C++ Polyline::length方法代码示例

bool
GCode::needs_retraction(const Polyline &travel, ExtrusionRole role)
{
    if (travel.length() < scale_(EXTRUDER_CONFIG(retract_before_travel))) {
        // skip retraction if the move is shorter than the configured threshold
        return false;
    }
    
    if (role == erSupportMaterial) {
        const SupportLayer* support_layer = dynamic_cast<const SupportLayer*>(this->layer);
        if (support_layer != NULL && support_layer->support_islands.contains(travel)) {
            // skip retraction if this is a travel move inside a support material island
            return false;
        }
    }
    
    if (this->config.only_retract_when_crossing_perimeters && this->layer != NULL) {
        if (this->config.fill_density.value > 0
            && this->layer->any_internal_region_slice_contains(travel)) {
            /*  skip retraction if travel is contained in an internal slice *and*
                internal infill is enabled (so that stringing is entirely not visible)  */
            return false;
        } else if (this->layer->any_bottom_region_slice_contains(travel)
            && this->layer->upper_layer != NULL
            && this->layer->upper_layer->slices.contains(travel)
            && (this->config.bottom_solid_layers.value >= 2 || this->config.fill_density.value > 0)) {
            /*  skip retraction if travel is contained in an *infilled* bottom slice
                but only if it's also covered by an *infilled* upper layer's slice
                so that it's not visible from above (a bottom surface might not have an
                upper slice in case of a thin membrane)  */
            return false;
        }
    }
    
    // retract if only_retract_when_crossing_perimeters is disabled or doesn't apply
    return true;
}

//.........这里部分代码省略.........
            if (edge->is_infinite()) continue;
            
            Polyline polyline;
            polyline.points.push_back(Point( edge->vertex0()->x(), edge->vertex0()->y() ));
            polyline.points.push_back(Point( edge->vertex1()->x(), edge->vertex1()->y() ));
            polylines->push_back(polyline);
        }
        return;
    }
    */
    
    // collect valid edges (i.e. prune those not belonging to MAT)
    // note: this keeps twins, so it contains twice the number of the valid edges
    this->edges.clear();
    for (VD::const_edge_iterator edge = this->vd.edges().begin(); edge != this->vd.edges().end(); ++edge) {
        // if we only process segments representing closed loops, none if the
        // infinite edges (if any) would be part of our MAT anyway
        if (edge->is_secondary() || edge->is_infinite()) continue;
        this->edges.insert(&*edge);
    }
    
    // count valid segments for each vertex
    std::map< const VD::vertex_type*,std::set<const VD::edge_type*> > vertex_edges;
    std::set<const VD::vertex_type*> entry_nodes;
    for (VD::const_vertex_iterator vertex = this->vd.vertices().begin(); vertex != this->vd.vertices().end(); ++vertex) {
        // get a reference to the list of valid edges originating from this vertex
        std::set<const VD::edge_type*>& edges = vertex_edges[&*vertex];
        
        // get one random edge originating from this vertex
        const VD::edge_type* edge = vertex->incident_edge();
        do {
            if (this->edges.count(edge) > 0)    // only count valid edges
                edges.insert(edge);
            edge = edge->rot_next();            // next edge originating from this vertex
        } while (edge != vertex->incident_edge());
        
        // if there's only one edge starting at this vertex then it's a leaf
        size_t edge_count = edges.size();
        if (edge_count == 1) {
            entry_nodes.insert(&*vertex);
        }
    }
    
    // prune recursively
    while (!entry_nodes.empty()) {
        // get a random entry node
        const VD::vertex_type* v = *entry_nodes.begin();
    
        // get edge starting from v
        assert(!vertex_edges[v].empty());
        const VD::edge_type* edge = *vertex_edges[v].begin();
        
        if (!this->is_valid_edge(*edge)) {
            // if edge is not valid, erase it from edge list
            (void)this->edges.erase(edge);
            (void)this->edges.erase(edge->twin());
            
            // decrement edge counters for the affected nodes
            const VD::vertex_type* v1 = edge->vertex1();
            (void)vertex_edges[v].erase(edge);
            (void)vertex_edges[v1].erase(edge->twin());
            
            // also, check whether the end vertex is a new leaf
            if (vertex_edges[v1].size() == 1) {
                entry_nodes.insert(v1);
            } else if (vertex_edges[v1].empty()) {
                entry_nodes.erase(v1);
            }
        }
        
        // remove node from the set to prevent it from being visited again
        entry_nodes.erase(v);
    }
    
    // iterate through the valid edges to build polylines
    while (!this->edges.empty()) {
        const VD::edge_type& edge = **this->edges.begin();
        
        // start a polyline
        Polyline polyline;
        polyline.points.push_back(Point( edge.vertex0()->x(), edge.vertex0()->y() ));
        polyline.points.push_back(Point( edge.vertex1()->x(), edge.vertex1()->y() ));
        
        // remove this edge and its twin from the available edges
        (void)this->edges.erase(&edge);
        (void)this->edges.erase(edge.twin());
        
        // get next points
        this->process_edge_neighbors(edge, &polyline.points);
        
        // get previous points
        Points pp;
        this->process_edge_neighbors(*edge.twin(), &pp);
        polyline.points.insert(polyline.points.begin(), pp.rbegin(), pp.rend());
        
        // append polyline to result if it's not too small
        if (polyline.length() > this->max_width)
            polylines->push_back(polyline);
    }
}