mapnik/bindings/python/python_grid_utils.hpp
2012-04-08 02:20:56 +02:00

485 lines
17 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 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_PYTHON_BINDING_GRID_UTILS_INCLUDED
#define MAPNIK_PYTHON_BINDING_GRID_UTILS_INCLUDED
// boost
#include <boost/python.hpp>
#include <boost/scoped_array.hpp>
#include <boost/foreach.hpp>
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/grid/grid_renderer.hpp>
#include <mapnik/grid/grid.hpp>
#include <mapnik/grid/grid_util.hpp>
#include <mapnik/grid/grid_view.hpp>
#include <mapnik/value_error.hpp>
#include <mapnik/feature.hpp>
#include <mapnik/feature_kv_iterator.hpp>
#include "mapnik_value_converter.hpp"
namespace mapnik {
template <typename T>
static void grid2utf(T const& grid_type,
boost::python::list& l,
std::vector<grid::lookup_type>& key_order)
{
typename T::data_type const& data = grid_type.data();
typename T::feature_key_type const& feature_keys = grid_type.get_feature_keys();
typename T::key_type keys;
typename T::key_type::const_iterator key_pos;
typename T::feature_key_type::const_iterator feature_pos;
// start counting at utf8 codepoint 32, aka space character
boost::uint16_t codepoint = 32;
unsigned array_size = data.width();
for (unsigned y = 0; y < data.height(); ++y)
{
boost::uint16_t idx = 0;
boost::scoped_array<Py_UNICODE> line(new Py_UNICODE[array_size]);
typename T::value_type const* row = data.getRow(y);
for (unsigned x = 0; x < data.width(); ++x)
{
feature_pos = feature_keys.find(row[x]);
if (feature_pos != feature_keys.end())
{
mapnik::grid::lookup_type val = feature_pos->second;
key_pos = keys.find(val);
if (key_pos == keys.end())
{
// Create a new entry for this key. Skip the codepoints that
// can't be encoded directly in JSON.
if (codepoint == 34) ++codepoint; // Skip "
else if (codepoint == 92) ++codepoint; // Skip backslash
keys[val] = codepoint;
key_order.push_back(val);
line[idx++] = static_cast<Py_UNICODE>(codepoint);
++codepoint;
}
else
{
line[idx++] = static_cast<Py_UNICODE>(key_pos->second);
}
}
// else, shouldn't get here...
}
l.append(boost::python::object(
boost::python::handle<>(
PyUnicode_FromUnicode(line.get(), array_size))));
}
}
template <typename T>
static void grid2utf(T const& grid_type,
boost::python::list& l,
std::vector<typename T::lookup_type>& key_order,
unsigned int resolution)
{
//typename T::data_type const& data = grid_type.data();
typename T::feature_key_type const& feature_keys = grid_type.get_feature_keys();
typename T::key_type keys;
typename T::key_type::const_iterator key_pos;
typename T::feature_key_type::const_iterator feature_pos;
// start counting at utf8 codepoint 32, aka space character
boost::uint16_t codepoint = 32;
// TODO - use double?
unsigned array_size = static_cast<unsigned int>(grid_type.width()/resolution);
for (unsigned y = 0; y < grid_type.height(); y=y+resolution)
{
boost::uint16_t idx = 0;
boost::scoped_array<Py_UNICODE> line(new Py_UNICODE[array_size]);
mapnik::grid::value_type const* row = grid_type.getRow(y);
for (unsigned x = 0; x < grid_type.width(); x=x+resolution)
{
feature_pos = feature_keys.find(row[x]);
if (feature_pos != feature_keys.end())
{
mapnik::grid::lookup_type val = feature_pos->second;
key_pos = keys.find(val);
if (key_pos == keys.end())
{
// Create a new entry for this key. Skip the codepoints that
// can't be encoded directly in JSON.
if (codepoint == 34) ++codepoint; // Skip "
else if (codepoint == 92) ++codepoint; // Skip backslash
keys[val] = codepoint;
key_order.push_back(val);
line[idx++] = static_cast<Py_UNICODE>(codepoint);
++codepoint;
}
else
{
line[idx++] = static_cast<Py_UNICODE>(key_pos->second);
}
}
// else, shouldn't get here...
