->vertical_down() : this->vertical_up(); }
LinkQuality vertical_outside_quality() const { return this->is_low() ? this->vertical_down_quality() : this->vertical_up_quality(); }
// Compare two y intersection points given by rational numbers.
// Note that the rational number is given as pos_p/pos_q, where pos_p is int64 and pos_q is uint32.
// This function calculates pos_p * other.pos_q < other.pos_p * pos_q as a 48bit number.
// We don't use 128bit intrinsic data types as these are usually not supported by 32bit compilers and
// we don't need the full 128bit precision anyway.
bool operator<(const SegmentIntersection &other) const
{
assert(pos_q > 0);
assert(other.pos_q > 0);
if (pos_p == 0 || other.pos_p == 0) {
// Because the denominators are positive and one of the nominators is zero,
// following simple statement holds.
return pos_p < other.pos_p;
} else {
// None of the nominators is zero.
int sign1 = (pos_p > 0) ? 1 : -1;
int sign2 = (other.pos_p > 0) ? 1 : -1;
int signs = sign1 * sign2;
assert(signs == 1 || signs == -1);
if (signs < 0) {
// The nominators have different signs.
return sign1 < 0;
} else {
// The nominators have the same sign.
// Absolute values
uint64_t p1, p2;
if (sign1 > 0) {
p1 = uint64_t(pos_p);
p2 = uint64_t(other.pos_p);
} else {
p1 = uint64_t(- pos_p);
p2 = uint64_t(- other.pos_p);
};
// Multiply low and high 32bit words of p1 by other_pos.q
// 32bit x 32bit => 64bit
// l_hi and l_lo overlap by 32 bits.
uint64_t l_hi = (p1 >> 32) * uint64_t(other.pos_q);
uint64_t l_lo = (p1 & 0xffffffffll) * uint64_t(other.pos_q);
l_hi += (l_lo >> 32);
uint64_t r_hi = (p2 >> 32) * uint64_t(pos_q);
uint64_t r_lo = (p2 & 0xffffffffll) * uint64_t(pos_q);
r_hi += (r_lo >> 32);
// Compare the high 64 bits.
if (l_hi == r_hi) {
// Compare the low 32 bits.
l_lo &= 0xffffffffll;
r_lo &= 0xffffffffll;
return (sign1 < 0) ? (l_lo > r_lo) : (l_lo < r_lo);
}
return (sign1 < 0) ? (l_hi > r_hi) : (l_hi < r_hi);
}
}
}
bool operator==(const SegmentIntersection &other) const
{
assert(pos_q > 0);
assert(other.pos_q > 0);
if (pos_p == 0 || other.pos_p == 0) {
// Because the denominators are positive and one of the nominators is zero,
// following simple statement holds.
return pos_p == other.pos_p;
}
// None of the nominators is zero, none of the denominators is zero.
bool positive = pos_p > 0;
if (positive != (other.pos_p > 0))
return false;
// The nominators have the same sign.
// Absolute values
uint64_t p1 = positive ? uint64_t(pos_p) : uint64_t(- pos_p);
uint64_t p2 = positive ? uint64_t(other.pos_p) : uint64_t(- other.pos_p);
// Multiply low and high 32bit words of p1 by other_pos.q
// 32bit x 32bit => 64bit
// l_hi and l_lo overlap by 32 bits.
uint64_t l_lo = (p1 & 0xffffffffll) * uint64_t(other.pos_q);
uint64_t r_lo = (p2 & 0xffffffffll) * uint64_t(pos_q);
if (l_lo != r_lo)
return false;
uint64_t l_hi = (p1 >> 32) * uint64_t(other.pos_q);
uint64_t r_hi = (p2 >> 32) * uint64_t(pos_q);
return l_hi + (l_lo >> 32) == r_hi + (r_lo >> 32);
}
};
static_assert(sizeof(SegmentIntersection::pos_q) == 4, "SegmentIntersection::pos_q has to be 32bit long!");
// A vertical line with intersection points with polygons.
struct SegmentedIntersectionLine
{
// Index of this vertical intersection line.
size_t idx;
// x position of this vertical intersection line.
coord_t pos;
// List of intersection points with polygons, sorted increasingly by the y axis.
std::vector<SegmentIntersection> intersections;
};
static SegmentIntersection phony_outer_intersection(SegmentIntersection::SegmentIntersectionType type, coord_t pos)
{
assert(type == SegmentIntersection::OUTER_LOW || type == SegmentIntersection::OUTER_HIGH);
SegmentIntersection out;
// Invalid contour & segment.
out.iContour = std::numeric_limits<size_t>::max();
out.iSegment = std::numeric_limits<size_t>::max();
out.pos_p = pos;
out.type = type;
// Invalid prev / next.
out.prev_on_contour = -1;
out.next_on_contour = -1;
out.prev_on_contour_type = SegmentIntersection::LinkType::Phony;
out.next_on_contour_type = SegmentIntersection::LinkType::Phony;
out.prev_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
out.next_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
return out;
}
// A container maintaining an expolygon with its inner offsetted polygon.
// The purpose of the inner offsetted polygon is to provide segments to connect the infill lines.
struct ExPolygonWithOffset
{
public:
ExPolygonWithOffset(
const ExPolygon &expolygon,
float angle,
coord_t aoffset1,
// If the 2nd offset is zero, then it is ignored and only OUTER_LOW / OUTER_HIGH intersections are
// populated into vertical intersection lines.
coord_t aoffset2 = 0)
{
// Copy and rotate the source polygons.
polygons_src = expolygon;
if (angle != 0.f) {
polygons_src.contour.rotate(angle);
for (Polygon &hole : polygons_src.holes)
hole.rotate(angle);
}
double mitterLimit = 3.;
// for the infill pattern, don't cut the corners.
// default miterLimt = 3
//double mitterLimit = 10.;
assert(aoffset1 < 0);
assert(aoffset2 <= 0);
assert(aoffset2 == 0 || aoffset2 < aoffset1);
// bool sticks_removed =
remove_sticks(polygons_src);
// if (sticks_removed) BOOST_LOG_TRIVIAL(error) << "Sticks removed!";
polygons_outer = offset(polygons_src, float(aoffset1), ClipperLib::jtMiter, mitterLimit);
if (aoffset2 < 0)
polygons_inner = offset(polygons_outer, float(aoffset2 - aoffset1), ClipperLib::jtMiter, mitterLimit);
// Filter out contours with zero area or small area, contours with 2 points only.
const double min_area_threshold = 0.01 * aoffset2 * aoffset2;
remove_small(polygons_outer, min_area_threshold);
remove_small(polygons_inner, min_area_threshold);
remove_sticks(polygons_outer);
remove_sticks(polygons_inner);
n_contours_outer = polygons_outer.size();
n_contours_inner = polygons_inner.size();
n_contours = n_contours_outer + n_contours_inner;
polygons_ccw.assign(n_contours, false);
for (size_t i = 0; i < n_contours; ++ i) {
contour(i).remove_duplicate_points();
assert(! contour(i).has_duplicate_points());
polygons_ccw[i] = Slic3r::Geometry::is_ccw(contour(i));
}
}
ExPolygonWithOffset(const ExPolygonWithOffset &rhs, float angle) : ExPolygonWithOffset(rhs) {
if (angle != 0.f) {
this->polygons_src.contour.rotate(angle);
for (Polygon &hole : this->polygons_src.holes)
hole.rotate(angle);
for (Polygon &poly : this->polygons_outer)
poly.rotate(angle);
for (Polygon &poly : this->polygons_inner)
poly.rotate(angle);
}
}
// Any contour with offset1
bool is_contour_outer(size_t idx) const { return idx < n_contours_outer; }
// Any contour with offset2
bool is_contour_inner(size_t idx) const { return idx >= n_contours_outer; }
const Polygon& contour(size_t idx) const
{ return is_contour_outer(idx) ? polygons_outer[idx] : polygons_inner[idx - n_contours_outer]; }
Polygon& contour(size_t idx)
{ return is_contour_outer(idx) ? polygons_outer[idx] : polygons_inner[idx - n_contours_outer]; }
bool is_contour_ccw(size_t idx) const { return polygons_ccw[idx]; }
BoundingBox bounding_box_src() const
{ return get_extents(polygons_src); }
BoundingBox bounding_box_outer() const
{ return get_extents(polygons_outer); }
BoundingBox bounding_box_inner() const
{ return get_extents(polygons_inner); }
#ifdef SLIC3R_DEBUG
void export_to_svg(Slic3r::SVG &svg) {
svg.draw_outline(polygons_src, "black");
svg.draw_outline(polygons_outer, "green");
svg.draw_outline(polygons_inner, "brown");
}
#endif /* SLIC3R_DEBUG */
ExPolygon polygons_src;
Polygons polygons_outer;
Polygons polygons_inner;
size_t n_contours_outer;
size_t n_contours_inner;
size_t n_contours;
protected:
// For each polygon of polygons_inner, remember its orientation.
std::vector<unsigned char> polygons_ccw;
};
static inline int distance_of_segmens(const Polygon &poly, size_t seg1, size_t seg2, bool forward)
{
int d = int(seg2) - int(seg1);
if (! forward)
d = - d;
if (d < 0)
d += int(poly.points.size());
return d;
}
// Find an intersection on a previous line, but return -1, if the connecting segment of a perimeter was already extruded.
static inline bool intersection_on_prev_next_vertical_line_valid(
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iIntersection,
SegmentIntersection::Side side)
{
const SegmentedIntersectionLine &vline_this = segs[iVerticalLine];
const SegmentIntersection &it_this = vline_this.intersections[iIntersection];
if (it_this.has_vertical(side))
// Not the first intersection along the contor. This intersection point
// has been preceded by an intersection point along the vertical line.
return false;
int iIntersectionOther = it_this.horizontal(side);
if (iIntersectionOther == -1)
return false;
assert(side == SegmentIntersection::Side::Right ? (iVerticalLine + 1 < segs.size()) : (iVerticalLine > 0));
const SegmentedIntersectionLine &vline_other = segs[side == SegmentIntersection::Side::Right ? (iVerticalLine + 1) : (iVerticalLine - 1)];
const SegmentIntersection &it_other = vline_other.intersections[iIntersectionOther];
assert(it_other.is_inner());
assert(iIntersectionOther > 0);
assert(iIntersectionOther + 1 < vline_other.intersections.size());
// Is iIntersectionOther at the boundary of a vertical segment?
const SegmentIntersection &it_other2 = vline_other.intersections[it_other.is_low() ? iIntersectionOther - 1 : iIntersectionOther + 1];
if (it_other2.is_inner())
// Cannot follow a perimeter segment into the middle of another vertical segment.
// Only perimeter segments connecting to the end of a vertical segment are followed.
return false;
assert(it_other.is_low() == it_other2.is_low());
if (it_this.horizontal_quality(side) != SegmentIntersection::LinkQuality::Valid)
return false;
if (side == SegmentIntersection::Side::Right ? it_this.consumed_perimeter_right : it_other.consumed_perimeter_right)
// This perimeter segment was already consumed.
return false;
if (it_other.is_low() ? it_other.consumed_vertical_up : vline_other.intersections[iIntersectionOther - 1].consumed_vertical_up)
// This vertical segment was already consumed.
return false;
#if 0
if (it_other.vertical_outside() != -1 && it_other.vertical_outside_quality() == SegmentIntersection::LinkQuality::Valid)
// Landed inside a vertical run. Stop here.
return false;
#endif
return true;
}
static inline bool intersection_on_prev_vertical_line_valid(
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iIntersection)
{
return intersection_on_prev_next_vertical_line_valid(segs, iVerticalLine, iIntersection, SegmentIntersection::Side::Left);
}
static inline bool intersection_on_next_vertical_line_valid(
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iIntersection)
{
return intersection_on_prev_next_vertical_line_valid(segs, iVerticalLine, iIntersection, SegmentIntersection::Side::Right);
}
// Measure an Euclidian length of a perimeter segment when going from iIntersection to iIntersection2.
static inline coordf_t measure_perimeter_horizontal_segment_length(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iIntersection,
size_t iIntersection2)
{
size_t iVerticalLineOther = iVerticalLine + 1;
assert(iVerticalLineOther < segs.size());
const SegmentedIntersectionLine &vline = segs[iVerticalLine];
const SegmentIntersection &it = vline.intersections[iIntersection];
const SegmentedIntersectionLine &vline2 = segs[iVerticalLineOther];
const SegmentIntersection &it2 = vline2.intersections[iIntersection2];
assert(it.iContour == it2.iContour);
const Polygon &poly = poly_with_offset.contour(it.iContour);
// const bool ccw = poly_with_offset.is_contour_ccw(vline.iContour);
assert(it.type == it2.type);
assert(it.iContour == it2.iContour);
Point p1(vline.pos, it.pos());
Point p2(vline2.pos, it2.pos());
return it.is_low() ?
segment_length(poly, it .iSegment, p1, it2.iSegment, p2) :
segment_length(poly, it2.iSegment, p2, it .iSegment, p1);
}
// Append the points of a perimeter segment when going from iIntersection to iIntersection2.
// The first point (the point of iIntersection) will not be inserted,
// the last point will be inserted.
static inline void emit_perimeter_prev_next_segment(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iInnerContour,
size_t iIntersection,
size_t iIntersection2,
Polyline &out,
bool dir_is_next)
{
size_t iVerticalLineOther = iVerticalLine;
if (dir_is_next) {
++ iVerticalLineOther;
assert(iVerticalLineOther < segs.size());
} else {
assert(iVerticalLineOther > 0);
-- iVerticalLineOther;
}
const SegmentedIntersectionLine &il = segs[iVerticalLine];
const SegmentIntersection &itsct = il.intersections[iIntersection];
const SegmentedIntersectionLine &il2 = segs[iVerticalLineOther];
const SegmentIntersection &itsct2 = il2.intersections[iIntersection2];
const Polygon &poly = poly_with_offset.contour(iInnerContour);
// const bool ccw = poly_with_offset.is_contour_ccw(iInnerContour);
assert(itsct.type == itsct2.type);
assert(itsct.iContour == itsct2.iContour);
assert(itsct.is_inner());
const bool forward = itsct.is_low() == dir_is_next;
// Do not append the first point.
// out.points.push_back(Point(il.pos, itsct.pos));
if (forward)
polygon_segment_append(out.points, poly, itsct.iSegment, itsct2.iSegment);
else
polygon_segment_append_reversed(out.points, poly, itsct.iSegment, itsct2.iSegment);
// Append the last point.
out.points.push_back(Point(il2.pos, itsct2.pos()));
}
static inline coordf_t measure_perimeter_segment_on_vertical_line_length(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iIntersection,
size_t iIntersection2,
bool forward)
{
const SegmentedIntersectionLine &il = segs[iVerticalLine];
const SegmentIntersection &itsct = il.intersections[iIntersection];
const SegmentIntersection &itsct2 = il.intersections[iIntersection2];
const Polygon &poly = poly_with_offset.contour(itsct.iContour);
assert(itsct.is_inner() == itsct2.is_inner());
assert(itsct.type != itsct2.type);
assert(itsct.iContour == itsct2.iContour);
Point p1(il.pos, itsct.pos());
Point p2(il.pos, itsct2.pos());
return forward ?
segment_length(poly, itsct .iSegment, p1, itsct2.iSegment, p2) :
segment_length(poly, itsct2.iSegment, p2, itsct .iSegment, p1);
}
// Append the points of a perimeter segment when going from iIntersection to iIntersection2.
