BambuStudio/libslic3r/Fill/Lightning/TreeNode.cpp

441 lines
17 KiB
C++

//Copyright (c) 2021 Ultimaker B.V.
//CuraEngine is released under the terms of the AGPLv3 or higher.
#include "TreeNode.hpp"
#include "../../Geometry.hpp"
namespace Slic3r::FillLightning {
coord_t Node::getWeightedDistance(const Point& unsupported_location, const coord_t& supporting_radius) const
{
constexpr coord_t min_valence_for_boost = 0;
constexpr coord_t max_valence_for_boost = 4;
constexpr coord_t valence_boost_multiplier = 4;
const size_t valence = (!m_is_root) + m_children.size();
const coord_t valence_boost = (min_valence_for_boost < valence && valence < max_valence_for_boost) ? valence_boost_multiplier * supporting_radius : 0;
const auto dist_here = coord_t((getLocation() - unsupported_location).cast<double>().norm());
return dist_here - valence_boost;
}
bool Node::hasOffspring(const NodeSPtr& to_be_checked) const
{
if (to_be_checked == shared_from_this())
return true;
for (auto& child_ptr : m_children)
if (child_ptr->hasOffspring(to_be_checked))
return true;
return false;
}
NodeSPtr Node::addChild(const Point& child_loc)
{
assert(m_p != child_loc);
NodeSPtr child = Node::create(child_loc);
return addChild(child);
}
NodeSPtr Node::addChild(NodeSPtr& new_child)
{
assert(new_child != shared_from_this());
//assert(p != new_child->p); // NOTE: No problem for now. Issue to solve later. Maybe even afetr final. Low prio.
m_children.push_back(new_child);
new_child->m_parent = shared_from_this();
new_child->m_is_root = false;
return new_child;
}
void Node::propagateToNextLayer(
std::vector<NodeSPtr>& next_trees,
const Polygons& next_outlines,
const EdgeGrid::Grid& outline_locator,
const coord_t prune_distance,
const coord_t smooth_magnitude,
const coord_t max_remove_colinear_dist) const
{
auto tree_below = deepCopy();
tree_below->prune(prune_distance);
tree_below->straighten(smooth_magnitude, max_remove_colinear_dist);
if (tree_below->realign(next_outlines, outline_locator, next_trees))
next_trees.push_back(tree_below);
}
// NOTE: Depth-first, as currently implemented.
// Skips the root (because that has no root itself), but all initial nodes will have the root point anyway.
void Node::visitBranches(const std::function<void(const Point&, const Point&)>& visitor) const
{
for (const auto& node : m_children) {
assert(node->m_parent.lock() == shared_from_this());
visitor(m_p, node->m_p);
node->visitBranches(visitor);
}
}
// NOTE: Depth-first, as currently implemented.
void Node::visitNodes(const std::function<void(NodeSPtr)>& visitor)
{
visitor(shared_from_this());
for (const auto& node : m_children) {
assert(node->m_parent.lock() == shared_from_this());
node->visitNodes(visitor);
}
}
Node::Node(const Point& p, const std::optional<Point>& last_grounding_location /*= std::nullopt*/) :
m_is_root(true), m_p(p), m_last_grounding_location(last_grounding_location)
{}
NodeSPtr Node::deepCopy() const
{
NodeSPtr local_root = Node::create(m_p);
local_root->m_is_root = m_is_root;
if (m_is_root)
{
local_root->m_last_grounding_location = m_last_grounding_location.value_or(m_p);
}
local_root->m_children.reserve(m_children.size());
for (const auto& node : m_children)
{
NodeSPtr child = node->deepCopy();
child->m_parent = local_root;
local_root->m_children.push_back(child);
}
return local_root;
}
void Node::reroot(const NodeSPtr &new_parent)
{
if (! m_is_root) {
auto old_parent = m_parent.lock();
old_parent->reroot(shared_from_this());
m_children.push_back(old_parent);
}
if (new_parent) {
m_children.erase(std::remove(m_children.begin(), m_children.end(), new_parent), m_children.end());
m_is_root = false;
m_parent = new_parent;
} else {
m_is_root = true;
m_parent.reset();
}
}
NodeSPtr Node::closestNode(const Point& loc)
{
NodeSPtr result = shared_from_this();
auto closest_dist2 = coord_t((m_p - loc).cast<double>().norm());
for (const auto& child : m_children) {
NodeSPtr candidate_node = child->closestNode(loc);
const auto child_dist2 = coord_t((candidate_node->m_p - loc).cast<double>().norm());
