void operator () (line_pattern_symbolizer const& sym)
{
path_expression_ptr const& filename_expr = sym.get_filename();
if (filename_expr)
{
path_processor_type::collect_attributes(*filename_expr,names_);
}
collect_transform(sym.get_image_transform());
collect_transform(sym.get_transform());
}
void grid_renderer<T>::process(line_pattern_symbolizer const& sym,
mapnik::feature_impl & feature,
proj_transform const& prj_trans)
{
std::string filename = path_processor_type::evaluate( *sym.get_filename(), feature);
boost::optional<marker_ptr> mark = marker_cache::instance().find(filename,true);
if (!mark) return;
if (!(*mark)->is_bitmap())
{
MAPNIK_LOG_DEBUG(agg_renderer) << "agg_renderer: Only images (not '" << filename << "') are supported in the line_pattern_symbolizer";
return;
}
boost::optional<image_ptr> pat = (*mark)->get_bitmap_data();
if (!pat) return;
typedef typename grid_renderer_base_type::pixfmt_type pixfmt_type;
typedef typename grid_renderer_base_type::pixfmt_type::color_type color_type;
typedef agg::renderer_scanline_bin_solid<grid_renderer_base_type> renderer_type;
typedef boost::mpl::vector<clip_line_tag, transform_tag,
offset_transform_tag, affine_transform_tag,
simplify_tag, smooth_tag, stroke_tag> conv_types;
agg::scanline_bin sl;
grid_rendering_buffer buf(pixmap_.raw_data(), width_, height_, width_);
pixfmt_type pixf(buf);
grid_renderer_base_type renb(pixf);
renderer_type ren(renb);
ras_ptr->reset();
int stroke_width = (*pat)->width();
agg::trans_affine tr;
evaluate_transform(tr, feature, sym.get_transform(), scale_factor_);
box2d<double> clipping_extent = query_extent_;
if (sym.clip())
{
double padding = (double)(query_extent_.width()/pixmap_.width());
double half_stroke = stroke_width/2.0;
if (half_stroke > 1)
padding *= half_stroke;
if (std::fabs(sym.offset()) > 0)
padding *= std::fabs(sym.offset()) * 1.2;
padding *= scale_factor_;
clipping_extent.pad(padding);
}
// to avoid the complexity of using an agg pattern filter instead
// we create a line_symbolizer in order to fake the pattern
stroke str;
str.set_width(stroke_width);
line_symbolizer line(str);
vertex_converter<box2d<double>, grid_rasterizer, line_symbolizer,
CoordTransform, proj_transform, agg::trans_affine, conv_types>
converter(clipping_extent,*ras_ptr,line,t_,prj_trans,tr,scale_factor_);
if (sym.clip()) converter.set<clip_line_tag>(); // optional clip (default: true)
converter.set<transform_tag>(); // always transform
if (std::fabs(sym.offset()) > 0.0) converter.set<offset_transform_tag>(); // parallel offset
converter.set<affine_transform_tag>(); // optional affine transform
if (sym.simplify_tolerance() > 0.0) converter.set<simplify_tag>(); // optional simplify converter
if (sym.smooth() > 0.0) converter.set<smooth_tag>(); // optional smooth converter
converter.set<stroke_tag>(); //always stroke
for (geometry_type & geom : feature.paths())
{
if (geom.size() > 1)
{
converter.apply(geom);
}
}
// render id
ren.color(color_type(feature.id()));
agg::render_scanlines(*ras_ptr, sl, ren);
// add feature properties to grid cache
pixmap_.add_feature(feature);
}
