C++ const_iterator::simplify_p方法代码示例

void
PerimeterGenerator::process()
{
    // other perimeters
    this->_mm3_per_mm           = this->perimeter_flow.mm3_per_mm();
    coord_t pwidth              = this->perimeter_flow.scaled_width();
    coord_t pspacing            = this->perimeter_flow.scaled_spacing();
    
    // external perimeters
    this->_ext_mm3_per_mm       = this->ext_perimeter_flow.mm3_per_mm();
    coord_t ext_pwidth          = this->ext_perimeter_flow.scaled_width();
    coord_t ext_pspacing        = this->ext_perimeter_flow.scaled_spacing();
    coord_t ext_pspacing2       = this->ext_perimeter_flow.scaled_spacing(this->perimeter_flow);
    
    // overhang perimeters
    this->_mm3_per_mm_overhang  = this->overhang_flow.mm3_per_mm();
    
    // solid infill
    coord_t ispacing            = this->solid_infill_flow.scaled_spacing();
    coord_t gap_area_threshold  = pwidth * pwidth;
    
    // Calculate the minimum required spacing between two adjacent traces.
    // This should be equal to the nominal flow spacing but we experiment
    // with some tolerance in order to avoid triggering medial axis when
    // some squishing might work. Loops are still spaced by the entire
    // flow spacing; this only applies to collapsing parts.
    // For ext_min_spacing we use the ext_pspacing calculated for two adjacent
    // external loops (which is the correct way) instead of using ext_pspacing2
    // which is the spacing between external and internal, which is not correct
    // and would make the collapsing (thus the details resolution) dependent on 
    // internal flow which is unrelated.
    coord_t min_spacing         = pspacing      * (1 - INSET_OVERLAP_TOLERANCE);
    coord_t ext_min_spacing     = ext_pspacing  * (1 - INSET_OVERLAP_TOLERANCE);
    
    // prepare grown lower layer slices for overhang detection
    if (this->lower_slices != NULL && this->config->overhangs) {
        // We consider overhang any part where the entire nozzle diameter is not supported by the
        // lower layer, so we take lower slices and offset them by half the nozzle diameter used 
        // in the current layer
        double nozzle_diameter = this->print_config->nozzle_diameter.get_at(this->config->perimeter_extruder-1);
        
        this->_lower_slices_p = offset(*this->lower_slices, scale_(+nozzle_diameter/2));
    }
    
    // we need to process each island separately because we might have different
    // extra perimeters for each one
    for (Surfaces::const_iterator surface = this->slices->surfaces.begin();
        surface != this->slices->surfaces.end(); ++surface) {
        // detect how many perimeters must be generated for this island
        signed short loop_number = this->config->perimeters + surface->extra_perimeters;
        loop_number--;  // 0-indexed loops
        
        Polygons gaps;
        
        Polygons last = surface->expolygon.simplify_p(SCALED_RESOLUTION);
        if (loop_number >= 0) {  // no loops = -1
            
            std::vector<PerimeterGeneratorLoops> contours(loop_number+1);    // depth => loops
            std::vector<PerimeterGeneratorLoops> holes(loop_number+1);       // depth => loops
            Polylines thin_walls;
            
            // we loop one time more than needed in order to find gaps after the last perimeter was applied
            for (signed short i = 0; i <= loop_number+1; ++i) {  // outer loop is 0
                Polygons offsets;
                if (i == 0) {
                    // the minimum thickness of a single loop is:
                    // ext_width/2 + ext_spacing/2 + spacing/2 + width/2
                    if (this->config->thin_walls) {
                        offsets = offset2(
                            last,
                            -(ext_pwidth/2 + ext_min_spacing/2 - 1),
                            +(ext_min_spacing/2 - 1)
                        );
                    } else {
                        offsets = offset(last, -ext_pwidth/2);
                    }
                    
                    // look for thin walls
                    if (this->config->thin_walls) {
                        Polygons diffpp = diff(
                            last,
                            offset(offsets, +ext_pwidth/2),
                            true  // medial axis requires non-overlapping geometry
                        );
                        
                        // the following offset2 ensures almost nothing in @thin_walls is narrower than $min_width
                        // (actually, something larger than that still may exist due to mitering or other causes)
                        coord_t min_width = ext_pwidth / 2;
                        ExPolygons expp = offset2_ex(diffpp, -min_width/2, +min_width/2);
                        
                        // the maximum thickness of our thin wall area is equal to the minimum thickness of a single loop
                        Polylines pp;
                        for (ExPolygons::const_iterator ex = expp.begin(); ex != expp.end(); ++ex)
                            ex->medial_axis(ext_pwidth + ext_pspacing2, min_width, &pp);
                        
                        double threshold = ext_pwidth * 2;
                        for (Polylines::const_iterator p = pp.begin(); p != pp.end(); ++p) {
                            if (p->length() > threshold) {
                                thin_walls.push_back(*p);
                            }
//.........这里部分代码省略.........