// The first point (the point of iIntersection) will not be inserted,
// the last point will be inserted.
static inline void emit_perimeter_segment_on_vertical_line(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
size_t iVerticalLine,
size_t iInnerContour,
size_t iIntersection,
size_t iIntersection2,
Polyline &out,
bool forward)
{
const SegmentedIntersectionLine &il = segs[iVerticalLine];
const SegmentIntersection &itsct = il.intersections[iIntersection];
const SegmentIntersection &itsct2 = il.intersections[iIntersection2];
const Polygon &poly = poly_with_offset.contour(iInnerContour);
assert(itsct.is_inner());
assert(itsct2.is_inner());
assert(itsct.type != itsct2.type);
assert(itsct.iContour == iInnerContour);
assert(itsct.iContour == itsct2.iContour);
// Do not append the first point.
// out.points.push_back(Point(il.pos, itsct.pos));
if (forward)
polygon_segment_append(out.points, poly, itsct.iSegment, itsct2.iSegment);
else
polygon_segment_append_reversed(out.points, poly, itsct.iSegment, itsct2.iSegment);
// Append the last point.
out.points.push_back(Point(il.pos, itsct2.pos()));
}
//TBD: For precise infill, measure the area of a slab spanned by an infill line.
/*
static inline float measure_outer_contour_slab(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
size_t i_vline,
size_t iIntersection)
{
const SegmentedIntersectionLine &il = segs[i_vline];
const SegmentIntersection &itsct = il.intersections[i_vline];
const SegmentIntersection &itsct2 = il.intersections[iIntersection2];
const Polygon &poly = poly_with_offset.contour((itsct.iContour);
assert(itsct.is_outer());
assert(itsct2.is_outer());
assert(itsct.type != itsct2.type);
assert(itsct.iContour == itsct2.iContour);
if (! itsct.is_outer() || ! itsct2.is_outer() || itsct.type == itsct2.type || itsct.iContour != itsct2.iContour)
// Error, return zero area.
return 0.f;
// Find possible connection points on the previous / next vertical line.
int iPrev = intersection_on_prev_vertical_line(poly_with_offset, segs, i_vline, itsct.iContour, i_intersection);
int iNext = intersection_on_next_vertical_line(poly_with_offset, segs, i_vline, itsct.iContour, i_intersection);
// Find possible connection points on the same vertical line.
int iAbove = iBelow = -1;
// Does the perimeter intersect the current vertical line above intrsctn?
for (size_t i = i_intersection + 1; i + 1 < seg.intersections.size(); ++ i)
if (seg.intersections[i].iContour == itsct.iContour)
{ iAbove = i; break; }
// Does the perimeter intersect the current vertical line below intrsctn?
for (int i = int(i_intersection) - 1; i > 0; -- i)
if (seg.intersections[i].iContour == itsct.iContour)
{ iBelow = i; break; }
if (iSegAbove != -1 && seg.intersections[iAbove].type == SegmentIntersection::OUTER_HIGH) {
// Invalidate iPrev resp. iNext, if the perimeter crosses the current vertical line earlier than iPrev resp. iNext.
// The perimeter contour orientation.
const Polygon &poly = poly_with_offset.contour(itsct.iContour);
{
int d_horiz = (iPrev == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, segs[i_vline-1].intersections[iPrev].iSegment, itsct.iSegment, true);
int d_down = (iBelow == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, iSegBelow, itsct.iSegment, true);
int d_up = (iAbove == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, iSegAbove, itsct.iSegment, true);
if (intrsection_type_prev == INTERSECTION_TYPE_OTHER_VLINE_OK && d_horiz > std::min(d_down, d_up))
// The vertical crossing comes eralier than the prev crossing.
// Disable the perimeter going back.
intrsection_type_prev = INTERSECTION_TYPE_OTHER_VLINE_NOT_FIRST;
if (d_up > std::min(d_horiz, d_down))
// The horizontal crossing comes earlier than the vertical crossing.
vert_seg_dir_valid_mask &= ~DIR_BACKWARD;
}
{
int d_horiz = (iNext == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, itsct.iSegment, segs[i_vline+1].intersections[iNext].iSegment, true);
int d_down = (iSegBelow == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, itsct.iSegment, iSegBelow, true);
int d_up = (iSegAbove == -1) ? std::numeric_limits<int>::max() :
distance_of_segmens(poly, itsct.iSegment, iSegAbove, true);
if (d_up > std::min(d_horiz, d_down))
// The horizontal crossing comes earlier than the vertical crossing.
vert_seg_dir_valid_mask &= ~DIR_FORWARD;
}
}
}
*/
enum DirectionMask
{
DIR_FORWARD = 1,
DIR_BACKWARD = 2
};
static std::vector<SegmentedIntersectionLine> slice_region_by_vertical_lines(const ExPolygonWithOffset &poly_with_offset, size_t n_vlines, coord_t x0, coord_t line_spacing)
{
// Allocate storage for the segments.
std::vector<SegmentedIntersectionLine> segs(n_vlines, SegmentedIntersectionLine());
for (coord_t i = 0; i < coord_t(n_vlines); ++ i) {
segs[i].idx = i;
segs[i].pos = x0 + i * line_spacing;
}
// For each contour
for (size_t iContour = 0; iContour < poly_with_offset.n_contours; ++ iContour) {
const Points &contour = poly_with_offset.contour(iContour).points;
if (contour.size() < 2)
continue;
// For each segment
for (size_t iSegment = 0; iSegment < contour.size(); ++ iSegment) {
size_t iPrev = ((iSegment == 0) ? contour.size() : iSegment) - 1;
const Point &p1 = contour[iPrev];
const Point &p2 = contour[iSegment];
// Which of the equally spaced vertical lines is intersected by this segment?
coord_t l = p1(0);
coord_t r = p2(0);
if (l > r)
std::swap(l, r);
// il, ir are the left / right indices of vertical lines intersecting a segment
int il = (l - x0) / line_spacing;
while (il * line_spacing + x0 < l)
++ il;
il = std::max(int(0), il);
int ir = (r - x0 + line_spacing) / line_spacing;
while (ir * line_spacing + x0 > r)
-- ir;
ir = std::min(int(segs.size()) - 1, ir);
if (il > ir)
// No vertical line intersects this segment.
continue;
assert(il >= 0 && size_t(il) < segs.size());
assert(ir >= 0 && size_t(ir) < segs.size());
for (int i = il; i <= ir; ++ i) {
coord_t this_x = segs[i].pos;
assert(this_x == i * line_spacing + x0);
SegmentIntersection is;
is.iContour = iContour;
is.iSegment = iSegment;
assert(l <= this_x);
assert(r >= this_x);
// Calculate the intersection position in y axis. x is known.
if (p1(0) == this_x) {
if (p2(0) == this_x) {
// Ignore strictly vertical segments.
continue;
}
is.pos_p = p1(1);
is.pos_q = 1;
} else if (p2(0) == this_x) {
is.pos_p = p2(1);
is.pos_q = 1;
} else {
// First calculate the intersection parameter 't' as a rational number with non negative denominator.
if (p2(0) > p1(0)) {
is.pos_p = this_x - p1(0);
is.pos_q = p2(0) - p1(0);
} else {
is.pos_p = p1(0) - this_x;
is.pos_q = p1(0) - p2(0);
}
assert(is.pos_p >= 0 && is.pos_p <= is.pos_q);
// Make an intersection point from the 't'.
is.pos_p *= int64_t(p2(1) - p1(1));
is.pos_p += p1(1) * int64_t(is.pos_q);
}
// +-1 to take rounding into account.
assert(is.pos() + 1 >= std::min(p1(1), p2(1)));
assert(is.pos() <= std::max(p1(1), p2(1)) + 1);
segs[i].intersections.push_back(is);
}
}
}
// Sort the intersections along their segments, specify the intersection types.
for (size_t i_seg = 0; i_seg < segs.size(); ++ i_seg) {
SegmentedIntersectionLine &sil = segs[i_seg];
// Sort the intersection points using exact rational arithmetic.
std::sort(sil.intersections.begin(), sil.intersections.end());
// Assign the intersection types, remove duplicate or overlapping intersection points.
// When a loop vertex touches a vertical line, intersection point is generated for both segments.
// If such two segments are oriented equally, then one of them is removed.
// Otherwise the vertex is tangential to the vertical line and both segments are removed.
// The same rule applies, if the loop is pinched into a single point and this point touches the vertical line:
// The loop has a zero vertical size at the vertical line, therefore the intersection point is removed.
size_t j = 0;
for (size_t i = 0; i < sil.intersections.size(); ++ i) {
// What is the orientation of the segment at the intersection point?
size_t iContour = sil.intersections[i].iContour;
const Points &contour = poly_with_offset.contour(iContour).points;
size_t iSegment = sil.intersections[i].iSegment;
size_t iPrev = ((iSegment == 0) ? contour.size() : iSegment) - 1;
coord_t dir = contour[iSegment](0) - contour[iPrev](0);
bool low = dir > 0;
sil.intersections[i].type = poly_with_offset.is_contour_outer(iContour) ?
(low ? SegmentIntersection::OUTER_LOW : SegmentIntersection::OUTER_HIGH) :
(low ? SegmentIntersection::INNER_LOW : SegmentIntersection::INNER_HIGH);
if (j > 0 && sil.intersections[i].iContour == sil.intersections[j-1].iContour) {
// Two successive intersection points on a vertical line with the same contour. This may be a special case.
if (sil.intersections[i].pos() == sil.intersections[j-1].pos()) {
// Two successive segments meet exactly at the vertical line.
#ifdef SLIC3R_DEBUG
// Verify that the segments of sil.intersections[i] and sil.intersections[j-1] are adjoint.
size_t iSegment2 = sil.intersections[j-1].iSegment;
size_t iPrev2 = ((iSegment2 == 0) ? contour.size() : iSegment2) - 1;
assert(iSegment == iPrev2 || iSegment2 == iPrev);
#endif /* SLIC3R_DEBUG */
if (sil.intersections[i].type == sil.intersections[j-1].type) {
// Two successive segments of the same direction (both to the right or both to the left)
// meet exactly at the vertical line.
// Remove the second intersection point.
} else {
// This is a loop returning to the same point.
// It may as well be a vertex of a loop touching this vertical line.
// Remove both the lines.
-- j;
}
} else if (sil.intersections[i].type == sil.intersections[j-1].type) {
// Two non successive segments of the same direction (both to the right or both to the left)
// meet exactly at the vertical line. That means there is a Z shaped path, where the center segment
// of the Z shaped path is aligned with this vertical line.
// Remove one of the intersection points while maximizing the vertical segment length.
if (low) {
// Remove the second intersection point, keep the first intersection point.
} else {
// Remove the first intersection point, keep the second intersection point.
sil.intersections[j-1] = sil.intersections[i];
}
} else {
// Vertical line intersects a contour segment at a general position (not at one of its end points).
// or the contour just touches this vertical line with a vertical segment or a sequence of vertical segments.
// Keep both intersection points.
if (j < i)
sil.intersections[j] = sil.intersections[i];
++ j;
}
} else {
// Vertical line intersects a contour segment at a general position (not at one of its end points).
if (j < i)
sil.intersections[j] = sil.intersections[i];
++ j;
}
}
// Shrink the list of intersections, if any of the intersection was removed during the classification.
if (j < sil.intersections.size())
sil.intersections.erase(sil.intersections.begin() + j, sil.intersections.end());
}
// Verify the segments. If something is wrong, give up.
#define ASSERT_THROW(CONDITION) do { assert(CONDITION); if (! (CONDITION)) throw InfillFailedException(); } while (0)
for (size_t i_seg = 0; i_seg < segs.size(); ++ i_seg) {
SegmentedIntersectionLine &sil = segs[i_seg];
// The intersection points have to be even.
ASSERT_THROW((sil.intersections.size() & 1) == 0);
for (size_t i = 0; i < sil.intersections.size();) {
// An intersection segment crossing the bigger contour may cross the inner offsetted contour even number of times.
ASSERT_THROW(sil.intersections[i].type == SegmentIntersection::OUTER_LOW);
size_t j = i + 1;
ASSERT_THROW(j < sil.intersections.size());
ASSERT_THROW(sil.intersections[j].type == SegmentIntersection::INNER_LOW || sil.intersections[j].type == SegmentIntersection::OUTER_HIGH);
for (; j < sil.intersections.size() && sil.intersections[j].is_inner(); ++ j) ;
ASSERT_THROW(j < sil.intersections.size());
ASSERT_THROW((j & 1) == 1);
ASSERT_THROW(sil.intersections[j].type == SegmentIntersection::OUTER_HIGH);
ASSERT_THROW(i + 1 == j || sil.intersections[j - 1].type == SegmentIntersection::INNER_HIGH);
i = j + 1;
}
}
#undef ASSERT_THROW
return segs;
}
#ifndef NDEBUG
bool validate_segment_intersection_connectivity(const std::vector<SegmentedIntersectionLine> &segs)
{
// Validate the connectivity.
for (size_t i_vline = 0; i_vline + 1 < segs.size(); ++ i_vline) {
const SegmentedIntersectionLine &il_left = segs[i_vline];
const SegmentedIntersectionLine &il_right = segs[i_vline + 1];
for (const SegmentIntersection &it : il_left.intersections) {
if (it.has_right_horizontal()) {
const SegmentIntersection &it_right = il_right.intersections[it.right_horizontal()];
// For a right link there is a symmetric left link.
assert(it.iContour == it_right.iContour);
assert(it.type == it_right.type);
assert(it_right.has_left_horizontal());
assert(it_right.left_horizontal() == int(&it - il_left.intersections.data()));
}
}
for (const SegmentIntersection &it : il_right.intersections) {
if (it.has_left_horizontal()) {
const SegmentIntersection &it_left = il_left.intersections[it.left_horizontal()];
// For a right link there is a symmetric left link.
assert(it.iContour == it_left.iContour);
assert(it.type == it_left.type);
assert(it_left.has_right_horizontal());
assert(it_left.right_horizontal() == int(&it - il_right.intersections.data()));
}
}
}
for (size_t i_vline = 0; i_vline < segs.size(); ++ i_vline) {
const SegmentedIntersectionLine &il = segs[i_vline];
for (const SegmentIntersection &it : il.intersections) {
auto i_it = int(&it - il.intersections.data());
if (it.has_left_vertical_up()) {
assert(il.intersections[it.left_vertical_up()].left_vertical_down() == i_it);
assert(il.intersections[it.left_vertical_up()].prev_on_contour_quality == it.prev_on_contour_quality);
}
if (it.has_left_vertical_down()) {
assert(il.intersections[it.left_vertical_down()].left_vertical_up() == i_it);
assert(il.intersections[it.left_vertical_down()].prev_on_contour_quality == it.prev_on_contour_quality);
}
if (it.has_right_vertical_up()) {
assert(il.intersections[it.right_vertical_up()].right_vertical_down() == i_it);
assert(il.intersections[it.right_vertical_up()].next_on_contour_quality == it.next_on_contour_quality);
}
if (it.has_right_vertical_down()) {
assert(il.intersections[it.right_vertical_down()].right_vertical_up() == i_it);
assert(il.intersections[it.right_vertical_down()].next_on_contour_quality == it.next_on_contour_quality);
}
}
}
return true;
}
#endif /* NDEBUG */
// Connect each contour / vertical line intersection point with another two contour / vertical line intersection points.
