mapnik/include/mapnik/transform_processor.hpp
2016-03-11 13:44:30 -08:00

240 lines
7.3 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2015 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>
#include <mapnik/value.hpp>
#include <mapnik/transform_expression.hpp>
#include <mapnik/expression_evaluator.hpp>
#include <mapnik/util/variant.hpp>
#pragma GCC diagnostic push
#include <mapnik/warning_ignore_agg.hpp>
#include <agg_trans_affine.h>
#pragma GCC diagnostic pop
// stl
#include <cmath>
namespace mapnik {
class feature_impl;
template <typename Container> struct expression_attributes;
template <typename T, typename T1>
struct transform_processor
{
using feature_type = T;
using variable_type = T1;
using transform_type = agg::trans_affine;
template <typename Container>
struct attribute_collector
{
expression_attributes<Container> collect_;
attribute_collector(Container& names)
: collect_(names) {}
void operator() (identity_node const&) const
{
}
void operator() (matrix_node const& node) const
{
util::apply_visitor(collect_, node.a_);
util::apply_visitor(collect_, node.b_);
util::apply_visitor(collect_, node.c_);
util::apply_visitor(collect_, node.d_);
util::apply_visitor(collect_, node.e_);
util::apply_visitor(collect_, node.f_);
}
void operator() (translate_node const& node) const
{
util::apply_visitor(collect_, node.tx_);
util::apply_visitor(collect_, node.ty_);
}
void operator() (scale_node const& node) const
{
util::apply_visitor(collect_, node.sx_);
util::apply_visitor(collect_, node.sy_);
}
void operator() (rotate_node const& node) const
{
util::apply_visitor(collect_, node.angle_);
util::apply_visitor(collect_, node.cx_);
util::apply_visitor(collect_, node.cy_);
}
void operator() (skewX_node const& node) const
{
util::apply_visitor(collect_, node.angle_);
}
void operator() (skewY_node const& node) const
{
util::apply_visitor(collect_, node.angle_);
}
};
struct node_evaluator
{
node_evaluator(transform_type& tr,
feature_type const& feat,
variable_type const& v,
double scale_factor)
: transform_(tr),
feature_(feat),
vars_(v),
scale_factor_(scale_factor) {}
void operator() (identity_node const&) const
{
}
void operator() (matrix_node const& node) const
{
double a = eval(node.a_); // scale x;
double b = eval(node.b_);
double c = eval(node.c_);
double d = eval(node.d_); // 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) const
{
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) const
{
double sx = eval(node.sx_);
double sy = eval(node.sy_, sx);
transform_.scale(sx, sy);
}
void operator() (rotate_node const& node) const
{
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) const
{
auto degrees = std::fmod(eval(node.angle_),90.0);
if (degrees < -89.0) degrees = -89.0;
else if (degrees > 89.0) degrees = 89.0;
auto angle = deg2rad(degrees);
transform_.multiply(agg::trans_affine_skewing(angle, 0.0));
}
void operator() (skewY_node const& node) const
{
auto degrees = std::fmod(eval(node.angle_),90.0);
if (degrees < -89.0) degrees = -89.0;
else if (degrees > 89.0) degrees = 89.0;
auto angle = deg2rad(degrees);
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, variable_type> e(feature_,vars_);
return util::apply_visitor(e, x).to_double();
}
double eval(expr_node const& x, double def) const
{
return detail::is_null_node(x) ? def : eval(x);
}
transform_type& transform_;
feature_type const& feature_;
variable_type const& vars_;
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)
{
util::apply_visitor(collect, *node);
}
}
static void evaluate(transform_type& tr,
feature_type const& feat,
variable_type const& vars,
transform_list const& list,
double scale_factor)
{
node_evaluator eval(tr, feat, vars, scale_factor);
transform_list::const_reverse_iterator rit;
for (rit = list.rbegin(); rit!= list.rend(); ++rit)
{
util::apply_visitor(eval, *(*rit));
}
}
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);
}
};
using transform_processor_type = mapnik::transform_processor<feature_impl,attributes>;
} // namespace mapnik
#endif // MAPNIK_TRANSFORM_PROCESSOR_HPP