mapnik/src/warp.cpp
2015-05-04 12:49:11 +02:00

226 lines
9.1 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2014 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
*
*****************************************************************************/
// mapnik
#include <mapnik/warp.hpp>
#include <mapnik/config.hpp>
#include <mapnik/image.hpp>
#include <mapnik/image_scaling_traits.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/view_transform.hpp>
#include <mapnik/raster.hpp>
#include <mapnik/proj_transform.hpp>
// agg
#include "agg_image_filters.h"
#include "agg_trans_bilinear.h"
#include "agg_span_interpolator_linear.h"
#include "agg_span_image_filter_rgba.h"
#include "agg_rendering_buffer.h"
#include "agg_pixfmt_rgba.h"
#include "agg_rasterizer_scanline_aa.h"
#include "agg_basics.h"
#include "agg_scanline_bin.h"
#include "agg_renderer_scanline.h"
#include "agg_span_allocator.h"
#include "agg_image_accessors.h"
#include "agg_renderer_scanline.h"
namespace mapnik {
template <typename T>
MAPNIK_DECL void warp_image (T & target, T const& source, proj_transform const& prj_trans,
box2d<double> const& target_ext, box2d<double> const& source_ext,
double offset_x, double offset_y, unsigned mesh_size, scaling_method_e scaling_method, double filter_factor)
{
using image_type = T;
using pixel_type = typename image_type::pixel_type;
using pixfmt_pre = typename detail::agg_scaling_traits<image_type>::pixfmt_pre;
using color_type = typename detail::agg_scaling_traits<image_type>::color_type;
using renderer_base = agg::renderer_base<pixfmt_pre>;
using interpolator_type = typename detail::agg_scaling_traits<image_type>::interpolator_type;
constexpr std::size_t pixel_size = sizeof(pixel_type);
view_transform ts(source.width(), source.height(),
source_ext);
view_transform tt(target.width(), target.height(),
target_ext, offset_x, offset_y);
std::size_t mesh_nx = std::ceil(source.width()/double(mesh_size) + 1);
std::size_t mesh_ny = std::ceil(source.height()/double(mesh_size) + 1);
image_gray64f xs(mesh_nx, mesh_ny, false);
image_gray64f ys(mesh_nx, mesh_ny, false);
// Precalculate reprojected mesh
for(std::size_t j = 0; j < mesh_ny; ++j)
{
for (std::size_t i=0; i<mesh_nx; ++i)
{
xs(i,j) = std::min(i*mesh_size,source.width());
ys(i,j) = std::min(j*mesh_size,source.height());
ts.backward(&xs(i,j), &ys(i,j));
}
}
prj_trans.backward(xs.data(), ys.data(), nullptr, mesh_nx*mesh_ny);
agg::rasterizer_scanline_aa<> rasterizer;
agg::scanline_bin scanline;
agg::rendering_buffer buf(target.bytes(),
target.width(),
target.height(),
target.width() * pixel_size);
pixfmt_pre pixf(buf);
renderer_base rb(pixf);
rasterizer.clip_box(0, 0, target.width(), target.height());
agg::rendering_buffer buf_tile(
const_cast<unsigned char*>(source.bytes()),
source.width(),
source.height(),
source.width() * pixel_size);
pixfmt_pre pixf_tile(buf_tile);
using img_accessor_type = agg::image_accessor_clone<pixfmt_pre>;
img_accessor_type ia(pixf_tile);
agg::span_allocator<color_type> sa;
// Project mesh cells into target interpolating raster inside each one
for (std::size_t j = 0; j < mesh_ny - 1; ++j)
{
for (std::size_t i = 0; i < mesh_nx - 1; ++i)
{
double polygon[8] = {xs(i,j), ys(i,j),
xs(i+1,j), ys(i+1,j),
xs(i+1,j+1), ys(i+1,j+1),
xs(i,j+1), ys(i,j+1)};
tt.forward(polygon+0, polygon+1);
tt.forward(polygon+2, polygon+3);
tt.forward(polygon+4, polygon+5);
tt.forward(polygon+6, polygon+7);
rasterizer.reset();