// (fill in SegmentIntersection::{prev_on_contour, prev_on_contour_vertical, next_on_contour, next_on_contour_vertical}.
// These contour points are either on the same vertical line, or on the vertical line left / right to the current one.
static void connect_segment_intersections_by_contours(
const ExPolygonWithOffset &poly_with_offset, std::vector<SegmentedIntersectionLine> &segs,
const FillParams &params, const coord_t link_max_length)
{
for (size_t i_vline = 0; i_vline < segs.size(); ++ i_vline) {
SegmentedIntersectionLine &il = segs[i_vline];
const SegmentedIntersectionLine *il_prev = i_vline > 0 ? &segs[i_vline - 1] : nullptr;
const SegmentedIntersectionLine *il_next = i_vline + 1 < segs.size() ? &segs[i_vline + 1] : nullptr;
for (int i_intersection = 0; i_intersection < int(il.intersections.size()); ++ i_intersection) {
SegmentIntersection &itsct = il.intersections[i_intersection];
const Polygon &poly = poly_with_offset.contour(itsct.iContour);
const bool forward = itsct.is_low(); // == poly_with_offset.is_contour_ccw(intrsctn->iContour);
// 1) Find possible connection points on the previous / next vertical line.
// Find an intersection point on il_prev, intersecting i_intersection
// at the same orientation as i_intersection, and being closest to i_intersection
// in the number of contour segments, when following the direction of the contour.
//FIXME this has O(n) time complexity. Likely an O(log(n)) scheme is possible.
int iprev = -1;
int d_prev = std::numeric_limits<int>::max();
if (il_prev) {
for (int i = 0; i < int(il_prev->intersections.size()); ++ i) {
const SegmentIntersection &itsct2 = il_prev->intersections[i];
if (itsct.iContour == itsct2.iContour && itsct.type == itsct2.type) {
// The intersection points lie on the same contour and have the same orientation.
// Find the intersection point with a shortest path in the direction of the contour.
int d = distance_of_segmens(poly, itsct2.iSegment, itsct.iSegment, forward);
if (d < d_prev) {
iprev = i;
d_prev = d;
}
}
}
}
// The same for il_next.
int inext = -1;
int d_next = std::numeric_limits<int>::max();
if (il_next) {
for (int i = 0; i < int(il_next->intersections.size()); ++ i) {
const SegmentIntersection &itsct2 = il_next->intersections[i];
if (itsct.iContour == itsct2.iContour && itsct.type == itsct2.type) {
// The intersection points lie on the same contour and have the same orientation.
// Find the intersection point with a shortest path in the direction of the contour.
int d = distance_of_segmens(poly, itsct.iSegment, itsct2.iSegment, forward);
if (d < d_next) {
inext = i;
d_next = d;
}
}
}
}
// 2) Find possible connection points on the same vertical line.
bool same_prev = false;
bool same_next = false;
// Does the perimeter intersect the current vertical line above intrsctn?
for (int i = 0; i < int(il.intersections.size()); ++ i)
if (const SegmentIntersection &it2 = il.intersections[i];
i != i_intersection && it2.iContour == itsct.iContour && it2.type != itsct.type) {
int d = distance_of_segmens(poly, it2.iSegment, itsct.iSegment, forward);
if (d < d_prev) {
iprev = i;
d_prev = d;
same_prev = true;
}
d = distance_of_segmens(poly, itsct.iSegment, it2.iSegment, forward);
if (d < d_next) {
inext = i;
d_next = d;
same_next = true;
}
}
assert(iprev >= 0);
assert(inext >= 0);
itsct.prev_on_contour = iprev;
itsct.prev_on_contour_type = same_prev ?
(iprev < i_intersection ? SegmentIntersection::LinkType::Down : SegmentIntersection::LinkType::Up) :
SegmentIntersection::LinkType::Horizontal;
itsct.next_on_contour = inext;
itsct.next_on_contour_type = same_next ?
(inext < i_intersection ? SegmentIntersection::LinkType::Down : SegmentIntersection::LinkType::Up) :
SegmentIntersection::LinkType::Horizontal;
if (same_prev) {
// Only follow a vertical perimeter segment if it skips just the outer intersections.
SegmentIntersection *it = &itsct;
SegmentIntersection *end = il.intersections.data() + iprev;
assert(it != end);
if (it > end)
std::swap(it, end);
for (++ it; it != end; ++ it)
if (it->is_inner()) {
itsct.prev_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
break;
}
}
if (same_next) {
// Only follow a vertical perimeter segment if it skips just the outer intersections.
SegmentIntersection *it = &itsct;
SegmentIntersection *end = il.intersections.data() + inext;
assert(it != end);
if (it > end)
std::swap(it, end);
for (++ it; it != end; ++ it)
if (it->is_inner()) {
itsct.next_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
break;
}
}
// If both iprev and inext are on this vline, then there must not be any intersection with the previous or next contour and we will
// not trace this contour when generating infill.
if (same_prev && same_next) {
assert(iprev != i_intersection);
assert(inext != i_intersection);
if ((iprev > i_intersection) == (inext > i_intersection)) {
// Both closest intersections of this contour are on the same vertical line and at the same side of this point.
// Ignore them when tracing the infill.
itsct.prev_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
itsct.next_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
}
}
if (params.dont_connect()) {
if (itsct.prev_on_contour_quality == SegmentIntersection::LinkQuality::Valid)
itsct.prev_on_contour_quality = SegmentIntersection::LinkQuality::TooLong;
if (itsct.next_on_contour_quality == SegmentIntersection::LinkQuality::Valid)
itsct.next_on_contour_quality = SegmentIntersection::LinkQuality::TooLong;
} else if (link_max_length > 0) {
// Measure length of the links.
if (itsct.prev_on_contour_quality == SegmentIntersection::LinkQuality::Valid &&
(same_prev ?
measure_perimeter_segment_on_vertical_line_length(poly_with_offset, segs, i_vline, iprev, i_intersection, forward) :
measure_perimeter_horizontal_segment_length(poly_with_offset, segs, i_vline - 1, iprev, i_intersection)) > link_max_length)
itsct.prev_on_contour_quality = SegmentIntersection::LinkQuality::TooLong;
if (itsct.next_on_contour_quality == SegmentIntersection::LinkQuality::Valid &&
(same_next ?
measure_perimeter_segment_on_vertical_line_length(poly_with_offset, segs, i_vline, i_intersection, inext, forward) :
measure_perimeter_horizontal_segment_length(poly_with_offset, segs, i_vline, i_intersection, inext)) > link_max_length)
itsct.next_on_contour_quality = SegmentIntersection::LinkQuality::TooLong;
}
}
// Make the LinkQuality::Invalid symmetric on vertical connections.
for (int i_intersection = 0; i_intersection < int(il.intersections.size()); ++ i_intersection) {
SegmentIntersection &it = il.intersections[i_intersection];
if (it.has_left_vertical() && it.prev_on_contour_quality == SegmentIntersection::LinkQuality::Invalid) {
SegmentIntersection &it2 = il.intersections[it.left_vertical()];
assert(it2.left_vertical() == i_intersection);
it2.prev_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
}
if (it.has_right_vertical() && it.next_on_contour_quality == SegmentIntersection::LinkQuality::Invalid) {
SegmentIntersection &it2 = il.intersections[it.right_vertical()];
assert(it2.right_vertical() == i_intersection);
it2.next_on_contour_quality = SegmentIntersection::LinkQuality::Invalid;
}
}
}
assert(validate_segment_intersection_connectivity(segs));
}
static void pinch_contours_insert_phony_outer_intersections(std::vector<SegmentedIntersectionLine> &segs)
{
// Keep the vector outside the loops, so they will not be reallocated.
// Where to insert new outer points.
std::vector<size_t> insert_after;
// Mapping of indices of current intersection line after inserting new outer points.
std::vector<int32_t> map;
std::vector<SegmentIntersection> temp_intersections;
for (size_t i_vline = 1; i_vline < segs.size(); ++ i_vline) {
SegmentedIntersectionLine &il = segs[i_vline];
assert(il.intersections.empty() || il.intersections.size() >= 2);
if (! il.intersections.empty()) {
assert(il.intersections.front().type == SegmentIntersection::OUTER_LOW);
assert(il.intersections.back().type == SegmentIntersection::OUTER_HIGH);
auto end = il.intersections.end() - 1;
insert_after.clear();
for (auto it = il.intersections.begin() + 1; it != end;) {
if (it->type == SegmentIntersection::OUTER_HIGH) {
++ it;
assert(it->type == SegmentIntersection::OUTER_LOW);
++ it;
} else {
auto lo = it;
assert(lo->type == SegmentIntersection::INNER_LOW);
auto hi = ++ it;
assert(hi->type == SegmentIntersection::INNER_HIGH);
auto lo2 = ++ it;
if (lo2->type == SegmentIntersection::INNER_LOW) {
// INNER_HIGH followed by INNER_LOW. The outer contour may have squeezed the inner contour into two separate loops.
// In that case one shall insert a phony OUTER_HIGH / OUTER_LOW pair.
int up = hi->vertical_up();
int dn = lo2->vertical_down();
#ifndef _NDEBUG
assert(up == -1 || up > 0);
assert(dn == -1 || dn >= 0);
assert((up == -1 && dn == -1) || (dn + 1 == up));
#endif // _NDEBUG
bool pinched = dn + 1 != up;
if (pinched) {
// hi is not connected with its inner contour to lo2.
// Insert a phony OUTER_HIGH / OUTER_LOW pair.
#if 0
static int pinch_idx = 0;
printf("Pinched %d\n", pinch_idx++);
#endif
insert_after.emplace_back(hi - il.intersections.begin());
}
}
}
}
if (! insert_after.empty()) {
// Insert phony OUTER_HIGH / OUTER_LOW pairs, adjust indices pointing to intersection points on this contour.
map.clear();
{
size_t i = 0;
temp_intersections.clear();
for (size_t idx_inset_after : insert_after) {
for (; i <= idx_inset_after; ++ i) {
map.emplace_back(temp_intersections.size());
temp_intersections.emplace_back(il.intersections[i]);
}
coord_t pos = (temp_intersections.back().pos() + il.intersections[i].pos()) / 2;
temp_intersections.emplace_back(phony_outer_intersection(SegmentIntersection::OUTER_HIGH, pos));
temp_intersections.emplace_back(phony_outer_intersection(SegmentIntersection::OUTER_LOW, pos));
}
for (; i < il.intersections.size(); ++ i) {
map.emplace_back(temp_intersections.size());
temp_intersections.emplace_back(il.intersections[i]);
}
temp_intersections.swap(il.intersections);
}
// Reindex references on current intersection line.
for (SegmentIntersection &ip : il.intersections) {
if (ip.has_left_vertical())
ip.prev_on_contour = map[ip.prev_on_contour];
if (ip.has_right_vertical())
ip.next_on_contour = map[ip.next_on_contour];
}
// Reindex references on previous intersection line.
for (SegmentIntersection &ip : segs[i_vline - 1].intersections)
if (ip.has_right_horizontal())
ip.next_on_contour = map[ip.next_on_contour];
if (i_vline < segs.size()) {
// Reindex references on next intersection line.
for (SegmentIntersection &ip : segs[i_vline + 1].intersections)
if (ip.has_left_horizontal())
ip.prev_on_contour = map[ip.prev_on_contour];
}
}
}
}
assert(validate_segment_intersection_connectivity(segs));
}
// Find the last INNER_HIGH intersection starting with INNER_LOW, that is followed by OUTER_HIGH intersection.
// Such intersection shall always exist.
static const SegmentIntersection& end_of_vertical_run_raw(const SegmentIntersection &start)
{
assert(start.type == SegmentIntersection::INNER_LOW);
// Step back to the beginning of the vertical segment to mark it as consumed.
auto *it = &start;
do {
++ it;
} while (it->type != SegmentIntersection::OUTER_HIGH);
if ((it - 1)->is_inner()) {
// Step back.
-- it;
assert(it->type == SegmentIntersection::INNER_HIGH);
}
return *it;
}
static SegmentIntersection& end_of_vertical_run_raw(SegmentIntersection &start)
{
return const_cast<SegmentIntersection&>(end_of_vertical_run_raw(std::as_const(start)));
}
// Find the last INNER_HIGH intersection starting with INNER_LOW, that is followed by OUTER_HIGH intersection, traversing vertical up contours if enabled.
// Such intersection shall always exist.
static const SegmentIntersection& end_of_vertical_run(const SegmentedIntersectionLine &il, const SegmentIntersection &start)
{
assert(start.type == SegmentIntersection::INNER_LOW);
const SegmentIntersection *end = &end_of_vertical_run_raw(start);
assert(end->type == SegmentIntersection::INNER_HIGH);
for (;;) {
int up = end->vertical_up();
if (up == -1 || (end->has_left_vertical_up() ? end->prev_on_contour_quality : end->next_on_contour_quality) != SegmentIntersection::LinkQuality::Valid)
break;
const SegmentIntersection &new_start = il.intersections[up];
assert(end->iContour == new_start.iContour);
assert(new_start.type == SegmentIntersection::INNER_LOW);
end = &end_of_vertical_run_raw(new_start);
}
assert(end->type == SegmentIntersection::INNER_HIGH);
return *end;
}
static SegmentIntersection& end_of_vertical_run(SegmentedIntersectionLine &il, SegmentIntersection &start)
{
return const_cast<SegmentIntersection&>(end_of_vertical_run(std::as_const(il), std::as_const(start)));
}
static void traverse_graph_generate_polylines(
const ExPolygonWithOffset& poly_with_offset, const FillParams& params, const coord_t link_max_length, std::vector<SegmentedIntersectionLine>& segs, Polylines& polylines_out)
{
// For each outer only chords, measure their maximum distance to the bow of the outer contour.
