#include "catch.hpp" // mapnik #include <mapnik/global.hpp> #include <mapnik/coord.hpp> #include <mapnik/vertex_cache.hpp> // stl #include <stdexcept> #include <iostream> #include <fstream> #include <vector> #include <tuple> #include <algorithm> struct fake_path { using coord_type = std::tuple<double, double, unsigned>; using cont_type = std::vector<coord_type>; cont_type vertices_; cont_type::iterator itr_; fake_path(std::initializer_list<double> l) : fake_path(l.begin(), l.size()) { } fake_path(std::vector<double> const &v) : fake_path(v.begin(), v.size()) { } template <typename Itr> fake_path(Itr itr, size_t sz) { size_t num_coords = sz >> 1; vertices_.reserve(num_coords); for (size_t i = 0; i < num_coords; ++i) { double x = *itr++; double y = *itr++; unsigned cmd = (i == 0) ? agg::path_cmd_move_to : agg::path_cmd_line_to; vertices_.push_back(std::make_tuple(x, y, cmd)); } itr_ = vertices_.begin(); } unsigned vertex(double *x, double *y) { if (itr_ == vertices_.end()) { return agg::path_cmd_stop; } *x = std::get<0>(*itr_); *y = std::get<1>(*itr_); unsigned cmd = std::get<2>(*itr_); ++itr_; return cmd; } void rewind(unsigned) { itr_ = vertices_.begin(); } }; double dist(mapnik::pixel_position const &a, mapnik::pixel_position const &b) { mapnik::pixel_position d = a - b; return std::sqrt(d.x*d.x + d.y*d.y); } void test_simple_segment(double const &offset) { const double dx = 0.01; fake_path path = {0, 0, 1, 0}, off_path = {0, offset, 1, offset}; mapnik::vertex_cache vc(path), off_vc(off_path); vc.reset(); vc.next_subpath(); off_vc.reset(); off_vc.next_subpath(); while (vc.move(dx)) { double pos = vc.linear_position(); double off_pos = off_vc.position_closest_to(vc.current_position()); REQUIRE(std::abs(pos - off_pos) < 1.0e-6); } } void test_straight_line(double const &offset) { const double dx = 0.01; fake_path path = {0, 0, 0.1, 0, 0.9, 0, 1, 0}, off_path = {0, offset, 0.4, offset, 0.6, offset, 1, offset}; mapnik::vertex_cache vc(path), off_vc(off_path); vc.reset(); vc.next_subpath(); off_vc.reset(); off_vc.next_subpath(); while (vc.move(dx)) { double pos = vc.linear_position(); double off_pos = off_vc.position_closest_to(vc.current_position()); REQUIRE(std::abs(pos - off_pos) < 1.0e-6); } } void test_offset_curve(double const &offset) { const double dx = 0.01; const double r = (1.0 + offset); std::vector<double> pos, off_pos; const size_t max_i = 1000; for (size_t i = 0; i <= max_i; ++i) { double x = M_PI * double(i) / max_i; pos.push_back(-std::cos(x)); pos.push_back(std::sin(x)); off_pos.push_back(-r * std::cos(x)); off_pos.push_back(r * std::sin(x)); } fake_path path(pos), off_path(off_pos); mapnik::vertex_cache vc(path), off_vc(off_path); vc.reset(); vc.next_subpath(); off_vc.reset(); off_vc.next_subpath(); while (vc.move(dx)) { double mpos = vc.linear_position(); double moff_pos = off_vc.position_closest_to(vc.current_position()); { mapnik::vertex_cache::scoped_state s(off_vc); off_vc.move(moff_pos); auto eps = (1.001 * offset); auto actual = dist(vc.current_position(), off_vc.current_position()); REQUIRE(actual < eps); } REQUIRE(std::abs((mpos / vc.length()) - (moff_pos / off_vc.length())) < 1.0e-3); } } void test_s_shaped_curve(double const &offset) { const double dx = 0.01; const double r = (1.0 + offset); const double r2 = (1.0 - offset); std::vector<double> pos, off_pos; const size_t max_i = 1000; for (size_t i = 0; i <= max_i; ++i) { double x = M_PI * double(i) / max_i; pos.push_back(-std::cos(x) - 1); pos.push_back(std::sin(x)); off_pos.push_back(-r * std::cos(x) - 1); off_pos.push_back(r * std::sin(x)); } for (size_t i = 0; i <= max_i; ++i) { double x = M_PI * double(i) / max_i; pos.push_back(-std::cos(x) + 1); pos.push_back(-std::sin(x)); off_pos.push_back(-r2 * std::cos(x) + 1); off_pos.push_back(-r2 * std::sin(x)); } fake_path path(pos), off_path(off_pos); mapnik::vertex_cache vc(path), off_vc(off_path); vc.reset(); vc.next_subpath(); off_vc.reset(); off_vc.next_subpath(); while (vc.move(dx)) { double moff_pos = off_vc.position_closest_to(vc.current_position()); { mapnik::vertex_cache::scoped_state s(off_vc); off_vc.move(moff_pos); REQUIRE(dist(vc.current_position(), off_vc.current_position()) < (1.002 * offset)); } } } TEST_CASE("offsets") { SECTION("line") { try { std::vector<double> offsets = { 0.01, 0.02, 0.1, 0.2 }; for (double offset : offsets) { // test simple straight line segment - should be easy to // find the correspondance here. test_simple_segment(offset); // test straight line consisting of more than one segment. test_straight_line(offset); // test an offset outer curve test_offset_curve(offset); // test an offset along an S-shaped curve, which is harder // because the positions along the offset are no longer // linearly related to the positions along the original // curve. test_s_shaped_curve(offset); } } catch (std::exception const& ex) { std::cerr << ex.what() << "\n"; REQUIRE(false); } } }