if (child_dist2 < closest_dist2) {
closest_dist2 = child_dist2;
result = candidate_node;
}
}
return result;
}
bool inside(const Polygons &polygons, const Point &p)
{
int poly_count_inside = 0;
for (const Polygon &poly : polygons) {
const int is_inside_this_poly = ClipperLib::PointInPolygon(p, poly.points);
if (is_inside_this_poly == -1)
return true;
poly_count_inside += is_inside_this_poly;
}
return (poly_count_inside % 2) == 1;
}
bool lineSegmentPolygonsIntersection(const Point& a, const Point& b, const EdgeGrid::Grid& outline_locator, Point& result, const coord_t within_max_dist)
{
struct Visitor {
bool operator()(coord_t iy, coord_t ix) {
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second; ++it_contour_and_segment) {
// End points of the line segment and their vector.
auto segment = grid.segment(*it_contour_and_segment);
if (Vec2d ip; Geometry::segment_segment_intersection(segment.first.cast<double>(), segment.second.cast<double>(), this->line_a, this->line_b, ip))
if (double d = (this->intersection_pt - this->line_b).squaredNorm(); d < d2min) {
this->d2min = d;
this->intersection_pt = ip;
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid& grid;
Vec2d line_a;
Vec2d line_b;
Vec2d intersection_pt;
double d2min { std::numeric_limits<double>::max() };
} visitor { outline_locator, a.cast<double>(), b.cast<double>() };
outline_locator.visit_cells_intersecting_line(a, b, visitor);
if (visitor.d2min < double(within_max_dist) * double(within_max_dist)) {
result = Point(visitor.intersection_pt);
return true;
}
return false;
}
bool Node::realign(const Polygons& outlines, const EdgeGrid::Grid& outline_locator, std::vector<NodeSPtr>& rerooted_parts)
{
if (outlines.empty())
return false;
if (inside(outlines, m_p)) {
// Only keep children that have an unbroken connection to here, realign will put the rest in rerooted parts due to recursion:
Point coll;
bool reground_me = false;
m_children.erase(std::remove_if(m_children.begin(), m_children.end(), [&](const NodeSPtr &child) {
bool connect_branch = child->realign(outlines, outline_locator, rerooted_parts);
// Find an intersection of the line segment from p to child->p, at maximum outline_locator.resolution() * 2 distance from p.
if (connect_branch && lineSegmentPolygonsIntersection(child->m_p, m_p, outline_locator, coll, outline_locator.resolution() * 2)) {
child->m_last_grounding_location.reset();
child->m_parent.reset();
child->m_is_root = true;
rerooted_parts.push_back(child);
reground_me = true;
connect_branch = false;
}
return ! connect_branch;
}), m_children.end());
if (reground_me)
m_last_grounding_location.reset();
return true;
}
// 'Lift' any decendants out of this tree:
for (auto& child : m_children)
if (child->realign(outlines, outline_locator, rerooted_parts)) {
child->m_last_grounding_location = m_p;
child->m_parent.reset();
child->m_is_root = true;
rerooted_parts.push_back(child);
}
m_children.clear();
return false;
}
void Node::straighten(const coord_t magnitude, const coord_t max_remove_colinear_dist)
{
straighten(magnitude, m_p, 0, int64_t(max_remove_colinear_dist) * int64_t(max_remove_colinear_dist));
}
Node::RectilinearJunction Node::straighten(
const coord_t magnitude,
const Point& junction_above,
const coord_t accumulated_dist,
const int64_t max_remove_colinear_dist2)
{
constexpr coord_t junction_magnitude_factor_numerator = 3;
constexpr coord_t junction_magnitude_factor_denominator = 4;
const coord_t junction_magnitude = magnitude * junction_magnitude_factor_numerator / junction_magnitude_factor_denominator;
if (m_children.size() == 1)
{
auto child_p = m_children.front();
auto child_dist = coord_t((m_p - child_p->m_p).cast<double>().norm());
RectilinearJunction junction_below = child_p->straighten(magnitude, junction_above, accumulated_dist + child_dist, max_remove_colinear_dist2);
coord_t total_dist_to_junction_below = junction_below.total_recti_dist;
const Point& a = junction_above;
Point b = junction_below.junction_loc;
if (a != b) // should always be true!