// Mark an outer only chord as consumed, if the distance is low.
for (int i_vline = 0; i_vline < int(segs.size()); ++ i_vline) {
SegmentedIntersectionLine &vline = segs[i_vline];
for (int i_intersection = 0; i_intersection + 1 < int(vline.intersections.size()); ++ i_intersection) {
if (vline.intersections[i_intersection].type == SegmentIntersection::OUTER_LOW &&
vline.intersections[i_intersection + 1].type == SegmentIntersection::OUTER_HIGH) {
bool consumed = false;
// if (params.full_infill()) {
// measure_outer_contour_slab(poly_with_offset, segs, i_vline, i_ntersection);
// } else
consumed = true;
vline.intersections[i_intersection].consumed_vertical_up = consumed;
}
}
}
// Now construct a graph.
// Find the first point.
// Naively one would expect to achieve best results by chaining the paths by the shortest distance,
// but that procedure does not create the longest continuous paths.
// A simple "sweep left to right" procedure achieves better results.
int i_vline = 0;
int i_intersection = -1;
// Follow the line, connect the lines into a graph.
// Until no new line could be added to the output path:
Point pointLast;
Polyline* polyline_current = nullptr;
if (! polylines_out.empty())
pointLast = polylines_out.back().points.back();
for (;;) {
if (i_intersection == -1) {
// The path has been interrupted. Find a next starting point, closest to the previous extruder position.
coordf_t dist2min = std::numeric_limits<coordf_t>().max();
for (int i_vline2 = 0; i_vline2 < int(segs.size()); ++ i_vline2) {
const SegmentedIntersectionLine &vline = segs[i_vline2];
if (! vline.intersections.empty()) {
assert(vline.intersections.size() > 1);
// Even number of intersections with the loops.
assert((vline.intersections.size() & 1) == 0);
assert(vline.intersections.front().type == SegmentIntersection::OUTER_LOW);
for (int i = 0; i < int(vline.intersections.size()); ++ i) {
const SegmentIntersection& intrsctn = vline.intersections[i];
if (intrsctn.is_outer()) {
assert(intrsctn.is_low() || i > 0);
bool consumed = intrsctn.is_low() ?
intrsctn.consumed_vertical_up :
vline.intersections[i - 1].consumed_vertical_up;
if (! consumed) {
coordf_t dist2 = sqr(coordf_t(pointLast(0) - vline.pos)) + sqr(coordf_t(pointLast(1) - intrsctn.pos()));
if (dist2 < dist2min) {
dist2min = dist2;
i_vline = i_vline2;
i_intersection = i;
//FIXME We are taking the first left point always. Verify, that the caller chains the paths
// by a shortest distance, while reversing the paths if needed.
//if (polylines_out.empty())
// Initial state, take the first line, which is the first from the left.
goto found;
}
}
}
}
}
}
if (i_intersection == -1)
// We are finished.
break;
found:
// Start a new path.
polylines_out.push_back(Polyline());
polyline_current = &polylines_out.back();
// Emit the first point of a path.
pointLast = Point(segs[i_vline].pos, segs[i_vline].intersections[i_intersection].pos());
polyline_current->points.push_back(pointLast);
}
// From the initial point (i_vline, i_intersection), follow a path.
SegmentedIntersectionLine &vline = segs[i_vline];
SegmentIntersection *it = &vline.intersections[i_intersection];
bool going_up = it->is_low();
bool try_connect = false;
if (going_up) {
assert(! it->consumed_vertical_up);
assert(i_intersection + 1 < vline.intersections.size());
// Step back to the beginning of the vertical segment to mark it as consumed.
if (it->is_inner()) {
assert(i_intersection > 0);
-- it;
-- i_intersection;
}
// Consume the complete vertical segment up to the outer contour.
do {
it->consumed_vertical_up = true;
++ it;
++ i_intersection;
assert(i_intersection < vline.intersections.size());
} while (it->type != SegmentIntersection::OUTER_HIGH);
if ((it - 1)->is_inner()) {
// Step back.
-- it;
-- i_intersection;
assert(it->type == SegmentIntersection::INNER_HIGH);
try_connect = true;
}
} else {
// Going down.
assert(it->is_high());
assert(i_intersection > 0);
assert(!(it - 1)->consumed_vertical_up);
// Consume the complete vertical segment up to the outer contour.
if (it->is_inner())
it->consumed_vertical_up = true;
do {
assert(i_intersection > 0);
-- it;
-- i_intersection;
it->consumed_vertical_up = true;
} while (it->type != SegmentIntersection::OUTER_LOW);
if ((it + 1)->is_inner()) {
// Step back.
++ it;
++ i_intersection;
assert(it->type == SegmentIntersection::INNER_LOW);
try_connect = true;
}
}
if (try_connect) {
// Decide, whether to finish the segment, or whether to follow the perimeter.
// 1) Find possible connection points on the previous / next vertical line.
int i_prev = it->left_horizontal();
int i_next = it->right_horizontal();
bool intersection_prev_valid = intersection_on_prev_vertical_line_valid(segs, i_vline, i_intersection);
bool intersection_next_valid = intersection_on_next_vertical_line_valid(segs, i_vline, i_intersection);
bool intersection_horizontal_valid = intersection_prev_valid || intersection_next_valid;
// Mark both the left and right connecting segment as consumed, because one cannot go to this intersection point as it has been consumed.
if (i_prev != -1)
segs[i_vline - 1].intersections[i_prev].consumed_perimeter_right = true;
if (i_next != -1)
it->consumed_perimeter_right = true;
// Try to connect to a previous or next vertical line, making a zig-zag pattern.
if (intersection_horizontal_valid) {
// A horizontal connection along the perimeter line exists.
assert(it->is_inner());
bool take_next = intersection_next_valid;
if (intersection_prev_valid && intersection_next_valid) {
// Take the shorter segment. This greedy heuristics may not be the best.
coordf_t dist_prev = measure_perimeter_horizontal_segment_length(poly_with_offset, segs, i_vline - 1, i_prev, i_intersection);
coordf_t dist_next = measure_perimeter_horizontal_segment_length(poly_with_offset, segs, i_vline, i_intersection, i_next);
take_next = dist_next < dist_prev;
}
polyline_current->points.emplace_back(vline.pos, it->pos());
emit_perimeter_prev_next_segment(poly_with_offset, segs, i_vline, it->iContour, i_intersection, take_next ? i_next : i_prev, *polyline_current, take_next);
//FIXME consume the left / right connecting segments at the other end of this line? Currently it is not critical because a perimeter segment is not followed if the vertical segment at the other side has already been consumed.
// Advance to the neighbor line.
if (take_next) {
++ i_vline;
i_intersection = i_next;
}
else {
-- i_vline;
i_intersection = i_prev;
}
continue;
}
// Try to connect to a previous or next point on the same vertical line.
int i_vertical = it->vertical_outside();
auto vertical_link_quality = (i_vertical == -1 || vline.intersections[i_vertical + (going_up ? 0 : -1)].consumed_vertical_up) ?
SegmentIntersection::LinkQuality::Invalid : it->vertical_outside_quality();
#if 0
if (vertical_link_quality == SegmentIntersection::LinkQuality::Valid ||
// Follow the link if there is no horizontal link available.
(! intersection_horizontal_valid && vertical_link_quality != SegmentIntersection::LinkQuality::Invalid)) {
#else
if (vertical_link_quality != SegmentIntersection::LinkQuality::Invalid) {
#endif
assert(it->iContour == vline.intersections[i_vertical].iContour);
polyline_current->points.emplace_back(vline.pos, it->pos());
if (vertical_link_quality == SegmentIntersection::LinkQuality::Valid)
// Consume the connecting contour and the next segment.
emit_perimeter_segment_on_vertical_line(poly_with_offset, segs, i_vline, it->iContour, i_intersection, i_vertical,
*polyline_current, going_up ? it->has_left_vertical_up() : it->has_right_vertical_down());
else {
// Just skip the connecting contour and start a new path.
polylines_out.emplace_back();
polyline_current = &polylines_out.back();
polyline_current->points.emplace_back(vline.pos, vline.intersections[i_vertical].pos());
}
// Mark both the left and right connecting segment as consumed, because one cannot go to this intersection point as it has been consumed.
// If there are any outer intersection points skipped (bypassed) by the contour,
// mark them as processed.
if (going_up)
for (int i = i_intersection; i < i_vertical; ++i)
vline.intersections[i].consumed_vertical_up = true;
else
for (int i = i_vertical; i < i_intersection; ++i)
vline.intersections[i].consumed_vertical_up = true;
// seg.intersections[going_up ? i_intersection : i_intersection - 1].consumed_vertical_up = true;
it->consumed_perimeter_right = true;
(going_up ? ++it : --it)->consumed_perimeter_right = true;
i_intersection = i_vertical;
continue;
}
// No way to continue the current polyline. Take the rest of the line up to the outer contour.
// This will finish the polyline, starting another polyline at a new point.
going_up ? ++ it : -- it;
}
// Finish the current vertical line,
// reset the current vertical line to pick a new starting point in the next round.
assert(it->is_outer());
assert(it->is_high() == going_up);
pointLast = Point(vline.pos, it->pos());
polyline_current->points.emplace_back(pointLast);
// Handle duplicate points and zero length segments.
polyline_current->remove_duplicate_points();
assert(! polyline_current->has_duplicate_points());
// Handle nearly zero length edges.
if (polyline_current->points.size() <= 1 ||
(polyline_current->points.size() == 2 &&
std::abs(polyline_current->points.front()(0) - polyline_current->points.back()(0)) < SCALED_EPSILON &&
std::abs(polyline_current->points.front()(1) - polyline_current->points.back()(1)) < SCALED_EPSILON))
polylines_out.pop_back();
it = nullptr;
i_intersection = -1;
polyline_current = nullptr;
}
}
struct MonotonicRegion
{
struct Boundary {
int vline;
int low;
int high;
};
Boundary left;
Boundary right;
// Length when starting at left.low
float len1 { 0.f };
// Length when starting at left.high
float len2 { 0.f };
// If true, then when starting at left.low, then ending at right.high and vice versa.
// If false, then ending at the same side as starting.
bool flips { false };
float length(bool region_flipped) const { return region_flipped ? len2 : len1; }
int left_intersection_point(bool region_flipped) const { return region_flipped ? left.high : left.low; }
int right_intersection_point(bool region_flipped) const { return (region_flipped == flips) ? right.low : right.high; }
#if NDEBUG
// Left regions are used to track whether all regions left to this one have already been printed.
boost::container::small_vector<MonotonicRegion*, 4> left_neighbors;
// Right regions are held to pick a next region to be extruded using the "Ant colony" heuristics.
boost::container::small_vector<MonotonicRegion*, 4> right_neighbors;
#else
// For debugging, use the normal vector as it is better supported by debug visualizers.
std::vector<MonotonicRegion*> left_neighbors;
std::vector<MonotonicRegion*> right_neighbors;
#endif
};
struct AntPath
{
float length { -1. }; // Length of the link to the next region.
float visibility { -1. }; // 1 / length. Which length, just to the next region, or including the path accross the region?
float pheromone { 0 }; // <0, 1>
};
struct MonotonicRegionLink
{
MonotonicRegion *region;
bool flipped;
// Distance of right side of this region to left side of the next region, if the "flipped" flag of this region and the next region
// is applied as defined.
AntPath *next;
// Distance of right side of this region to left side of the next region, if the "flipped" flag of this region and the next region
// is applied in reverse order as if the zig-zags were flipped.
AntPath *next_flipped;
};
// Matrix of paths (AntPath) connecting ends of MontonousRegions.
// AntPath lengths and their derived visibilities refer to the length of the perimeter line if such perimeter segment exists.
class AntPathMatrix
{
public:
AntPathMatrix(
const std::vector<MonotonicRegion> &regions,
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
const float initial_pheromone) :
m_regions(regions),
m_poly_with_offset(poly_with_offset),
m_segs(segs),
// From end of one region to the start of another region, both flipped or not flipped.
m_matrix(regions.size() * regions.size() * 4, AntPath{ -1., -1., initial_pheromone}) {}
void update_inital_pheromone(float initial_pheromone)
{
for (AntPath &ap : m_matrix)
ap.pheromone = initial_pheromone;
}
AntPath& operator()(const MonotonicRegion &region_from, bool flipped_from, const MonotonicRegion &region_to, bool flipped_to)
{
int row = 2 * int(&region_from - m_regions.data()) + flipped_from;
int col = 2 * int(&region_to - m_regions.data()) + flipped_to;
AntPath &path = m_matrix[row * m_regions.size() * 2 + col];
if (path.length == -1.) {
// This path is accessed for the first time. Update the length and cost.
int i_from = region_from.right_intersection_point(flipped_from);
int i_to = region_to.left_intersection_point(flipped_to);
const SegmentedIntersectionLine &vline_from = m_segs[region_from.right.vline];
const SegmentedIntersectionLine &vline_to = m_segs[region_to.left.vline];
if (region_from.right.vline + 1 == region_from.left.vline) {
int i_right = vline_from.intersections[i_from].right_horizontal();
if (i_right == i_to && vline_from.intersections[i_from].next_on_contour_quality == SegmentIntersection::LinkQuality::Valid) {
// Measure length along the contour.
path.length = unscale<float>(measure_perimeter_horizontal_segment_length(m_poly_with_offset, m_segs, region_from.right.vline, i_from, i_to));
}
}
if (path.length == -1.) {
// Just apply the Eucledian distance of the end points.
path.length = unscale<float>(Vec2f(vline_to.pos - vline_from.pos, vline_to.intersections[i_to].pos() - vline_from.intersections[i_from].pos()).norm());
}
path.visibility = 1.f / (path.length + float(EPSILON));
}
return path;
}
AntPath& operator()(const MonotonicRegionLink &region_from, const MonotonicRegion &region_to, bool flipped_to)
{ return (*this)(*region_from.region, region_from.flipped, region_to, flipped_to); }
AntPath& operator()(const MonotonicRegion &region_from, bool flipped_from, const MonotonicRegionLink &region_to)
{ return (*this)(region_from, flipped_from, *region_to.region, region_to.flipped); }
AntPath& operator()(const MonotonicRegionLink &region_from, const MonotonicRegionLink &region_to)
{ return (*this)(*region_from.region, region_from.flipped, *region_to.region, region_to.flipped); }
private:
// Source regions, used for addressing and updating m_matrix.
const std::vector<MonotonicRegion> &m_regions;
// To calculate the intersection points and contour lengths.
const ExPolygonWithOffset &m_poly_with_offset;
const std::vector<SegmentedIntersectionLine> &m_segs;
// From end of one region to the start of another region, both flipped or not flipped.
