C++ mapnik::feature_impl类代码示例

void grid_renderer<T>::process(polygon_pattern_symbolizer const& sym,
                               mapnik::feature_impl & feature,
                               proj_transform const& prj_trans)
{
    std::string filename = path_processor_type::evaluate( *sym.get_filename(), feature);

    boost::optional<marker_ptr> mark = marker_cache::instance().find(filename,true);
    if (!mark) return;

    if (!(*mark)->is_bitmap())
    {
        MAPNIK_LOG_DEBUG(agg_renderer) << "agg_renderer: Only images (not '" << filename << "') are supported in the line_pattern_symbolizer";
        return;
    }

    boost::optional<image_ptr> pat = (*mark)->get_bitmap_data();
    if (!pat) return;

    ras_ptr->reset();

    agg::trans_affine tr;
    evaluate_transform(tr, feature, sym.get_transform());

    typedef boost::mpl::vector<clip_poly_tag,transform_tag,affine_transform_tag,smooth_tag> conv_types;
    vertex_converter<box2d<double>, grid_rasterizer, polygon_pattern_symbolizer,
                     CoordTransform, proj_transform, agg::trans_affine, conv_types>
        converter(query_extent_,*ras_ptr,sym,t_,prj_trans,tr,scale_factor_);

    if (prj_trans.equal() && sym.clip()) converter.set<clip_poly_tag>(); //optional clip (default: true)
    converter.set<transform_tag>(); //always transform
    converter.set<affine_transform_tag>();
    if (sym.smooth() > 0.0) converter.set<smooth_tag>(); // optional smooth converter


    for ( geometry_type & geom : feature.paths())
    {
        if (geom.size() > 2)
        {
            converter.apply(geom);
        }
    }
    typedef typename grid_renderer_base_type::pixfmt_type pixfmt_type;
    typedef typename grid_renderer_base_type::pixfmt_type::color_type color_type;
    typedef agg::renderer_scanline_bin_solid<grid_renderer_base_type> renderer_type;

    grid_rendering_buffer buf(pixmap_.raw_data(), width_, height_, width_);
    pixfmt_type pixf(buf);

    grid_renderer_base_type renb(pixf);
    renderer_type ren(renb);

    // render id
    ren.color(color_type(feature.id()));
    agg::scanline_bin sl;
    ras_ptr->filling_rule(agg::fill_even_odd);
    agg::render_scanlines(*ras_ptr, sl, ren);

    // add feature properties to grid cache
    pixmap_.add_feature(feature);
}

void agg_renderer<T0,T1>::process(debug_symbolizer const& sym,
                              mapnik::feature_impl & feature,
                              proj_transform const& prj_trans)
{

    debug_symbolizer_mode_enum mode = get<debug_symbolizer_mode_enum>(sym, keys::mode, feature, common_.vars_, DEBUG_SYM_MODE_COLLISION);

    ras_ptr->reset();
    if (gamma_method_ != GAMMA_POWER || gamma_ != 1.0)
    {
        ras_ptr->gamma(agg::gamma_power());
        gamma_method_ = GAMMA_POWER;
        gamma_ = 1.0;
    }

    if (mode == DEBUG_SYM_MODE_RINGS)
    {
        RingRenderer<buffer_type> renderer(*ras_ptr,*current_buffer_,common_.t_,prj_trans);
        render_ring_visitor<buffer_type> apply(renderer);
        mapnik::util::apply_visitor(apply,feature.get_geometry());
    }
    else if (mode == DEBUG_SYM_MODE_COLLISION)
    {
        for (auto const& n : *common_.detector_)
        {
            draw_rect(pixmap_, n.get().box);
        }
    }
    else if (mode == DEBUG_SYM_MODE_VERTEX)
    {
        using apply_vertex_mode = apply_vertex_mode<buffer_type>;
        apply_vertex_mode apply(pixmap_, common_.t_, prj_trans);
        util::apply_visitor(geometry::vertex_processor<apply_vertex_mode>(apply), feature.get_geometry());
    }
}

        void start_tile_feature(mapnik::feature_impl const& feature)
        {
            current_feature_ = current_layer_->add_features();
            x_ = y_ = 0;

