Exemplo n.º 1
0
    inline void apply(PointIn const& penultimate_point, 
                PointIn const& perp_left_point,
                PointIn const& ultimate_point,
                PointIn const& perp_right_point,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                RangeOut& range_out) const
    {
        promoted_type const dist_left = distance.apply(penultimate_point, ultimate_point, buffer_side_left);
        promoted_type const dist_right = distance.apply(penultimate_point, ultimate_point, buffer_side_right);

        bool reversed = (side == buffer_side_left && dist_right < 0 && -dist_right > dist_left)
                    || (side == buffer_side_right && dist_left < 0 && -dist_left > dist_right)
                    ;
        if (reversed)
        {
            range_out.push_back(perp_right_point);
            range_out.push_back(perp_left_point);
        }
        else
        {
            range_out.push_back(perp_left_point);
            range_out.push_back(perp_right_point);
        }
        // Don't add the ultimate_point (endpoint of the linestring).
        // The buffer might be generated completely at one side.
        // In other cases it does no harm but is further useless
    }
Exemplo n.º 2
0
    static inline void generate_side(Point const& ip1, Point const& ip2,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                output_point_type& p1, output_point_type& p2)
    {
        // Generate a block along (left or right of) the segment

        // Simulate a vector d (dx,dy)
        coordinate_type dx = get<0>(ip2) - get<0>(ip1);
        coordinate_type dy = get<1>(ip2) - get<1>(ip1);

        // For normalization [0,1] (=dot product d.d, sqrt)
        // TODO promoted_type
        coordinate_type const length = sqrt(dx * dx + dy * dy);

        // Because coordinates are not equal, length should not be zero
        BOOST_ASSERT((! geometry::math::equals(length, 0)));

        // Generate the normalized perpendicular p, to the left (ccw)
        coordinate_type const px = -dy / length;
        coordinate_type const py = dx / length;

        coordinate_type const d = distance.apply(ip1, ip2, side);

        set<0>(p1, get<0>(ip1) + px * d);
        set<1>(p1, get<1>(ip1) + py * d);
        set<0>(p2, get<0>(ip2) + px * d);
        set<1>(p2, get<1>(ip2) + py * d);
    }
Exemplo n.º 3
0
    inline void apply(Point const& penultimate_point,
                Point const& perp_left_point,
                Point const& ultimate_point,
                Point const& ,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                RangeOut& range_out) const
    {
        typedef typename coordinate_type<Point>::type coordinate_type;

        typedef typename geometry::select_most_precise
        <
            coordinate_type,
            double
        >::type promoted_type;

        promoted_type const alpha = calculate_angle<promoted_type>(perp_left_point, ultimate_point);

        promoted_type const dist_left = distance.apply(penultimate_point, ultimate_point, buffer_side_left);
        promoted_type const dist_right = distance.apply(penultimate_point, ultimate_point, buffer_side_right);
        if (geometry::math::equals(dist_left, dist_right))
        {
            generate_points(ultimate_point, alpha, dist_left, range_out);
        }
        else
        {
            promoted_type const two = 2.0;
            promoted_type dist_half_diff = (dist_left - dist_right) / two;

            if (side == buffer_side_right)
            {
                dist_half_diff = -dist_half_diff;
            }

            Point shifted_point;
            set<0>(shifted_point, get<0>(ultimate_point) + dist_half_diff * cos(alpha));
            set<1>(shifted_point, get<1>(ultimate_point) + dist_half_diff * sin(alpha));
            generate_points(shifted_point, alpha, (dist_left + dist_right) / two, range_out);
        }
    }
Exemplo n.º 4
0
    static inline void apply(
                Point const& input_p1, Point const& input_p2,
                strategy::buffer::buffer_side_selector side,
                DistanceStrategy const& distance,
                OutputRange& output_range)
    {
        typedef typename coordinate_type<Point>::type coordinate_type;
        typedef typename geometry::select_most_precise
        <
            coordinate_type,
            double
        >::type promoted_type;

        // Generate a block along (left or right of) the segment

        // Simulate a vector d (dx,dy)
        coordinate_type dx = get<0>(input_p2) - get<0>(input_p1);
        coordinate_type dy = get<1>(input_p2) - get<1>(input_p1);

        // For normalization [0,1] (=dot product d.d, sqrt)
        promoted_type const length = geometry::math::sqrt(dx * dx + dy * dy);

        // Because coordinates are not equal, length should not be zero
        BOOST_ASSERT((! geometry::math::equals(length, 0)));

