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refactor warping code to work with different pixel_types and minimise code duplication

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This commit is contained in:
artemp 2014-12-16 12:04:18 +01:00
parent 7518459ba1
commit 1df88908e4
2 changed files with 104 additions and 89 deletions
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183
src/warp.cpp
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@ -24,6 +24,7 @@
#include <mapnik/warp.hpp> #include <mapnik/warp.hpp>
#include <mapnik/config.hpp> #include <mapnik/config.hpp>
#include <mapnik/image_data.hpp> #include <mapnik/image_data.hpp>
#include <mapnik/image_scaling_traits.hpp>
#include <mapnik/image_util.hpp> #include <mapnik/image_util.hpp>
#include <mapnik/box2d.hpp> #include <mapnik/box2d.hpp>
#include <mapnik/view_transform.hpp> #include <mapnik/view_transform.hpp>
@ -47,19 +48,29 @@
namespace mapnik { namespace mapnik {
void reproject_and_scale_raster(raster & target, raster const& source, namespace detail {
proj_transform const& prj_trans,
double offset_x, double offset_y,
unsigned mesh_size,
scaling_method_e scaling_method)
{
view_transform ts(source.data_.width(), source.data_.height(),
source.ext_);
view_transform tt(target.data_.width(), target.data_.height(),
target.ext_, offset_x, offset_y);
std::size_t mesh_nx = std::ceil(source.data_.width()/double(mesh_size) + 1); template <typename T>
std::size_t mesh_ny = std::ceil(source.data_.height()/double(mesh_size) + 1); 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_data_type = T;
using pixel_type = typename image_data_type::pixel_type;
using pixfmt_pre = typename detail::agg_scaling_traits<image_data_type>::pixfmt_pre;
using color_type = typename detail::agg_scaling_traits<image_data_type>::color_type;
using renderer_base = agg::renderer_base<pixfmt_pre>;
using interpolator_type = typename detail::agg_scaling_traits<image_data_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_data<double> xs(mesh_nx, mesh_ny); image_data<double> xs(mesh_nx, mesh_ny);
image_data<double> ys(mesh_nx, mesh_ny); image_data<double> ys(mesh_nx, mesh_ny);
@ -69,81 +80,36 @@ void reproject_and_scale_raster(raster & target, raster const& source,
{ {
for (std::size_t i=0; i<mesh_nx; ++i) for (std::size_t i=0; i<mesh_nx; ++i)
{ {
xs(i,j) = std::min(i*mesh_size,source.data_.width()); xs(i,j) = std::min(i*mesh_size,source.width());
ys(i,j) = std::min(j*mesh_size,source.data_.height()); ys(i,j) = std::min(j*mesh_size,source.height());
ts.backward(&xs(i,j), &ys(i,j)); ts.backward(&xs(i,j), &ys(i,j));
} }
} }
prj_trans.backward(xs.getData(), ys.getData(), nullptr, mesh_nx*mesh_ny); prj_trans.backward(xs.getData(), ys.getData(), nullptr, mesh_nx*mesh_ny);
// Initialize AGG objects
using pixfmt = agg::pixfmt_rgba32_pre;
using color_type = pixfmt::color_type;
using renderer_base = agg::renderer_base<pixfmt>;
agg::rasterizer_scanline_aa<> rasterizer; agg::rasterizer_scanline_aa<> rasterizer;
agg::scanline_bin scanline; agg::scanline_bin scanline;
agg::rendering_buffer buf(target.data_.getBytes(), agg::rendering_buffer buf(target.getBytes(),
target.data_.width(), target.width(),
target.data_.height(), target.height(),
target.data_.width()*4); target.width() * pixel_size);
pixfmt pixf(buf); pixfmt_pre pixf(buf);
renderer_base rb(pixf); renderer_base rb(pixf);
rasterizer.clip_box(0, 0, target.data_.width(), target.data_.height()); rasterizer.clip_box(0, 0, target.width(), target.height());