            // TODO - encode as sint64: (n << 1) ^ ( n >> 63)
            // test current behavior with negative numbers
            current_feature_->set_id(feature.id());

            feature_kv_iterator itr = feature.begin();
            feature_kv_iterator end = feature.end();
            for ( ;itr!=end; ++itr)
            {
                std::string const& name = MAPNIK_GET<0>(*itr);
                mapnik::value const& val = MAPNIK_GET<1>(*itr);
                if (!val.is_null())
                {
                    // Insert the key index
                    keys_container::const_iterator key_itr = keys_.find(name);
                    if (key_itr == keys_.end())
                    {
                        // The key doesn't exist yet in the dictionary.
                        current_layer_->add_keys(name.c_str(), name.length());
                        size_t index = keys_.size();
                        keys_.insert(keys_container::value_type(name, index));
                        current_feature_->add_tags(index);
                    }
                    else
                    {
                        current_feature_->add_tags(key_itr->second);
                    }

                    // Insert the value index
                    values_container::const_iterator val_itr = values_.find(val);
                    if (val_itr == values_.end())
                    {
                        // The value doesn't exist yet in the dictionary.
                        to_tile_value visitor(current_layer_->add_values());
#if MAPNIK_VERSION >= 300000
                        MAPNIK_APPLY_VISITOR(visitor, val);
#else
                        MAPNIK_APPLY_VISITOR(visitor, val.base());
#endif
                        size_t index = values_.size();
                        values_.insert(values_container::value_type(val, index));
                        current_feature_->add_tags(index);
                    }
                    else
                    {
                        current_feature_->add_tags(val_itr->second);
                    }
                }
            }
        }

void grid_renderer<T>::process(building_symbolizer const& sym,
                               mapnik::feature_impl & feature,
                               proj_transform const& prj_trans)
{
    using pixfmt_type = typename grid_renderer_base_type::pixfmt_type;
    using color_type = typename grid_renderer_base_type::pixfmt_type::color_type;
    using renderer_type = agg::renderer_scanline_bin_solid<grid_renderer_base_type>;
    using transform_path_type = transform_path_adapter<view_transform, vertex_adapter>;
    agg::scanline_bin sl;

    grid_rendering_buffer buf(pixmap_.raw_data(), common_.width_, common_.height_, common_.width_);
    pixfmt_type pixf(buf);

    grid_renderer_base_type renb(pixf);
    renderer_type ren(renb);

    ras_ptr->reset();

    double height = get<value_double>(sym, keys::height, feature, common_.vars_, 0.0);

    render_building_symbolizer(
        feature, height,
        [&](path_type const& faces)
        {
            vertex_adapter va(faces);
            transform_path_type faces_path (common_.t_,va,prj_trans);
            ras_ptr->add_path(faces_path);
            ren.color(color_type(feature.id()));
            agg::render_scanlines(*ras_ptr, sl, ren);
            ras_ptr->reset();
        },
        [&](path_type const& frame)
        {
            vertex_adapter va(frame);
            transform_path_type path(common_.t_,va,prj_trans);
            agg::conv_stroke<transform_path_type> stroke(path);
            ras_ptr->add_path(stroke);
            ren.color(color_type(feature.id()));
            agg::render_scanlines(*ras_ptr, sl, ren);
            ras_ptr->reset();
        },
        [&](path_type const& roof)
        {
            vertex_adapter va(roof);
            transform_path_type roof_path (common_.t_,va,prj_trans);
            ras_ptr->add_path(roof_path);
            ren.color(color_type(feature.id()));
            agg::render_scanlines(*ras_ptr, sl, ren);
        });

    pixmap_.add_feature(feature);
}

void grid_renderer<T>::process(polygon_symbolizer const& sym,
                               mapnik::feature_impl & feature,
                               proj_transform const& prj_trans)
{
    typedef agg::renderer_scanline_bin_solid<grid_renderer_base_type> renderer_type;
    typedef typename grid_renderer_base_type::pixfmt_type pixfmt_type;
    typedef typename grid_renderer_base_type::pixfmt_type::color_type color_type;

    ras_ptr->reset();

    agg::trans_affine tr;
    evaluate_transform(tr, feature, sym.get_transform(), scale_factor_);

    typedef boost::mpl::vector<clip_poly_tag,transform_tag,affine_transform_tag,simplify_tag,smooth_tag> conv_types;
    vertex_converter<box2d<double>, grid_rasterizer, polygon_symbolizer,
                     CoordTransform, proj_transform, agg::trans_affine, conv_types>
        converter(query_extent_,*ras_ptr,sym,t_,prj_trans,tr,scale_factor_);