{
Point ab = b - a;
Point destination = (a.cast<int64_t>() + ab.cast<int64_t>() * int64_t(accumulated_dist) / std::max(int64_t(1), int64_t(total_dist_to_junction_below))).cast<coord_t>();
if ((destination - m_p).cast<int64_t>().squaredNorm() <= int64_t(magnitude) * int64_t(magnitude))
m_p = destination;
else
m_p += ((destination - m_p).cast<double>().normalized() * magnitude).cast<coord_t>();
}
{ // remove nodes on linear segments
constexpr coord_t close_enough = 10;
child_p = m_children.front(); //recursive call to straighten might have removed the child
const NodeSPtr& parent_node = m_parent.lock();
if (parent_node &&
(child_p->m_p - parent_node->m_p).cast<int64_t>().squaredNorm() < max_remove_colinear_dist2 &&
Line::distance_to_squared(m_p, parent_node->m_p, child_p->m_p) < close_enough * close_enough) {
child_p->m_parent = m_parent;
for (auto& sibling : parent_node->m_children)
{ // find this node among siblings
if (sibling == shared_from_this())
{
sibling = child_p; // replace this node by child
break;
}
}
}
}
return junction_below;
}
else
{
constexpr coord_t weight = 1000;
Point junction_moving_dir = ((junction_above - m_p).cast<double>().normalized() * weight).cast<coord_t>();
bool prevent_junction_moving = false;
for (auto& child_p : m_children)
{
const auto child_dist = coord_t((m_p - child_p->m_p).cast<double>().norm());
RectilinearJunction below = child_p->straighten(magnitude, m_p, child_dist, max_remove_colinear_dist2);
junction_moving_dir += ((below.junction_loc - m_p).cast<double>().normalized() * weight).cast<coord_t>();
if (below.total_recti_dist < magnitude) // TODO: make configurable?
{
prevent_junction_moving = true; // prevent flipflopping in branches due to straightening and junctoin moving clashing
}
}
if (junction_moving_dir != Point(0, 0) && ! m_children.empty() && ! m_is_root && ! prevent_junction_moving)
{
auto junction_moving_dir_len = coord_t(junction_moving_dir.norm());
if (junction_moving_dir_len > junction_magnitude)
{
junction_moving_dir = junction_moving_dir * junction_magnitude / junction_moving_dir_len;
}
m_p += junction_moving_dir;
}
return RectilinearJunction{ accumulated_dist, m_p };
}
}
// Prune the tree from the extremeties (leaf-nodes) until the pruning distance is reached.