agg::rendering_buffer buf_tile( agg::rendering_buffer buf_tile(
const_cast<unsigned char*>(source.data_.getBytes()), const_cast<unsigned char*>(source.getBytes()),
source.data_.width(), source.width(),
source.data_.height(), source.height(),
source.data_.width() * 4); source.width() * pixel_size);
pixfmt pixf_tile(buf_tile); pixfmt_pre pixf_tile(buf_tile);
using img_accessor_type = agg::image_accessor_clone<pixfmt>; using img_accessor_type = agg::image_accessor_clone<pixfmt_pre>;
img_accessor_type ia(pixf_tile); img_accessor_type ia(pixf_tile);
agg::span_allocator<color_type> sa; agg::span_allocator<color_type> sa;
// Initialize filter
agg::image_filter_lut filter;
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(source.get_filter_factor()), true); break;
case SCALING_LANCZOS:
filter.calculate(agg::image_filter_lanczos(source.get_filter_factor()), true); break;
case SCALING_BLACKMAN:
filter.calculate(agg::image_filter_blackman(source.get_filter_factor()), true); break;
}
// Project mesh cells into target interpolating raster inside each one // 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 j = 0; j < mesh_ny - 1; ++j)
{ {
for (std::size_t i = 0; i < mesh_nx - 1; ++i) for (std::size_t i = 0; i < mesh_nx - 1; ++i)
{ {
@ -166,33 +132,82 @@ void reproject_and_scale_raster(raster & target, raster const& source,
std::size_t y0 = j * mesh_size; std::size_t y0 = j * mesh_size;
std::size_t x1 = (i+1) * mesh_size; std::size_t x1 = (i+1) * mesh_size;
std::size_t y1 = (j+1) * mesh_size; std::size_t y1 = (j+1) * mesh_size;
x1 = std::min(x1, source.data_.width()); x1 = std::min(x1, source.width());
y1 = std::min(y1, source.data_.height()); y1 = std::min(y1, source.height());
agg::trans_affine tr(polygon, x0, y0, x1, y1); agg::trans_affine tr(polygon, x0, y0, x1, y1);
if (tr.is_valid()) if (tr.is_valid())
{ {
using interpolator_type = agg::span_interpolator_linear<agg::trans_affine>;
interpolator_type interpolator(tr); interpolator_type interpolator(tr);
if (scaling_method == SCALING_NEAR) if (scaling_method == SCALING_NEAR)
{ {
using span_gen_type = agg::span_image_filter_rgba_nn using span_gen_type = typename detail::agg_scaling_traits<image_data_type>::span_image_filter;
<img_accessor_type, interpolator_type>;
span_gen_type sg(ia, interpolator); span_gen_type sg(ia, interpolator);
agg::render_scanlines_bin(rasterizer, scanline, rb, agg::render_scanlines_bin(rasterizer, scanline, rb, sa, sg);
sa, sg);
} }
else else
{ {
using span_gen_type = agg::span_image_resample_rgba_affine using span_gen_type = typename detail::agg_scaling_traits<image_data_type>::span_image_resample_affine;
<img_accessor_type>; agg::image_filter_lut filter;
set_scaling_method(filter, scaling_method, filter_factor);
span_gen_type sg(ia, interpolator, filter); span_gen_type sg(ia, interpolator, filter);
agg::render_scanlines_bin(rasterizer, scanline, rb, agg::render_scanlines_bin(rasterizer, scanline, rb, sa, sg);
sa, sg);
} }
} }
} }
} }
} }
struct warp_image_visitor : util::static_visitor<void>
{
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_data_null const&) {}
template <typename T>
void operator() (T const& source)
{
using image_data_type = T;
//source and target image data types must match
if (target_raster_.data_.template is<image_data_type>())
{
image_data_type & target = util::get<image_data_type>(target_raster_.data_);
detail::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_);
}
}// namespace mapnik }// namespace mapnik