C++ feature_impl::num_geometries方法代码示例

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 cairo_renderer<T>::process(polygon_pattern_symbolizer const& sym,
                                mapnik::feature_impl & feature,
                                proj_transform const& prj_trans)
{
    composite_mode_e comp_op = get<composite_mode_e, keys::comp_op>(sym, feature, common_.vars_);
    std::string filename = get<std::string, keys::file>(sym, feature, common_.vars_);
    value_bool clip = get<value_bool, keys::clip>(sym, feature, common_.vars_);
    value_double simplify_tolerance = get<value_double, keys::simplify_tolerance>(sym, feature, common_.vars_);
    value_double smooth = get<value_double, keys::smooth>(sym, feature, common_.vars_);
    value_double opacity = get<value_double, keys::opacity>(sym, feature, common_.vars_);
    agg::trans_affine image_tr = agg::trans_affine_scaling(common_.scale_factor_);
    auto image_transform = get_optional<transform_type>(sym, keys::image_transform);
    if (image_transform) evaluate_transform(image_tr, feature, common_.vars_, *image_transform);

    cairo_save_restore guard(context_);
    context_.set_operator(comp_op);

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

    unsigned offset_x=0;
    unsigned offset_y=0;
    box2d<double> const& clip_box = clipping_extent(common_);
    pattern_alignment_enum alignment = get<pattern_alignment_enum, keys::alignment>(sym, feature, common_.vars_);
    if (alignment == LOCAL_ALIGNMENT)
    {
        double x0 = 0.0;
        double y0 = 0.0;

        if (feature.num_geometries() > 0)
        {
            using clipped_geometry_type = agg::conv_clip_polygon<geometry_type>;
            using path_type = transform_path_adapter<view_transform,clipped_geometry_type>;
            clipped_geometry_type clipped(feature.get_geometry(0));
            clipped.clip_box(clip_box.minx(), clip_box.miny(),
                             clip_box.maxx(), clip_box.maxy());
            path_type path(common_.t_, clipped, prj_trans);
            path.vertex(&x0, &y0);
        }
        offset_x = std::abs(clip_box.width() - x0);
        offset_y = std::abs(clip_box.height() - y0);
    }

    if ((*marker)->is_bitmap())
    {
        cairo_pattern pattern(**((*marker)->get_bitmap_data()), opacity);
        pattern.set_extend(CAIRO_EXTEND_REPEAT);
        pattern.set_origin(offset_x, offset_y);
        context_.set_pattern(pattern);
    }
    else
    {
        mapnik::rasterizer ras;
        image_ptr image = render_pattern(ras, **marker, image_tr, 1.0); //
        cairo_pattern pattern(*image, opacity);
        pattern.set_extend(CAIRO_EXTEND_REPEAT);
        pattern.set_origin(offset_x, offset_y);
        context_.set_pattern(pattern);
    }

    agg::trans_affine tr;
    auto geom_transform = get_optional<transform_type>(sym, keys::geometry_transform);
    if (geom_transform) {
        evaluate_transform(tr, feature, common_.vars_, *geom_transform, common_.scale_factor_);
    }

    vertex_converter<cairo_context,clip_poly_tag,transform_tag,affine_transform_tag,simplify_tag,smooth_tag>
    converter(clip_box, context_,sym,common_.t_,prj_trans,tr,feature,common_.vars_,common_.scale_factor_);

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

    for ( geometry_type & geom : feature.paths())
    {
        if (geom.size() > 2)
        {
            converter.apply(geom);
        }
    }
    // fill polygon
    context_.set_fill_rule(CAIRO_FILL_RULE_EVEN_ODD);
    context_.fill();
}

void render_point_symbolizer(point_symbolizer const &sym,
                             mapnik::feature_impl &feature,
                             proj_transform const &prj_trans,
                             RendererType &common,
                             F render_marker)
{
    std::string filename = get<std::string>(sym, keys::file, feature, common.vars_);
    boost::optional<mapnik::marker_ptr> marker = filename.empty()
       ? std::make_shared<mapnik::marker>()
       : marker_cache::instance().find(filename, true);

    if (marker)
    {
        double opacity = get<double>(sym,keys::opacity,feature, common.vars_, 1.0);
        bool allow_overlap = get<bool>(sym, keys::allow_overlap, feature, common.vars_, false);
        bool ignore_placement = get<bool>(sym, keys::ignore_placement, feature, common.vars_, false);
        point_placement_enum placement= get<point_placement_enum>(sym, keys::point_placement_type, feature, common.vars_, CENTROID_POINT_PLACEMENT);

        box2d<double> const& bbox = (*marker)->bounding_box();
        coord2d center = bbox.center();

        agg::trans_affine tr;
        auto image_transform = get_optional<transform_type>(sym, keys::image_transform);
        if (image_transform) evaluate_transform(tr, feature, common.vars_, *image_transform);

        agg::trans_affine_translation recenter(-center.x, -center.y);
        agg::trans_affine recenter_tr = recenter * tr;
        box2d<double> label_ext = bbox * recenter_tr * agg::trans_affine_scaling(common.scale_factor_);

        for (std::size_t i=0; i<feature.num_geometries(); ++i)
        {
            geometry_type const& geom = feature.get_geometry(i);
            double x;
            double y;
            double z=0;
            if (placement == CENTROID_POINT_PLACEMENT)
            {
                if (!label::centroid(geom, x, y))
                    return;
            }
            else
            {
                if (!label::interior_position(geom ,x, y))
                    return;
            }

            prj_trans.backward(x,y,z);
            common.t_.forward(&x,&y);
            label_ext.re_center(x,y);
            if (allow_overlap ||
                common.detector_->has_placement(label_ext))
            {

