mapnik/plugins/input/pgraster/pgraster_wkb_reader.hpp
2021-01-05 11:59:41 +00:00

85 lines
2.7 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
*
*****************************************************************************
*
* Initially developed by Sandro Santilli <strk@keybit.net> for CartoDB
*
*****************************************************************************/
#ifndef PGRASTER_WKB_READER_HPP
#define PGRASTER_WKB_READER_HPP
// mapnik
#include <mapnik/feature.hpp> // for raster_ptr
#include <mapnik/box2d.hpp>
enum pgraster_color_interp {
// Automatic color interpretation:
// uses grayscale for single band, rgb for 3 bands
// rgba for 4 bands
pgr_auto,
// Grayscale interpretation
pgr_grayscale,
pgr_indexed,
pgr_rgb,
pgr_rgba
};
class pgraster_wkb_reader
{
public:
pgraster_wkb_reader(const uint8_t* wkb, int size, int bnd=0)
: ptr_(wkb), bandno_(bnd)
{}
mapnik::raster_ptr get_raster();
/// @param bnd band number. If 0 (default) it'll try to read all bands
/// with automatic color interpretation (rgb for 3 bands,
/// rgba for 4 bands, grayscale for 1 band).
/// Any other value results in pixel
/// values being copied verbatim into the returned raster
/// for interpretation by the caller.
static mapnik::raster_ptr read(const uint8_t* wkb, int size, int bnd=0)
{
pgraster_wkb_reader reader(wkb,size,bnd);
return reader.get_raster();
}
private:
mapnik::raster_ptr read_indexed(mapnik::box2d<double> const& bbox, uint16_t width, uint16_t height);
mapnik::raster_ptr read_grayscale(mapnik::box2d<double> const& bbox, uint16_t width, uint16_t height);
mapnik::raster_ptr read_rgba(mapnik::box2d<double> const& bbox, uint16_t width, uint16_t height);
//int wkbsize_;
//const uint8_t* wkb_;
//const uint8_t* wkbend_;
const uint8_t* ptr_;
uint8_t endian_;
int bandno_;
uint16_t numBands_;
uint16_t width_;
uint16_t height_;
};
#endif // PGRASTER_WKB_READER_HPP