coord_t Node::prune(const coord_t& pruning_distance)
{
if (pruning_distance <= 0)
return 0;
coord_t max_distance_pruned = 0;
for (auto child_it = m_children.begin(); child_it != m_children.end(); ) {
auto& child = *child_it;
coord_t dist_pruned_child = child->prune(pruning_distance);
if (dist_pruned_child >= pruning_distance)
{ // pruning is finished for child; dont modify further
max_distance_pruned = std::max(max_distance_pruned, dist_pruned_child);
++child_it;
} else {
const Point a = getLocation();
const Point b = child->getLocation();
const Point ba = a - b;
const auto ab_len = coord_t(ba.cast<double>().norm());
if (dist_pruned_child + ab_len <= pruning_distance) {
// we're still in the process of pruning
assert(child->m_children.empty() && "when pruning away a node all it's children must already have been pruned away");
max_distance_pruned = std::max(max_distance_pruned, dist_pruned_child + ab_len);
child_it = m_children.erase(child_it);
} else {
// pruning stops in between this node and the child
const Point n = b + (ba.cast<double>().normalized() * (pruning_distance - dist_pruned_child)).cast<coord_t>();
assert(std::abs((n - b).cast<double>().norm() + dist_pruned_child - pruning_distance) < 10 && "total pruned distance must be equal to the pruning_distance");
max_distance_pruned = std::max(max_distance_pruned, pruning_distance);
child->setLocation(n);
++child_it;
}
}
}
return max_distance_pruned;
}
void Node::convertToPolylines(Polylines &output, const coord_t line_overlap) const
{
Polylines result;
result.emplace_back();
convertToPolylines(0, result);
removeJunctionOverlap(result, line_overlap);
append(output, std::move(result));
}
void Node::convertToPolylines(size_t long_line_idx, Polylines &output) const
{
if (m_children.empty()) {
output[long_line_idx].points.push_back(m_p);
return;
}
size_t first_child_idx = rand() % m_children.size();
m_children[first_child_idx]->convertToPolylines(long_line_idx, output);
output[long_line_idx].points.push_back(m_p);
for (size_t idx_offset = 1; idx_offset < m_children.size(); idx_offset++) {
size_t child_idx = (first_child_idx + idx_offset) % m_children.size();
const Node& child = *m_children[child_idx];
output.emplace_back();
size_t child_line_idx = output.size() - 1;
child.convertToPolylines(child_line_idx, output);
output[child_line_idx].points.emplace_back(m_p);
}
}
void Node::removeJunctionOverlap(Polylines &result_lines, const coord_t line_overlap) const
{
const coord_t reduction = line_overlap;
size_t res_line_idx = 0;
while (res_line_idx < result_lines.size()) {
Polyline &polyline = result_lines[res_line_idx];
if (polyline.size() <= 1) {
polyline = std::move(result_lines.back());
result_lines.pop_back();
continue;
}
coord_t to_be_reduced = reduction;
Point a = polyline.back();
for (int point_idx = int(polyline.size()) - 2; point_idx >= 0; point_idx--) {
const Point b = polyline.points[point_idx];
const Point ab = b - a;
const auto ab_len = coord_t(ab.cast<double>().norm());
if (ab_len >= to_be_reduced) {
polyline.points.back() = a + (ab.cast<double>() * (double(to_be_reduced) / ab_len)).cast<coord_t>();
break;
} else {
to_be_reduced -= ab_len;
polyline.points.pop_back();
}
a = b;
}
if (polyline.size() <= 1) {
polyline = std::move(result_lines.back());
result_lines.pop_back();
} else
++ res_line_idx;
}
}
#ifdef LIGHTNING_TREE_NODE_DEBUG_OUTPUT
void export_to_svg(const NodeSPtr &root_node, SVG &svg)
{
for (const NodeSPtr &children : root_node->m_children) {
svg.draw(Line(root_node->getLocation(), children->getLocation()), "red");
export_to_svg(children, svg);
}
}
void export_to_svg(const std::string &path, const Polygons &contour, const std::vector<NodeSPtr> &root_nodes) {
BoundingBox bbox = get_extents(contour);
bbox.offset(SCALED_EPSILON);
SVG svg(path, bbox);
svg.draw_outline(contour, "blue");
for (const NodeSPtr &root_node: root_nodes) {
for (const NodeSPtr &children: root_node->m_children) {
svg.draw(Line(root_node->getLocation(), children->getLocation()), "red");
export_to_svg(children, svg);
}
}
}
#endif /* LIGHTNING_TREE_NODE_DEBUG_OUTPUT */
} // namespace Slic3r::FillLightning