                render_marker(pixel_position(x, y),
                              **marker,
                              tr,
                              opacity);

                if (!ignore_placement)
                    common.detector_->insert(label_ext);
            }
        }
    }
}

void agg_renderer<T>::process(building_symbolizer const& sym,
                              mapnik::feature_impl & feature,
                              proj_transform const& prj_trans)
{
    typedef coord_transform<CoordTransform,geometry_type> path_type;
    typedef agg::renderer_base<agg::pixfmt_rgba32> ren_base;
    typedef agg::renderer_scanline_aa_solid<ren_base> renderer;

    agg::rendering_buffer buf(current_buffer_->raw_data(),width_,height_, width_ * 4);
    agg::pixfmt_rgba32 pixf(buf);
    ren_base renb(pixf);

    color const& fill_  = sym.get_fill();
    unsigned r=fill_.red();
    unsigned g=fill_.green();
    unsigned b=fill_.blue();
    unsigned a=fill_.alpha();
    renderer ren(renb);
    agg::scanline_u8 sl;

    ras_ptr->reset();
    ras_ptr->gamma(agg::gamma_power());

    double height = 0.0;
    expression_ptr height_expr = sym.height();
    if (height_expr)
    {
        value_type result = boost::apply_visitor(evaluate<Feature,value_type>(feature), *height_expr);
        height = result.to_double() * scale_factor_;
    }

    for (unsigned i=0;i<feature.num_geometries();++i)
    {
        geometry_type const& geom = feature.get_geometry(i);
        if (geom.size() > 2)
        {
            boost::scoped_ptr<geometry_type> frame(new geometry_type(LineString));
            boost::scoped_ptr<geometry_type> roof(new geometry_type(Polygon));
            std::deque<segment_t> face_segments;
            double x0 = 0;
            double y0 = 0;
            double x,y;
            geom.rewind(0);
            for (unsigned cm = geom.vertex(&x, &y); cm != SEG_END;
                 cm = geom.vertex(&x, &y))
            {
                if (cm == SEG_MOVETO)
                {
                    frame->move_to(x,y);
                }
                else if (cm == SEG_LINETO || cm == SEG_CLOSE)
                {
                    frame->line_to(x,y);
                    face_segments.push_back(segment_t(x0,y0,x,y));
                }
                x0 = x;
                y0 = y;
            }

            std::sort(face_segments.begin(),face_segments.end(), y_order);
            std::deque<segment_t>::const_iterator itr=face_segments.begin();
            std::deque<segment_t>::const_iterator end=face_segments.end();

            for (; itr!=end; ++itr)
            {
                boost::scoped_ptr<geometry_type> faces(new geometry_type(Polygon));
                faces->move_to(itr->get<0>(),itr->get<1>());
                faces->line_to(itr->get<2>(),itr->get<3>());
                faces->line_to(itr->get<2>(),itr->get<3>() + height);
                faces->line_to(itr->get<0>(),itr->get<1>() + height);

                path_type faces_path (t_,*faces,prj_trans);
                ras_ptr->add_path(faces_path);
                ren.color(agg::rgba8(int(r*0.8), int(g*0.8), int(b*0.8), int(a * sym.get_opacity())));
                agg::render_scanlines(*ras_ptr, sl, ren);
                ras_ptr->reset();
                //
                frame->move_to(itr->get<0>(),itr->get<1>());
                frame->line_to(itr->get<0>(),itr->get<1>()+height);

            }

            geom.rewind(0);
            for (unsigned cm = geom.vertex(&x, &y); cm != SEG_END;
                 cm = geom.vertex(&x, &y))
            {
                if (cm == SEG_MOVETO)
                {
                    frame->move_to(x,y+height);
                    roof->move_to(x,y+height);
                }
                else if (cm == SEG_LINETO || cm == SEG_CLOSE)
                {
                    frame->line_to(x,y+height);
                    roof->line_to(x,y+height);
                }
            }

            path_type path(t_,*frame,prj_trans);
            agg::conv_stroke<path_type> stroke(path);
//.........这里部分代码省略.........

void agg_renderer<T>::process(point_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<mapnik::marker_ptr> marker;
    if ( !filename.empty() )
    {
        marker = marker_cache::instance()->find(filename, true);
    }
    else
    {
        marker.reset(boost::make_shared<mapnik::marker>());
    }

    if (marker)
    {
        box2d<double> const& bbox = (*marker)->bounding_box();
        coord2d center = bbox.center();

        agg::trans_affine tr;
        evaluate_transform(tr, feature, sym.get_image_transform());
        agg::trans_affine_translation recenter(-center.x, -center.y);
        agg::trans_affine recenter_tr = recenter * tr;
        box2d<double> label_ext = bbox * recenter_tr;

        for (unsigned i=0; i<feature.num_geometries(); ++i)
        {
            geometry_type const& geom = feature.get_geometry(i);
            double x;
            double y;
            double z=0;
            if (sym.get_point_placement() == CENTROID_POINT_PLACEMENT)
            {
                if (!label::centroid(geom, x, y))
                    return;
            }
            else
            {
                if (!label::interior_position(geom ,x, y))
                    return;
            }

            prj_trans.backward(x,y,z);
            t_.forward(&x,&y);
            label_ext.re_center(x,y);
            if (sym.get_allow_overlap() ||
                detector_->has_placement(label_ext))
            {

                render_marker(pixel_position(x, y),
                              **marker,
                              tr,
                              sym.get_opacity(),
                              sym.comp_op());

                if (!sym.get_ignore_placement())
                    detector_->insert(label_ext);
            }
        }
    }

}