//FIXME one may possibly use sparse representation of the matrix, likely using hashing.
std::vector<AntPath> m_matrix;
};
static const SegmentIntersection& vertical_run_bottom(const SegmentedIntersectionLine &vline, const SegmentIntersection &start)
{
assert(start.is_inner());
const SegmentIntersection *it = &start;
// Find the lowest SegmentIntersection::INNER_LOW starting with right.
for (;;) {
while (it->type != SegmentIntersection::INNER_LOW)
-- it;
if ((it - 1)->type == SegmentIntersection::INNER_HIGH)
-- it;
else {
int down = it->vertical_down();
if (down == -1 || it->vertical_down_quality() != SegmentIntersection::LinkQuality::Valid)
break;
it = &vline.intersections[down];
assert(it->type == SegmentIntersection::INNER_HIGH);
}
}
return *it;
}
static SegmentIntersection& vertical_run_bottom(SegmentedIntersectionLine& vline, SegmentIntersection& start)
{
return const_cast<SegmentIntersection&>(vertical_run_bottom(std::as_const(vline), std::as_const(start)));
}
static const SegmentIntersection& vertical_run_top(const SegmentedIntersectionLine &vline, const SegmentIntersection &start)
{
assert(start.is_inner());
const SegmentIntersection *it = &start;
// Find the lowest SegmentIntersection::INNER_LOW starting with right.
for (;;) {
while (it->type != SegmentIntersection::INNER_HIGH)
++ it;
if ((it + 1)->type == SegmentIntersection::INNER_LOW)
++ it;
else {
int up = it->vertical_up();
if (up == -1 || it->vertical_up_quality() != SegmentIntersection::LinkQuality::Valid)
break;
it = &vline.intersections[up];
assert(it->type == SegmentIntersection::INNER_LOW);
}
}
return *it;
}
static SegmentIntersection& vertical_run_top(SegmentedIntersectionLine& vline, SegmentIntersection& start)
{
return const_cast<SegmentIntersection&>(vertical_run_top(std::as_const(vline), std::as_const(start)));
}
static SegmentIntersection* overlap_bottom(SegmentIntersection &start, SegmentIntersection &end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_other, SegmentIntersection::Side side)
{
SegmentIntersection *other = nullptr;
assert(start.is_inner());
assert(end.is_inner());
const SegmentIntersection *it = &start;
for (;;) {
if (it->is_inner()) {
int i = it->horizontal(side);
if (i != -1) {
other = &vline_other.intersections[i];
break;
}
if (it == &end)
break;
}
if (it->type != SegmentIntersection::INNER_HIGH)
++ it;
else if ((it + 1)->type == SegmentIntersection::INNER_LOW)
++ it;
else {
int up = it->vertical_up();
if (up == -1 || it->vertical_up_quality() != SegmentIntersection::LinkQuality::Valid)
break;
it = &vline_this.intersections[up];
assert(it->type == SegmentIntersection::INNER_LOW);
}
}
return other == nullptr ? nullptr : &vertical_run_bottom(vline_other, *other);
}
static SegmentIntersection* overlap_top(SegmentIntersection &start, SegmentIntersection &end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_other, SegmentIntersection::Side side)
{
SegmentIntersection *other = nullptr;
assert(start.is_inner());
assert(end.is_inner());
const SegmentIntersection *it = &end;
for (;;) {
if (it->is_inner()) {
int i = it->horizontal(side);
if (i != -1) {
other = &vline_other.intersections[i];
break;
}
if (it == &start)
break;
}
if (it->type != SegmentIntersection::INNER_LOW)
-- it;
else if ((it - 1)->type == SegmentIntersection::INNER_HIGH)
-- it;
else {
int down = it->vertical_down();
if (down == -1 || it->vertical_down_quality() != SegmentIntersection::LinkQuality::Valid)
break;
it = &vline_this.intersections[down];
assert(it->type == SegmentIntersection::INNER_HIGH);
}
}
return other == nullptr ? nullptr : &vertical_run_top(vline_other, *other);
}
static std::pair<SegmentIntersection*, SegmentIntersection*> left_overlap(SegmentIntersection &start, SegmentIntersection &end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_left)
{
std::pair<SegmentIntersection*, SegmentIntersection*> out(nullptr, nullptr);
out.first = overlap_bottom(start, end, vline_this, vline_left, SegmentIntersection::Side::Left);
if (out.first != nullptr)
out.second = overlap_top(start, end, vline_this, vline_left, SegmentIntersection::Side::Left);
assert((out.first == nullptr && out.second == nullptr) || out.first < out.second);
return out;
}
static std::pair<SegmentIntersection*, SegmentIntersection*> left_overlap(std::pair<SegmentIntersection*, SegmentIntersection*> &start_end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_left)
{
assert((start_end.first == nullptr) == (start_end.second == nullptr));
return start_end.first == nullptr ? start_end : left_overlap(*start_end.first, *start_end.second, vline_this, vline_left);
}
static std::pair<SegmentIntersection*, SegmentIntersection*> right_overlap(SegmentIntersection &start, SegmentIntersection &end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_right)
{
std::pair<SegmentIntersection*, SegmentIntersection*> out(nullptr, nullptr);
out.first = overlap_bottom(start, end, vline_this, vline_right, SegmentIntersection::Side::Right);
if (out.first != nullptr)
out.second = overlap_top(start, end, vline_this, vline_right, SegmentIntersection::Side::Right);
assert((out.first == nullptr && out.second == nullptr) || out.first < out.second);
return out;
}
static std::pair<SegmentIntersection*, SegmentIntersection*> right_overlap(std::pair<SegmentIntersection*, SegmentIntersection*> &start_end, SegmentedIntersectionLine &vline_this, SegmentedIntersectionLine &vline_right)
{
assert((start_end.first == nullptr) == (start_end.second == nullptr));
return start_end.first == nullptr ? start_end : right_overlap(*start_end.first, *start_end.second, vline_this, vline_right);
}
static std::vector<MonotonicRegion> generate_montonous_regions(std::vector<SegmentedIntersectionLine> &segs)
{
std::vector<MonotonicRegion> monotonic_regions;
#ifndef NDEBUG
#define SLIC3R_DEBUG_MONOTONOUS_REGIONS
#endif
#ifdef SLIC3R_DEBUG_MONOTONOUS_REGIONS
std::vector<std::vector<std::pair<int, int>>> consumed(segs.size());
auto test_overlap = [&consumed](int segment, int low, int high) {
for (const std::pair<int, int>& interval : consumed[segment])
if ((low >= interval.first && low <= interval.second) ||
(interval.first >= low && interval.first <= high))
return true;
consumed[segment].emplace_back(low, high);
return false;
};
#else
auto test_overlap = [](int, int, int) { return false; };
#endif
for (int i_vline_seed = 0; i_vline_seed < int(segs.size()); ++ i_vline_seed) {
SegmentedIntersectionLine &vline_seed = segs[i_vline_seed];
for (int i_intersection_seed = 1; i_intersection_seed + 1 < int(vline_seed.intersections.size()); ) {
while (i_intersection_seed < int(vline_seed.intersections.size()) &&
vline_seed.intersections[i_intersection_seed].type != SegmentIntersection::INNER_LOW)
++ i_intersection_seed;
if (i_intersection_seed == int(vline_seed.intersections.size()))
break;
SegmentIntersection *start = &vline_seed.intersections[i_intersection_seed];
SegmentIntersection *end = &end_of_vertical_run(vline_seed, *start);
if (! start->consumed_vertical_up) {
// Draw a new monotonic region starting with this segment.
// while there is only a single right neighbor
int i_vline = i_vline_seed;
std::pair<SegmentIntersection*, SegmentIntersection*> left(start, end);
MonotonicRegion region;
region.left.vline = i_vline;
region.left.low = int(left.first - vline_seed.intersections.data());
region.left.high = int(left.second - vline_seed.intersections.data());
region.right = region.left;
assert(! test_overlap(region.left.vline, region.left.low, region.left.high));
start->consumed_vertical_up = true;
int num_lines = 1;
while (++ i_vline < int(segs.size())) {
SegmentedIntersectionLine &vline_left = segs[i_vline - 1];
SegmentedIntersectionLine &vline_right = segs[i_vline];
std::pair<SegmentIntersection*, SegmentIntersection*> right = right_overlap(left, vline_left, vline_right);
if (right.first == nullptr)
// No neighbor at the right side of the current segment.
break;
SegmentIntersection* right_top_first = &vertical_run_top(vline_right, *right.first);
if (right_top_first != right.second)
// This segment overlaps with multiple segments at its right side.
break;
std::pair<SegmentIntersection*, SegmentIntersection*> right_left = left_overlap(right, vline_right, vline_left);
if (left != right_left)
// Left & right draws don't overlap exclusively, right neighbor segment overlaps with multiple segments at its left.
break;
region.right.vline = i_vline;
region.right.low = int(right.first - vline_right.intersections.data());
region.right.high = int(right.second - vline_right.intersections.data());
right.first->consumed_vertical_up = true;
assert(! test_overlap(region.right.vline, region.right.low, region.right.high));
++ num_lines;
left = right;
}
// Even number of lines makes the infill zig-zag to exit on the other side of the region than where it starts.
region.flips = (num_lines & 1) != 0;
monotonic_regions.emplace_back(region);
}
i_intersection_seed = int(end - vline_seed.intersections.data()) + 1;
}
}
return monotonic_regions;
}
#ifdef INFILL_DEBUG_OUTPUT
static void export_monotonous_regions_to_svg(
const ExPolygonWithOffset &poly_with_offset,
const std::vector<SegmentedIntersectionLine> &segs,
const std::vector<MonotonicRegion> &monotonic_regions,
const std::string &path)
{
BoundingBox bbox = get_extents(poly_with_offset.polygons_src);
bbox.offset(scale_(3.));
::Slic3r::SVG svg(path, bbox);
svg.draw(poly_with_offset.polygons_src);
svg.draw_outline(poly_with_offset.polygons_src, "green");
svg.draw_outline(poly_with_offset.polygons_outer, "green");
svg.draw_outline(poly_with_offset.polygons_inner, "green");
// Draw the infill line candidates in red.
for (const SegmentedIntersectionLine &sil : segs) {
for (size_t i = 0; i + 1 < sil.intersections.size(); ++ i)
if (sil.intersections[i].type == SegmentIntersection::INNER_LOW && sil.intersections[i + 1].type == SegmentIntersection::INNER_HIGH) {
Line l(Point(sil.pos, sil.intersections[i].pos()), Point(sil.pos, sil.intersections[i + 1].pos()));
svg.draw(l, "blue");
} else if (sil.intersections[i].type == SegmentIntersection::INNER_HIGH && sil.intersections[i].has_vertical_up()) {
std::string color;
const SegmentIntersection *it = &sil.intersections[i];
switch (it->vertical_up_quality()) {
case SegmentIntersection::LinkQuality::Invalid: color = "red"; break;
case SegmentIntersection::LinkQuality::Valid: color = "blue"; break;
case SegmentIntersection::LinkQuality::TooLong:
default: color = "yellow"; break;
}
Polyline polyline;
polyline.points.push_back({ sil.pos, it->pos() });
emit_perimeter_segment_on_vertical_line(poly_with_offset, segs, &sil - segs.data() , it->iContour, it - sil.intersections.data(), it->vertical_up(), polyline, it->has_left_vertical_up());
svg.draw(polyline, color, scale_(0.05));
}
}
// Draw the monotonic regions.
for (const MonotonicRegion &region : monotonic_regions) {
auto draw_boundary_line = [&poly_with_offset, &segs, &svg](const MonotonicRegion::Boundary &boundary) {
const SegmentedIntersectionLine &sil = segs[boundary.vline];
for (size_t i = boundary.low; i < boundary.high; ++ i)
if (sil.intersections[i].type == SegmentIntersection::INNER_LOW && sil.intersections[i + 1].type == SegmentIntersection::INNER_HIGH) {
Line l(Point(sil.pos, sil.intersections[i].pos()), Point(sil.pos, sil.intersections[i + 1].pos()));
svg.draw(l, "red", scale_(0.05));
}
};
draw_boundary_line(region.left);
draw_boundary_line(region.right);
}
}
#endif // INFILL_DEBUG_OUTPUT
// Traverse path, calculate length of the draw for the purpose of optimization.
// This function is very similar to polylines_from_paths() in the way how it traverses the path, but
// polylines_from_paths() emits a path, while this function just calculates the path length.
static float montonous_region_path_length(const MonotonicRegion &region, bool dir, const ExPolygonWithOffset &poly_with_offset, const std::vector<SegmentedIntersectionLine> &segs)
{
// From the initial point (i_vline, i_intersection), follow a path.
int i_intersection = region.left_intersection_point(dir);
int i_vline = region.left.vline;
float total_length = 0.;
bool no_perimeter = false;
Vec2f last_point;
for (;;) {
const SegmentedIntersectionLine &vline = segs[i_vline];
const SegmentIntersection *it = &vline.intersections[i_intersection];
const bool going_up = it->is_low();
if (no_perimeter)
total_length += (last_point - Vec2f(vline.pos, (it + (going_up ? - 1 : 1))->pos())).norm();
int iright = it->right_horizontal();
if (going_up) {
// Traverse the complete vertical segment up to the inner contour.
for (;;) {
do {
++ it;
iright = std::max(iright, it->right_horizontal());
assert(it->is_inner());
} while (it->type != SegmentIntersection::INNER_HIGH || (it + 1)->type != SegmentIntersection::OUTER_HIGH);
int inext = it->vertical_up();
if (inext == -1 || it->vertical_up_quality() != SegmentIntersection::LinkQuality::Valid)
break;
assert(it->iContour == vline.intersections[inext].iContour);
it = vline.intersections.data() + inext;
}
} else {
// Going down.
assert(it->is_high());
assert(i_intersection > 0);
for (;;) {
do {
-- it;
if (int iright_new = it->right_horizontal(); iright_new != -1)
iright = iright_new;
assert(it->is_inner());
} while (it->type != SegmentIntersection::INNER_LOW || (it - 1)->type != SegmentIntersection::OUTER_LOW);
int inext = it->vertical_down();
if (inext == -1 || it->vertical_down_quality() != SegmentIntersection::LinkQuality::Valid)
break;
assert(it->iContour == vline.intersections[inext].iContour);
it = vline.intersections.data() + inext;
}
}
if (i_vline == region.right.vline)
break;
int inext = it->right_horizontal();
assert(iright != -1);
assert(inext == -1 || inext == iright);
// Find the end of the next overlapping vertical segment.
const SegmentedIntersectionLine &vline_right = segs[i_vline + 1];
const SegmentIntersection *right = going_up ?
&vertical_run_top(vline_right, vline_right.intersections[iright]) : &vertical_run_bottom(vline_right, vline_right.intersections[iright]);
i_intersection = int(right - vline_right.intersections.data());
if (inext == i_intersection && it->next_on_contour_quality == SegmentIntersection::LinkQuality::Valid) {
// Summarize length of the connection line along the perimeter.
//FIXME should it be weighted with a lower weight than non-extruding connection line? What weight?