        // Generate the normalized perpendicular p, to the left (ccw)
        promoted_type const px = -dy / length;
        promoted_type const py = dx / length;

        promoted_type const d = distance.apply(input_p1, input_p2, side);

        output_range.resize(2);

        set<0>(output_range.front(), get<0>(input_p1) + px * d);
        set<1>(output_range.front(), get<1>(input_p1) + py * d);
        set<0>(output_range.back(), get<0>(input_p2) + px * d);
        set<1>(output_range.back(), get<1>(input_p2) + py * d);
    }
Exemplo n.º 5
0
    inline void apply(Point const& point,
                DistanceStrategy const& distance_strategy,
                OutputRange& output_range) const
    {
        typedef typename boost::range_value<OutputRange>::type output_point_type;

        typedef typename geometry::select_most_precise
            <
                typename geometry::select_most_precise
                    <
                        typename geometry::coordinate_type<Point>::type,
                        typename geometry::coordinate_type<output_point_type>::type
                    >::type,
                double
            >::type promoted_type;

        promoted_type const buffer_distance = distance_strategy.apply(point, point,
                        strategy::buffer::buffer_side_left);

        promoted_type const two = 2.0;
        promoted_type const two_pi = two * geometry::math::pi<promoted_type>();

        promoted_type const diff = two_pi / promoted_type(m_count);
        promoted_type a = 0;

        for (std::size_t i = 0; i < m_count; i++, a -= diff)
        {
            output_point_type p;
            set<0>(p, get<0>(point) + buffer_distance * cos(a));
            set<1>(p, get<1>(point) + buffer_distance * sin(a));
            output_range.push_back(p);
        }

        // Close it:
        output_range.push_back(output_range.front());
    }
Exemplo n.º 6
0
    static inline void iterate(Inserter& inserter,
                Iterator begin, Iterator end,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                JoinStrategy const& join
#ifdef BOOST_GEOMETRY_DEBUG_WITH_MAPPER
                , Mapper& mapper
#endif
            )
    {
        output_point_type previous_p1, previous_p2;
        output_point_type first_p1, first_p2;

#ifdef BOOST_GEOMETRY_DEBUG_WITH_MAPPER
        int index = 0;
#endif

        bool first = true;

        Iterator it = begin;
        for (Iterator prev = it++; it != end; ++it)
        {
            if (! detail::equals::equals_point_point(*prev, *it))
            {
                bool skip = false;

                // Simulate a vector d (dx,dy)
                coordinate_type dx = get<0>(*it) - get<0>(*prev);
                coordinate_type dy = get<1>(*it) - get<1>(*prev);

                // For normalization [0,1] (=dot product d.d, sqrt)
                coordinate_type length = sqrt(dx * dx + dy * dy);

                // Because coordinates are not equal, length should not be zero
                BOOST_ASSERT((! geometry::math::equals(length, 0)));

                // Generate the normalized perpendicular p, to the left (ccw)
                coordinate_type px = -dy / length;
                coordinate_type py = dx / length;

                output_point_type p1, p2;

                coordinate_type d = distance.apply(*prev, *it, side);

                set<0>(p2, get<0>(*it) + px * d);
                set<1>(p2, get<1>(*it) + py * d);

                set<0>(p1, get<0>(*prev) + px * d);
                set<1>(p1, get<1>(*prev) + py * d);

                {
#ifdef BOOST_GEOMETRY_DEBUG_WITH_MAPPER
                    ring_type block;
                    block.push_back(*prev);
                    block.push_back(*it);
                    block.push_back(p2);
                    block.push_back(p1);
                    block.push_back(*prev);

                    mapper.map(block, "opacity:0.4;fill:rgb(0,255,0);stroke:rgb(0,0,0);stroke-width:1");
#endif
                }

                if (! first)
                {
                    output_point_type p;
                    segment_type s1(p1, p2);
                    segment_type s2(previous_p1, previous_p2);
                    if (line_line_intersection<output_point_type, segment_type>::apply(s1, s2, p))
                    {
                        join.apply(p, *prev, previous_p2, p1,
                                    distance.apply(*prev, *it, side),
                                    inserter.get_ring());
                        {
#ifdef BOOST_GEOMETRY_DEBUG_WITH_MAPPER
                            mapper.map(p, "fill:rgb(0,0,0);", 3);

                            std::ostringstream out;
                            out << index++;
                            mapper.text(p, out.str(), "fill:rgb(0,0,0);font-family='Arial';", 5, 5);
#endif
                        }
                    }
                    else
                    {
                        skip = false;
                    }
                }
                else
                {
                    first = false;
                    first_p1 = p1;
                    first_p2 = p2;

                    inserter.insert(p1);
                }

                if (! skip)
                {
                    previous_p1 = p1;
                    previous_p2 = p2;
                    prev = it;
                }
            }
        }

        // Last one
        inserter.insert(previous_p2);
    }
Exemplo n.º 7
0
    static inline void iterate(Collection& collection,
                Iterator begin, Iterator end,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                JoinStrategy const& join_strategy, bool close = false)
    {
        output_point_type previous_p1, previous_p2;
        output_point_type first_p1, first_p2;

        bool first = true;

        Iterator it = begin;