}
l.append(boost::python::object(
boost::python::handle<>(
PyUnicode_FromUnicode(line.get(), array_size))));
}
}
template <typename T>
static void grid2utf2(T const& grid_type,
boost::python::list& l,
std::vector<typename T::lookup_type>& key_order,
unsigned int resolution)
{
typename T::data_type const& data = grid_type.data();
typename T::feature_key_type const& feature_keys = grid_type.get_feature_keys();
typename T::key_type keys;
typename T::key_type::const_iterator key_pos;
typename T::feature_key_type::const_iterator feature_pos;
// start counting at utf8 codepoint 32, aka space character
uint16_t codepoint = 32;
mapnik::grid::data_type target(data.width()/resolution,data.height()/resolution);
mapnik::scale_grid(target,grid_type.data(),0.0,0.0);
unsigned array_size = target.width();
for (unsigned y = 0; y < target.height(); ++y)
{
uint16_t idx = 0;
boost::scoped_array<Py_UNICODE> line(new Py_UNICODE[array_size]);
mapnik::grid::value_type * row = target.getRow(y);
unsigned x;
for (x = 0; x < target.width(); ++x)
{
feature_pos = feature_keys.find(row[x]);
if (feature_pos != feature_keys.end())
{
mapnik::grid::lookup_type val = feature_pos->second;
key_pos = keys.find(val);
if (key_pos == keys.end())
{
// Create a new entry for this key. Skip the codepoints that
// can't be encoded directly in JSON.
if (codepoint == 34) ++codepoint; // Skip "
else if (codepoint == 92) ++codepoint; // Skip backslash
keys[val] = codepoint;
key_order.push_back(val);
line[idx++] = static_cast<Py_UNICODE>(codepoint);
++codepoint;
}
else
{
line[idx++] = static_cast<Py_UNICODE>(key_pos->second);
}
}
// else, shouldn't get here...
}
l.append(boost::python::object(
boost::python::handle<>(
PyUnicode_FromUnicode(line.get(), array_size))));
}
}
template <typename T>
static void write_features(T const& grid_type,
boost::python::dict& feature_data,
std::vector<typename T::lookup_type> const& key_order)
{
std::string const& key = grid_type.get_key();
std::set<std::string> const& attributes = grid_type.property_names();
typename T::feature_type const& g_features = grid_type.get_grid_features();
typename T::feature_type::const_iterator feat_itr = g_features.begin();
typename T::feature_type::const_iterator feat_end = g_features.end();
bool include_key = (attributes.find(key) != attributes.end());
for (; feat_itr != feat_end; ++feat_itr)
{
mapnik::feature_ptr feature = feat_itr->second;
boost::optional<std::string> join_value;
if (key == grid_type.key_name())
{
std::stringstream s;
s << feature->id();
join_value = s.str();
}
else if (feature->has_key(key))
{
join_value = feature->get(key).to_string();
}
if (join_value)
{
// only serialize features visible in the grid
if(std::find(key_order.begin(), key_order.end(), *join_value) != key_order.end()) {
boost::python::dict feat;
bool found = false;
if (key == grid_type.key_name())
{
// drop key unless requested
if (include_key) {
found = true;
//TODO - add __id__ as data key?
//feat[key] = *join_value;
}
}
feature_kv_iterator itr = feature->begin();
feature_kv_iterator end = feature->end();
for ( ;itr!=end; ++itr)
{
std::string const& key_name = boost::get<0>(*itr);
if (key_name == key) {
// drop key unless requested
if (include_key) {
found = true;
feat[key_name] = boost::get<1>(*itr);
}
}
else if ( (attributes.find(key_name) != attributes.end()) )
{
found = true;
feat[key_name] = boost::get<1>(*itr);
}
}
if (found)
{
feature_data[feat_itr->first] = feat;
}
}
}
else
{
#ifdef MAPNIK_LOG
mapnik::log() << "write_features: Should not get here: key " << key << " not found in grid feature properties";
#endif
}
}
}
template <typename T>
static void grid_encode_utf(T const& grid_type,
boost::python::dict & json,
bool add_features,
unsigned int resolution)
{
// convert buffer to utf and gather key order
boost::python::list l;
std::vector<typename T::lookup_type> key_order;
if (resolution != 1) {
// resample on the fly - faster, less accurate
mapnik::grid2utf<T>(grid_type,l,key_order,resolution);
// resample first - slower, more accurate
//mapnik::grid2utf2<T>(grid_type,l,key_order,resolution);
}
else
{
mapnik::grid2utf<T>(grid_type,l,key_order);
}
// convert key order to proper python list
boost::python::list keys_a;
BOOST_FOREACH ( typename T::lookup_type const& key_id, key_order )
{
keys_a.append(key_id);
}
// gather feature data
boost::python::dict feature_data;
if (add_features) {
mapnik::write_features<T>(grid_type,feature_data,key_order);