// Taking half of the length.
total_length += 0.5f * float(measure_perimeter_horizontal_segment_length(poly_with_offset, segs, i_vline, it - vline.intersections.data(), inext));
// Don't add distance to the next vertical line start to the total length.
no_perimeter = false;
} else {
// Finish the current vertical line,
going_up ? ++ it : -- it;
assert(it->is_outer());
assert(it->is_high() == going_up);
// Mark the end of this vertical line.
last_point = Vec2f(vline.pos, it->pos());
// Remember to add distance to the last point.
no_perimeter = true;
}
++ i_vline;
}
return unscale<float>(total_length);
}
static void connect_monotonic_regions(std::vector<MonotonicRegion> &regions, const ExPolygonWithOffset &poly_with_offset, std::vector<SegmentedIntersectionLine> &segs)
{
// Map from low intersection to left / right side of a monotonic region.
using MapType = std::pair<SegmentIntersection*, MonotonicRegion*>;
std::vector<MapType> map_intersection_to_region_start;
std::vector<MapType> map_intersection_to_region_end;
map_intersection_to_region_start.reserve(regions.size());
map_intersection_to_region_end.reserve(regions.size());
for (MonotonicRegion &region : regions) {
map_intersection_to_region_start.emplace_back(&segs[region.left.vline].intersections[region.left.low], &region);
map_intersection_to_region_end.emplace_back(&segs[region.right.vline].intersections[region.right.low], &region);
}
auto intersections_lower = [](const MapType &l, const MapType &r){ return l.first < r.first ; };
auto intersections_equal = [](const MapType &l, const MapType &r){ return l.first == r.first ; };
std::sort(map_intersection_to_region_start.begin(), map_intersection_to_region_start.end(), intersections_lower);
std::sort(map_intersection_to_region_end.begin(), map_intersection_to_region_end.end(), intersections_lower);
// Scatter links to neighboring regions.
for (MonotonicRegion &region : regions) {
if (region.left.vline > 0) {
auto &vline = segs[region.left.vline];
auto &vline_left = segs[region.left.vline - 1];
auto[lbegin, lend] = left_overlap(vline.intersections[region.left.low], vline.intersections[region.left.high], vline, vline_left);
if (lbegin != nullptr) {
for (;;) {
MapType key(lbegin, nullptr);
auto it = std::lower_bound(map_intersection_to_region_end.begin(), map_intersection_to_region_end.end(), key);
assert(it != map_intersection_to_region_end.end() && it->first == key.first);
it->second->right_neighbors.emplace_back(&region);
SegmentIntersection *lnext = &vertical_run_top(vline_left, *lbegin);
if (lnext == lend)
break;
while (lnext->type != SegmentIntersection::INNER_LOW)
++ lnext;
lbegin = lnext;
}
}
}
if (region.right.vline + 1 < int(segs.size())) {
auto &vline = segs[region.right.vline];
auto &vline_right = segs[region.right.vline + 1];
auto [rbegin, rend] = right_overlap(vline.intersections[region.right.low], vline.intersections[region.right.high], vline, vline_right);
if (rbegin != nullptr) {
for (;;) {
MapType key(rbegin, nullptr);
auto it = std::lower_bound(map_intersection_to_region_start.begin(), map_intersection_to_region_start.end(), key);
assert(it != map_intersection_to_region_start.end() && it->first == key.first);
it->second->left_neighbors.emplace_back(&region);
SegmentIntersection *rnext = &vertical_run_top(vline_right, *rbegin);
if (rnext == rend)
break;
while (rnext->type != SegmentIntersection::INNER_LOW)
++ rnext;
rbegin = rnext;
}
}
}
}
// Sometimes a segment may indicate that it connects to a segment on the other side while the other does not.
// This may be a valid case if one side contains runs of OUTER_LOW, INNER_LOW, {INNER_HIGH, INNER_LOW}*, INNER_HIGH, OUTER_HIGH,
// where the part in the middle does not connect to the other side, but it will be extruded through.
for (MonotonicRegion &region : regions) {
std::sort(region.left_neighbors.begin(), region.left_neighbors.end());
std::sort(region.right_neighbors.begin(), region.right_neighbors.end());
}
for (MonotonicRegion &region : regions) {
for (MonotonicRegion *neighbor : region.left_neighbors) {
auto it = std::lower_bound(neighbor->right_neighbors.begin(), neighbor->right_neighbors.end(), &region);
if (it == neighbor->right_neighbors.end() || *it != &region)
neighbor->right_neighbors.insert(it, &region);
}
for (MonotonicRegion *neighbor : region.right_neighbors) {
auto it = std::lower_bound(neighbor->left_neighbors.begin(), neighbor->left_neighbors.end(), &region);
if (it == neighbor->left_neighbors.end() || *it != &region)
neighbor->left_neighbors.insert(it, &region);
}
}
#ifndef NDEBUG
// Verify symmetry of the left_neighbors / right_neighbors.
for (MonotonicRegion &region : regions) {
for (MonotonicRegion *neighbor : region.left_neighbors) {
assert(std::count(region.left_neighbors.begin(), region.left_neighbors.end(), neighbor) == 1);
assert(std::find(neighbor->right_neighbors.begin(), neighbor->right_neighbors.end(), &region) != neighbor->right_neighbors.end());
}
for (MonotonicRegion *neighbor : region.right_neighbors) {
assert(std::count(region.right_neighbors.begin(), region.right_neighbors.end(), neighbor) == 1);
assert(std::find(neighbor->left_neighbors.begin(), neighbor->left_neighbors.end(), &region) != neighbor->left_neighbors.end());
}
}
#endif /* NDEBUG */
// Fill in sum length of connecting lines of a region. This length is used for optimizing the infill path for minimum length.
for (MonotonicRegion &region : regions) {
region.len1 = montonous_region_path_length(region, false, poly_with_offset, segs);
region.len2 = montonous_region_path_length(region, true, poly_with_offset, segs);
// Subtract the smaller length from the longer one, so we will optimize just with the positive difference of the two.
if (region.len1 > region.len2) {
region.len1 -= region.len2;
region.len2 = 0;
} else {
region.len2 -= region.len1;
region.len1 = 0;
}
}
}
// Raad Salman: Algorithms for the Precedence Constrained Generalized Travelling Salesperson Problem
// https://www.chalmers.se/en/departments/math/research/research-groups/optimization/OptimizationMasterTheses/MScThesis-RaadSalman-final.pdf
// Algorithm 6.1 Lexicographic Path Preserving 3-opt
// Optimize path while maintaining the ordering constraints.
void monotonic_3_opt(std::vector<MonotonicRegionLink> &path, const std::vector<SegmentedIntersectionLine> &segs)
{
// When doing the 3-opt path preserving flips, one has to fulfill two constraints:
//
// 1) The new path should be shorter than the old path.
// 2) The precedence constraints shall be satisified on the new path.
//
// Branch & bound with KD-tree may be used with the shorter path constraint, but the precedence constraint will have to be recalculated for each
// shorter path candidate found, which has a quadratic cost for a dense precedence graph. For a sparse precedence graph the precedence
// constraint verification will be cheaper.
//
// On the other side, if the full search space is traversed as in the diploma thesis by Raad Salman (page 24, Algorithm 6.1 Lexicographic Path Preserving 3-opt),
// then the precedence constraint verification is amortized inside the O(n^3) loop. Now which is better for our task?
//
// It is beneficial to also try flipping of the infill zig-zags, for which a prefix sum of both flipped and non-flipped paths over
// MonotonicRegionLinks may be utilized, however updating the prefix sum has a linear complexity, the same complexity as doing the 3-opt
// exchange by copying the pieces.
}
// #define SLIC3R_DEBUG_ANTS
template<typename... TArgs>
inline void print_ant(const std::string& fmt, TArgs&&... args) {
#ifdef SLIC3R_DEBUG_ANTS
std::cout << Slic3r::format(fmt, std::forward<TArgs>(args)...) << std::endl;
#endif
}
// Find a run through monotonic infill blocks using an 'Ant colony" optimization method.
// http://www.scholarpedia.org/article/Ant_colony_optimization
static std::vector<MonotonicRegionLink> chain_monotonic_regions(
std::vector<MonotonicRegion> &regions, const ExPolygonWithOffset &poly_with_offset, const std::vector<SegmentedIntersectionLine> &segs, std::mt19937_64 &rng)
{
// Number of left neighbors (regions that this region depends on, this region cannot be printed before the regions left of it are printed) + self.
std::vector<int32_t> left_neighbors_unprocessed(regions.size(), 1);
// Queue of regions, which have their left neighbors already printed.
std::vector<MonotonicRegion*> queue;
queue.reserve(regions.size());
for (MonotonicRegion &region : regions)
if (region.left_neighbors.empty())
queue.emplace_back(&region);
else
left_neighbors_unprocessed[&region - regions.data()] += int(region.left_neighbors.size());
// Make copy of structures that need to be initialized at each ant iteration.
auto left_neighbors_unprocessed_initial = left_neighbors_unprocessed;
auto queue_initial = queue;
std::vector<MonotonicRegionLink> path, best_path;
path.reserve(regions.size());
best_path.reserve(regions.size());
float best_path_length = std::numeric_limits<float>::max();
struct NextCandidate {
MonotonicRegion *region;
AntPath *link;
AntPath *link_flipped;
float probability;
bool dir;
};
std::vector<NextCandidate> next_candidates;
auto validate_unprocessed =
#ifdef NDEBUG
[]() { return true; };
#else
[&regions, &left_neighbors_unprocessed, &path, &queue]() {
std::vector<unsigned char> regions_processed(regions.size(), false);
std::vector<unsigned char> regions_in_queue(regions.size(), false);
for (const MonotonicRegion *region : queue) {
// This region is not processed yet, his predecessors are processed.
assert(left_neighbors_unprocessed[region - regions.data()] == 1);
regions_in_queue[region - regions.data()] = true;
}
for (const MonotonicRegionLink &link : path) {
assert(left_neighbors_unprocessed[link.region - regions.data()] == 0);
regions_processed[link.region - regions.data()] = true;
}
for (size_t i = 0; i < regions_processed.size(); ++ i) {
assert(! regions_processed[i] || ! regions_in_queue[i]);
const MonotonicRegion &region = regions[i];
if (regions_processed[i] || regions_in_queue[i]) {
assert(left_neighbors_unprocessed[i] == (regions_in_queue[i] ? 1 : 0));
// All left neighbors should be processed already.
for (const MonotonicRegion *left : region.left_neighbors) {
assert(regions_processed[left - regions.data()]);
assert(left_neighbors_unprocessed[left - regions.data()] == 0);
}
} else {
// Some left neihgbor should not be processed yet.
assert(left_neighbors_unprocessed[i] > 1);
size_t num_predecessors_unprocessed = 0;
bool has_left_last_on_path = false;
for (const MonotonicRegion* left : region.left_neighbors) {
size_t iprev = left - regions.data();
if (regions_processed[iprev]) {
assert(left_neighbors_unprocessed[iprev] == 0);
if (left == path.back().region) {
// This region should actually be on queue, but to optimize the queue management
// this item will be processed in the next round by traversing path.back().region->right_neighbors before processing the queue.
assert(! has_left_last_on_path);
has_left_last_on_path = true;
++ num_predecessors_unprocessed;
}
} else {
if (regions_in_queue[iprev])
assert(left_neighbors_unprocessed[iprev] == 1);
else
assert(left_neighbors_unprocessed[iprev] > 1);
++ num_predecessors_unprocessed;
}
}
assert(num_predecessors_unprocessed > 0);
assert(left_neighbors_unprocessed[i] == num_predecessors_unprocessed + 1);
}
}
return true;
};
#endif /* NDEBUG */
// How many times to repeat the ant simulation (number of ant generations).
constexpr int num_rounds = 25;
// After how many rounds without an improvement to exit?
constexpr int num_rounds_no_change_exit = 8;
// With how many ants each of the run will be performed?
const int num_ants = std::min(int(regions.size()), 10);
// Base (initial) pheromone level. This value will be adjusted based on the length of the first greedy path found.
float pheromone_initial_deposit = 0.5f;
// Evaporation rate of pheromones.
constexpr float pheromone_evaporation = 0.1f;
// Evaporation rate to diversify paths taken by individual ants.
constexpr float pheromone_diversification = 0.1f;
// Probability at which to take the next best path. Otherwise take the the path based on the cost distribution.
constexpr float probability_take_best = 0.9f;
// Exponents of the cost function.
constexpr float pheromone_alpha = 1.f; // pheromone exponent
constexpr float pheromone_beta = 2.f; // attractiveness weighted towards edge length
AntPathMatrix path_matrix(regions, poly_with_offset, segs, pheromone_initial_deposit);
// Find an initial path in a greedy way, set the initial pheromone value to 10% of the cost of the greedy path.
{
// Construct the first path in a greedy way to calculate an initial value of the pheromone value.
queue = queue_initial;
left_neighbors_unprocessed = left_neighbors_unprocessed_initial;
assert(validate_unprocessed());
// Pick the last of the queue.
MonotonicRegionLink path_end { queue.back(), false };
queue.pop_back();
-- left_neighbors_unprocessed[path_end.region - regions.data()];
float total_length = path_end.region->length(false);
while (! queue.empty() || ! path_end.region->right_neighbors.empty()) {
// Chain.
MonotonicRegion &region = *path_end.region;
bool dir = path_end.flipped;
NextCandidate next_candidate;
next_candidate.probability = 0;
for (MonotonicRegion *next : region.right_neighbors) {
int &unprocessed = left_neighbors_unprocessed[next - regions.data()];
assert(unprocessed > 1);
if (left_neighbors_unprocessed[next - regions.data()] == 2) {
// Dependencies of the successive blocks are satisfied.
AntPath &path1 = path_matrix(region, dir, *next, false);
AntPath &path2 = path_matrix(region, dir, *next, true);
if (path1.visibility > next_candidate.probability)
next_candidate = { next, &path1, &path1, path1.visibility, false };
if (path2.visibility > next_candidate.probability)
next_candidate = { next, &path2, &path2, path2.visibility, true };
}
}
bool from_queue = next_candidate.probability == 0;
if (from_queue) {
for (MonotonicRegion *next : queue) {
AntPath &path1 = path_matrix(region, dir, *next, false);
AntPath &path2 = path_matrix(region, dir, *next, true);
if (path1.visibility > next_candidate.probability)
next_candidate = { next, &path1, &path1, path1.visibility, false };
if (path2.visibility > next_candidate.probability)
next_candidate = { next, &path2, &path2, path2.visibility, true };
}
}
// Move the other right neighbors with satisified constraints to the queue.
for (MonotonicRegion *next : region.right_neighbors)
if (-- left_neighbors_unprocessed[next - regions.data()] == 1 && next_candidate.region != next)
queue.emplace_back(next);
if (from_queue) {
// Remove the selected path from the queue.
auto it = std::find(queue.begin(), queue.end(), next_candidate.region);
assert(it != queue.end());
*it = queue.back();
queue.pop_back();
}
// Extend the path.
