void reproject_and_scale_raster(raster & target, raster const& source,
proj_transform const& prj_trans,
double offset_x, double offset_y,
unsigned mesh_size,
double filter_radius,
scaling_method_e scaling_method)
{
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;
switch(scaling_method)
{
case SCALING_NEAR: break;
case SCALING_BILINEAR8: // TODO - impl this or remove?
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 mapnik::span_image_resample_rgba_affine
<img_accessor_type> span_gen_type;
span_gen_type sg(ia, interpolator, filter);
agg::render_scanlines_aa(rasterizer, scanline, rb_pre,
sa, sg);
}
}
}
}
}
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.getData(), ys.getData(), nullptr, mesh_nx*mesh_ny);
agg::rasterizer_scanline_aa<> rasterizer;
agg::scanline_bin scanline;
agg::rendering_buffer buf(target.getBytes(),
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.getBytes()),
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);
}
}
}
}
}