    if (prj_trans.equal() && sym.clip()) converter.set<clip_poly_tag>(); //optional clip (default: true)
    converter.set<transform_tag>(); //always transform
    converter.set<affine_transform_tag>();
    if (sym.simplify_tolerance() > 0.0) converter.set<simplify_tag>(); // optional simplify converter
    if (sym.smooth() > 0.0) converter.set<smooth_tag>(); // optional smooth converter


    for ( geometry_type & geom : feature.paths())
    {
        if (geom.size() > 2)
        {
            converter.apply(geom);
        }
    }

    grid_rendering_buffer buf(pixmap_.raw_data(), width_, height_, width_);
    pixfmt_type pixf(buf);

    grid_renderer_base_type renb(pixf);
    renderer_type ren(renb);

    // render id
    ren.color(color_type(feature.id()));
    agg::scanline_bin sl;
    ras_ptr->filling_rule(agg::fill_even_odd);
    agg::render_scanlines(*ras_ptr, sl, ren);

    // add feature properties to grid cache
    pixmap_.add_feature(feature);
}

void cairo_renderer<T>::process(debug_symbolizer const& sym,
                                  mapnik::feature_impl & feature,
                                  proj_transform const& prj_trans)
{
    cairo_save_restore guard(context_);

    debug_symbolizer_mode_enum mode = get<debug_symbolizer_mode_enum>(sym, keys::mode, feature, common_.vars_, DEBUG_SYM_MODE_COLLISION);

    context_.set_operator(src_over);
    context_.set_color(mapnik::color(255, 0, 0), 1.0);
    context_.set_line_join(MITER_JOIN);
    context_.set_line_cap(BUTT_CAP);
    context_.set_miter_limit(4.0);
    context_.set_line_width(1.0);

    if (mode == DEBUG_SYM_MODE_COLLISION)
    {
        for (auto & n : *common_.detector_)
        {
            render_debug_box(context_, n.get().box);
        }
    }
    else if (mode == DEBUG_SYM_MODE_VERTEX)
    {
        using apply_vertex_mode = apply_vertex_mode<cairo_context>;
        apply_vertex_mode apply(context_, common_.t_, prj_trans);
        util::apply_visitor(geometry::vertex_processor<apply_vertex_mode>(apply), feature.get_geometry());
    }
}

void grid_renderer<T>::process(text_symbolizer const& sym,
                               mapnik::feature_impl & feature,
                               proj_transform const& prj_trans)
{
    text_symbolizer_helper<face_manager<freetype_engine>,
        label_collision_detector4> helper(
            sym, feature, prj_trans,
            width_, height_,
            scale_factor_ * (1.0/pixmap_.get_resolution()),
            t_, font_manager_, *detector_,
            query_extent_);
    bool placement_found = false;

    text_renderer<T> ren(pixmap_,
                         font_manager_,
                         sym.get_halo_rasterizer(),
                         sym.comp_op(),
                         scale_factor_);

    while (helper.next()) {
        placement_found = true;
        placements_type const& placements = helper.placements();
        for (unsigned int ii = 0; ii < placements.size(); ++ii)
        {
            ren.prepare_glyphs(placements[ii]);
            ren.render_id(feature.id(), placements[ii].center);
        }
    }
    if (placement_found) pixmap_.add_feature(feature);

}

void render_raster_marker(RendererType ren,
                          RasterizerType & ras,
                          image_data_rgba8 & src,
                          mapnik::feature_impl const& feature,
                          agg::trans_affine const& marker_tr,
                          double opacity)
{
    using color_type = typename RendererType::color_type;
    agg::scanline_bin sl;
    double width  = src.width();
    double height = src.height();
    double p[8];
    p[0] = 0;     p[1] = 0;
    p[2] = width; p[3] = 0;
    p[4] = width; p[5] = height;
    p[6] = 0;     p[7] = height;
    marker_tr.transform(&p[0], &p[1]);
    marker_tr.transform(&p[2], &p[3]);
    marker_tr.transform(&p[4], &p[5]);
    marker_tr.transform(&p[6], &p[7]);
    ras.move_to_d(p[0],p[1]);
    ras.line_to_d(p[2],p[3]);
    ras.line_to_d(p[4],p[5]);
    ras.line_to_d(p[6],p[7]);
    ren.color(color_type(feature.id()));
    agg::render_scanlines(ras, sl, ren);
}

