mapnik/src/warp.cpp

/*****************************************************************************
 *
 * 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
 *
 *****************************************************************************/

// mapnik
#include <mapnik/warp.hpp>
#include <mapnik/config.hpp>
#include <mapnik/image_data.hpp>
#include <mapnik/image_util.hpp>
#include <mapnik/box2d.hpp>
#include <mapnik/ctrans.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_u.h"
#include "agg_renderer_scanline.h"
#include "agg_span_allocator.h"
#include "agg_image_accessors.h"
#include "agg_renderer_scanline.h"

namespace mapnik {

void reproject_raster(raster &target, raster const& source,
                      proj_transform const& prj_trans,
                      double offset_x, double offset_y,
                      unsigned mesh_size,
                      double filter_radius,
                      double scale_factor,
                      std::string scaling_method_name)
{
    if (prj_trans.equal()) {

        if (scaling_method_name == "bilinear8"){
            scale_image_bilinear8<image_data_32>(target.data_,source.data_,
                                                 offset_x, offset_y);
        } else {
            scaling_method_e scaling_method = get_scaling_method_by_name(scaling_method_name);
            scale_image_agg<image_data_32>(target.data_,source.data_, (scaling_method_e)scaling_method, scale_factor, offset_x, offset_y, filter_radius);
        }
    } else {
        CoordTransform ts(source.data_.width(), source.data_.height(),
                          source.ext_);
        CoordTransform tt(target.data_.width(), target.data_.height(),
                          target.ext_, offset_x, offset_y);
        unsigned i, j;
        unsigned mesh_nx = ceil(source.data_.width()/double(mesh_size)+1);
        unsigned mesh_ny = ceil(source.data_.height()/double(mesh_size)+1);

        ImageData<double> xs(mesh_nx, mesh_ny);
        ImageData<double> ys(mesh_nx, mesh_ny);

        // Precalculate reprojected mesh
        for(j=0; j<mesh_ny; j++) {
            for (i=0; i<mesh_nx; i++) {
                xs(i,j) = i*mesh_size;
                ys(i,j) = j*mesh_size;
                ts.backward(&xs(i,j), &ys(i,j));
            }
        }
        prj_trans.backward(xs.getData(), ys.getData(), NULL, mesh_nx*mesh_ny);

        // Initialize AGG objects
        typedef agg::pixfmt_rgba32 pixfmt;
        typedef pixfmt::color_type color_type;
        typedef agg::renderer_base<pixfmt> renderer_base;
        typedef agg::pixfmt_rgba32_pre pixfmt_pre;
        typedef agg::renderer_base<pixfmt_pre> renderer_base_pre;

        agg::rasterizer_scanline_aa<> rasterizer;
        agg::scanline_u8  scanline;
        agg::rendering_buffer buf((unsigned char*)target.data_.getData(),
                                  target.data_.width(),
                                  target.data_.height(),
                                  target.data_.width()*4);
        pixfmt_pre pixf_pre(buf);
        renderer_base_pre rb_pre(pixf_pre);
        rasterizer.clip_box(0, 0, target.data_.width(), target.data_.height());
        agg::rendering_buffer buf_tile(
            (unsigned char*)source.data_.getData(),
            source.data_.width(),
            source.data_.height(),
            source.data_.width() * 4);

        pixfmt pixf_tile(buf_tile);

        typedef agg::image_accessor_clone<pixfmt> img_accessor_type;
        img_accessor_type ia(pixf_tile);

        agg::span_allocator<color_type> sa;

        // Initialize filter
        agg::image_filter_lut filter;
        scaling_method_e scaling_method = get_scaling_method_by_name(
            scaling_method_name);
        switch(scaling_method)
        {
        case SCALING_NEAR: break;
        case SCALING_BILINEAR:
            filter.calculate(agg::image_filter_bilinear(), true); break;
        case SCALING_BICUBIC:
            filter.calculate(agg::image_filter_bicubic(), true); break;
        case SCALING_SPLINE16:
            filter.calculate(agg::image_filter_spline16(), true); break;
        case SCALING_SPLINE36:
            filter.calculate(agg::image_filter_spline36(), true); break;
        case SCALING_HANNING:
            filter.calculate(agg::image_filter_hanning(), true); break;
        case SCALING_HAMMING:
            filter.calculate(agg::image_filter_hamming(), true); break;
        case SCALING_HERMITE:
            filter.calculate(agg::image_filter_hermite(), true); break;
        case SCALING_KAISER:
            filter.calculate(agg::image_filter_kaiser(), true); break;
        case SCALING_QUADRIC:
            filter.calculate(agg::image_filter_quadric(), true); break;
        case SCALING_CATROM:
            filter.calculate(agg::image_filter_catrom(), true); break;
        case SCALING_GAUSSIAN:
            filter.calculate(agg::image_filter_gaussian(), true); break;
        case SCALING_BESSEL:
            filter.calculate(agg::image_filter_bessel(), true); break;
        case SCALING_MITCHELL:
            filter.calculate(agg::image_filter_mitchell(), true); break;
        case SCALING_SINC:
            filter.calculate(agg::image_filter_sinc(filter_radius), true); break;
        case SCALING_LANCZOS:
            filter.calculate(agg::image_filter_lanczos(filter_radius), true); break;
        case SCALING_BLACKMAN:
            filter.calculate(agg::image_filter_blackman(filter_radius), true); break;
        }

        // Project mesh cells into target interpolating raster inside each one
        for(j=0; j<mesh_ny-1; j++) {
            for (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(polygon[0]-1, polygon[1]-1);
                rasterizer.line_to_d(polygon[2]+1, polygon[3]-1);
                rasterizer.line_to_d(polygon[4]+1, polygon[5]+1);
                rasterizer.line_to_d(polygon[6]-1, polygon[7]+1);

                unsigned x0 = i * mesh_size;
                unsigned y0 = j * mesh_size;
                unsigned x1 = (i+1) * mesh_size;
                unsigned y1 = (j+1) * mesh_size;

                agg::trans_affine tr(polygon, x0, y0, x1, y1);
                if (tr.is_valid())
                {
                    typedef agg::span_interpolator_linear<agg::trans_affine>
                        interpolator_type;
                    interpolator_type interpolator(tr);

                    if (scaling_method == SCALING_NEAR) {
                        typedef agg::span_image_filter_rgba_nn
                            <img_accessor_type, interpolator_type>
                            span_gen_type;
                        span_gen_type sg(ia, interpolator);
                        agg::render_scanlines_aa(rasterizer, scanline, rb_pre,
                                                 sa, sg);
                    } else {
                        typedef agg::span_image_filter_rgba_2x2
                            <img_accessor_type, interpolator_type>
                            span_gen_type;

                        span_gen_type sg(ia, interpolator, filter);
                        agg::render_scanlines_aa(rasterizer, scanline, rb_pre,
                                                 sa, sg);
                    }
                }

            }
        }
    }
}
}// namespace mapnik