mapnik/include/mapnik/transform_processor.hpp
2014-02-27 13:28:25 -08:00

242 lines
7.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2012 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
*
*****************************************************************************/
#ifndef MAPNIK_TRANSFORM_PROCESSOR_HPP
#define MAPNIK_TRANSFORM_PROCESSOR_HPP
// mapnik
#include <mapnik/config.hpp>
#ifdef MAPNIK_LOG
#include <mapnik/debug.hpp>
#endif
#include <mapnik/value.hpp>
#include <mapnik/transform_expression.hpp>
#include <mapnik/expression_evaluator.hpp>
// boost
#include <boost/variant/static_visitor.hpp>
#include <boost/variant/apply_visitor.hpp>
#include <boost/range/adaptor/reversed.hpp>
// agg
#include <agg_trans_affine.h>
namespace mapnik {
class feature_impl;
template <typename Container> struct expression_attributes;
template <typename T>
struct transform_processor
{
typedef T feature_type;
typedef agg::trans_affine transform_type;
template <typename Container>
struct attribute_collector : boost::static_visitor<void>
{
expression_attributes<Container> collect_;
attribute_collector(Container& names)
: collect_(names) {}
void operator() (identity_node const& node) const
{
boost::ignore_unused_variable_warning(node);
}
void operator() (matrix_node const& node) const
{
boost::apply_visitor(collect_, node.a_);
boost::apply_visitor(collect_, node.b_);
boost::apply_visitor(collect_, node.c_);
boost::apply_visitor(collect_, node.d_);
boost::apply_visitor(collect_, node.e_);
boost::apply_visitor(collect_, node.f_);
}
void operator() (translate_node const& node) const
{
boost::apply_visitor(collect_, node.tx_);
boost::apply_visitor(collect_, node.ty_);
}
void operator() (scale_node const& node) const
{
boost::apply_visitor(collect_, node.sx_);
boost::apply_visitor(collect_, node.sy_);
}
void operator() (rotate_node const& node) const
{
boost::apply_visitor(collect_, node.angle_);
boost::apply_visitor(collect_, node.cx_);
boost::apply_visitor(collect_, node.cy_);
}
void operator() (skewX_node const& node) const
{
boost::apply_visitor(collect_, node.angle_);
}
void operator() (skewY_node const& node) const
{
boost::apply_visitor(collect_, node.angle_);
}
};
struct node_evaluator : boost::static_visitor<void>
{
node_evaluator(transform_type& tr,
feature_type const& feat,
double scale_factor)
: transform_(tr),
feature_(feat),
scale_factor_(scale_factor) {}
void operator() (identity_node const& node)
{
boost::ignore_unused_variable_warning(node);
}
void operator() (matrix_node const& node)
{
double a = eval(node.a_) * scale_factor_; // scale x;
double b = eval(node.b_);
double c = eval(node.c_);
double d = eval(node.d_) * scale_factor_; // scale y;
double e = eval(node.e_) * scale_factor_; // translate x
double f = eval(node.f_) * scale_factor_; // translate y
transform_.multiply(agg::trans_affine(a, b, c, d, e, f));
}
void operator() (translate_node const& node)
{
double tx = eval(node.tx_) * scale_factor_;
double ty = eval(node.ty_, 0.0) * scale_factor_;
transform_.translate(tx, ty);
}
void operator() (scale_node const& node)
{
double sx = eval(node.sx_) * scale_factor_;
double sy = eval(node.sy_, sx) * scale_factor_;
transform_.scale(sx, sy);
}
void operator() (rotate_node const& node)
{
double angle = deg2rad(eval(node.angle_));
double cx = eval(node.cx_, 0.0);
double cy = eval(node.cy_, 0.0);
transform_.translate(-cx, -cy);
transform_.rotate(angle);
transform_.translate(cx, cy);
}
void operator() (skewX_node const& node)
{
double angle = deg2rad(eval(node.angle_));
transform_.multiply(agg::trans_affine_skewing(angle, 0.0));
}
void operator() (skewY_node const& node)
{
double angle = deg2rad(eval(node.angle_));
transform_.multiply(agg::trans_affine_skewing(0.0, angle));
}
private:
static double deg2rad(double d)
{
return d * M_PI / 180.0;
}
double eval(expr_node const& x) const
{
mapnik::evaluate<feature_type, value_type> e(feature_);
return boost::apply_visitor(e, x).to_double();
}
double eval(expr_node const& x, double def) const
{
return is_null(x) ? def : eval(x);
}
transform_type& transform_;
feature_type const& feature_;
double scale_factor_;
};
template <typename Container>
static void collect_attributes(Container& names,
transform_list const& list)
{
attribute_collector<Container> collect(names);
for (transform_node const& node : list)
{
boost::apply_visitor(collect, *node);
}
}
static void evaluate(transform_type& tr, feature_type const& feat,
transform_list const& list, double scale_factor)
{
node_evaluator eval(tr, feat, scale_factor);
#ifdef MAPNIK_LOG
MAPNIK_LOG_DEBUG(transform) << "transform: begin with " << to_string(matrix_node(tr));
#endif
for (transform_node const& node : boost::adaptors::reverse(list))
{
boost::apply_visitor(eval, *node);
#ifdef MAPNIK_LOG
MAPNIK_LOG_DEBUG(transform) << "transform: apply " << to_string(*node);
MAPNIK_LOG_DEBUG(transform) << "transform: result " << to_string(matrix_node(tr));
#endif
}
#ifdef MAPNIK_LOG
MAPNIK_LOG_DEBUG(transform) << "transform: end";
#endif
}
static std::string to_string(transform_node const& node)
{
return to_expression_string(node);
}
static std::string to_string(transform_list const& list)
{
return to_expression_string(list);
}
};
typedef mapnik::transform_processor<feature_impl> transform_processor_type;
} // namespace mapnik
#endif // MAPNIK_TRANSFORM_PROCESSOR_HPP