C++ Paths::begin方法代码示例

T
ClipperPaths_to_Slic3rMultiPoints(const ClipperLib::Paths &input)
{
    T retval;
    for (ClipperLib::Paths::const_iterator it = input.begin(); it != input.end(); ++it)
        retval.push_back(ClipperPath_to_Slic3rMultiPoint<typename T::value_type>(*it));
    return retval;
}

Slic3r::Polylines ClipperPaths_to_Slic3rPolylines(const ClipperLib::Paths &input)
{
    Slic3r::Polylines retval;
    retval.reserve(input.size());
    for (ClipperLib::Paths::const_iterator it = input.begin(); it != input.end(); ++it)
        retval.emplace_back(ClipperPath_to_Slic3rPolyline(*it));
    return retval;
}

void scaleClipperPolygons(ClipperLib::Paths &polygons)
{
    PROFILE_FUNC();
    for (ClipperLib::Paths::iterator it = polygons.begin(); it != polygons.end(); ++it)
        for (ClipperLib::Path::iterator pit = (*it).begin(); pit != (*it).end(); ++pit) {
            pit->X <<= CLIPPER_OFFSET_POWER_OF_2;
            pit->Y <<= CLIPPER_OFFSET_POWER_OF_2;
        }
}

// This is a safe variant of the polygon offset, tailored for a single ExPolygon:
// a single polygon with multiple non-overlapping holes.
// Each contour and hole is offsetted separately, then the holes are subtracted from the outer contours.
ClipperLib::Paths _offset(const Slic3r::ExPolygon &expolygon, const float delta,
    ClipperLib::JoinType joinType, double miterLimit)
{
//    printf("new ExPolygon offset\n");
    // 1) Offset the outer contour.
    const float delta_scaled = delta * float(CLIPPER_OFFSET_SCALE);
    ClipperLib::Paths contours;
    {
        ClipperLib::Path input = Slic3rMultiPoint_to_ClipperPath(expolygon.contour);
        scaleClipperPolygon(input);
        ClipperLib::ClipperOffset co;
        if (joinType == jtRound)
            co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
        else
            co.MiterLimit = miterLimit;
        co.ShortestEdgeLength = double(std::abs(delta_scaled * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR));
        co.AddPath(input, joinType, ClipperLib::etClosedPolygon);
        co.Execute(contours, delta_scaled);
    }

    // 2) Offset the holes one by one, collect the results.
    ClipperLib::Paths holes;
    {
        holes.reserve(expolygon.holes.size());
        for (Polygons::const_iterator it_hole = expolygon.holes.begin(); it_hole != expolygon.holes.end(); ++ it_hole) {
            ClipperLib::Path input = Slic3rMultiPoint_to_ClipperPath_reversed(*it_hole);
            scaleClipperPolygon(input);
            ClipperLib::ClipperOffset co;
            if (joinType == jtRound)
                co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
            else
                co.MiterLimit = miterLimit;
            co.ShortestEdgeLength = double(std::abs(delta_scaled * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR));
            co.AddPath(input, joinType, ClipperLib::etClosedPolygon);
            ClipperLib::Paths out;
            co.Execute(out, - delta_scaled);
            holes.insert(holes.end(), out.begin(), out.end());
        }
    }

    // 3) Subtract holes from the contours.
    ClipperLib::Paths output;
    if (holes.empty()) {
        output = std::move(contours);
    } else {
        ClipperLib::Clipper clipper;
        clipper.Clear();
        clipper.AddPaths(contours, ClipperLib::ptSubject, true);
        clipper.AddPaths(holes, ClipperLib::ptClip, true);
        clipper.Execute(ClipperLib::ctDifference, output, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
    }
    
    // 4) Unscale the output.
    unscaleClipperPolygons(output);
    return output;
}

void
scaleClipperPolygons(ClipperLib::Paths &polygons, const double scale)
{
    for (ClipperLib::Paths::iterator it = polygons.begin(); it != polygons.end(); ++it) {
        for (ClipperLib::Path::iterator pit = (*it).begin(); pit != (*it).end(); ++pit) {
            (*pit).X *= scale;
            (*pit).Y *= scale;
        }
    }
}

void unscaleClipperPolygons(ClipperLib::Paths &polygons)
{
    PROFILE_FUNC();
    for (ClipperLib::Paths::iterator it = polygons.begin(); it != polygons.end(); ++it)
        for (ClipperLib::Path::iterator pit = (*it).begin(); pit != (*it).end(); ++pit) {
            pit->X += CLIPPER_OFFSET_SCALE_ROUNDING_DELTA;
            pit->Y += CLIPPER_OFFSET_SCALE_ROUNDING_DELTA;
            pit->X >>= CLIPPER_OFFSET_POWER_OF_2;
            pit->Y >>= CLIPPER_OFFSET_POWER_OF_2;
        }
}

void
ClipperPaths_to_Slic3rMultiPoints(const ClipperLib::Paths &input, T* output)
{
    PROFILE_FUNC();
    output->clear();
    output->reserve(input.size());
    for (ClipperLib::Paths::const_iterator it = input.begin(); it != input.end(); ++it) {
        typename T::value_type p;
        ClipperPath_to_Slic3rMultiPoint(*it, &p);
        output->push_back(p);
    }
}