        // We want to memorize the last vector too.
        typedef BOOST_TYPEOF(*it) point_type;
        point_type last_ip1, last_ip2;


        for (Iterator prev = it++; it != end; ++it)
        {
            if (! detail::equals::equals_point_point(*prev, *it))
            {
                output_point_type p1, p2;
                last_ip1 = *prev;
                last_ip2 = *it;
                generate_side(*prev, *it, side, distance, p1, p2);

                std::vector<output_point_type> range_out;
                if (! first)
                {
                    output_point_type p;
                    segment_type s1(p1, p2);
                    segment_type s2(previous_p1, previous_p2);

                    if (line_line_intersection<output_point_type, segment_type>::apply(s1, s2, p))
                    {
                        join_strategy.apply(p, *prev, previous_p2, p1,
                                    distance.apply(*prev, *it, side),
                                    range_out);
                    }
                }
                else
                {
                    first = false;
                    first_p1 = p1;
                    first_p2 = p2;
                }
                if (! range_out.empty())
                {
                    collection.add_piece(buffered_join, *prev, range_out);
                    range_out.clear();
                }
                collection.add_piece(buffered_segment, *prev, *it, p1, p2);

                previous_p1 = p1;
                previous_p2 = p2;
                prev = it;
            }
        }

        // Might be replaced by specialization
        if(boost::is_same<Tag, ring_tag>::value)
        {
            // Generate closing corner
            output_point_type p;
            segment_type s1(previous_p1, previous_p2);
            segment_type s2(first_p1, first_p2);
            line_line_intersection<output_point_type, segment_type>::apply(s1, s2, p);

            std::vector<output_point_type> range_out;
            join_strategy.apply(p, *begin, previous_p2, first_p1,
                distance.apply(*(end - 1), *begin, side),
                range_out);
            if (! range_out.empty())
            {
                collection.add_piece(buffered_join, *begin, range_out);
            }

            // Buffer is closed automatically by last closing corner (NOT FOR OPEN POLYGONS - TODO)
        }
        else if (boost::is_same<Tag, linestring_tag>::value)
        {
            // Assume flat-end-strategy for now
            // TODO fix this (approach) for one-side buffer (1.5 - -1.0)
            output_point_type rp1, rp2;
            generate_side(last_ip2, last_ip1, 
                    side == buffer_side_left 
                    ? buffer_side_right 
                    : buffer_side_left, 
                distance, rp2, rp1);

            // For flat end:
            std::vector<output_point_type> range_out;
            range_out.push_back(previous_p2);
            if (close)
            {
                range_out.push_back(rp2);
            }
            collection.add_piece(buffered_flat_end, range_out);
        }
    }
    static inline result_code apply(
                Point const& input_p1, Point const& input_p2,
                buffer_side_selector side,
                DistanceStrategy const& distance,
                OutputRange& output_range)
    {
        typedef typename coordinate_type<Point>::type coordinate_type;
        typedef typename geometry::select_most_precise
        <
            coordinate_type,
            double
        >::type promoted_type;

        // Generate a block along (left or right of) the segment

        // Simulate a vector d (dx,dy)
        coordinate_type const dx = get<0>(input_p2) - get<0>(input_p1);
        coordinate_type const dy = get<1>(input_p2) - get<1>(input_p1);

        // For normalization [0,1] (=dot product d.d, sqrt)
        promoted_type const length = geometry::math::sqrt(dx * dx + dy * dy);

        if (! boost::math::isfinite(length))
        {
            // In case of coordinates differences of e.g. 1e300, length
            // will overflow and we should not generate output
#ifdef BOOST_GEOMETRY_DEBUG_BUFFER_WARN
            std::cout << "Error in length calculation for points "
                << geometry::wkt(input_p1) << " " << geometry::wkt(input_p2)
                << " length: " << length << std::endl;
#endif
            return result_error_numerical;
        }

        if (geometry::math::equals(length, 0))
        {
            // Coordinates are simplified and therefore most often not equal.
            // But if simplify is skipped, or for lines with two
            // equal points, length is 0 and we cannot generate output.
            return result_no_output;
        }

        promoted_type const d = distance.apply(input_p1, input_p2, side);

        // Generate the normalized perpendicular p, to the left (ccw)
        promoted_type const px = -dy / length;
        promoted_type const py = dx / length;

        if (geometry::math::equals(px, 0)
            && geometry::math::equals(py, 0))
        {
            // This basically should not occur - because of the checks above.
            // There are no unit tests triggering this condition
#ifdef BOOST_GEOMETRY_DEBUG_BUFFER_WARN
            std::cout << "Error in perpendicular calculation for points "
                << geometry::wkt(input_p1) << " " << geometry::wkt(input_p2)
                << " length: " << length
                << " distance: " << d
                << std::endl;
#endif
            return result_no_output;
        }

        output_range.resize(2);

        set<0>(output_range.front(), get<0>(input_p1) + px * d);
        set<1>(output_range.front(), get<1>(input_p1) + py * d);
        set<0>(output_range.back(), get<0>(input_p2) + px * d);
        set<1>(output_range.back(), get<1>(input_p2) + py * d);

        return result_normal;
    }