void grid_renderer<T>::process(text_symbolizer const& sym,
                               mapnik::feature_impl & feature,
                               proj_transform const& prj_trans)
{
    agg::trans_affine tr;
    auto transform = get_optional<transform_type>(sym, keys::geometry_transform);
    if (transform) evaluate_transform(tr, feature, common_.vars_, *transform, common_.scale_factor_);
    text_symbolizer_helper helper(
            sym, feature, common_.vars_, prj_trans,
            common_.width_, common_.height_,
            common_.scale_factor_ * (1.0/pixmap_.get_resolution()),
            common_.t_, common_.font_manager_, *common_.detector_,
            common_.query_extent_, tr);
    bool placement_found = false;

    composite_mode_e comp_op = get<composite_mode_e>(sym, keys::comp_op, feature, common_.vars_, src_over);

    grid_text_renderer<T> ren(pixmap_,
                              comp_op,
                              common_.scale_factor_);

    placements_list const& placements = helper.get();
    value_integer feature_id = feature.id();

    for (glyph_positions_ptr glyphs : placements)
    {
        ren.render(*glyphs, feature_id);
        placement_found = true;
    }
    if (placement_found)
    {
        pixmap_.add_feature(feature);
    }
}

void agg_renderer<T>::process(raster_symbolizer const& sym,
                              mapnik::feature_impl & feature,
                              proj_transform const& prj_trans)
{
    raster_ptr const& source = feature.get_raster();
    if (source)
    {
        // If there's a colorizer defined, use it to color the raster in-place
        raster_colorizer_ptr colorizer = sym.get_colorizer();
        if (colorizer)
            colorizer->colorize(source,feature);

        box2d<double> target_ext = box2d<double>(source->ext_);
        prj_trans.backward(target_ext, PROJ_ENVELOPE_POINTS);
        box2d<double> ext = t_.forward(target_ext);
        int start_x = static_cast<int>(ext.minx());
        int start_y = static_cast<int>(ext.miny());
        int end_x = static_cast<int>(ceil(ext.maxx()));
        int end_y = static_cast<int>(ceil(ext.maxy()));
        int raster_width = end_x - start_x;
        int raster_height = end_y - start_y;
        if (raster_width > 0 && raster_height > 0)
        {
            image_data_32 target_data(raster_width,raster_height);
            raster target(target_ext, target_data);
            scaling_method_e scaling_method = sym.get_scaling_method();
            double filter_radius = sym.calculate_filter_factor();
            double offset_x = ext.minx() - start_x;
            double offset_y = ext.miny() - start_y;
            if (!prj_trans.equal())
            {
                reproject_and_scale_raster(target, *source, prj_trans,
                                 offset_x, offset_y,
                                 sym.get_mesh_size(),
                                 filter_radius,
                                 scaling_method);
            }
            else
            {
                if (scaling_method == SCALING_BILINEAR8){
                    scale_image_bilinear8<image_data_32>(target.data_,source->data_, offset_x, offset_y);
                } else {
                    double scaling_ratio = ext.width() / source->data_.width();
                    scale_image_agg<image_data_32>(target.data_,
                                                   source->data_,
                                                   scaling_method,
                                                   scaling_ratio,
                                                   offset_x,
                                                   offset_y,
                                                   filter_radius);
                }
            }
            composite(current_buffer_->data(), target.data_, sym.comp_op(), sym.get_opacity(), start_x, start_y, true);
        }
    }
}

