mapnik/src/renderer_common/process_group_symbolizer.cpp

/*****************************************************************************
 *
 * This file is part of Mapnik (c++ mapping toolkit)
 *
 * Copyright (C) 2013 Artem Pavlenko
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *****************************************************************************/

#include <mapnik/renderer_common/process_group_symbolizer.hpp>

namespace mapnik {

point_render_thunk::point_render_thunk(pixel_position const &pos, marker const &m,
                                       agg::trans_affine const &tr, double opacity,
                                       composite_mode_e comp_op)
    : pos_(pos), marker_(std::make_shared<marker>(m)),
      tr_(tr), opacity_(opacity), comp_op_(comp_op)
{}


text_render_thunk::text_render_thunk(placements_list const &placements,
                                     double opacity, composite_mode_e comp_op,
                                     halo_rasterizer_enum halo_rasterizer)
    : placements_(), glyphs_(std::make_shared<std::vector<glyph_info> >()),
      opacity_(opacity), comp_op_(comp_op), halo_rasterizer_(halo_rasterizer)
{
    std::vector<glyph_info> &glyph_vec = *glyphs_;
    
    size_t glyph_count = 0;
    for (glyph_positions_ptr positions : placements)
    {
        glyph_count += std::distance(positions->begin(), positions->end());
    }
    glyph_vec.reserve(glyph_count);
    
    for (glyph_positions_ptr positions : placements)
    {
        glyph_positions_ptr new_positions = std::make_shared<glyph_positions>();
        new_positions->reserve(std::distance(positions->begin(), positions->end()));
        glyph_positions &new_pos = *new_positions;
        
        new_pos.set_base_point(positions->get_base_point());
        if (positions->marker())
        {
            new_pos.set_marker(positions->marker(), positions->marker_pos());
        }
        
        for (glyph_position const &pos : *positions)
        {
            glyph_vec.push_back(*pos.glyph);
            new_pos.push_back(glyph_vec.back(), pos.pos, pos.rot);
        }
        
        placements_.push_back(new_positions);
    }
}


render_thunk_extractor::render_thunk_extractor(box2d<double> &box,
                                               render_thunk_list &thunks,
                                               feature_impl &feature,
                                               attributes const& vars,
                                               proj_transform const &prj_trans,
                                               renderer_common &common,
                                               box2d<double> const &clipping_extent)
    : box_(box), thunks_(thunks), feature_(feature), vars_(vars), prj_trans_(prj_trans),
      common_(common), clipping_extent_(clipping_extent)
{}

void render_thunk_extractor::operator()(point_symbolizer const &sym) const
{
    composite_mode_e comp_op = get<composite_mode_e>(sym, keys::comp_op, feature_, common_.vars_, src_over);

    render_point_symbolizer(
        sym, feature_, prj_trans_, common_,
        [&](pixel_position const &pos, marker const &marker,
            agg::trans_affine const &tr, double opacity) {
            point_render_thunk thunk(pos, marker, tr, opacity, comp_op);
            thunks_.push_back(std::make_shared<render_thunk>(std::move(thunk)));
        });

    update_box();
}

void render_thunk_extractor::operator()(text_symbolizer const &sym) const
{
    box2d<double> clip_box = clipping_extent_;
    text_symbolizer_helper helper(
        sym, feature_, vars_, prj_trans_,
        common_.width_, common_.height_,
        common_.scale_factor_,
        common_.t_, common_.font_manager_, *common_.detector_,
        clip_box);

    extract_text_thunk(helper, sym);
}

void render_thunk_extractor::operator()(shield_symbolizer const &sym) const
{
    box2d<double> clip_box = clipping_extent_;
    text_symbolizer_helper helper(
        sym, feature_, vars_, prj_trans_,
        common_.width_, common_.height_,
        common_.scale_factor_,
        common_.t_, common_.font_manager_, *common_.detector_,
        clip_box);

    extract_text_thunk(helper, sym);
}

void render_thunk_extractor::extract_text_thunk(text_symbolizer_helper &helper, text_symbolizer const &sym) const
{
    double opacity = get<double>(sym, keys::opacity, feature_, common_.vars_, 1.0);
    composite_mode_e comp_op = get<composite_mode_e>(sym, keys::comp_op, feature_, common_.vars_, src_over);
    halo_rasterizer_enum halo_rasterizer = get<halo_rasterizer_enum>(sym, keys::halo_rasterizer, feature_, common_.vars_, HALO_RASTERIZER_FULL);

    placements_list const& placements = helper.get();
    text_render_thunk thunk(placements, opacity, comp_op, halo_rasterizer);
    thunks_.push_back(std::make_shared<render_thunk>(thunk));

    update_box();
}

void render_thunk_extractor::update_box() const
{
    label_collision_detector4 &detector = *common_.detector_;

    for (auto const &label : detector)
    {
        if (box_.width() > 0 && box_.height() > 0)
        {
            box_.expand_to_include(label.box);
        }
        else
        {
            box_ = label.box;
        }
    }

    detector.clear();
}


geometry_type *origin_point(proj_transform const &prj_trans,
                            renderer_common const &common)
{
    // note that we choose a point in the middle of the screen to
    // try to ensure that we don't get edge artefacts due to any
    // symbolizers with avoid-edges set: only the avoid-edges of
    // the group symbolizer itself should matter.
    double x = common.width_ / 2.0, y = common.height_ / 2.0, z = 0.0;
    common.t_.backward(&x, &y);
    prj_trans.forward(x, y, z);
    geometry_type *geom = new geometry_type(geometry_type::Point);
    geom->move_to(x, y);
    return geom;
}

} // namespace mapnik