}
json["grid"] = l;
json["keys"] = keys_a;
json["data"] = feature_data;
}
template <typename T>
static boost::python::dict grid_encode( T const& grid, std::string format, bool add_features, unsigned int resolution)
{
if (format == "utf") {
boost::python::dict json;
grid_encode_utf<T>(grid,json,add_features,resolution);
return json;
}
else
{
std::stringstream s;
s << "'utf' is currently the only supported encoding format.";
throw mapnik::value_error(s.str());
}
}
/* new approach: key comes from grid object
* grid size should be same as the map
* encoding, resizing handled as method on grid object
* whether features are dumped is determined by argument not 'fields'
*/
static void render_layer_for_grid(const mapnik::Map& map,
mapnik::grid& grid,
unsigned layer_idx, // TODO - layer by name or index
boost::python::list const& fields)
{
std::vector<mapnik::layer> const& layers = map.layers();
std::size_t layer_num = layers.size();
if (layer_idx >= layer_num) {
std::ostringstream s;
s << "Zero-based layer index '" << layer_idx << "' not valid, only '"
<< layer_num << "' layers are in map\n";
throw std::runtime_error(s.str());
}
// convert python list to std::vector
boost::python::ssize_t num_fields = boost::python::len(fields);
for(boost::python::ssize_t i=0; i<num_fields; i++) {
boost::python::extract<std::string> name(fields[i]);
if (name.check()) {
grid.add_property_name(name());
}
else
{
std::stringstream s;
s << "list of field names must be strings";
throw mapnik::value_error(s.str());
}
}
// copy property names
std::set<std::string> attributes = grid.property_names();
std::string const& key = grid.get_key();
// if key is special __id__ keyword
if (key == grid.key_name())
{
// TODO - should feature.id() be a first class attribute?
// if __id__ is requested to be dumped out
// remove it so that datasource queries will not break
if (attributes.find(key) != attributes.end())
{
attributes.erase(key);
}
}
// if key is not the special __id__ keyword
else if (attributes.find(key) == attributes.end())
{
// them make sure the datasource query includes this field
attributes.insert(key);
}
mapnik::grid_renderer<mapnik::grid> ren(map,grid,1.0,0,0);
mapnik::layer const& layer = layers[layer_idx];
ren.apply(layer,attributes);
}
/* old, original impl - to be removed after further testing
* grid object is created on the fly at potentially reduced size
*/
static boost::python::dict render_grid(const mapnik::Map& map,
unsigned layer_idx, // layer
std::string const& key, // key_name
unsigned int step, // resolution
boost::python::list const& fields)
{
std::vector<mapnik::layer> const& layers = map.layers();
std::size_t layer_num = layers.size();
if (layer_idx >= layer_num) {
std::ostringstream s;
s << "Zero-based layer index '" << layer_idx << "' not valid, only '"
<< layer_num << "' layers are in map\n";
throw std::runtime_error(s.str());
}
unsigned int grid_width = map.width()/step;
unsigned int grid_height = map.height()/step;
// TODO - no need to pass step here
mapnik::grid grid(grid_width,grid_height,key,step);
// convert python list to std::vector
boost::python::ssize_t num_fields = boost::python::len(fields);
for(boost::python::ssize_t i=0; i<num_fields; i++) {
boost::python::extract<std::string> name(fields[i]);
if (name.check()) {
grid.add_property_name(name());
}
else
{
std::stringstream s;
s << "list of field names must be strings";
throw mapnik::value_error(s.str());
}
}
// copy property names
std::set<std::string> attributes = grid.property_names();
// if key is special __id__ keyword
if (key == grid.key_name())
{
// TODO - should feature.id() be a first class attribute?
// if __id__ is requested to be dumped out
// remove it so that datasource queries will not break
if (attributes.find(key) != attributes.end())
{
attributes.erase(key);
}
}
// if key is not the special __id__ keyword
else if (attributes.find(key) == attributes.end())
{
// them make sure the datasource query includes this field
attributes.insert(key);
}
try
{
mapnik::grid_renderer<mapnik::grid> ren(map,grid,1.0,0,0);
mapnik::layer const& layer = layers[layer_idx];
ren.apply(layer,attributes);
}
catch (...)
{
throw;
}
bool add_features = false;
if (num_fields > 0)
add_features = true;
// build dictionary and return to python
boost::python::dict json;
grid_encode_utf(grid,json,add_features,1);
return json;
}
}
#endif // MAPNIK_PYTHON_BINDING_GRID_UTILS_INCLUDED