C++ ClipperOffset::Clear方法代码示例

void
offset2(const Slic3r::Polygons &polygons, ClipperLib::Paths &retval, const float delta1,
    const float delta2, const double scale, const ClipperLib::JoinType joinType, const double miterLimit)
{
    // read input
    ClipperLib::Paths input;
    Slic3rMultiPoints_to_ClipperPaths(polygons, input);
    
    // scale input
    scaleClipperPolygons(input, scale);
    
    // prepare ClipperOffset object
    ClipperLib::ClipperOffset co;
    if (joinType == jtRound) {
        co.ArcTolerance = miterLimit;
    } else {
        co.MiterLimit = miterLimit;
    }
    
    // perform first offset
    ClipperLib::Paths output1;
    co.AddPaths(input, joinType, ClipperLib::etClosedPolygon);
    co.Execute(output1, (delta1*scale));
    
    // perform second offset
    co.Clear();
    co.AddPaths(output1, joinType, ClipperLib::etClosedPolygon);
    co.Execute(retval, (delta2*scale));
    
    // unscale output
    scaleClipperPolygons(retval, 1/scale);
}

void
offset2(const Slic3r::Polygons &polygons, ClipperLib::Paths* retval, const float delta1,
    const float delta2, const ClipperLib::JoinType joinType, const double miterLimit)
{
    if (delta1 * delta2 >= 0) {
        // Both deltas are the same signum
        offset(polygons, retval, delta1 + delta2, joinType, miterLimit);
        return;
    }
#ifdef CLIPPER_UTILS_DEBUG
    BoundingBox bbox = get_extents(polygons);
    coordf_t stroke_width = scale_(0.005);
    static int iRun = 0;
    ++ iRun;
    bool flipY = false;
    SVG svg(debug_out_path("offset2-%d.svg", iRun), bbox, scale_(1.), flipY);
    for (Slic3r::Polygons::const_iterator it = polygons.begin(); it != polygons.end(); ++ it)
        svg.draw(it->lines(), "gray", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */

    // read input
    ClipperLib::Paths input;
    Slic3rMultiPoints_to_ClipperPaths(polygons, &input);
    
    // scale input
    scaleClipperPolygons(input);
    
    // prepare ClipperOffset object
    ClipperLib::ClipperOffset co;
    if (joinType == jtRound) {
        co.ArcTolerance = miterLimit * double(CLIPPER_OFFSET_SCALE);
    } else {
        co.MiterLimit = miterLimit;
    }
    
    // perform first offset
    ClipperLib::Paths output1;
    co.AddPaths(input, joinType, ClipperLib::etClosedPolygon);
    co.Execute(output1, delta1 * float(CLIPPER_OFFSET_SCALE));
#ifdef CLIPPER_UTILS_DEBUG
    svg.draw(output1, 1. / double(CLIPPER_OFFSET_SCALE), "red", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */
    
    // perform second offset
    co.Clear();
    co.AddPaths(output1, joinType, ClipperLib::etClosedPolygon);
    co.Execute(*retval, delta2 * float(CLIPPER_OFFSET_SCALE));
#ifdef CLIPPER_UTILS_DEBUG
    svg.draw(*retval, 1. / double(CLIPPER_OFFSET_SCALE), "green", stroke_width);
#endif /* CLIPPER_UTILS_DEBUG */

    // unscale output
    unscaleClipperPolygons(*retval);
}

void safety_offset(ClipperLib::Paths* paths)
{
    PROFILE_FUNC();

    // scale input
    scaleClipperPolygons(*paths);
    
    // perform offset (delta = scale 1e-05)
    ClipperLib::ClipperOffset co;
#ifdef CLIPPER_UTILS_DEBUG
	if (clipper_export_enabled) {
		static int iRun = 0;
		export_clipper_input_polygons_bin(debug_out_path("safety_offset-polygons-%d", ++iRun).c_str(), *paths, ClipperLib::Paths());
	}
#endif /* CLIPPER_UTILS_DEBUG */
    ClipperLib::Paths out;
    for (size_t i = 0; i < paths->size(); ++ i) {
        ClipperLib::Path &path = (*paths)[i];
		co.Clear();
        co.MiterLimit = 2;
        bool ccw = ClipperLib::Orientation(path);
        if (! ccw)
            std::reverse(path.begin(), path.end());
        {
            PROFILE_BLOCK(safety_offset_AddPaths);
            co.AddPath((*paths)[i], ClipperLib::jtMiter, ClipperLib::etClosedPolygon);
        }
        {
            PROFILE_BLOCK(safety_offset_Execute);
            // offset outside by 10um
            ClipperLib::Paths out_this;
            co.Execute(out_this, ccw ? 10.f * float(CLIPPER_OFFSET_SCALE) : -10.f * float(CLIPPER_OFFSET_SCALE));
            if (! ccw) {
                // Reverse the resulting contours once again.
                for (ClipperLib::Paths::iterator it = out_this.begin(); it != out_this.end(); ++ it)
                    std::reverse(it->begin(), it->end());
            }
            if (out.empty())
                out = std::move(out_this);
            else
                std::move(std::begin(out_this), std::end(out_this), std::back_inserter(out));
        }
    }
    *paths = std::move(out);
    
    // unscale output
    unscaleClipperPolygons(*paths);
}

ClipperLib::Paths
_offset2(const Polygons &polygons, const float delta1, const float delta2,
    const ClipperLib::JoinType joinType, const double miterLimit)
{
    // read input
    ClipperLib::Paths input = Slic3rMultiPoints_to_ClipperPaths(polygons);
    
    // scale input
    scaleClipperPolygons(input);
    
    // prepare ClipperOffset object
    ClipperLib::ClipperOffset co;
    if (joinType == jtRound) {
        co.ArcTolerance = miterLimit;
    } else {
        co.MiterLimit = miterLimit;
    }
    float delta_scaled1 = delta1 * float(CLIPPER_OFFSET_SCALE);
    float delta_scaled2 = delta2 * float(CLIPPER_OFFSET_SCALE);
    co.ShortestEdgeLength = double(std::max(std::abs(delta_scaled1), std::abs(delta_scaled2)) * CLIPPER_OFFSET_SHORTEST_EDGE_FACTOR);
    
    // perform first offset
    ClipperLib::Paths output1;
    co.AddPaths(input, joinType, ClipperLib::etClosedPolygon);
    co.Execute(output1, delta_scaled1);
    
    // perform second offset
    co.Clear();
    co.AddPaths(output1, joinType, ClipperLib::etClosedPolygon);
    ClipperLib::Paths retval;
    co.Execute(retval, delta_scaled2);
    
    // unscale output
    unscaleClipperPolygons(retval);
    return retval;
}