void agg_renderer<T0,T1>::process(dot_symbolizer const& sym,
                                  mapnik::feature_impl & feature,
                                  proj_transform const& prj_trans)
{
    double width = 0.0;
    double height = 0.0;
    bool has_width = has_key(sym,keys::width);
    bool has_height = has_key(sym,keys::height);
    if (has_width && has_height)
    {
        width = get<double>(sym, keys::width, feature, common_.vars_, 0.0);
        height = get<double>(sym, keys::height, feature, common_.vars_, 0.0);
    }
    else if (has_width)
    {
        width = height = get<double>(sym, keys::width, feature, common_.vars_, 0.0);
    }
    else if (has_height)
    {
        width = height = get<double>(sym, keys::height, feature, common_.vars_, 0.0);
    }
    double rx = width/2.0;
    double ry = height/2.0;
    double opacity = get<double>(sym, keys::opacity, feature, common_.vars_, 1.0);
    color const& fill = get<mapnik::color>(sym, keys::fill, feature, common_.vars_, mapnik::color(128,128,128));
    ras_ptr->reset();
    agg::rendering_buffer buf(current_buffer_->raw_data(),current_buffer_->width(),current_buffer_->height(),current_buffer_->width() * 4);
    using blender_type = agg::comp_op_adaptor_rgba_pre<agg::rgba8, agg::order_rgba>;
    using pixfmt_comp_type = agg::pixfmt_custom_blend_rgba<blender_type, agg::rendering_buffer>;
    using renderer_base = agg::renderer_base<pixfmt_comp_type>;
    using renderer_type = agg::renderer_scanline_aa_solid<renderer_base>;
    pixfmt_comp_type pixf(buf);
    pixf.comp_op(static_cast<agg::comp_op_e>(get<composite_mode_e>(sym, keys::comp_op, feature, common_.vars_, src_over)));
    renderer_base renb(pixf);
    renderer_type ren(renb);
    agg::scanline_u8 sl;
    ren.color(agg::rgba8_pre(fill.red(), fill.green(), fill.blue(), int(fill.alpha() * opacity)));
    agg::ellipse el(0,0,rx,ry);
    unsigned num_steps = el.num_steps();
    for (geometry_type const& geom : feature.paths()) {
        double x,y,z = 0;
        unsigned cmd = 1;
        geom.rewind(0);
        while ((cmd = geom.vertex(&x, &y)) != mapnik::SEG_END) {
            if (cmd == SEG_CLOSE) continue;
            prj_trans.backward(x,y,z);
            common_.t_.forward(&x,&y);
            el.init(x,y,rx,ry,num_steps);
            ras_ptr->add_path(el);
            agg::render_scanlines(*ras_ptr, sl, ren);
        }
    }
}

void hit_grid<T>::add_feature(mapnik::feature_impl const& feature)
{
    value_type feature_id = feature.id();
    // avoid adding duplicate features (e.g. in the case of both a line symbolizer and a polygon symbolizer)
    typename feature_key_type::const_iterator feature_pos = f_keys_.find(feature_id);
    if (feature_pos != f_keys_.end())
    {
        return;
    }

    if (ctx_->size() == 0)
    {
        context_type::map_type::const_iterator itr = feature.context()->begin();
        context_type::map_type::const_iterator end = feature.context()->end();
        for ( ;itr!=end; ++itr)
        {
            ctx_->add(itr->first,itr->second);
        }
    }
    // NOTE: currently lookup keys must be strings,
    // but this should be revisited
    lookup_type lookup_value;
    if (key_ == id_name_)
    {
        mapnik::util::to_string(lookup_value,feature_id);
    }
    else
    {
        if (feature.has_key(key_))
        {
            lookup_value = feature.get(key_).to_string();
        }
        else
        {
            MAPNIK_LOG_DEBUG(grid) << "hit_grid: Should not get here: key '" << key_ << "' not found in feature properties";
        }
    }

    if (!lookup_value.empty())
    {
        // TODO - consider shortcutting f_keys if feature_id == lookup_value
        // create a mapping between the pixel id and the feature key
        f_keys_.emplace(feature_id,lookup_value);
        // if extra fields have been supplied, push them into grid memory
        if (!names_.empty())
        {
            // it is ~ 2x faster to copy feature attributes compared
            // to building up a in-memory cache of feature_ptrs
            // https://github.com/mapnik/mapnik/issues/1198
            mapnik::feature_ptr feature2(mapnik::feature_factory::create(ctx_,feature_id));
            feature2->set_data(feature.get_data());
            features_.emplace(lookup_value,feature2);
        }
    }
    else
    {
        MAPNIK_LOG_DEBUG(grid) << "hit_grid: Warning - key '" << key_ << "' was blank for " << feature;
    }
}

bool svg_renderer<OutputIterator>::process(rule::symbolizers const& syms,
                                           mapnik::feature_impl & feature,
                                           proj_transform const& prj_trans)
{
    // svg renderer supports processing of multiple symbolizers.
    typedef coord_transform<CoordTransform, geometry_type> path_type;