MonotonicRegion *next_region = next_candidate.region;
bool next_dir = next_candidate.dir;
total_length += next_region->length(next_dir) + path_matrix(*path_end.region, path_end.flipped, *next_region, next_dir).length;
path_end = { next_region, next_dir };
assert(left_neighbors_unprocessed[next_region - regions.data()] == 1);
left_neighbors_unprocessed[next_region - regions.data()] = 0;
}
// Set an initial pheromone value to 10% of the greedy path's value.
pheromone_initial_deposit = 0.1f / total_length;
path_matrix.update_inital_pheromone(pheromone_initial_deposit);
}
// Probability (unnormalized) of traversing a link between two monotonic regions.
auto path_probability = [pheromone_alpha, pheromone_beta](AntPath &path) {
return pow(path.pheromone, pheromone_alpha) * pow(path.visibility, pheromone_beta);
};
#ifdef SLIC3R_DEBUG_ANTS
static int irun = 0;
++ irun;
#endif /* SLIC3R_DEBUG_ANTS */
int num_rounds_no_change = 0;
for (int round = 0; round < num_rounds && num_rounds_no_change < num_rounds_no_change_exit; ++ round)
{
bool improved = false;
for (int ant = 0; ant < num_ants; ++ ant)
{
// Find a new path following the pheromones deposited by the previous ants.
print_ant("Round %1% ant %2%", round, ant);
path.clear();
queue = queue_initial;
left_neighbors_unprocessed = left_neighbors_unprocessed_initial;
assert(validate_unprocessed());
// Pick randomly the first from the queue at random orientation.
//FIXME picking the 1st monotonic region should likely be done based on accumulated pheromone level as well,
// but the inefficiency caused by the random pick of the 1st monotonic region is likely insignificant.
int first_idx = std::uniform_int_distribution<>(0, int(queue.size()) - 1)(rng);
path.emplace_back(MonotonicRegionLink{ queue[first_idx], rng() > rng.max() / 2 });
*(queue.begin() + first_idx) = std::move(queue.back());
queue.pop_back();
-- left_neighbors_unprocessed[path.back().region - regions.data()];
assert(left_neighbors_unprocessed[path.back().region - regions.data()] == 0);
assert(validate_unprocessed());
print_ant("\tRegion (%1%:%2%,%3%) (%4%:%5%,%6%)",
path.back().region->left.vline,
path.back().flipped ? path.back().region->left.high : path.back().region->left.low,
path.back().flipped ? path.back().region->left.low : path.back().region->left.high,
path.back().region->right.vline,
path.back().flipped == path.back().region->flips ? path.back().region->right.high : path.back().region->right.low,
path.back().flipped == path.back().region->flips ? path.back().region->right.low : path.back().region->right.high);
while (! queue.empty() || ! path.back().region->right_neighbors.empty()) {
// Chain.
MonotonicRegion &region = *path.back().region;
bool dir = path.back().flipped;
// Sort by distance to pt.
next_candidates.clear();
next_candidates.reserve(region.right_neighbors.size() * 2);
for (MonotonicRegion *next : region.right_neighbors) {
int &unprocessed = left_neighbors_unprocessed[next - regions.data()];
assert(unprocessed > 1);
if (-- unprocessed == 1) {
// Dependencies of the successive blocks are satisfied.
AntPath &path1 = path_matrix(region, dir, *next, false);
AntPath &path1_flipped = path_matrix(region, ! dir, *next, true);
AntPath &path2 = path_matrix(region, dir, *next, true);
AntPath &path2_flipped = path_matrix(region, ! dir, *next, false);
next_candidates.emplace_back(NextCandidate{ next, &path1, &path1_flipped, path_probability(path1), false });
next_candidates.emplace_back(NextCandidate{ next, &path2, &path2_flipped, path_probability(path2), true });
}
}
size_t num_direct_neighbors = next_candidates.size();
//FIXME add the queue items to the candidates? These are valid moves as well.
if (num_direct_neighbors == 0) {
// Add the queue candidates.
for (MonotonicRegion *next : queue) {
assert(left_neighbors_unprocessed[next - regions.data()] == 1);
AntPath &path1 = path_matrix(region, dir, *next, false);
AntPath &path1_flipped = path_matrix(region, ! dir, *next, true);
AntPath &path2 = path_matrix(region, dir, *next, true);
AntPath &path2_flipped = path_matrix(region, ! dir, *next, false);
next_candidates.emplace_back(NextCandidate{ next, &path1, &path1_flipped, path_probability(path1), false });
next_candidates.emplace_back(NextCandidate{ next, &path2, &path2_flipped, path_probability(path2), true });
}
}
float dice = float(rng()) / float(rng.max());
std::vector<NextCandidate>::iterator take_path;
if (dice < probability_take_best) {
// Take the highest probability path.
take_path = std::max_element(next_candidates.begin(), next_candidates.end(), [](auto &l, auto &r){ return l.probability < r.probability; });
print_ant("\tTaking best path at probability %1% below %2%", dice, probability_take_best);
} else {
// Take the path based on the probability.
// Calculate the total probability.
float total_probability = std::accumulate(next_candidates.begin(), next_candidates.end(), 0.f, [](const float l, const NextCandidate& r) { return l + r.probability; });
// Take a random path based on the probability.
float probability_threshold = float(rng()) * total_probability / float(rng.max());
take_path = next_candidates.end();
-- take_path;
for (auto it = next_candidates.begin(); it < next_candidates.end(); ++ it)
if ((probability_threshold -= it->probability) <= 0.) {
take_path = it;
break;
}
print_ant("\tTaking path at probability threshold %1% of %2%", probability_threshold, total_probability);
}
// Move the other right neighbors with satisified constraints to the queue.
for (std::vector<NextCandidate>::iterator it_next_candidate = next_candidates.begin(); it_next_candidate != next_candidates.begin() + num_direct_neighbors; ++ it_next_candidate)
if ((queue.empty() || it_next_candidate->region != queue.back()) && it_next_candidate->region != take_path->region)
queue.emplace_back(it_next_candidate->region);
if (size_t(take_path - next_candidates.begin()) >= num_direct_neighbors) {
// Remove the selected path from the queue.
auto it = std::find(queue.begin(), queue.end(), take_path->region);
assert(it != queue.end());
*it = queue.back();
queue.pop_back();
}
// Extend the path.
MonotonicRegion *next_region = take_path->region;
bool next_dir = take_path->dir;
path.back().next = take_path->link;
path.back().next_flipped = take_path->link_flipped;
path.emplace_back(MonotonicRegionLink{ next_region, next_dir });
assert(left_neighbors_unprocessed[next_region - regions.data()] == 1);
left_neighbors_unprocessed[next_region - regions.data()] = 0;
print_ant("\tRegion (%1%:%2%,%3%) (%4%:%5%,%6%) length to prev %7%",
next_region->left.vline,
next_dir ? next_region->left.high : next_region->left.low,
next_dir ? next_region->left.low : next_region->left.high,
next_region->right.vline,
next_dir == next_region->flips ? next_region->right.high : next_region->right.low,
next_dir == next_region->flips ? next_region->right.low : next_region->right.high,
take_path->link->length);
print_ant("\tRegion (%1%:%2%,%3%) (%4%:%5%,%6%)",
path.back().region->left.vline,
path.back().flipped ? path.back().region->left.high : path.back().region->left.low,
path.back().flipped ? path.back().region->left.low : path.back().region->left.high,
path.back().region->right.vline,
path.back().flipped == path.back().region->flips ? path.back().region->right.high : path.back().region->right.low,
path.back().flipped == path.back().region->flips ? path.back().region->right.low : path.back().region->right.high);
// Update pheromones along this link, see Ant Colony System (ACS) update rule.
// http://www.scholarpedia.org/article/Ant_colony_optimization
// The goal here is to lower the pheromone trace for paths taken to diversify the next path picked in the same batch of ants.
take_path->link->pheromone = (1.f - pheromone_diversification) * take_path->link->pheromone + pheromone_diversification * pheromone_initial_deposit;
assert(validate_unprocessed());
}
// Perform 3-opt local optimization of the path.
monotonic_3_opt(path, segs);
// Measure path length.
assert(! path.empty());
float path_length = std::accumulate(path.begin(), path.end() - 1,
path.back().region->length(path.back().flipped),
[&path_matrix](const float l, const MonotonicRegionLink &r) {
const MonotonicRegionLink &next = *(&r + 1);
return l + r.region->length(r.flipped) + path_matrix(*r.region, r.flipped, *next.region, next.flipped).length;
});
// Save the shortest path.
print_ant("\tThis length: %1%, shortest length: %2%", path_length, best_path_length);
if (path_length < best_path_length) {
best_path_length = path_length;
std::swap(best_path, path);
#if 0 // #if ! defined(SLIC3R_DEBUG_ANTS) && ! defined(ndebug)
if (round == 0 && ant == 0)
std::cout << std::endl;
std::cout << Slic3r::format("round %1% ant %2% path length %3%", round, ant, path_length) << std::endl;
#endif
if (path_length == 0)
// Perfect path found.
goto end;
improved = true;
}
}
// Reinforce the path pheromones with the best path.
float total_cost = best_path_length + float(EPSILON);
for (size_t i = 0; i + 1 < path.size(); ++ i) {
MonotonicRegionLink &link = path[i];
link.next->pheromone = (1.f - pheromone_evaporation) * link.next->pheromone + pheromone_evaporation / total_cost;
}
if (improved)
num_rounds_no_change = 0;
else
++ num_rounds_no_change;
}
end:
return best_path;
}
// Traverse path, produce polylines.
static void polylines_from_paths(const std::vector<MonotonicRegionLink> &path, const ExPolygonWithOffset &poly_with_offset, const std::vector<SegmentedIntersectionLine> &segs, Polylines &polylines_out)
{
Polyline *polyline = nullptr;
auto finish_polyline = [&polyline, &polylines_out]() {
polyline->remove_duplicate_points();
// Handle duplicate points and zero length segments.
assert(!polyline->has_duplicate_points());
// Handle nearly zero length edges.
if (polyline->points.size() <= 1 ||
(polyline->points.size() == 2 &&
std::abs(polyline->points.front().x() - polyline->points.back().x()) < SCALED_EPSILON &&
std::abs(polyline->points.front().y() - polyline->points.back().y()) < SCALED_EPSILON))
polylines_out.pop_back();
else if (polylines_out.size() >= 2) {
assert(polyline->points.size() >= 2);
// Merge the two last polylines. An extrusion may have been split by an introduction of phony outer points on intersection lines
// to cope with pinching of inner offset contours.
Polyline &pl_prev = polylines_out[polylines_out.size() - 2];
if (std::abs(polyline->points.front().x() - pl_prev.points.back().x()) < SCALED_EPSILON &&
std::abs(polyline->points.front().y() - pl_prev.points.back().y()) < SCALED_EPSILON) {
pl_prev.points.back() = (pl_prev.points.back() + polyline->points.front()) / 2;
pl_prev.points.insert(pl_prev.points.end(), polyline->points.begin() + 1, polyline->points.end());
polylines_out.pop_back();
}
}
polyline = nullptr;
};
for (const MonotonicRegionLink &path_segment : path) {
MonotonicRegion &region = *path_segment.region;
bool dir = path_segment.flipped;
// From the initial point (i_vline, i_intersection), follow a path.
int i_intersection = region.left_intersection_point(dir);
int i_vline = region.left.vline;
if (polyline != nullptr && &path_segment != path.data()) {
// Connect previous path segment with the new one.
const MonotonicRegionLink &path_segment_prev = *(&path_segment - 1);
const MonotonicRegion &region_prev = *path_segment_prev.region;
bool dir_prev = path_segment_prev.flipped;
int i_vline_prev = region_prev.right.vline;
const SegmentedIntersectionLine &vline_prev = segs[i_vline_prev];
int i_intersection_prev = region_prev.right_intersection_point(dir_prev);
const SegmentIntersection *ip_prev = &vline_prev.intersections[i_intersection_prev];
bool extended = false;
if (i_vline_prev + 1 == i_vline) {
if (ip_prev->right_horizontal() == i_intersection && ip_prev->next_on_contour_quality == SegmentIntersection::LinkQuality::Valid) {
// Emit a horizontal connection contour.
emit_perimeter_prev_next_segment(poly_with_offset, segs, i_vline_prev, ip_prev->iContour, i_intersection_prev, i_intersection, *polyline, true);
extended = true;
}
}
if (! extended) {
// Finish the current vertical line,
assert(ip_prev->is_inner());
ip_prev->is_low() ? -- ip_prev : ++ ip_prev;
assert(ip_prev->is_outer());
polyline->points.back() = Point(vline_prev.pos, ip_prev->pos());
finish_polyline();
}
}
for (;;) {
const SegmentedIntersectionLine &vline = segs[i_vline];
const SegmentIntersection *it = &vline.intersections[i_intersection];
const bool going_up = it->is_low();
if (polyline == nullptr) {
polylines_out.emplace_back();
polyline = &polylines_out.back();
// Extend the infill line up to the outer contour.
polyline->points.emplace_back(vline.pos, (it + (going_up ? - 1 : 1))->pos());
} else
polyline->points.emplace_back(vline.pos, it->pos());
int iright = it->right_horizontal();
if (going_up) {
// Consume the complete vertical segment up to the inner contour.
for (;;) {
do {
++ it;
iright = std::max(iright, it->right_horizontal());
assert(it->is_inner());
} while (it->type != SegmentIntersection::INNER_HIGH || (it + 1)->type != SegmentIntersection::OUTER_HIGH);
polyline->points.emplace_back(vline.pos, it->pos());
int inext = it->vertical_up();
if (inext == -1 || it->vertical_up_quality() != SegmentIntersection::LinkQuality::Valid)
break;
assert(it->iContour == vline.intersections[inext].iContour);
emit_perimeter_segment_on_vertical_line(poly_with_offset, segs, i_vline, it->iContour, it - vline.intersections.data(), inext, *polyline, it->has_left_vertical_up());
it = vline.intersections.data() + inext;
}
} else {
// Going down.
assert(it->is_high());
assert(i_intersection > 0);
for (;;) {
do {
-- it;
if (int iright_new = it->right_horizontal(); iright_new != -1)
iright = iright_new;
assert(it->is_inner());
} while (it->type != SegmentIntersection::INNER_LOW || (it - 1)->type != SegmentIntersection::OUTER_LOW);
polyline->points.emplace_back(vline.pos, it->pos());
int inext = it->vertical_down();
if (inext == -1 || it->vertical_down_quality() != SegmentIntersection::LinkQuality::Valid)
break;
assert(it->iContour == vline.intersections[inext].iContour);
emit_perimeter_segment_on_vertical_line(poly_with_offset, segs, i_vline, it->iContour, it - vline.intersections.data(), inext, *polyline, it->has_right_vertical_down());
it = vline.intersections.data() + inext;
}
}
if (i_vline == region.right.vline)
break;
int inext = it->right_horizontal();
assert(iright != -1);
assert(inext == -1 || inext == iright);
// Find the end of the next overlapping vertical segment.
const SegmentedIntersectionLine &vline_right = segs[i_vline + 1];
const SegmentIntersection *right = going_up ?
