mapnik/plugins/input/gdal/gdal_datasource.cpp
2021-01-05 11:59:41 +00:00

267 lines
8.6 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2021 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 "gdal_datasource.hpp"
#include "gdal_featureset.hpp"
// mapnik
#include <mapnik/debug.hpp>
#include <mapnik/boolean.hpp>
#include <mapnik/geom_util.hpp>
#include <mapnik/timer.hpp>
#include <mapnik/value_types.hpp>
#include <gdal_version.h>
using mapnik::datasource;
using mapnik::parameters;
DATASOURCE_PLUGIN(gdal_datasource)
using mapnik::box2d;
using mapnik::coord2d;
using mapnik::query;
using mapnik::featureset_ptr;
using mapnik::layer_descriptor;
using mapnik::datasource_exception;
static std::once_flag once_flag;
extern "C" MAPNIK_EXP void on_plugin_load()
{
// initialize gdal formats
std::call_once(once_flag,[](){
GDALAllRegister();
});
}
gdal_datasource::gdal_datasource(parameters const& params)
: datasource(params),
dataset_(nullptr, &GDALClose),
desc_(gdal_datasource::name(), "utf-8"),
nodata_value_(params.get<double>("nodata")),
nodata_tolerance_(*params.get<double>("nodata_tolerance",1e-12))
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource: Initializing...";
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "gdal_datasource::init");
#endif
boost::optional<std::string> file = params.get<std::string>("file");
if (! file) throw datasource_exception("missing <file> parameter");
boost::optional<std::string> base = params.get<std::string>("base");
if (base)
{
dataset_name_ = *base + "/" + *file;
}
else
{
dataset_name_ = *file;
}
shared_dataset_ = *params.get<mapnik::boolean_type>("shared", false);
band_ = *params.get<mapnik::value_integer>("band", -1);
// Maximum memory limitation for image will be simply based on the maximum
// area we allow for an image. The true memory footprint therefore will vary based
// on the type of imagery that exists. This is not the maximum size of an image
// on disk but rather the maximum size we will load into mapnik from GDAL.
// max_im_area based on 50 mb limit for RGBA
max_image_area_ = *params.get<mapnik::value_integer>("max_image_area", (50*1024*1024) / 4);
#if GDAL_VERSION_NUM >= 1600
if (shared_dataset_)
{
auto ds = GDALOpenShared(dataset_name_.c_str(), GA_ReadOnly);
dataset_.reset(static_cast<GDALDataset*>(ds));
}
else
#endif
{
auto ds = GDALOpen(dataset_name_.c_str(), GA_ReadOnly);
dataset_.reset(static_cast<GDALDataset*>(ds));
}
if (! dataset_)
{
throw datasource_exception(CPLGetLastErrorMsg());
}
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: opened Dataset=" << dataset_.get();
nbands_ = dataset_->GetRasterCount();
width_ = dataset_->GetRasterXSize();
height_ = dataset_->GetRasterYSize();
desc_.add_descriptor(mapnik::attribute_descriptor("nodata", mapnik::Double));
double tr[6];
bool bbox_override = false;
boost::optional<std::string> bbox_s = params.get<std::string>("extent");
if (bbox_s)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource: BBox Parameter=" << *bbox_s;
bbox_override = extent_.from_string(*bbox_s);
if (! bbox_override)
{
throw datasource_exception("GDAL Plugin: bbox parameter '" + *bbox_s + "' invalid");
}
}
if (bbox_override)
{
tr[0] = extent_.minx();
tr[1] = extent_.width() / (double)width_;
tr[2] = 0;
tr[3] = extent_.maxy();
tr[4] = 0;
tr[5] = -extent_.height() / (double)height_;
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource extent override gives Geotransform="
<< tr[0] << "," << tr[1] << ","
<< tr[2] << "," << tr[3] << ","
<< tr[4] << "," << tr[5];
}
else
{
if (dataset_->GetGeoTransform(tr) != CPLE_None)
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource GetGeotransform failure gives="
<< tr[0] << "," << tr[1] << ","
<< tr[2] << "," << tr[3] << ","
<< tr[4] << "," << tr[5];
}
else
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource Geotransform="
<< tr[0] << "," << tr[1] << ","
<< tr[2] << "," << tr[3] << ","
<< tr[4] << "," << tr[5];
}
}
// TODO - We should throw for true non-north up images, but the check
// below is clearly too restrictive.
// https://github.com/mapnik/mapnik/issues/970
/*
if (tr[2] != 0 || tr[4] != 0)
{
throw datasource_exception("GDAL Plugin: only 'north up' images are supported");
}
*/
dx_ = tr[1];
dy_ = tr[5];
if (! bbox_override)
{
double x0 = tr[0];
double y0 = tr[3];
double x1 = tr[0] + width_ * dx_ + height_ *tr[2];
double y1 = tr[3] + width_ *tr[4] + height_ * dy_;
/*
double x0 = tr[0] + (height_) * tr[2]; // minx
double y0 = tr[3] + (height_) * tr[5]; // miny
double x1 = tr[0] + (width_) * tr[1]; // maxx
double y1 = tr[3] + (width_) * tr[4]; // maxy
*/
extent_.init(x0, y0, x1, y1);
}
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource: Raster Size=" << width_ << "," << height_;
MAPNIK_LOG_DEBUG(gdal) << "gdal_datasource: Raster Extent=" << extent_;
}
gdal_datasource::~gdal_datasource()
{
MAPNIK_LOG_DEBUG(gdal) << "gdal_featureset: Closing Dataset=" << dataset_.get();
}
datasource::datasource_t gdal_datasource::type() const
{
return datasource::Raster;
}
const char * gdal_datasource::name()
{
return "gdal";
}
box2d<double> gdal_datasource::envelope() const
{
return extent_;
}
boost::optional<mapnik::datasource_geometry_t> gdal_datasource::get_geometry_type() const
{
return boost::optional<mapnik::datasource_geometry_t>();
}
layer_descriptor gdal_datasource::get_descriptor() const
{
return desc_;
}
featureset_ptr gdal_datasource::features(query const& q) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "gdal_datasource::features");
#endif
return std::make_shared<gdal_featureset>(*dataset_,
band_,
gdal_query(q),
extent_,
width_,
height_,
nbands_,
dx_,
dy_,
nodata_value_,
nodata_tolerance_,
max_image_area_);
}
featureset_ptr gdal_datasource::features_at_point(coord2d const& pt, double tol) const
{
#ifdef MAPNIK_STATS
mapnik::progress_timer __stats__(std::clog, "gdal_datasource::features_at_point");
#endif
return std::make_shared<gdal_featureset>(*dataset_,
band_,
gdal_query(pt),
extent_,
width_,
height_,
nbands_,
dx_,
dy_,
nodata_value_,
nodata_tolerance_,
max_image_area_);
}