rectangular_layout.cpp

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/*
    Genesis - A toolkit for working with phylogenetic data.
    Copyright (C) 2014-2019 Lucas Czech and HITS gGmbH
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.
 
    This program 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 General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
    Contact:
    Lucas Czech <lucas.czech@h-its.org>
    Exelixis Lab, Heidelberg Institute for Theoretical Studies
    Schloss-Wolfsbrunnenweg 35, D-69118 Heidelberg, Germany
*/
 
#include "genesis/tree/drawing/rectangular_layout.hpp"
 
#include "genesis/tree/function/functions.hpp"
#include "genesis/tree/function/operators.hpp"
 
#include <algorithm>
#include <cassert>
#include <stdexcept>
 
namespace genesis {
namespace tree {
 
// =================================================================================================
//     Settings
// =================================================================================================
 
RectangularLayout& RectangularLayout::width( double const value )
{
    width_ = value;
    return *this;
}
 
double RectangularLayout::width() const
{
    return width_;
}
 
RectangularLayout& RectangularLayout::height( double const value )
{
    height_ = value;
    return *this;
}
 
double RectangularLayout::height() const
{
    return height_;
}
 
// =================================================================================================
//     Virtual Functions
// =================================================================================================
 
utils::SvgDocument RectangularLayout::to_svg_document_() const
{
    using namespace utils;
    SvgDocument doc;
    SvgGroup    tree_lines;
    SvgGroup    taxa_lines;
    SvgGroup    taxa_names;
    SvgGroup    edge_shapes;
    SvgGroup    node_shapes;
 
    // If no width and/or height is set, use automatic ones:
    // The height is at least 100, or depends on the node count, so that it scales well.
    // The factor of six is chosen based on the default svg font on our test system.
    // Might need to look into this for other systems.
    // Also, circular trees use node count without a factor as the default radius.
    // Because circumference is 2*pi*r, our factor of 6 is close to 2*pi,
    // which makes the font spacing similar for circular and rectangular trees ;-)
    // Furthermore, width is chosen to be half the height,
    // which usually is a good aspect ratio for tree figures.
    auto width = width_;
    auto height = height_;
    if( height <= 0.0 ) {
        height = std::max( 100.0, 6.0 * static_cast<double>( tree().node_count() ));
    }
    if( width <= 0.0 ) {
        width = height / 2.0;
    }
 
    size_t max_text_len = 0;
 
    for( auto const& node : tree().nodes() ) {
 
        auto const& node_data = node.data<LayoutNodeData>();
        auto const& prnt_data = tree().node_at( node_data.parent_index ).data<LayoutNodeData>();
 
        auto const node_x = node_data.distance * width;
        auto const node_y = node_data.spreading * height;
 
        // Get the edge between the node and its parent.
        auto edge_ptr = edge_between( node, tree().node_at( node_data.parent_index ) );
 
        // If there is an edge (i.e., we are not at the root), draw lines between the nodes.
        if( edge_ptr ) {
            auto const& edge_data = edge_ptr->data<LayoutEdgeData>();
 
            // Get line strokes
            auto spreading_stroke = edge_data.spreading_stroke;
            auto distance_stroke = edge_data.distance_stroke;
            // spreading_stroke.line_cap = utils::SvgStroke::LineCap::kSquare;
            // distance_stroke.line_cap = utils::SvgStroke::LineCap::kButt;
 
            // Calculate linear distance
            auto const dist_start_x = prnt_data.distance * width;
            auto const dist_start_y = node_y;
 
            // Draw lines
            tree_lines << SvgLine(
                prnt_data.distance * width, prnt_data.spreading * height,
                dist_start_x, dist_start_y,
                spreading_stroke
            );
            tree_lines << SvgLine(
                dist_start_x, dist_start_y,
                node_x, node_y,
                distance_stroke
            );
 
            // If there is an edge shape, draw it to the middle of the edge
            if( ! edge_data.shape.empty() ) {
                auto const shape_x = ( dist_start_x + node_x ) / 2.0;
                auto const shape_y = ( dist_start_y + node_y ) / 2.0;
 
                auto es = edge_data.shape;
                es.transform.append( SvgTransform::Translate( shape_x, shape_y ));
                edge_shapes << std::move( es );
            }
 
        } else {
 
            // If there is no edge, it must be the root.
            assert( is_root( node ));
        }
 
        // In the following, we will draw the label and the spacer (if labels shall be aligned).
        // As aligning chances the x dist of the label, we store it here first, change if needed,
        // and later use it for positioning the label text.
        auto label_dist = node_x;
 
        // If we want to align all labels, adjust the distance to the max,
        // and draw a line from the node to there. This line is also drawn if there is no label,
        // which is what we want. Users will have to explicitly set an empty line if they don't
        // want one. This makes sure that we can also draw these lines for inner nodes, which
        // might be needed in some scenarious.
        if( align_labels() ) {
            label_dist = width + extra_spacer();
 
            auto label_path = SvgPath( node_data.spacer_stroke, SvgFill( SvgFill::Type::kNone ));
            label_path.elements.push_back(
                "M " + std::to_string( node_x ) + " " + std::to_string( node_y )
            );
            label_path.elements.push_back(
                "L " + std::to_string( label_dist ) + " " + std::to_string( node_y )
            );
            taxa_lines << label_path;
            // taxa_lines << SvgLine(
            //     node_x, node_y,
            //     label_dist, node_y,
            //     node_data.spacer_stroke
            // );
        }
 
        // If the node has a name, print it.
        if( node_data.name != "" ) {
            // auto label = SvgText(
            //     node_data.name,
            //     SvgPoint( node_x + 5, node_y )
            // );
            // label.dy = "0.4em";
 
            auto label = text_template();
            label.text = node_data.name;
            label.alignment_baseline = SvgText::AlignmentBaseline::kMiddle;
 
            // Move label to tip node.
            label.transform.append( SvgTransform::Translate( label_dist + 5, node_y ));
            taxa_names << std::move( label );
            max_text_len = std::max( max_text_len, node_data.name.size() );
        }
 
        // If there is a node shape, draw it.
        if( ! node_data.shape.empty() ) {
            auto ns = node_data.shape;
            ns.transform.append( SvgTransform::Translate( node_x, node_y ));
            node_shapes << std::move( ns );
        }
    }
 
    // Make sure that the drawing is done from outside to inside,
    // so that the overlapping parts look nice.
    tree_lines.reverse();
 
    // Set the margins according to longest label.
    auto const marg_a = std::max( 20.0, text_template().font.size );
    auto const marg_r = std::max( 25.0, max_text_len * text_template().font.size );
    doc.margin = SvgMargin( marg_a, marg_r, marg_a, marg_a );
 
    // We are sure that we won't use the groups again, so let's move them!
    doc << std::move( tree_lines );
    if( ! taxa_lines.empty() ) {
        doc << std::move( taxa_lines );
    }
    if( ! taxa_names.empty() ) {
        doc << std::move( taxa_names );
    }
    if( ! edge_shapes.empty() ) {
        doc << std::move( edge_shapes );
    }
    if( ! node_shapes.empty() ) {
        doc << std::move( node_shapes );
    }
    return doc;
}
 
} // namespace tree
} // namespace genesis