    bool process_path = false;
    // process each symbolizer to collect its (path) information.
    // path information (attributes from line_ and polygon_ symbolizers)
    // is collected with the path_attributes_ data member.
    for (symbolizer const& sym : syms)
    {
        if (is_path_based(sym))
        {
            process_path = true;
        }
        boost::apply_visitor(symbol_dispatch(*this, feature, prj_trans), sym);
    }

    if (process_path)
    {
        // generate path output for each geometry of the current feature.
        for(std::size_t i=0; i<feature.num_geometries(); ++i)
        {
            geometry_type & geom = feature.get_geometry(i);
            if(geom.size() > 0)
            {
                path_type path(t_, geom, prj_trans);
                generator_.generate_path(path, path_attributes_);
            }
        }
        // set the previously collected values back to their defaults
        // for the feature that will be processed next.
        path_attributes_.reset();
    }
    return true;
}

void  grid_renderer<T>::process(shield_symbolizer const& sym,
                                mapnik::feature_impl & feature,
                                proj_transform const& prj_trans)
{
    shield_symbolizer_helper<face_manager<freetype_engine>,
        label_collision_detector4> helper(
            sym, feature, prj_trans,
            width_, height_,
            scale_factor_,
            t_, font_manager_, *detector_,
            query_extent_);
    bool placement_found = false;

    text_renderer<T> ren(pixmap_,
                         font_manager_,
                         sym.get_halo_rasterizer(),
                         sym.comp_op(),
                         scale_factor_);

    text_placement_info_ptr placement;
    while (helper.next())
    {
        placement_found = true;
        placements_type const& placements = helper.placements();
        for (unsigned int ii = 0; ii < placements.size(); ++ii)
        {
            // get_marker_position returns (minx,miny) corner position,
            // while (currently only) agg_renderer::render_marker newly
            // expects center position;
            // until all renderers and shield_symbolizer_helper are
            // modified accordingly, we must adjust the position here
            pixel_position pos = helper.get_marker_position(placements[ii]);
            pos.x += 0.5 * helper.get_marker_width();
            pos.y += 0.5 * helper.get_marker_height();
            render_marker(feature,
                          pixmap_.get_resolution(),
                          pos,
                          helper.get_marker(),
                          helper.get_image_transform(),
                          sym.get_opacity(),
                          sym.comp_op());

            ren.prepare_glyphs(placements[ii]);
            ren.render_id(feature.id(), placements[ii].center);
        }
    }
    if (placement_found)
        pixmap_.add_feature(feature);
}

void cairo_renderer<T>::process(debug_symbolizer const& sym,
                                  mapnik::feature_impl & feature,
                                  proj_transform const& prj_trans)
{
    using detector_type = label_collision_detector4;
    cairo_save_restore guard(context_);

    debug_symbolizer_mode_enum mode = get<debug_symbolizer_mode_enum>(sym, keys::mode, feature, common_.vars_, DEBUG_SYM_MODE_COLLISION);

    context_.set_operator(src_over);
    context_.set_color(mapnik::color(255, 0, 0), 1.0);
    context_.set_line_join(MITER_JOIN);
    context_.set_line_cap(BUTT_CAP);
    context_.set_miter_limit(4.0);
    context_.set_line_width(1.0);

    if (mode == DEBUG_SYM_MODE_COLLISION)
    {
        typename detector_type::query_iterator itr = common_.detector_->begin();
        typename detector_type::query_iterator end = common_.detector_->end();
        for ( ;itr!=end; ++itr)
        {
            render_debug_box(context_, itr->box);
        }
    }
    else if (mode == DEBUG_SYM_MODE_VERTEX)
    {
        for (auto const& geom : feature.paths())
        {
            double x;
            double y;
            double z = 0;
            geom.rewind(0);
            unsigned cmd = 1;
            while ((cmd = geom.vertex(&x, &y)) != mapnik::SEG_END)
            {
                if (cmd == SEG_CLOSE) continue;
                prj_trans.backward(x,y,z);
                common_.t_.forward(&x,&y);
                context_.move_to(std::floor(x) - 0.5, std::floor(y) + 0.5);
                context_.line_to(std::floor(x) + 1.5, std::floor(y) + 0.5);
                context_.move_to(std::floor(x) + 0.5, std::floor(y) - 0.5);
                context_.line_to(std::floor(x) + 0.5, std::floor(y) + 1.5);
                context_.stroke();
            }
        }
    }
}