void graphics<Canvas>::render(const Path& path, const Brush& brush)
{
static raster raster;
raster.rasterize(path);
for (int y = raster.bbox().top; y < raster.bbox().bottom; ++y)
for (const raster::span& span : raster.fetch_scanline(y))
for (int x = span.x, end_x = span.x + int(span.length); x < end_x; ++x)
canvas_.pixel(x, y, brush, span.coverage);
}
/**
* normalize [0, 1.0] in place
*/
inline raster normalize(raster& v) {
auto minmax = std::minmax_element(v.begin(), v.end());
float min = *minmax.first;
float max = *minmax.second;
float diff = max - min;
if (diff == 0) // max == min
return v;
// normalize in place
for (auto& f : v)
f = (f - min) / diff;
return v;
}
/** handy method to display a raster
*
* @param v vector of float
* @returns vector of uint8_t (unisgned char)
*
* distribute as:
* min(v) -> 0
* max(v) -> 255
*/
inline bytes_t raster2bytes(const raster& v) {
auto minmax = std::minmax_element(v.begin(), v.end());
float min = *minmax.first;
float max = *minmax.second;
float diff = max - min;
bytes_t b(v.size());
if (diff == 0) // max == min (useless band)
return b;
float coef = 255.0 / diff;
std::transform(v.begin(), v.end(), b.begin(),
// C++11 lambda, capture local varibles by reference [&]
[&](float f) -> uint8_t { return std::floor( coef * (f - min) ); });
return b;
}
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_);
}
color internal_smooth_pixel (double x, double y) {
return (color) r->internal_smooth_pixel (x, y); }
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)
{
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 mesh_nx = std::ceil(source.data_.width()/double(mesh_size) + 1);
unsigned mesh_ny = std::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(unsigned j=0; j<mesh_ny; ++j)
{
for (unsigned i=0; i<mesh_nx; ++i)
{
xs(i,j) = std::min(i*mesh_size,source.data_.width());
ys(i,j) = std::min(j*mesh_size,source.data_.height());
ts.backward(&xs(i,j), &ys(i,j));
}
}
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::scanline_u8 scanline;
agg::rendering_buffer buf((unsigned char*)target.data_.getData(),
target.data_.width(),
target.data_.height(),
target.data_.width()*4);
pixfmt pixf(buf);
renderer_base rb(pixf);
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);
using img_accessor_type = agg::image_accessor_clone<pixfmt>;
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(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
for(unsigned j=0; j<mesh_ny-1; ++j)
{
for (unsigned 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]));
unsigned x0 = i * mesh_size;
unsigned y0 = j * mesh_size;
unsigned x1 = (i+1) * mesh_size;
unsigned y1 = (j+1) * mesh_size;
x1 = std::min(x1, source.data_.width());
y1 = std::min(y1, source.data_.height());
agg::trans_affine tr(polygon, x0, y0, x1, y1);
if (tr.is_valid())
{
using interpolator_type = agg::span_interpolator_linear<agg::trans_affine>;
interpolator_type interpolator(tr);
if (scaling_method == SCALING_NEAR)
{
using span_gen_type = agg::span_image_filter_rgba_nn
<img_accessor_type, interpolator_type>;
span_gen_type sg(ia, interpolator);
agg::render_scanlines_aa(rasterizer, scanline, rb,
sa, sg);
}
else
{
using span_gen_type = agg::span_image_resample_rgba_affine
<img_accessor_type>;
span_gen_type sg(ia, interpolator, filter);
agg::render_scanlines_aa(rasterizer, scanline, rb,
sa, sg);
}
}
}
}
}