rasterizer.move_to_d(std::floor(polygon[0]), std::floor(polygon[1]));
rasterizer.line_to_d(std::floor(polygon[2]), std::floor(polygon[3]));
rasterizer.line_to_d(std::floor(polygon[4]), std::floor(polygon[5]));
rasterizer.line_to_d(std::floor(polygon[6]), std::floor(polygon[7]));
std::size_t x0 = i * mesh_size;
std::size_t y0 = j * mesh_size;
std::size_t x1 = (i+1) * mesh_size;
std::size_t y1 = (j+1) * mesh_size;
x1 = std::min(x1, source.width());
y1 = std::min(y1, source.height());
agg::trans_affine tr(polygon, x0, y0, x1, y1);
if (tr.is_valid())
{
interpolator_type interpolator(tr);
if (scaling_method == SCALING_NEAR)
{
using span_gen_type = typename detail::agg_scaling_traits<image_type>::span_image_filter;
span_gen_type sg(ia, interpolator);
agg::render_scanlines_bin(rasterizer, scanline, rb, sa, sg);
}
else
{
using span_gen_type = typename detail::agg_scaling_traits<image_type>::span_image_resample_affine;
agg::image_filter_lut filter;
detail::set_scaling_method(filter, scaling_method, filter_factor);
span_gen_type sg(ia, interpolator, filter);
agg::render_scanlines_bin(rasterizer, scanline, rb, sa, sg);
}
}
}
}
}
namespace detail {
struct warp_image_visitor
{
warp_image_visitor (raster & target_raster, proj_transform const& prj_trans, box2d<double> const& source_ext,
double offset_x, double offset_y, unsigned mesh_size,
scaling_method_e scaling_method, double filter_factor)
: target_raster_(target_raster),
prj_trans_(prj_trans),
source_ext_(source_ext),
offset_x_(offset_x),
offset_y_(offset_y),
mesh_size_(mesh_size),
scaling_method_(scaling_method),
filter_factor_(filter_factor) {}
void operator() (image_null const&) {}
template <typename T>
void operator() (T const& source)
{
using image_type = T;
//source and target image data types must match
if (target_raster_.data_.template is<image_type>())
{
image_type & target = util::get<image_type>(target_raster_.data_);
warp_image (target, source, prj_trans_, target_raster_.ext_, source_ext_,
offset_x_, offset_y_, mesh_size_, scaling_method_, filter_factor_);
}
}
raster & target_raster_;
proj_transform const& prj_trans_;
box2d<double> const& source_ext_;
double offset_x_;
double offset_y_;
unsigned mesh_size_;
scaling_method_e scaling_method_;
double filter_factor_;
};
}
void reproject_and_scale_raster(raster & target, raster const& source,
proj_transform const& prj_trans,
double offset_x, double offset_y,
unsigned mesh_size,
scaling_method_e scaling_method)
{
detail::warp_image_visitor warper(target, prj_trans, source.ext_, offset_x, offset_y, mesh_size,
scaling_method, source.get_filter_factor());
util::apply_visitor(warper, source.data_);
}
template MAPNIK_DECL void warp_image (image_rgba8&, image_rgba8 const&, proj_transform const&,
box2d<double> const&, box2d<double> const&, double, double, unsigned, scaling_method_e, double);
template MAPNIK_DECL void warp_image (image_gray8&, image_gray8 const&, proj_transform const&,
box2d<double> const&, box2d<double> const&, double, double, unsigned, scaling_method_e, double);
template MAPNIK_DECL void warp_image (image_gray16&, image_gray16 const&, proj_transform const&,
box2d<double> const&, box2d<double> const&, double, double, unsigned, scaling_method_e, double);
template MAPNIK_DECL void warp_image (image_gray32f&, image_gray32f const&, proj_transform const&,
box2d<double> const&, box2d<double> const&, double, double, unsigned, scaling_method_e, double);
}// namespace mapnik