std::vector<polygon> polygon::from(const ClipperLib::Paths& paths, base_int maxDenom)
{
	std::vector<polygon> ret;
	for(auto iter = paths.begin(); iter != paths.end(); iter++)
	{
		ret.push_back(polygon());
		auto& polyRef = ret.back();
		for(auto point = iter->begin(); point != iter->end(); point++)
		{
			polyRef.vertexes.push_back(vec2d(int_frac(point->X, maxDenom), int_frac(point->Y, maxDenom)));
		}
	}
	return ret;
}

void ElementGeometryClipper::visitArea(const Area& area)
{
    ClipperLib::Path areaShape;
    PointLocation pointLocation = setPath(quadKeyBbox_, area, areaShape);
    // 1. all geometry inside current quadkey: no need to truncate.
    if (pointLocation == PointLocation::AllInside) {
        callback_(area, quadKey_);
        return;
    }

    // 2. all geometry outside: skip
    if (pointLocation == PointLocation::AllOutside) {
        return;
    }

    ClipperLib::Paths solution;
    clipper_.AddPath(areaShape, ClipperLib::ptSubject, true);
    clipper_.AddPath(createPathFromBoundingBox(), ClipperLib::ptClip, true);
    clipper_.Execute(ClipperLib::ctIntersection, solution);
    clipper_.Clear();

    // 3. way intersects border only once: store a copy with clipped geometry
    if (solution.size() == 1) {
        Area clippedArea;
        setData(clippedArea, area, solution[0]);
        callback_(clippedArea, quadKey_);
    }
        // 4. in this case, result should be stored as relation (collection of areas)
    else {
        Relation relation;
        relation.id = area.id;
        relation.tags = area.tags;
        relation.elements.reserve(solution.size());
        for (auto it = solution.begin(); it != solution.end(); ++it) {
            auto clippedArea = std::make_shared<Area> ();
            clippedArea->id = area.id;
            setCoordinates(*clippedArea, *it);
            relation.elements.push_back(clippedArea);
        }
        callback_(relation, quadKey_);
    }
}

// This is a safe variant of the polygon offset, tailored for a single ExPolygon:
// a single polygon with multiple non-overlapping holes.
// Each contour and hole is offsetted separately, then the holes are subtracted from the outer contours.
void offset(const Slic3r::ExPolygons &expolygons, ClipperLib::Paths* retval, const float delta,
    ClipperLib::JoinType joinType, double miterLimit)
{
//    printf("new ExPolygon offset\n");
    const float delta_scaled = delta * float(CLIPPER_OFFSET_SCALE);
    ClipperLib::Paths contours;
    ClipperLib::Paths holes;
    contours.reserve(expolygons.size());
    {
        size_t n_holes = 0;
        for (size_t i = 0; i < expolygons.size(); ++ i)
            n_holes += expolygons[i].holes.size();
        holes.reserve(n_holes);
    }

    for (Slic3r::ExPolygons::const_iterator it_expoly = expolygons.begin(); it_expoly != expolygons.end(); ++ it_expoly) {
        // 1) Offset the outer contour.
        {
            ClipperLib::Path input;
            Slic3rMultiPoint_to_ClipperPath(it_expoly->contour, &input);
            scaleClipperPolygon(input);
            ClipperLib::ClipperOffset co;
            if (joinType == jtRound)
                co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
            else
                co.MiterLimit = miterLimit;
            co.AddPath(input, joinType, ClipperLib::etClosedPolygon);
            ClipperLib::Paths out;
            co.Execute(out, delta_scaled);
            contours.insert(contours.end(), out.begin(), out.end());
        }

        // 2) Offset the holes one by one, collect the results.
        {
            for (Polygons::const_iterator it_hole = it_expoly->holes.begin(); it_hole != it_expoly->holes.end(); ++ it_hole) {
                ClipperLib::Path input;
                Slic3rMultiPoint_to_ClipperPath_reversed(*it_hole, &input);
                scaleClipperPolygon(input);
                ClipperLib::ClipperOffset co;
                if (joinType == jtRound)
                    co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
                else
                    co.MiterLimit = miterLimit;
                co.AddPath(input, joinType, ClipperLib::etClosedPolygon);
                ClipperLib::Paths out;
                co.Execute(out, - delta_scaled);
                holes.insert(holes.end(), out.begin(), out.end());
            }
        }
    }

    // 3) Subtract holes from the contours.
    ClipperLib::Paths output;
    {
        ClipperLib::Clipper clipper;
        clipper.Clear();
        clipper.AddPaths(contours, ClipperLib::ptSubject, true);
        clipper.AddPaths(holes, ClipperLib::ptClip, true);
        clipper.Execute(ClipperLib::ctDifference, *retval, ClipperLib::pftNonZero, ClipperLib::pftNonZero);
    }
    
    // 4) Unscale the output.
    unscaleClipperPolygons(*retval);
}

void 
SVG::draw(const ClipperLib::Paths &polygons, double scale, std::string stroke, coordf_t stroke_width)
{
    for (ClipperLib::Paths::const_iterator it = polygons.begin(); it != polygons.end(); ++ it)
        draw(*it, scale, stroke, stroke_width);
}