&vertical_run_top(vline_right, vline_right.intersections[iright]) : &vertical_run_bottom(vline_right, vline_right.intersections[iright]);
i_intersection = int(right - vline_right.intersections.data());
if (inext == i_intersection && it->next_on_contour_quality == SegmentIntersection::LinkQuality::Valid) {
// Emit a horizontal connection contour.
emit_perimeter_prev_next_segment(poly_with_offset, segs, i_vline, it->iContour, it - vline.intersections.data(), inext, *polyline, true);
} else {
// Finish the current vertical line,
going_up ? ++ it : -- it;
assert(it->is_outer());
assert(it->is_high() == going_up);
polyline->points.back() = Point(vline.pos, it->pos());
finish_polyline();
}
++ i_vline;
}
}
if (polyline != nullptr) {
// Finish the current vertical line,
const MonotonicRegion &region = *path.back().region;
const SegmentedIntersectionLine &vline = segs[region.right.vline];
const SegmentIntersection *ip = &vline.intersections[region.right_intersection_point(path.back().flipped)];
assert(ip->is_inner());
ip->is_low() ? -- ip : ++ ip;
assert(ip->is_outer());
polyline->points.back() = Point(vline.pos, ip->pos());
finish_polyline();
}
}
bool FillRectilinear::fill_surface_by_lines(const Surface *surface, const FillParams &params, float angleBase, float pattern_shift, Polylines &polylines_out)
{
// At the end, only the new polylines will be rotated back.
size_t n_polylines_out_initial = polylines_out.size();
// Shrink the input polygon a bit first to not push the infill lines out of the perimeters.
// const float INFILL_OVERLAP_OVER_SPACING = 0.3f;
const float INFILL_OVERLAP_OVER_SPACING = 0.45f;
assert(INFILL_OVERLAP_OVER_SPACING > 0 && INFILL_OVERLAP_OVER_SPACING < 0.5f);
// Rotate polygons so that we can work with vertical lines here
std::pair<float, Point> rotate_vector = this->_infill_direction(surface);
rotate_vector.first += angleBase;
assert(params.density > 0.0001f && params.density <= 1.f);
coord_t line_spacing = coord_t(scale_(this->spacing) / params.density);
// On the polygons of poly_with_offset, the infill lines will be connected.
ExPolygonWithOffset poly_with_offset(
surface->expolygon,
- rotate_vector.first,
float(scale_(this->overlap - (0.5 - INFILL_OVERLAP_OVER_SPACING) * this->spacing)),
float(scale_(this->overlap - 0.5f * this->spacing)));
if (poly_with_offset.n_contours_inner == 0) {
// Not a single infill line fits.
//FIXME maybe one shall trigger the gap fill here?
return true;
}
BoundingBox bounding_box = poly_with_offset.bounding_box_src();
// define flow spacing according to requested density
if (params.full_infill() && !params.dont_adjust) {
line_spacing = this->_adjust_solid_spacing(bounding_box.size()(0), line_spacing);
this->spacing = unscale<double>(line_spacing);
} else {
// extend bounding box so that our pattern will be aligned with other layers
// Transform the reference point to the rotated coordinate system.
Point refpt = rotate_vector.second.rotated(- rotate_vector.first);
// _align_to_grid will not work correctly with positive pattern_shift.
coord_t pattern_shift_scaled = coord_t(scale_(pattern_shift)) % line_spacing;
refpt.x() -= (pattern_shift_scaled >= 0) ? pattern_shift_scaled : (line_spacing + pattern_shift_scaled);
bounding_box.merge(_align_to_grid(
bounding_box.min,
Point(line_spacing, line_spacing),
refpt));
}
// Intersect a set of euqally spaced vertical lines wiht expolygon.
// n_vlines = ceil(bbox_width / line_spacing)
size_t n_vlines = (bounding_box.max(0) - bounding_box.min(0) + line_spacing - 1) / line_spacing;
coord_t x0 = bounding_box.min(0);
if (params.full_infill())
x0 += (line_spacing + coord_t(SCALED_EPSILON)) / 2;
#ifdef SLIC3R_DEBUG
static int iRun = 0;
BoundingBox bbox_svg = poly_with_offset.bounding_box_outer();
::Slic3r::SVG svg(debug_out_path("FillRectilinear-%d.svg", iRun), bbox_svg); // , scale_(1.));
poly_with_offset.export_to_svg(svg);
{
::Slic3r::SVG svg(debug_out_path("FillRectilinear-initial-%d.svg", iRun), bbox_svg); // , scale_(1.));
poly_with_offset.export_to_svg(svg);
}
iRun ++;
#endif /* SLIC3R_DEBUG */
std::vector<SegmentedIntersectionLine> segs = slice_region_by_vertical_lines(poly_with_offset, n_vlines, x0, line_spacing);
// Connect by horizontal / vertical links, classify the links based on link_max_length as too long.
connect_segment_intersections_by_contours(poly_with_offset, segs, params, link_max_length);
#ifdef SLIC3R_DEBUG
// Paint the segments and finalize the SVG file.
for (size_t i_seg = 0; i_seg < segs.size(); ++ i_seg) {
SegmentedIntersectionLine &sil = segs[i_seg];
for (size_t i = 0; i < sil.intersections.size();) {
size_t j = i + 1;
for (; j < sil.intersections.size() && sil.intersections[j].is_inner(); ++ j) ;
if (i + 1 == j) {
svg.draw(Line(Point(sil.pos, sil.intersections[i].pos()), Point(sil.pos, sil.intersections[j].pos())), "blue");
} else {
svg.draw(Line(Point(sil.pos, sil.intersections[i].pos()), Point(sil.pos, sil.intersections[i+1].pos())), "green");
svg.draw(Line(Point(sil.pos, sil.intersections[i+1].pos()), Point(sil.pos, sil.intersections[j-1].pos())), (j - i + 1 > 4) ? "yellow" : "magenta");
svg.draw(Line(Point(sil.pos, sil.intersections[j-1].pos()), Point(sil.pos, sil.intersections[j].pos())), "green");
}
i = j + 1;
}
}
svg.Close();
#endif /* SLIC3R_DEBUG */
//FIXME this is a hack to get the monotonic infill rolling. We likely want a smarter switch, likely based on user decison.
bool monotonic_infill = params.monotonic; // || params.density > 0.99;
if (monotonic_infill) {
// Sometimes the outer contour pinches the inner contour from both sides along a single vertical line.
// This situation is not handled correctly by generate_montonous_regions().
// Insert phony OUTER_HIGH / OUTER_LOW pairs at the position where the contour is pinched.
pinch_contours_insert_phony_outer_intersections(segs);
std::vector<MonotonicRegion> regions = generate_montonous_regions(segs);
#ifdef INFILL_DEBUG_OUTPUT
{
static int iRun;
export_monotonous_regions_to_svg(poly_with_offset, segs, regions, debug_out_path("%s-%03d.svg", "MontonousRegions-initial", iRun ++));
}
#endif // INFILL_DEBUG_OUTPUT
connect_monotonic_regions(regions, poly_with_offset, segs);
if (! regions.empty()) {
std::mt19937_64 rng;
std::vector<MonotonicRegionLink> path = chain_monotonic_regions(regions, poly_with_offset, segs, rng);
polylines_from_paths(path, poly_with_offset, segs, polylines_out);
}
} else
traverse_graph_generate_polylines(poly_with_offset, params, this->link_max_length, segs, polylines_out);
#ifdef SLIC3R_DEBUG
{
{
::Slic3r::SVG svg(debug_out_path("FillRectilinear-final-%03d.svg", iRun), bbox_svg); // , scale_(1.));
poly_with_offset.export_to_svg(svg);
for (size_t i = n_polylines_out_initial; i < polylines_out.size(); ++ i)
svg.draw(polylines_out[i].lines(), "black");
}
// Paint a picture per polyline. This makes it easier to discover the order of the polylines and their overlap.
for (size_t i_polyline = n_polylines_out_initial; i_polyline < polylines_out.size(); ++ i_polyline) {
::Slic3r::SVG svg(debug_out_path("FillRectilinear-final-%03d-%03d.svg", iRun, i_polyline), bbox_svg); // , scale_(1.));
svg.draw(polylines_out[i_polyline].lines(), "black");
}
}
#endif /* SLIC3R_DEBUG */
// paths must be rotated back
for (Polylines::iterator it = polylines_out.begin() + n_polylines_out_initial; it != polylines_out.end(); ++ it) {
// No need to translate, the absolute position is irrelevant.
// it->translate(- rotate_vector.second(0), - rotate_vector.second(1));
assert(! it->has_duplicate_points());
it->rotate(rotate_vector.first);
//FIXME rather simplify the paths to avoid very short edges?
//assert(! it->has_duplicate_points());
it->remove_duplicate_points();
}
#ifdef SLIC3R_DEBUG
// Verify, that there are no duplicate points in the sequence.
for (Polyline &polyline : polylines_out)
assert(! polyline.has_duplicate_points());
#endif /* SLIC3R_DEBUG */
return true;
}
bool FillRectilinear::fill_surface_by_multilines(const Surface *surface, FillParams params, const std::initializer_list<SweepParams> &sweep_params, Polylines &polylines_out)
{
assert(sweep_params.size() > 1);
assert(! params.full_infill());
params.density /= double(sweep_params.size());
assert(params.density > 0.0001f && params.density <= 1.f);
ExPolygonWithOffset poly_with_offset_base(surface->expolygon, 0, float(scale_(this->overlap - 0.5 * this->spacing)));
if (poly_with_offset_base.n_contours == 0)
// Not a single infill line fits.
return true;
Polylines fill_lines;
coord_t line_width = coord_t(scale_(this->spacing));
coord_t line_spacing = coord_t(scale_(this->spacing) / params.density);
std::pair<float, Point> rotate_vector = this->_infill_direction(surface);
for (const SweepParams &sweep : sweep_params) {
size_t n_fill_lines_initial = fill_lines.size();
// Rotate polygons so that we can work with vertical lines here
double angle = rotate_vector.first + sweep.angle_base;
ExPolygonWithOffset poly_with_offset(poly_with_offset_base, - angle);
BoundingBox bounding_box = poly_with_offset.bounding_box_src();
// Don't produce infill lines, which fully overlap with the infill perimeter.
coord_t x_min = bounding_box.min.x() + line_width + coord_t(SCALED_EPSILON);
coord_t x_max = bounding_box.max.x() - line_width - coord_t(SCALED_EPSILON);
// extend bounding box so that our pattern will be aligned with other layers
// Transform the reference point to the rotated coordinate system.
Point refpt = rotate_vector.second.rotated(- angle);
// _align_to_grid will not work correctly with positive pattern_shift.
coord_t pattern_shift_scaled = coord_t(scale_(sweep.pattern_shift)) % line_spacing;
refpt.x() -= (pattern_shift_scaled >= 0) ? pattern_shift_scaled : (line_spacing + pattern_shift_scaled);
bounding_box.merge(_align_to_grid(bounding_box.min, Point(line_spacing, line_spacing), refpt));
// Intersect a set of euqally spaced vertical lines wiht expolygon.
// n_vlines = ceil(bbox_width / line_spacing)
const size_t n_vlines = (bounding_box.max.x() - bounding_box.min.x() + line_spacing - 1) / line_spacing;
const double cos_a = cos(angle);
const double sin_a = sin(angle);
for (const SegmentedIntersectionLine &vline : slice_region_by_vertical_lines(poly_with_offset, n_vlines, bounding_box.min.x(), line_spacing))
if (vline.pos > x_min) {
if (vline.pos >= x_max)
break;
for (auto it = vline.intersections.begin(); it != vline.intersections.end();) {
auto it_low = it ++;
assert(it_low->type == SegmentIntersection::OUTER_LOW);
if (it_low->type != SegmentIntersection::OUTER_LOW)
continue;
auto it_high = it;
assert(it_high->type == SegmentIntersection::OUTER_HIGH);
if (it_high->type == SegmentIntersection::OUTER_HIGH) {
fill_lines.emplace_back(Point(vline.pos, it_low->pos()).rotated(cos_a, sin_a), Point(vline.pos, it_high->pos()).rotated(cos_a, sin_a));
++ it;
}
}
}
}
if (params.dont_connect() || fill_lines.size() <= 1) {
if (fill_lines.size() > 1)
fill_lines = chain_polylines(std::move(fill_lines));
append(polylines_out, std::move(fill_lines));
} else
connect_infill(std::move(fill_lines), poly_with_offset_base.polygons_outer, get_extents(surface->expolygon.contour), polylines_out, this->spacing, params);
return true;
}
Polylines FillRectilinear::fill_surface(const Surface *surface, const FillParams &params)
{
Polylines polylines_out;
if (! fill_surface_by_lines(surface, params, 0.f, 0.f, polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillRectilinear::fill_surface() failed to fill a region.";
return polylines_out;
}
Polylines FillMonotonic::fill_surface(const Surface *surface, const FillParams &params)
{
FillParams params2 = params;
params2.monotonic = true;
Polylines polylines_out;
if (! fill_surface_by_lines(surface, params2, 0.f, 0.f, polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillMonotonous::fill_surface() failed to fill a region.";
return polylines_out;
}
Polylines FillGrid::fill_surface(const Surface *surface, const FillParams &params)
{
Polylines polylines_out;
if (! this->fill_surface_by_multilines(
surface, params,
{ { 0.f, 0.f }, { float(M_PI / 2.), 0.f } },
polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillGrid::fill_surface() failed to fill a region.";
return polylines_out;
}
Polylines FillTriangles::fill_surface(const Surface *surface, const FillParams &params)
{
Polylines polylines_out;
if (! this->fill_surface_by_multilines(
surface, params,
{ { 0.f, 0.f }, { float(M_PI / 3.), 0.f }, { float(2. * M_PI / 3.), 0. } },
polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillTriangles::fill_surface() failed to fill a region.";
return polylines_out;
}
Polylines FillStars::fill_surface(const Surface *surface, const FillParams &params)
{
Polylines polylines_out;
if (! this->fill_surface_by_multilines(
surface, params,
{ { 0.f, 0.f }, { float(M_PI / 3.), 0.f }, { float(2. * M_PI / 3.), float((3./2.) * this->spacing / params.density) } },
polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillStars::fill_surface() failed to fill a region.";
return polylines_out;
}
Polylines FillCubic::fill_surface(const Surface *surface, const FillParams &params)
{
Polylines polylines_out;
coordf_t dx = sqrt(0.5) * z;
if (! this->fill_surface_by_multilines(
surface, params,
{ { 0.f, float(dx) }, { float(M_PI / 3.), - float(dx) }, { float(M_PI * 2. / 3.), float(dx) } },
polylines_out))
BOOST_LOG_TRIVIAL(error) << "FillCubic::fill_surface() failed to fill a region.";
return polylines_out;
}
} // namespace Slic3r
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